White Paper on the Development of Broadband in China-1

Sharing and discussion about  “China’s broadband development white paper”

The China Academy of Information and Communications Technology is the most important research institute in the field of information and communications (ICT) in China. A lot of work has been done on the national development strategy of information communication, independent innovation, industrial policy, industry management, planning and design, technical standards, testing and certification, and on 4G/5G, industrial Internet, smart manufacturing, mobile Internet, Internet of Things, Internet of Vehicles, future network, cloud computing, big data, artificial intelligence, virtual reality/augmented reality (VR/AR), smart hardware, etc. In-depth research and prospective layout of network and information security are carried out.

On October 15, 2020, China Academy of Information and Communications Technology issued a series of white papers concerning ICT. Among them, the white paper on broadband development in China (2020) combines the measures and effectiveness of broadband development in China from 2016 to 2020, and makes a comprehensive judgment on the evolution trend of broadband development at home and abroad in the future. Based on the challenges of the new and old problems facing the development of broadband, this paper puts forward some suggestions to continuously promote the construction of broadband facilities under the new situation.

The customers of C-Data include many overseas Fix-network operators, ISPs and so on. In order to let overseas customers better understand the development trend of China’s broadband network and learn from China’s experience, C-Data has specifically translated the excerpts related to “Fixed Broadband Access Network” in the “White Paper on China’s Broadband Development (2020)” for you, hoping to help you.


The following contents are selected from China’s broadband development white paper:

As an “information superhighway”, the development level of fixed broadband network has become a “barometer” of the national ICT development level and one of the important indicators to measure the country’s comprehensive national strength. The global trend of accelerating the deployment of fixed network Gigabit is significant, and all countries are actively promoting the process of high-speed broadband network.

According to the data of OVUM , the penetration rate of FTTH in the world is 54% and increasing continuously. All-optical access has become the mainstream of the industry. 234 operators in 57 countries have published Gigabit business, and more than 20 operators have published Gigabit business.

North American cable service providers have a regional competitive advantage by providing access networks up to gigabytes based on coaxial cables and using DOCSIS3.0 technology. The United States developed the earliest, and most operators have introduced Gigabit business, but it is still in the stage of popularization.

European telecom operators still maintain a large number of copper wire access network and operate faster through new technologies such as Vectoring and G.Fast. At the same time, most countries have published Gigabit business, but the overall development is slightly slower in Asian countries such as China, Japan and South Korea. For example, Spain’s all-optical network plan will cover 100% of the country’s population in 2021; The German Gigabit Strategic Plan will have full Gigabit access capacity in 2025.

Japan, South Korea and Singapore in Asia started later than the United States, but they are developing rapidly and have entered the later stage of Gigabit development, with the coverage of Gigabit households in Korea and Singapore reaching 93% and 95%, respectively.In other countries, the trend of power companies (with pipeline resources and construction capacity) cooperating with operators to build all-optical access network has gradually emerged in recent years, accelerating the development of high-speed broadband.

In particular, in February 2020, the European Telecommunications Standardization Association (ETSI) established the Working Group on the Fifth Generation Fixed Network (F5G) to study the F5G standards and applications and promote the intergenerational evolution of fixed broadband.

According to ETSI definition, F5G is the fifth generation of fixed network represented by 10G PON access, Wi-Fi6 and 200G/400G transmission technology. It contains three main application scenarios: GRE (High Reliability Experience), eFBB (Enhanced Fixed Bandwidth), FFC (All-Optical Connection), and opens a new era of optical connectivity from optical fiber to home to rooms, desktops, parks, factories and even machines.

China is leading the world in the basic advantage of optical network, and is entering a new Gigabit ultra-wide stage represented by 10G PON technology. In 2019, the Ministry of Industry and Information launched the “Double G Double Tip” action, which pushes the dual fixed and mobile broadband into the Gigabit era, providing basic network guarantee for innovation and promotion of high-bandwidth applications.

Basic telecommunication operators responded positively and proposed clear plans for the development of Gigabit optical network successively. At present, Gigabit broadband access network has been deployed in more than 300 cities throughout the country, covering more than 80 million household users. Most provincial telecommunication operators have issued Gigabit commercial packages, and more than 2.7 million National Gigabit broadband access users. In just five months, the number of new users exceeded last year’s total number of users (870,000).

Beijing Mobile will accelerate the construction of F5G and create thousands of double Gigabyte boutique communities throughout the city. Guangzhou Telecom and Huawei released the industry’s first FTTR White Paper, which guarantees Gigabit broadband full house coverage through an all-optical home network solution. Hangzhou Mobile released the “Double 5G” Digital City White Paper to consolidate the solid base of the digital economy.

In the next five years, optical access networks will accelerate into the Gigabyte era. The 10G PON passive optical network technology is characterized by large bandwidth and wide coverage. A single system can provide Gigabyte access for 30-40 families, making it the preferred technology choice for operators all over the world when deploying high-speed optical access networks.

China’s Gigabit Broadband will continue to expand its coverage to achieve multi-scenario applications such as home, enterprise, business and factory manufacturing, connect a large number of devices and terminals, and provide users with stable and high-speed bandwidth access capacity. Specifically, the future construction and development of optical access network will focus on the following three aspects:

(1) Gigabit Speed Up: Targeting home Gigabit rate access, fully using 10G PON technology; Gigabit wireless local area network (WLAN) is used in home scenarios to increase the endpoint access rate and provide Gigabit bandwidth to user terminals in conjunction with 10G PON.

(2) Fibre to Everywhere: In the physical layer, the scene of optical connection extends from home to thousands of industries, including optical fiber to room, industrial PON (industrial optical network, optical fiber to machine), optical fiber to park enterprises (various types of government enterprises, parks, education, power, transportation and other vertical industries), through a new generation of high performance, high integration, Low power photoelectric chips and algorithms to ensure fast response, low latency, high reliability and safety in industrial level.

(3) Ultimate experience: Through the application of large data collection, edge computing, artificial intelligence and other technologies, plus end-to-end network slicing, multi-level scheduling and guarantee algorithm, to provide different and accurate service guarantee for different users and different businesses, and to enhance users’business experience.



Each country has different national conditions and broad development stages, but based on 10G PON as well as higher-speed passive optical network technology, which provides up to Gigabytes of optical access per household, the construction of broadband access network around Gigabyte speed-up, optical connectivity and ultimate experience is undoubtedly the mainstream development direction in the world. Gigabit access to the home and dual Gigabit access to mobile and fixed networks are currently in its infancy, and it will take at least 5 to 10 years for the experiment, promotion and popularization to take place.

According to the relevant statistics, in the current purchasing market of broadband access devices, 2.5 GPON ONU products are still the mainstay of the market and account for at least 70% of the total market share. However, in OLT products, the market share of 10G PON OLT ports is increasing year by year.

Compared with China, North America, Japan and South Korea, the permeability of optical access in Southeast Asia and South America is low. Providing GPON-based optical broadband access remains the main demand for a long time.


Source material: The China Academy of Information and Communications Technology: White Paper on the Development of Broadband in China (2020)


What is the relationship among 5G、F5G and WiFi6?

Introduction: Recently, 5G, F5G, WiFi6 have become hot topics in the communications industry. But what is the difference and the relationship between them? What are the main applications? In this issue, let’s discuss this topic together.


  1. WiFi6 is one of the core technologies of F5G

Since December 2019, the European Telecommunications Standards Institute (ETSI) established the F5G Industry Specification Group (ISG), which defines three major features of F5G: enhanced fixed broadband (eFBB), all-optical connection (FFC), and guaranteed reliable experience (GRE). F5G aims at all-optical network and takes 10GPON, WiFi6, 200G/400G, next generation OTN as representative technologies. The technical support of F5G gigabit optical fiber pushes all human beings to a new era of “extreme speed interconnection” and “optical link everything”.

At the same time, F5G technology provides the possibility for many new scenarios to land. Different application scenarios also have more and more differentiated requirements for network services. These requirements also prompt and promote the development of technologies such as WiFi6 , 10G-PON, 200G/400G ultra-high speed transmission technology, next generation OSU-OTN.

Wi-Fi 6, the 6th generation wireless technology, IEEE 802.11 ax, is a new generation wireless network technology introduced in 2009. With the development of Wi-Fi for 20 years, the latest Wi-Fi 6 has reached a maximum transmission rate of 9.6 Gbps, which is between 900 times that of the first generation WiFi 1.

Compared with previous generation WiFi 5, WiFi6 has the following characteristics: it supports 1024QAM modulation, has higher bandwidth utilization and transmits more data; Using OFDMA technology, the utilization of spectral resources is further improved, and the transmission efficiency and speed are improved. A more complete upstream and downstream MU-MIMO is used to achieve multi-terminal connection. Supports “TWT” technology to save power; Support spatial reuse technology, more anti-jamming.


2. 5G and F5G cooperate with each other

Compared with 5G, F5G has higher bandwidth, lower network latency by 90% and higher security stability by 99.999%. Therefore, the interweaving of 5G and F5G constitutes the dual network parallel between the sky and the ground in the era of optical union.

The applications of 5G and F5G complement each other. Although 5G has some deficiencies in network bandwidth, it is more mobile and multi-connected, so it is more suitable for mobile networks such as unmanned aerial vehicles and the Internet of Things in vehicles. The fixed connection of F5G performs better in the connection of industrial parks and data centers due to its large bandwidth, low latency and high reliability. It is also supported by Wi-Fi 6, making F5G suitable for many indoor applications at the same time.

F5G provides basic support for 5G. 5G is mainly used in terminals, which connect to base stations wirelessly. However, the connection between base station and access network, convergence network and transmission network still depends on fixed optical network, so F5G is one of the important foundations for the flourishing development of 5G.


3. Main Application Scenarios

In practical applications, F5G performs better than 5G in high bandwidth, low delay, low jitter, anti-jamming and high reliability, while 5G has more advantages in mobility and number of connections than F5G. For example:

In areas such as smart manufacturing, smart healthcare, cloud games, and smart finance, 5G is very sensitive to time delay and jitter, not enough to meet, and is dominated by F5G. In addition, F5G is more suitable for smart grid and smart mining scenarios because of strong electromagnetic interference from the power grid and weak 5G signal underground in mines and explosion prone.

F5G has the potential to gradually replace 5G in such scenarios as smart agriculture, enterprise cloud, smart government, smart home, smart education, smart oil field and so on. Devices connected to such scenes are mobile, but usually only live in fixed areas. As F5G+WiFi 6 technology becomes more and more popular, 5G will be gradually replaced.

In the fields of Ultra-Definition Video, AR/VR, Live Intelligence, Intelligent Logistics, it belongs to F5G and 5G hybrid scenes according to the terminal and access modes.

Therefore, F5G and 5G work together instead of substituting each other. They are only suitable for different occasions, such as: WiFi access network is usually used at home and in various indoor scenarios, so they can also play a significant role in promoting F5G.



F5G, the conception of the fifth generation fixed network, integrates 10GPON、WiFi6、200G/400G and other technologies to provide optical fiber access and wireless coverage of ultra Gigabit bandwidth . It is an organic combination of optical fiber and wireless.

F5G and 5G not only support each other, but also can be used independently. They are not simple mutual exclusion and substitution. They are intertwined with each other, forming the dual network parallel of fixed network and mobile network in the era of optical fiber connecting everything.


WiFi Mesh (EasyMesh) technology and products

1.The summary of mesh technology

1.1. Whats mesh

WiFi Mesh network (wireless mesh network), also known as “multi-hop” network, is a new wireless networking solution developed based on WiFi technology. Unlike traditional WiFi network, WiFi Mesh network is a network technology based on multi-hop routing and peer-to-peer network, which is a new network structure.

Compared with traditional wireless networks, the transmission distance and mobility of WiFi Mesh network will be greatly improved, especially, it is compatible with the WiFi function. Therefore, WiFi Mesh network is very helpful to increase the transmission distance and mobility of wireless networks, expand the application of wireless networks, and has intelligent features such as network self-organization, automatic repair and roaming.


1.2. Why use Mesh technology

In the traditional wireless network, WiFi technology constitutes the internal network. The terminal joins the network through WiFi. The connection port on the device is Ethernet or optical port. In the network deployment, once the wired distance is determined, the location of the device WiFi will also be fixed. If you want to change the location of WiFi, you need to adjust the corresponding wired network, which is more difficult to operate and consumes a lot of time and wiring costs.

Therefore, the traditional WiFi construction method has the shortcomings of high cost, poor flexibility, complex operation, etc. It is not suitable for building online services in scenarios such as high wireless quality and aesthetics, less maintenance investment and weak wired network. Mesh network only needs to install corresponding subnodes, no need to change the wired network, and it is very convenient and fast to set up a network.


1.3. What are the advantages of Mesh networking over traditional WiFi networking?

Compared with traditional WIFI networking, The scalability and mobility of WiFi Mesh networking has significantly improved. Its self-organizing, self-governing, roaming seamless switching characteristics make WIFI Mesh networking have the following significant advantages:

Simple and fast networking: The installation of Mesh network is very convenient and simple. Connect the main device (controller) to the Internet, place the area that needs online business from the routing agent, and complete the network setup, which is time-saving and convenient. In traditional networking, wired connections are required between each node, which is complex and time-consuming to operate.

Dynamically modify the network layout: When an area needs to add or delete network nodes, only join or remove the corresponding nodes through the ad hoc network nodes. Adding or deleting nodes in traditional networks requires changing physical wiring, which requires a lot of time and material resources.

Flexibility and robustness: When a node in a region fails, the Mesh network will automatically rebuild the network structure to ensure the normal use of the network, without troubleshooting, to avoid the phenomenon that a node fails and results in network congestion in one or more regions.

Suitable scenarios and cost-effective ratio: Mesh network is basically suitable for the current scenarios in traditional networks. In addition, Mesh network has obvious advantages in some scenarios that require fewer wiring, more network nodes and lower costs.

   2. The Mesh products of C-Data

2.1 Introduction to C-Datas Mesh product model

C-Data, as a professional provider of access network products, provides a variety of network construction solutions. In the abundant product line, some C-Data’s ONU products and its subsidiary Ceres router products already support Mesh technology, such as ONU FD604GW-DX, router WR625G, WR535, etc.

2.2 The features of C-Datas Mesh Product

2.2.1 MESH networking method

Mode 1: controller<—>agent1As shown in the diagram, agent1, agent2, and controllers form a WiFi mesh network, in which agent1 and agent2 are child node of the network, and controllers are the primary nodes and the parent nodes of agent1 and agent2. In other terminal devices, such as pc, can enjoy online services through WiFi connection with agent1, agent2, controller.

Mode 2:controller<—>agent<—>agent


As shown in the figure above, controller, agent1, agent2, agent3, and agent4 form a WiFi mesh network. Where agent4 and agent3 are the outermost child nodes, their parent nodes are agent1 and agent2 respectively. Agent1 and agent2 are the innermost child nodes, which share a common parent node controller.


2.2.2 MESH network setup

MESH Network Limitations:

(1) WIFI MESH network has only one controller and can have several agents.

(2) Each node (controller and agent) allows WiFi connections such as phone and PC.

(3) Only one parent node is allowed per agent node.


2.2.3 Features and functions of MESH

a. Role Self-Adaptation


ONU devices have four role attributes:

(1) Run in controller mode as primary node

(2) Run in agent mode as a child node

(3) Run in auto mode, it can play the role of both agent and controller. When the device is connected to the Internet, it plays the role of controller. Otherwise, play the role of agent.

(4) Run in disable mode,turn off the function of EasyMesh

b. Flexible networking


(1) Paired networking

One controller and one agent, after two devices are powered on, press the WPS button of that two device within two minutes, and the two devices will start to automatically network. After successful networking, the two devices turn on automatic networking after power failure, without the need to press the button again.


(2) Network Switching

There are three devices, controller1, controller2 and agent1, among which controller1 and agent1 have been successfully networked; If you want to switch the agent1 network to controller2 at this time, reset the network configuration via WEB UI, and press WPS button to group the network by agent1 and controller2 respectively.


(3) Network expansion

There are three devices, controller1, agent1 and agent2. controller1 and agent1 have been successfully networked. Agent2 is too far away from the controller. If you want to connect to the mesh network through agent1, press WPS button respectively for agent1 and agent2 to connect to the group network.

c. Configuration Synchronization

Through the protocol message of IEEE1905, the SSID configuration information of the controller is synchronized to the access agent.



(1) Agent node sends autoconfig-search message to find controller

(2) After the controller node receives the message, reply to autoconfig-response and return

(3) Agent node sends autoconfig WSC M1 message and reports support capability set

(4) When the controller node receives the message, it replies to the autoconfig WSC M2 message and sends the configuration of the corresponding capability.

d. Network Self-healing


As shown in the figure above, there are three devices, controller1, agent1, and agent2. Agent2 makes up a MESH network by using Agent1 and Controller. When agent1 is powered off, agent2 is disconnected from the MESH network. At this point, agent 2 will re-open the scan (first scan three times on the current channel, and then global scan if not found), attempting to initiate a connection with the scanned node.

e. Topological Data



(1) The device cycle sends Topology Discovery, this message is only sent to neigbor, not forward

(2) Send Topology when a node detects a TOPO change (new link/up, sta assoc/disassoc)

Notification, this message will be Relayed and notified to other nodes

(3) Device actively sends Topology Query to specified node, unicast

(4) Device replies to Topology response, unicast

f. Roaming

Roaming refers to the technology that automatically connects to a better signal strength AP when clients move between the coverage of different APs with the same (wireless network name) SSID in a MESH network.



(1) The default threshold for roaming from Controller to Agent is 20. Roaming occurs when rssi<(20-90)

(2) The default threshold for initiating roaming from the Agent side is 40. Roaming occurs when rssi<(40-90)

Move by:

When the roaming condition is triggered, the node connected by the terminal device disconnects the device through a blacklist, thereby connecting the device to other nodes.

3. The Expectations of Mesh Technology for the Future

Mesh plays an important role in device interconnection under the trends of cloud management, interconnection of everything, and the Internet of Things. Whether in large or small places, Mesh networking is favored by all fields because of its simple and fast networking, dynamic modification of network layout, extremely low construction cost and short construction cycle, saving manpower and manpower, flexibility and robustness. Mesh technology will also continue to optimize and become more intelligent to accommodate more scenarios.

Concluding remarks

With the rapid development of network, the cost, complexity and maintainability of network are more and more stringent in various fields. These requirements constantly urge the existing network to optimize or update, and create new network schemes. Mesh networking is currently a competitive way of networking. C-Data, as a professional provider of access network products, will adopt the latest networking technologies. Our Mesh products are Home ONU, Router product, ONU Mesh can be combined with router Mesh, which is powerful. Thank you for choosing C-Data’s Mesh-enabled devices and discussing Mesh technology with us.


FTTR is too expensive. Maybe you can try CTTR!

Recently, FTTR has become a hot topic in the communication industry. In our last article, we introduced the concept of FTTR and the difference between FTTR and FTTH.

Today, let’s talk about another scheme similar to FTTR.

In the FTTR solution, key devices include FTTR gateways and FTTR slave terminals. The gateway hardware of FTTR consists of ONU part and a Mini single-port OLT part. The ONU part in the gateway run ONU function supporting 10GE PON protocol and connecting to OLT in the Operator’s PON network. The single-port OLT part in the gateway provide user side PON port  for indoor networking with other FTTRs slave terminals.  The fiber network in the FTTR gateway and slave is based on the GPON standard. Both gateway and FTTR slave terminals can provide WIFI access, and support EasyMesh, suppport fix and wireless backhaul .

FTTR is a good indoor networking scheme, but the high cost may be a problem. The price of one gateway plus four slaver FTTR bundle even more than $600. Whether the cost is borne by the operator or the user, we have to admit that it is expensive. So is there another solution? The cost is lower, but it can achieve the networking effect similar to FTTR.

Based on C-Data’s technology reserve, I think there is a solution that meets this need, I call it CTTR(Coax to the Room).

CTTR is the conversion of transmission media from optical fibers to coaxial cables. The gateway (called Master in CTTR) and the terminal (Slaver) are networked by the EOC protocol (HomePlug AV).Because optical fibers are replaced by coaxial cables, there is no need for optical components in the equipment, and coaxial cables are easier to construct than optical cables, it has advantage in cost.


I expanded the table of “What is different of FTTR & FTTH”, and added a CTTR column.

FTTR CTTR Ethernet(UTP) Wireless
Transmission Stability High High High Low
Bandwidth High

Gigabit shared


Gigabit shared




Depends on the quality of the wireless link

Range Sufficient for home

(To be defined)

Sufficient for home

(<40dB Link loss )

<100m Uncertain

(depends on channel)

Manageable Could be managed

(To be defined)

Could be managed by Master No No
Architecture Star & Tree Star & Tree Star & Bus
EasyMesh Wireless or Wire(Fiber) Wireless or Wire(Coaxial Cable) Wireless or Wire(UTP) Wireless
Number of supported terminals 8 (For Home application);

64 (For dense apartment building and office application)

Limited by PON protocol and hardware of Gateway


Limited by Homeplug Protocol

NA Limited by hardware of AC

If you are interested in the scenarios FTTR involves, but you want a solution that is cheaper than FTTR, we can disscuss and promote the CTTR solution together.From the table, we can see that FTTR and CTTR both support star and tree topology, which is suitable for different types of housing networking and better than UTP networking scheme. Moreover, both FTTR and CTTR have a large network range, which can meet the networking needs of families and even buildings. In terms of bandwidth, it can provide stable Gigabit sharing.

difference between managed ethernet switch and unmanaged ethernet switch

What’s the difference between managed switch and unmanaged switch

At present, the switches on the market can be divided into managed switches and non-managed switches. How much do you know about these two types of switches?What is the difference between the two?How should I choose?This article will talk about some of the most common questions about managed and unmanaged switches.

What is managed switch?

The managed switch can monitor its ports,devide VLANS, and set Trunk ports etc. through the console port.Because the managed switch has the characteristics of VLAN, CLI, SNMP, IP routing, QoS, etc., it is often used in the core layer of the network, especially in large and complex data centers.

4ge+2sfp managed ethernet switch

48GE + 6SFP+ l2 commercial managed ethernet switch


What is unmanaged switch?

The unmanaged switch is a plug-and-play Ethernet switch, which does not directly process data.Because the unmanaged switch does not require any settings, it can be used by plugging in the network cable, and it is also called a fool-type switch.

unmanaged ethernet switch

What is the difference between managed switch and unmnaged switch?

Regardless of whether it is a managed switch or a unmanaged switch, they are used for network port expansion and data exchange, but the network managed switch adds a series of management functions on this basis, some of them shown in the following table:

Item Managed switch Unmanaged switch
Configuration needed yes no
VLAN devided yes no
DHCP function yes no
MAC address binding yes no
Port mirroring yes no
ARP protection yes no
SNMP yes no
Flow control yes no


How to choose between managed switch and unmanaged switch?

To ensure the smooth operation of the entire network system, it is very important to choose a suitable switch. So how should one choose between a managed switch and a non-managed switch? You can consider from two aspects of network environment and cost:

In complex data centers and large enterprise networks, the network needs to continuously transmit large amounts of data. At this time, the switch has to undertake thousands of data traffic transmission and management functions. In this case, it is very wise to choose a managed switch.Because the network management switch can perform detection management and user control management on network equipment according to the equipment and users on the switch.

In simple network environments such as small offices, homes, etc., complex management functions are not required, so you can choose unmanaged switches because the price of unmanaged switches is cheaper and more affordable than managed switches.


What is different between FTTR & FTTH?

In recent years, the communication industry has been continuously accelerating the upgrade of optical bandwidth. The continuous improvement of optical access and other network infrastructure has brought convenience to our life. At the same time, innovative business applications are also increasing, such as ultra-high definition video, cloud VR, cloud games, online education, etc. which put forward higher and higher requirements for network bandwidth, delay, jitter and so on.Therefore, FTTR has emerged on the basis of both Fiber-to-Building and Fiber-to-Home.


The conception of FTTR and FTTH

FTTH: Fiber To The Home, it is a transmission method of optical fiber communication. Specifically, FTTH refers to the installation of optical network unit (ONU) at home users or enterprise users.

FTTR: Fiber To The Room, it is a new kind of in-premises networking technology which is based on optical fibre communication.


What is different between the FTTR & FTTH?

At present, fiber to the home is usually completed by the operator’s fiber to the home, excluding the indoor network. Users need to arrange the indoor network by using wireless router, PLC, MOCA and other technologies according to their needs. FTTR is not only an optical fiber into the home, but also an optical fiber network covering all rooms can be established through FTTR equipment.

The application and requirements of FTTR are described in detail in ITU-T GSTP-FTTR document, among which the indoor high-quality WiFi networking requirements are ranked first.

WIFI technology has spread to a wide range of products including computers, PADs, smartphones, televisions and smart speakers. WIFI is an essential part of home networks, and people increasingly rely on WIFI connections to support their network connection needs. In FTTH mentioned earlier, after optical access, we can provide network access for all kinds of WIFI terminals by connecting to self-purchased home routers through the Ethernet port of ONU (insert single-port ONU link) or by integrating WIFI function into ONU with WIFI function.

Since the first version of WIFI standard IEEE 802.11a was released in 1997, WIFI technology has been developing and updating, and the transmission rate has been increasing. Currently, WIFI6 technology supports up to 9.6 Gbit/s. The higher rate WIFI7 (802.11be) standard is also under study.


WiFi version WiFi standards Release time Maximum rate Operating frequency band
WiFi 6 IEEE 802.11ax 2019 11Gbps 2.4GHz 或 5GHz
WiFi 5 IEEE 802.11ac 2014 1Gbps 5GHz
WiFi 4 IEEE 802.11n 2009 600Mbps 2.4GhHz 或 5GHz
WiFi 3 IEEE 802.11g 2003 54Mbps 2.4GHz
WiFi 2 IEEE 802.11b 1999 11Mbps 2.4GHz
WiFi 1 IEEE 802.11a 1999 54Mbps 5GHz
WiFi 0 IEEE 802.11 1997 2Mbps 2.4GHz

WIFI Standards and Version Development

Because of the diversity of housing types and the attenuation of wireless signals by space and walls, it is difficult for a single router to cover the whole house with wireless WIFI signals, so the WIFI Alliance has introduced an EasyMesh solution.

In this solution, multiple Wi-Fi access points (AP) are formed as a local area network (LAN).

Indoor wireless networking for large-sized houses can be achieved by networking multiple wireless routers that support EasyMesh function. However, because Mesh routers are distributed in different rooms and 5GHz signal attenuation is large, the installation point of the router does not guarantee the quality of direct wireless connection between routers and gateways.

When you enjoy the home network services, such as video call,video conference,high-definition video (8k), augmented reality/virtual reality (AR/VR) or hologram in the future, you would like to sit or move freely without causing any inconveniences for service delay, loss connection, etc. So to form such a mesh network with high connection data rate & reliable roaming,FTTR, a fiber-based backhaul link with enough capacity is necessary compare with Wireless or UTP.

FTTR Ethernet(UTP) Wireless
Transmission Stability High High Low
Bandwidth High

(speed upgrade independent to ODN)


(speed upgrade dependent to UTP cable)

Range Sufficient for home

(To be defined)

<100m Uncertain

(depends on channel)

Manageable Could be managed

(To be defined)

No No


Compared with the traditional network technology and FTTH, FTTR (Fibre to The Room) all-optical Wi-Fi network solution allows users to achieve high-speed Internet experience at any time. It can directly extend the optical fiber to every room, and it is the only new technology in the industry that can realize the coverage of the whole house (not just one or two rooms) above Gigabit.


FTTH & FTTR Network


Network provides support for service. High-quality service also takes full advantage of the network. Service and network complement each other. FTTR is a further extension to home network based on FTTH. FTTR has been piloted, but it is still a long way from popularization. It can only develop gradually with the development and popularization of high-definition video, VR/AR, cloud games and other services.



Test Environment Topology Diagram

What is WiFi6?WiFi6 Vs WiFi5 in Performance

As the primary choice of millions of internet users, Wi-Fi technology has to elevate its performance to satisfy the bandwidth requirement in such fast-developing network communication surroundings. And as the latest generation of Wi-Fi technology, Wi-Fi 6 has greatly improved in every aspect. Let’s learn more information about Wi-Fi technology and its related products from C-DATA.

About Wi-Fi 6 Technology

Wi-Fi 6 (Original Called: IEEE 802.11.ax) means the six-generation wireless internet technology; it is the standard call of Wi-Fi. In the coming 5G era, the advanced Wi-Fi 6 technology meets the rigorous requirement of bandwidth. It is widely used on the internet due to its convenient organizing network as the terminal network unit.

Wi-Fi 6 uses the innovative technology of MU-MIMO and OFDMA. MU-MIMO changes the communication style from single-device to multi-device. And OFDMA technology greatly improves the data transmission efficiency and network capacity. So compared with previous Wi-Fi technology, Wi-Fi 6 has more advantages as below:

  • High Rate: The maximum transmission rate of Wi-Fi 6 is 9.6Gbps, which is the triple efficiency of Wi-Fi 5. Wi-Fi 6 also has a larger data capacity and wider frequency bands, making it adapt to all the devices no matter low or high speed.
  • Low Latency:MU-MIMO technology of Wi-Fi 6 allows multiple users to communicate in uplink and downlink simultaneously. OFDMA technology also allows different users to share the same channel to shorten the data interaction response time.
  • Wide Connectivity: Adding a coloring mechanism, Wi-Fi 6 labels each device and its data accordingly. So that there is no confusion in transmitting, it can meet the multi-user scenarios and achieve high-speed transmission.
  • High Security: Wi-Fi 6 uses the upgraded version WPA3, which has higher security in preventing illegal network attacks.
  • Power Saving Mode: Wi-Fi 6 uses Target Wake Time (TWT) technology. It allows planning communication time between two devices, so it helps to save power consumption by reducing signal search time.

With the development of wireless technology, Wi-Fi 6 will become more and more popular in the future. A new generation of wireless communication equipment based on Wi-Fi 6 is in high demand to catch the trend. C-DATA commits to satisfy users in enjoying new Wi-Fi 6 technology by innovative wireless communication equipment. In the next step, let’s check how C-DATA Wi-Fi 6 products can meet your need.

About C-DATA Wi-Fi 6 Products

The home router is an essential network unit at the access end of the internet. As the network entry terminal and the closest network device to the users, the router’s performance greatly affects the user experience.

To adapt to the development of global 5G networks and meet the requirement of low latency in using the wireless device, C-DATA’s CERESTEC router is equipped with Wi-Fi 6 technology. Compared to previous routers, the CERESTEC router adds the 802.11ax mode and WPA3PSK mode option. It allows users to complete a faster and more secure Wi-Fi experience through an easier configuration. The router is also compatible with different modes so that users can cut to the required mode easily.

Here, we have a randomized trial on Wi-Fi 6 router of C-DATA’s CERESTEC Antenna 2X2 model WR525-AX1800:

  1. Test Purpose: 802.11ax mode vs. 802.11ac mode
  2. Test Samples: C-DATA’s CERESTEC router WR525-AX1800, oneset
  3. The Involved Tools and The Hitting Stream Environment: Shield Box, Wi-Fi 6 AX200 network card, IxChariot, two sets of personal computers
  4. Test Environment Topology Diagram as Figure 1:
Test Environment Topology Diagram

Figure 1

      5.Wi-Fi 6 AX200 NIC connected to WR525-AX1800 router with 5G wireless, IxChariot creates ten new streams, running steams for 2 minutes.

  • 11ac mode

LAN to Wi-Fi, the actual negotiated rate of the NIC is 866Mbps, the measured rate chart as Figure 2:

802.11ac mode

Figure 2


Wi-Fi to LAN, the actual negotiated rate of the NIC is 866Mbps, the measured rate chart as Figure 3:

Wi-Fi to LAN

Figure 3

LAN to Wi-Fi, Wi-Fi to LAN at the same time. The actual negotiated rate of the NIC is 866Mbps, and the measured rate chart as Figure 4:

LAN to Wi-Fi

Figure 4

  • 11ax mode

LAN to Wi-Fi, the actual negotiated rate of the NIC is 1Gbps, the measured rate chart as Figure 5:

LAN to Wi-Fi

Figure 5

Wi-Fi to LAN, the actual negotiated rate of the NIC is 1Gbps, the measured rate chart as Figure 6:

Wi-Fi to LAN

Figure 6

LAN to Wi-Fi, Wi-Fi to LAN at the same time. The actual negotiated rate of the NIC is 1Gbps, and the measured rate chart as Figure 7:

LAN to Wi-Fi

Figure 7

         6.Running stream data of 802.11ax mode and 802.11ac mode as Form 1

Test Item Mode RX(Mbps) TX(Mbps) RX+TX(Mbps)

LAN   Wi-Fi

802.11ac-20MHz 143 142 148
802.11ac-40MHz 350 343 348
802.11ac-80MHz 714 703 723

LAN   Wi-Fi

802.11ax-20MHz 201 226 220
802.11ax-40MHz 410 436 420
802.11ax-80MHz 821 846 830

Form 1

In the same broadband transmission condition, 802.11ax’s protocol transmission rate is faster, and its carry capacity is bigger than 802.11ac’s.

Here, there are some Wi-Fi 6 capable router devices from C-DATA for selection.

No. Router Form Router Model Router Feature Support Description
1 4x Gbps LAN+1x Gbps WAN+ 4 Internal Antenna+ Dual-band WR525G-AX1800 1. Support WPA3PSK Encryption Mode,2.4/5G support technology 802.11ax mode, can be switched to 802.11ac/an 802.11b/g/n mode

2. Support WISP/Repeat mode

3. Support Wi-Fi6 wireless Mesh networking

2 2x Gbps LAN +1x Gbps WAN+ 4External Antenna+Dual-band WR535G-AX1800 1. Support WPA3PSK encryption mode, 2.4/5G support technology 802.11ax mode, can be switched to 802.11ac/an 802.11b/g/n mode

2. Support WISP/Repeat mode

3. Support Wi-Fi6 wireless Mesh networking



With the popularity of information technology, Wi-Fi wireless communication technology is widely used in communication products. Wi-Fi 6 products are available in home routers and other terminal products step by step. As a professional access network products supplier, C-DATA will certainly adopt the latest communication technology in our products and supply customers more user-friendly products.

Next-Generation PON technology War 25G PON VS 50G PON

Next-Generation PON technology “War”: 25G PON VS 50G PON

The PON (Passive Optic Network) is the emerging avenue for the digital tussle for the stakeholders. Several high-tech giants battle with each other in fields like 5G and broadband. It is worth mentioning that the two tech giants, Nokia and Huawei, have come face to face, locking horns with each other in the battlefield of broadband. Here let’s take a look at this heated topic.

Next-Generation PON technology War 25G PON VS 50G PON

25G PON by Nokia VS 50G PON by Huawei, which is better? 

Nokia favors 25G PON compared to Huawei that supports 50G PON. On the one hand, Huawei has launched a 50G PON prototype, they think that the 25G PON can not meet the bandwidth requirements and is unnecessary. Chinese manufacturers, led by Huawei, together with some South American enterprises, are in favor of 50G PON. They believe that it will bring much convenience and opportunities to them.


On the other hand, Nokia claims to launch the world’s fastest 25G PON technology with the help of Proximus, a digital communication company in Belgium. One of the fixed customers of Nokia claims that he is super supported for 25G PON. He had established long-term cooperation with Nokia since the XGS-PON system, also known as 10 G PON, was considered the latest technology globally. In its fight with Huawei, Nokia won the support of many industry leaders who are currently reluctant to jump to 50G PON directly, claiming it as a much more advanced technology, which can only be a reality in the future.


The features of the Passive Optical Network technology

Disparate people hold different opinions toward this heated discussion. It is hard for us to draw a conclusion. However, we cannot deny that the ever-increasing user demands have increased the need for the Passive Optical Network accessing. This type of internet reduces the internet budget while increasing the speed exponentially. Here we will introduce the features of the PON(passive optical network)  technology to help you figure out why it is so popular.


As PON technology is a point-to-multipoint structure, which means a single fiber optic will facilitate multiple users, the installation cost is also reduced manifold. As no electricity is used in transmitting data on the PON network, this technology is free from electromagnetic interference, resulting in no signal loss. Due to its unique structure, PON technology is a scalable solution, which is a big win for businesses that would not need extra investments while scaling their business up.


The transmission process of the PON technology

As mentioned above, the PON technology is a point-to-multipoint system that needs only one optical fiber to distribute the internet to several users. And the PON consists of three parts, and they are OLT, ONU, and ODN. The Optical Line Terminal (OLT) is a carrier device that assigns upper-layer service network data to users. At the same time, Optical Network Units (ONU) are devices on the user side that receive data from the OLT and directly provide services for users. Also, the Optical Distribution Node (ODN) is the network between the OLT and the ONU and is responsible for the transmission channel of optical signals.


olt onu odn

As it is a point-to-multipoint system, one OLT is used while the number of ONU may vary from case to case. A single optical fiber is attached with the splitter that splits the fiber bandwidth and distributes it among ONU or the end-users. As both the downstream and upstream traffic are necessary for any internet service provider, the PON technology uses different wavelengths to simultaneously proceed with the downstream and upstream traffic. This way, a seamless operation is possible without any systematic hurdle.

The differences between 25G PON and 50G PON

Although 10 G PON is a widely used technology these days, the pursuit of 25G/50G PON has made the future speedy and internet-driven. However, there is still something different in these two PONs. They mainly include the following:


  • The downstream speeds of 25G and 50G PON are 25G bps and 50Gbpstransmission rates over a single wavelength , respectively.
  • 50G PON Viewpoint: A25 Gbps upgrade step would be considered too close to 10 Gbps and so not sufficiently future proof and, hence, wasteful of the huge investment by network operators in FTTH deployment. 100 Gbps would be nice to have, but this is currently considered too challenging when considered from the whole PON industry perspective. Weigh the pros and cons of technology and requirements, it should select 50G PON.
  • 25G PON Viewpoint: 50G will require a number of new technologies, and the industry is at least 10 years away from 50G PON maturity. That is just too long a wait for broadband operators.
  • Standard:  ITU-T 50G PON standard have released G.9804 (also referred to as HSP – Higher Speed PON) .  Nokia has marched 25G PON outside ITU and set up what is now called the 25GS-PON MSA (for multi-source agreement) Group.
  • Both 25G PON and 50G PON can coexistence with GPON, XG-PON, XGS-PON, and 10G EPON, support  PON evolution and upgrade.

The applications of 25G PON and 50G PON

It is acknowledged that the 50G PON may have more applications with its higher downstream speeds and transmission rate. The 50G PON technology will be a big win for enterprises, which are in pursuit of rigorous connectivity among all their branches and cloud services through private lines. In the data revolution and the emerging Artificial Intelligence technology, the need for continuous high-speed bandwidth can only be fulfilled with 50G PON services.


While 25G PON, on the other hand, applies to mobile transport services and business sectors that need technology beyond 10 G PON urgently.

Final words

Though there is a heated discussion between 25G PON and 50G PON supported by Nokia and Huawei, it is tough for us to figure out which is the best. However, they all represent the speed at which the internet is spreading faster than ever. It is a positive signal for our humans.







There is another CPON, besides EPON and GPON xpon

There is another CPON, besides EPON and GPON

There is another CPON, besides EPON and GPON

CPON? You must be familiar with EPON\GPON, but do you know what is CPON?

CPON:Coherent PON.

CableLabs recently launched that project – dubbed Single-wavelength 100G PON.

What is the difference between this CPON and the traditional PON?

CPON is like traditional PON:Passive optical distribution network,Point-to-multipoint topology. Yet, CPON is different: Uses coherent modulation and detection instead of IM-DD ,Optimizes optical power distribution,Provides longer reach & higher split ratio with improved power budget, Enables 100 Gbps and beyond data rate (per lambda)…

Where can this CPON be used?

It can be applied to optical access networks such as residential broadband; wireless transmission such as midhaul and fronthaul; optical fiber to enterprises and multi-residential units…

knittle, vice president of cablelabs, believes this is the future development direction of PON. But what will happen in the future? let us wait and see!
It’s interesting to follow the development of technology. In the next article, I’m going to talk about Nokia 25g PON vs        Huawei 50G PON.

For more details of CPON, please click this link:https://www.lightreading.com/cable-tech/10g/cablelabs-sparks-100-gig-pon-project-/d/d-id/769116

POE交换机 (1)

The Global Market Situation of Ethernet Switches and Routers in 2021

According to information recently released by industry media, the global Ethernet switch market reported revenue of USD6.70 billion in Q1 2021, up 7.60% YoY, while the global enterprise and service provider (SP) router market grew by 14.40% YoY to USD3.40 billion.

Overview of the Ethernet Switch Market

Revenue of the global Ethernet switch market differed in Q1 2021, by region:

  • Asia Pacific (excluding China and Japan) performed strongly: up 7.20% YoY in total, pushed by the 17.90% growth in South Korean
    • China: up 19.80% YoY
    • Japan: reaching an annualized rate of 23.50%
  • Europe showed mixed results:
    • Western Europe: up 16.70% YoY
      • Germany: up 14.30% YoY
      • Central and Eastern Europe: down 7.80% YoY
    • Middle East and Africa: down 3.70% YoY
    • America:
      • The US: up 2.50% YoY
      • Canada: down 11.80% YoY
      • Latin America: up 2.50% YoY

The highest-speed switch platforms remained the key impetus for the Ethernet switch market. For instance, the shipment of 100Gb switch ports grew by 16.90% YoY, while revenue was up by 27.20%, making up 24.50% of the Ethernet switch market. Impressive increases were also seen in 25Gb/50Gb switches, with revenue rising by 28% YoY and the shipment of switch ports up 21.0% YoY.

Conversely, low-speed switches, a more mature segment of the Ethernet switch market, produced mixed results:

  • 10Gb switch ports:
    • Shipment: up 18.10% YoY
    • Revenue: down 0.40% YoY, making up 23.30% of the whole Ethernet switch market
  • 1Gb switch ports:
    • Shipment: up 12.20% YoY
    • Revenue: down 2.40% YoY, 35% of the whole Ethernet switch market

In Q1 2021, the emerging market segments for 200Gb/400Gb and 2.5Gb/5Gb were added in the IDC report, expected to proliferate in the coming quarters.

Strongly pushed by the applications of both data centers and non-data centers, the overall shipment of Ethernet switch ports rose by 15.40% in Q1 2021:

Specific data are indicated as follows:

  • Data centers:
    • Revenue: up 10.20% YoY, accounting for 43.10% of the whole Ethernet switch market
    • Port shipments: 13% of the whole Ethernet switch market
  • Non-data centers:
    • Revenue: up 5.80% YoY, 56.90% of the Ethernet switch market
    • Port shipments: 87% of the Ethernet switch market

POE交换机 (1)

Overview of the Router Market

The global enterprise and service provider (SP) router market reported 14.40% YoY growth in Q1 2021. Revenue of SP routers increased by 18%, making up 77.50% of the global enterprise and SP router market. In comparison, the revenue of enterprise routers only grew by 3.70%.

Specific revenue performance of the router market was indicated by region as follows:

  • Asia Pacific (excluding Japan and China): up 27.80%
    • Japan: down 2.60%
    • China: down 0.80%
  • Europe
    • Western Europe: up 19.90%
    • Central and Eastern Europe: up 18.10%
  • Middle East and Africa: up 11%
  • The US: up 25.70%, due to the 38.7% growth from the SP router market despite enterprise routers dropped by 5.40%

Latin America: an annualized rate of 4.60%

路由器 (1)

service configuration management 2

TR069 Protocol or WAN Connection, Which is Better?

TR069 Protocol or WAN Connection, Which is Better?


The rapid development of information technology and extensive use of a large number of terminal access devices are challenging the types, volume, and scale of services carried by PON (Passive Optical Network). The increasing service of PON requires effective management for the customer premises equipment.

We learn from the previous article titled Differences between HGU ONU and SFU ONU that OLT configures and manages ONU through OAM / OMCI. There is a one-to-one mapping between the GEM port on the WAN side and the UNI port on the LAN side in SFU ONU, so OLT can control each port and monitor the traffic of the ONU.

However, OLT fails to remote manage the HGU ONU due to that the data docking between OLT and ONU is through VEIP whose tasks nevertheless are configured by ONU itself, which is unacceptable for the gateway type ONU terminals widely used in the network of operators.

Management mode based on the TR069 protocol and the development of WAN connection based on private OMCI is two solutions applied to the remote management of ONU, facilitating the business distribution and saving the maintenance cost of operators.

The rest of this article will focus on the introduction and applications of the TR069 protocol and WAN connection configuration.

  1. TR069 Protocol

TR069 short for “Customer Premises Equipment (CPE) WAN Management Protocol (CWMP)”, is an Internet Protocol developed by DSL forum suitable for remote management of CPE. As the document number used to carry the protocol is TR069 in the DSL forum, it is referred to as TR069 protocol.

1.1Management Mode of TR069 Protocol

The management server, such as ONU, in the management mode defined by TR069 protocol, goes by the name of the Auto-Configuration Server (ACS) that is responsible for the management of Customer Premise Equipment (CPE). The interface between ACS and CPE calls the southbound interface, and the interface between ACS and other network management systems, service management systems, and billing systems (OSS / BSS) of operators is the northbound interface. While TR069 protocol mainly defines the standard of southbound interface and allows ACS to provide services to a CPE or a group of CPEs based on multiple standards.

service configuration management

Figure 1.1 Management Mode of TR069 Protocol

1.2 Functions of TR069 Protocol

TR069 protocol describes a mechanism that builds a safe framework of automatic configuration and management for CPE by ACS and adds the management function of CPE to this framework. The purpose is to manage a CPE or CPE collection by achieving the following functions.

1.2.1 Auto-configuration and dynamic services provisioning. The parameters involved in the mechanism include both general parameters and user-defined parameters (such as WAN connection, Wi-Fi, voice, etc.), leaving more independent space for software implementation.

1.2.2 Software and firmware image management. Downloading and uploading files are available for CPE. The protocol provides a method to check the software or firmware version and can process files of signature data. After the end of file transfer, ACS will be notified whether return successfully or not.

1.2.3 Diagnosis. TR069 protocol supports the generation of effective diagnostic information by CPE. ACS diagnoses and solves connectivity or service problems with this information and powers with the pre-defined diagnostic ability.

1.2.4 Alarm. Event reports are actively sent by CPE to realize real-time alarms of equipment.

1.2.5 Traversing NAT connection. TR069 protocol allows ACS to manage devices following NAT but limits initiating sessions. The mechanism of TR111 is a supplement to TR069, which enables ACS to initiate a session. CPE will search for ACS server automatically in initial installation (CPE, when it leaves the factory, is configured with a default URL address that points to ACS server). Communication and download with ACS after successful connection can achieve, and the management after NAT gateway will be perfect..

1.3 Protocol Stack Structure

The protocol stack structure of TR069 is shown in the following table:

Layer Description
CPE/ACS Management Application The CWMP protocol can be achieved by the management application on the CPE and ACS respectively. The application is defined locally but not as part of the CWMP protocol.
RPC Methods CWMP protocol defines various RPC methods to realize the interaction between ACS and CPE. The RPC method includes defining CPE parameters which can be accessed by ACS and the PRC method associated with this parameter.
SOAP Remote encode based on standard XML syntax to avoid the conflict with firewall.
SSL/TLS Standard network transport layer security protocol (optional). SSL protocol specifies a layered mechanism that ensures data security between application protocol and TCP / IP protocol. It provides data encryption, server witness, message integrity and optional client authentication for TCP / IP connection to ensure that the data will not be changed during transmission.
TCP/IP Standard TCP/IP

1.4 TR069 Session

The TR069 session begins with the connection between CPE and the TCP / IP of ACS. In the process of connection, CPE as the HTTP client sends its SOAP requests to ACS through HTTP post, while ACS as the HTTP server sends its SOAP request to the user’s device through the HTTP response. Each HTTP request can contain multiple SOAP requests or responses. Moreover, the parameter information of CPE can be configured and obtained through the set and get operations in this process. Finally, the connection closes.

To ensure the security of the management system, the TR069 protocol suggests SSL / TLS the authentication for the user equipment. The authentication method defined in HTTP 1.1 should be used if SSL / TLS is not allowed. The specific TR069 session flow is shown in figure 1.2.


Figure 1.2 TR069 Session Flow

In particular, since ACS and CPE are from different manufacturers, the node settings of ACS’s and CPE’s parameters are more or less different. There is a need for CPE manufacturers to make adjustments according to the parameters of ACS. This is the reason why we get feedback from customers that it is impossible to configure C-Data ONU through TR069 protocol on ACS.


Generally, the HGU ONU on the market, for the convenience of management, configuration, and monitoring, has to support the TR069 protocol.

2. WAN Connection of ONU

2.1 What is WAN Connection?

WAN is the abbreviation of Wide Area Network. WAN connection refers to the way a device connects to a WAN. For example, there are user-oriented interfaces, including POTS telephone interface, broadband LAN interface, WiFi wireless interface, and so on in a home gateway.

2.2 Principle of WAN Connection

In EPON and GPON, the protocols that OLT used to manage ONU in EPON and GPON are OAM and OMCI, respectively. Here we take OMCI as an example.

OMCI (ONU Management and Control Interface) is a kind of transmission channel defined in GPON standard to transmit OMCI messages by establishing a proprietary ATM PVC or GEM PORT between OLT and ONT. It is available for configuration management, fault management, performance management, and security management of ONU devices. ONT establishes the OMCI channel when registering with OLT. OMCI is a master-slave management protocol in which the OLT is master, and the ONT is the slave. OLT controls multiple ONT devices under OLT through the OMCI channel. Figure 2.1 shows the OMCI model for reference.

ONT management and control interface

Figure 2.1 OMCI Model for Reference

2.3 Analysis of OMCI Message Format

OLT and ONU interact through OMCI. GPON standard protocol defines the OMCI message format, as shown in Table 2.1:

Segment ATM/GEM Header Transaction



Message Type Device Identifier Device Identifier Message contents OMCI Trailer
Length(byte) 5 2 1 1 4 Baseling 8
2 0-1964

Table 2.1 OMCI Message Format

The explanation of each field is as follows:

  • ATM/GEM Header:Itcontains information to distinguish different GEM ports。
  • Transaction Correlation Identifier: the numericalvalue of this field should be consistent in a group of messages corresponding to requests and responses. In the Baseline OMCI message, the highest bit of this field indicates the priority of the OMCI message.
  • Device identifier: 0xA represents the Baseline list, and 0xB stands for the Extend list.
  • Message identifier: a 2-byte entity or instance ID
  • Message Contents: packet payload.
  • OMCI trailer: two bytes are packet length 0x28 and four bytes are CRC32 for Baseline OMCI message; while only four bytes for Extend OMCI.

Message Type:

  • DB (Destination Bit): it is consistently 0.
  • AR (Acknowledge Request): whether an OMCI message requires the response.
  • AK (Acknowledge): whether an OMCI message is a response.
  • MT (Message Type): supports up to 32 message types and message types 4 through 28 are defined in the protocol.

The specific definition of relevant configuration parameters of WAN connection will not be detailed here as they are defined by the equipment manufacturer in Baseline list.

As a matter of fact, there is no relevant configuration parameters of WAN connection in G984 / G988 standard. Therefore, some relevant parameters is defined in Extend list by the device manufacturers to meet the needs of users and the WAN connection becomes a private protocol of the equipment manufacturer. It throws out the requirement that private protocol of the equipment manufacturer should be available for both OLT and ONU.

3. Comparison of TR069 Protocoland WAN Connection

TR069 protocol and WAN connection differ in application due to difference of protocols. Three aspects are compared as follows:

  • Cost performance

A TR069 server has to be set up in the network if TR069 management method is applied. The configuration and operation cost of TR069 server is nothing to large-scale operators or ISPs. Moreover, TR069 can effectively solve the problem of batch distribution for ONU’s service. However, small-scale operators or ISPs prefer more economical solution as the cost of TR069 server is too high for them. WAN connection that only need to be compatible with software on OLT is the key to them, without any hardware cost.

  • Compatibility

There are compatibility problems for TR069 protocol and WAN connection due to the difference of device manufacturers and definitions. It is relatively easy to deal with the compatibility problem of TR069 protocol by providing the information of each TR069 node they need to the home gateway manufacturers for software compatibility processing.

As for the compatibility of WAN connection, C-Data sets its own private protocol to realize the configuration of WAN connection. Nevertheless, if there are third-party ONU devices in the system, the third-party ONU manufacturers requires to do compatibility development.

  • Easy to manage

Only the network between the TR069 server and the home gateway device is interoperable can the TR069 server effectively manage the home gateway and automatically configure the terminal device successfully registered on the server. There are many subnets and routers between the server and CPE, so the network is relatively complex. If the network is unstable, TR069 server will be difficult to manage the home gateway equipment. Therefore, a strict requirement is for TR069 server and its network.

It is much more convenient and easier for WAN connection to configure and manage home gateway than that of TR069 server. That is because there is only one optical fiber between OLT and ONU and no complex network structure. OLT still manage ONU even if the user’s Internet service is not available as long as the ONU is registered with OLT.

4. ONU Models that Support TR069 Protocol / WAN Connection

No. ONU Configuration ONU Model TR069 WAN Connection
1 EPON&GPON&XPON 1GE/1GE+CATV FD511G&FD701G series Not support Support
2 EPON&GPON&XPON 1GE+wifi/1GE+1FE+wifi/


FD511GW&FD512XW&FD702XW&FD604GW&FD804GW series Support Support


FD50X&FD704X&FD504G series Not support Not support

5. Conclusion

You may come to a clear understanding for TR069 protocol and WAN connection from the above introduction. TR069 protocol and WAN connection are two management methods that both can realize the remote management of gateway ONU and have their own characteristics. When it comes to which one is the best, it spends on your specific networking and requirements.

As a professional supplier of FTTH broadband access products, Shenzhen C-Data Technology Co., Ltd. will forge ahead to enhance technical ability, develop applicable products that cater to customers’ needs, and escort the construction and development of customers’ network.

1GE ONU adopts Realtek RTL9601D chip solution

C-Data latest products 1GE ONU adopts Realtek RTL9601D chip solution

Recently, Shenzhen C-Data launched the latest products 1GE ONU. The ONU is based on Realtek RTL9601D chip solution, support GPON and EPON dual-mode passive optical network, and provide users up to Gigabit data access service through the PON network, and can be used for fiber access for home or SOHO business users. Features of high cost performance, high reliability and easy maintenance. The product is fully compatible with ITU G.984.x and IEEE802.3ah technical standards, and meets the technical requirements of operators for passive optical network terminal equipment.

C31 场景图

The ONU has an integrated white body and uses environmentally friendly, flame-retardant ABS material. The overall design conforms to the prevailing simple and fashionable style. The rear panel of the ONU is equipped with optical ports and LAN ports. The optical ports are used to connect to the network-side optical fiber link, and the electrical ports are used to connect to terminal devices such as PCs on the user side. The electrical port uses a standard RJ45 interface, 8-pin, to ensure the stability and reliability of data transmission. The equipment can be remotely configured and managed by the OLT, which is very convenient for installation and management. A set of LED indicators are provided on the top of the front of the fuselage, a POWER, an optical port, a LAN port, and system and link indicators. The working status of the equipment can be displayed to facilitate users to understand the operation of the equipment. The indicator light is yellow-green, clear, soft and pleasant. The fine heat dissipation holes on the sides and bottom of the shell are conducive to the dissipation of heat, which helps the internal chip to dissipate heat and ensure the stability of the product for a long time.

C-Data and Realtek have maintained a good cooperative relationship in a number of product areas. C-Data will take advantage of the performance and supply capacity of the RTL9601D chip to further consolidate the market position of C-Data ONU products and achieve a win-win cooperation.

different between HGU and SFU

Differences between HGU ONU and SFU ONU

Brief video ☞  Differences between HGU ONU and SFU ONU


The development of information technology and network shortens the distance between people and makes people increasingly inseparable from the network. PON (Passive Optical Network) technology, mainly composed of OLT, ODN, and ONU, as we all know, tends to mature and has been widely used so far. ONU is usually placed in the user’s home and varies with the diversity of users’ needs. As for the types of ONU, HGU ONU and SFU ONU are always come into our eyes, but few people can tell the difference between them. What exactly are SFU ONU and HGU ONU? You will get the answer in the rest of the article.

1.PON System

From the beginning, there is necessary to learn about PON as the critical part of ONU. PON (Passive Optical Network) is a kind of single-fiber bidirectional optical access network with a point to multipoint (P2MP) structure with a typical tree-type topology. The system composed of OLT (Optical Line Terminal), ONU (Optical Network Unit), and ODN (Optical Distribution Network) which provides a transmission channel, is what we call the PON system.

In the downlink direction (OLT to ONU), the signal sent by OLT reaches each ONUs through ODN. While in the uplink direction (from ONU to OLT), the signal sent by ONU only reaches OLT, not other ONUs. To avoid data conflict and improve network efficiency, the uplink direction adopts TDMA mode and manages the data transmission of each ONU. ODN provides an optical channel between OLT and ONU. The structure of PON is shown in Figure 1.1.

PON Structure for Reference

Figure 1.1 PON Structure for Reference

2.What is ONU?

ONU belongs to the terminal equipment of PON technology, playing an essential role in the PON system. ONU, in between the ODN and user equipment, provides the optical interface and the electrical interface to realize the processing, maintenance, and management of various photoelectric signals. There are currently user-side ONU devices, also known as the optical modem, directly installed in home.

The core layer, service layer, and public layer consist of the inner part of ONU. The core layer provides multiplexing and optical interface; the service layer mainly refers to user port, and the public layer ensures power supply and maintenance management. ONU is divided into active optical network units and passive optical network units. Generally, the equipment with an optical receiver, uplink optical transmitter, and multiple bridge amplifiers is called an optical node. The PON connects to the OLT which connects to the ONU through a single fiber. ONU can access various user terminals, such as set-top box, wireless router, TV, etc., and occupies functions of photoelectric conversion, maintenance, and monitoring.

3.Classification and Application of ONU

According to the application, ONU can be divided into six types, namely SFU (Single Family Unit) ONU, HGU (Home Gateway Unit) ONU, MDU (Multi-Dwelling Unit) ONU, SBU (Single Business Unit) ONU, MTU (Multi-Tenant Unit) ONU and CBU (Cellular Backhaul Unit) ONU. However, only SFU (Single Family Unit) ONU and HGU (Home Gateway Unit) ONU are used by the end-users in practical application.

These two types of ONUs will be introduced in the following.

(1)HGU(Home Gateway Unit)ONU

HGU ONU takes the Virtual Ethernet interface point (VEIP) as the partition point of the OMCI management domain and the non OMCI management domain (TR069, SNMP, etc.) in the data plane. The ME achieves management only through OMCI. The non OMCI management domain can only manage all services and functional modules under the VEIP. Only one VEIP is allowed in each HGU. ONU will report VEIP or PPTP (Physical Path Termination Point) when MIB is uploaded according to the type of the device, while HGU can only use and report VEIP rather than PPTP. OLT will judge the type of ONU devices according to the attribution of ONU type in ONU capability. Figure 3.1 shows the service process of HGU ONU.

Service Process of HGU ONU

Figure 3.1 Service Process of HGU ONU

HGU ONU, a home gateway with an uplink interface of the PON, is designed for the single family unit, which is similar to SFU ONU. Compared to SFU ONU, HGU ONU integrates the functions of ONU and RG to realize more complex control and management and provide Ethernet / IP service, VoIP service, and optional CATV service. HGU ONU has an Ethernet interface and pots interface, and WLAN interface, USB interface, and CATV RF interface are also available. Besides, TR-069 remote management and EMS local and remote management of physical layer and link layer related to PON interface are supported by HGU ONU that mainly used in FTTH scenarios.

Classified by the differences in service processes and interface numbers of ONUs, HGU ONUs has two specific forms shown in table 3-1.

Table 3-1 Specific Forms of HGU ONU

Number Interface Type Quantity of Ethernet Ports Quantity of POTS Port Quantity of WLAN Ports Quantity of USB Ports CATV RF Port
HGU-1A 1G 4 FE 2(or 1) 1(or 2) 1 optional
HGU-1B 10G/1G 4 GE or FE 2(or 1) 1(or 2) 1 optional
HGU-2A 1G 4(or 2)FE 2(or 1) 0 0 optional
HGU-2B 10G/1G 4(or 2)GE or FE 2(or 1) 0 0 optional


PPTP is that OLT directly sends VLAN data to each physical interface of ONU, fixing the whole processing process of data flow. VEIP virtualizes the total interface of an ONU. OLT and ONU conduct data docking through VEI. The services under VEIP are managed by ONU through their configuration. In short, PPTP is a LAN port, and VEIP is the virtual WAN port in HGU.

(2)SFU(Single Family Unit)ONU

SFU ONU only supports the OMCI management domain. PPTP is what SFU uses and reports, while VEIP is not available. The processing mode of OMCI configured data flow is different from that of RG flow. For OMCI data flow, there is a one-to-one mapping between the GEM port on the WAN side and the UNI port on the LAN side. All data packets can pass through without MAC address learning or forwarding. Wireless interfaces are not allowed in OMCI. Figure 3.2 shows the service process of SFU ONU.

Service Process of SFU ONU

Figure 3.2 Service Process of SFU ONU

SFU ONU is designed for a single family unit with broadband access terminal function without a more complex home gateway function from the perspective of application and ONU capacity. SFU ONU, mainly used in FTTH scenarios, has 1 or 4 Ethernet interfaces and is available for Ethernet / IP services, optional VoIP services (built-in IAD), or CATV services.

There are three specific forms of SFU ONU according to the difference of service process and interface quantity of ONU shown in Table 3-2.

Table 3-2 Specific Forms of SFU ONU


Interface type Quantity of Ethernet Ports Quantity of POTS Ports CATV RF Port
SFU-1A 1G 1 GE or FE 0 optional
SFU-1B 10G/1G 1 GE or FE 0 optional
SFU-2A 1G 4 FE 0 optional
SFU-2B 10G/1G 4 GE or FE 0 optional
SFU-3 1G 4 FE 2 optional

Note: SFU is suitable for commercial customers if TDM service is not included.

SFU ONU works under the bridging mode (layer 2 of ISO model), supports multiple VLAN functions, and its Ethernet port can be configured and managed by OLT through OMCI / OAM. Combined with a home gateway, SFU ONU is good at providing strong service capability. However, SFU ONU does not have a three-layer routing function and WAN connection configuration. The Single port 1GE ONU of C-Data is an exception as it has three-layer routing, static routing, PPPoE, DHCP function, etc.

(3)Functional Differences between HGU ONU and SFU ONU

EPON/GPON Standard IEEE 802.3/802.3ah


IEEE 802.3/802.3ah


Bridging /Routing Bridging/L2 Bridging/L2 and Routing/L3
WAN Configuration Not support Support
TR069 Function Not support Support
OLT to configure its  Ethernet Ports Support Not support
NAT Function Not support Support
Port Forwarding Function Not support Support
Loop Detection Function Support Not support
DHCP Server Not support Support
Wireless WIFI Not support Support


Number ONU Form ONU Model SFU/HGU
1 EPON & GPON & XPON 1GE / 1GE + CATV FD511G & FD701G series SFU ONU(with routing function)
2 EPON & GPON & XPON 1GE + Wi-Fi / 1GE + 1FE + Wi-Fi /

4GE + 2 pots + Wi-Fi (AC)

FD511GW & FD512XW & FD702XW & FD604GW & FD804GW series HGU ONU

1GE + 3FE / 1GE + 3FE + CATV / 4GE

FD50X & FD704X & FD504G series SFU ONU (without routing function)



Both SFU ONU and HGU ONU have their advantages and disadvantages. The truth is that the main role of ONU is to provide end-users with bandwidth access, playing a vital role in the “last mile” of the access network so that end users can better enjoy the network. Therefore, choosing the right ONU should depend on your network environment.

As a professional ONU supplier, C-Data Shenzhen will focus more on the accumulation and research of technical knowledge to improve our ONU products and meet the customers’ needs for unimpeded network experience. Moreover, C-Data Shenzhen will step further with our customers by improving the quality of products and services without delay.

epon to gpon keep xpon

What is xPON(EPON/GPON dual mode) ONU?

Brief video ☞  What is xPON(EPON/GPON dual mode) ONU?

In the access network, Passive Optical Network(PON) is the best transmission medium to realize triple-play and solve the “last mile” of the information highway. EPON and GPON are the most prevailing and mature access network standard in the PON network. EPON, a kind of mainstream broadband access technology based on IEEE 802.3ah standard, realizes the integrated service access of data, voice, and video through a single optical access system, being economical. As for GPON (Gigabit Passive Optical Network), it is the latest generation of broadband access technology based on ITU -TG.984.x standard. GPON is regarded by most operators as the ideal technology to realize broadband and integrated transformation of access network services because of its high bandwidth, high efficiency, extensive coverage, rich user interface, and so on. Therefore, communications equipment manufacturers have developed products that compatible with both EPON and GPON standards, commonly known as xPON.

1. Overview of xPON ONU

It is well-known that the passive optical network system is composed of an optical line terminal (OLT), optical distribution network (ODN), and optical network unit (ONU). xPON ONU is an optical network unit that supports both EPON IEEE 802.3ah standard and GPON ITU-TG.984.x standard, which means it can be used in both EPON and GPON networks. xPON ONU also can automatically switch in EPON or GPON mode.

2.xPON ONU Technology

2.1 Software

At first, two concepts of PLOAM and MPCP are brought to you.

In GPON, the physical layer OAM (PLOAM) channel has to be built by ONU and OLT before ONU wants to register with OLT (it calls the registration phase). PLOAM channel is a formatted information system carried by GTC lock in the designated location. It is used to transmit other PMD (Physical Media Dependent) and GTC (GPON Transmission Convergence) management information that is not sent by the embedded OAM channel. OMCI channel is used to manage the business definition of the GTC upper layer. GTC must provide a transport interface for OMCI. An optional channel, including defining the transport protocol ID (Port-ID), is offered by GTC according to the configuration of the device.

In EPON, ONU and OLT have to establish an MPCP control mechanism if ONU wants to register with OLT (it calls the registration stage). MPCP (Multi-Point Control Protocol) is the protocol of the EPON MAC control sublayer. MPCP defines the control mechanism between OLT and ONU to coordinate the effective sending and receiving of data.

Building PLOAM channel in GPON and MPCP control mechanism in EPON are both called the registration stage.

xPON ONU will be embedded in a special process to detect the optical signal of the OLT downlink to identify whether it is GPON or EPON mode because EPON and GPON have different interaction protocol messages and fields, which give aid to ONU’s identification in the registration phase. If the result of identification is inconsistent with the PON mode of ONU, ONU will restart automatically to switch to the PON mode consistent with the current network.

2.2 Hardware

Usually, ONU optical module is used in ONU equipment composed of burst mode laser driver, receiving limiting amplifier, BOSA, MCU, APD boost circuit, etc.

There are two kinds of lasers in the ONU module: FP and DFB.

As the receiver receives the signal continuously, it needs a special limiting amplifier to amplify the electrical signal converted from PD. APD-TIA and PIN-TIA are two kinds of receivers.

According to the performance requirements, 1310nm DFB LD and InGaAs Super-TIA receiver with 1490nm WDM filter is required for GPON ONU optical module. As for EPON ONU optical module, 1310nm FP LD and InGaAs PIN-TIA receiver with 1490nm WDM filter is required.

Burst transmitters and receivers are usually used in optical devices, but it is a key technical difficulty for all TDM-PON. There are great differences in timing requirements when optical devices deal with burst transmitters and receivers because of the different transmission protocols of EPON and GPON. In fact, the uplink burst timing requirements of GPON are much more stringent than EPON’s. As shown in Figure 1, the setting time required by the burst reception threshold of GPON is within 96 bytes, i.e., 77ns, while that of EPON is 400ns. Moreover, GPON also treats the on-off time of the laser in the burst emission control of ONU more strictly.

Figure 1

To sum up, GPON optical devices are generally used in xPON ONU. As the saying goes, “technology is downward compatible”, GPON optical devices are used to be compatible with the network environment of EPON.

3.Applications and Advantages of xPON ONU

3.1 Compatible with the existing network

xPON ONU can work on EPON or GPON mode. It can automatically identify whether the OLT is EPON type or GPON type and switch the operation mode . Therefore, whether the current network of Operators or ISPs is EPON or GPON, xPON ONU can run in it.

3.2 Upgrade deployment faster

Because the implementation of the EPON network is earlier than the GPON network, the EPON network accounts for a large proportion of the current network. However, the EPON network will be gradually replaced by the GPON network due to the advantage of bandwidth.

xPON ONU plays an important role in the transition from the EPON network to the GPON network. When operators decide to upgrade to GPON, a more smooth network transition, and huge upgrade cost saving can be achieved by only replacing the  EPON OLT to GPON in head-end without any operations for the user end.


3.3 Investment protection

The original EPON ONU and EPON OLT equipment must be eliminated in the process of system upgrading from EPON to GPON. But xPON ONU can avoid the elimination as it is compatible with both EPON and GPON standard, which greatly protects the investment of users.

3.4 conducive to network operation and maintenance management

xPON ONU makes EPON and GPON transparent and provides a unified interface for the upper management after the differences between EPON and GPON are blocked. Thus, no matter the terminal is EPON or GPON, the terminal configuration is the same. In this case, the network administrator only needs to focus on business management, which greatly improves the operation and maintenance management efficiency.

4.Types of C-Data xPON ONU

Number ONU Configuration ONU Model PON Mode Supporting
1 EPON&GPON&XPON 1GE/1GE+CATV FD511G&FD701G series 1. Support automatic recognition of EPON / GPON mode

2. Support manual switching of EPON/GPON mode

2 EPON&GPON&XPON 1GE+wifi/1GE+1FE+wifi/


FD511GW&FD512XW&FD702XW&FD604GW&FD804GW series 1. Support automatic recognition of EPON / GPON mode

2. Support manual switching of EPON/GPON mode



FD50X&FD704X&FD504G series 1. Support automatic recognition of EPON / GPON mode

2. Support manual switching of EPON/GPON mode

5. Prospect and Summary

xPON ONU has overwhelming advantages in compatibility, anti-interference, bandwidth characteristics, access distance, maintenance management, and so on. It is prevailing in the market and got highly concerned by ISP regarding its application. xPON ONU may become the mainstream in the next few years from the current situation given that the EPON network has been basically solidified, and only with the support of xPON ONU can the transition from EPON to GPON network be successful.

As a professional FTTH broadband access product supplier, Shenzhen C-Data Technology Co., Ltd. will keep abreast of the market trends and demand to produce better products for the Internet industry.




PON Protection Switching Technology


With the increase of PON networks’ services, it is necessary to implement PON protection switching technology to ensure the stability of engineering applications stability and deal with service interruptions caused by various communication failures. This article mainly introduces several different PON protection technologies on OLT and describes some implementation points based on a dual PON port protection solution. The ONU remains online, and services are not interrupted before and after the solution is switched. And the delay is less than 100 ms, which greatly guarantees network stability.


PON (Passive Optical Network) is an optical fiber broadband access technology covering the last mile. It only needs to install a simple optical splitter at the optical branch point, which has the advantages of saving optical cable resources, bandwidth resource sharing, no electromagnetic interference, equipment safety, high performance, and low-cost comprehensive network construction. Among them, saving the backbone fiber is a huge advantage of the PON system, but it also brings greater risk. Once the backbone fiber in the PON system fails, it will cause all-optical network units (ONUs) connected to the backbone fiber interrupted simultaneously.

Besides, the system also has the probability of the optical module’s failure and the failure of the port, which is connected to the main fiber. To ensure the service’s stability in engineering applications and deal with the service interruption caused by various communication failures, an efficient and reliable protection switching solution is required. When the backbone fiber fails, the protection switching can be realized in the shortest possible time and recover the services without affecting users’ use.

1、Introduction to PON Protection Switching Technology

   1.1 PON ProtectionOverview

At present, the commonly used PON protection technologies are the four protection types A, B, C, and D defined in the ITU-TG.984 standards. The protection range of types A and B is the protection from the PON port of the OLT to the optical splitter. The difference between the two is whether the OLT’s PON port is included in the protection range. The protection scope of types C and D is comprehensive protection from the PON port of the OLT to the PON port of the ONU. The difference between the two is whether the ONU’s PON port is included in the protection scope.

  1.2 PON Protection Type A

PON protection type A mainly uses a single PON port for the OLT, which has a built-in 1×2 optical switch for the optical module’s gating and then switches the working line. In the optical distribution network (ODN), a 2: N optical splitter is used, and two relatively independent and mutually backup optical fiber links are established between the optical splitter and the OLT. The OLT will detect the line status periodically. When the optical link fails, it switches to the backup optical link.

PON protection switching technology (1)

  1.3 PON Protection Type B

The OLT’s two PON ports in the PON protection type B adopt independent PON MAC chips and optical modules and are identified as the main PON port and the backup PON port. The main PON port is in a working state, and the standby PON port is in a cold backup state.

In ODN’s optical splitter use, two relatively independent and mutually backup optical fiber links are simultaneously connected between the optical splitter and the OLT. The OLT ensures that the main PON port’s business information can be backed up synchronously and periodically inspect line status and PON port operating status. When the main fiber link or PON port fails, the OLT immediately switches to the backup PON port and fiber link. The backup PON port can maintain the ONU’s service attributes unchanged, and the service is transferred to the backup link.

pon protection switching technology(2)

   1.4 PON Protection Type C

PON protection type C uses two PON ports on the OLT, and the main standby PON ports are mutually hot backup. ONU uses a PON MAC and different optical modules; a 1×2 optical switch is built in front of the PON port. Two 1: N optical splitters are used to establish two independent and mutually backup optical fiber links between ONU and OLT. The OLT guarantees that the main PON port’s service information can be backed up to the backup PON port simultaneously. Both the ONU and the OLT detect the link status and decide whether to switch according to the link status.

pon protection switching technology(3)

  1.5 PON Protection Type D

In PON protection type D, OLT dual PON ports, ONU dual PON ports, backbone fiber, optical splitter, and distribution fiber are all dual redundant. Both the main and standby OLT PON ports are in working condition. OLT guarantees that the active PON port’s service information can be backed up to the backup PON port synchronously. As a result, the backup PON port can maintain the ONU’s service attributes unchanged during the protection switching process.

ONU uses different PON MAC chips and different optical modules. The ONU should ensure that the primary PON port’s service information can be backed up to the backup PON port simultaneously so that the ONU can maintain the local service attributes during the PON port protection switching process. The ONU’s main and backup PON ports are in a working state. The backup PON port does not need to perform the ONU’s initialization configuration and service attribute configuration during the PON port protection switching process. Both ONU and OLT detect the link status and decide whether to switch according to the link status.

pon protection switching technology(4)

  1.6 Choice of 4 Types of PON Protection

The four PON protection types A, B, C, and D protection solutions are introduced above. The OLT’s two PON ports in Type A use 1 PON MAC chip, which is connected to 2 optical modules through a 1×2 switch to realize 2 PON ports’ protection. This type is only applicable to the protection in the same PON board. Although the C and D protection types protect the entire network, making the system the best reliable, the protection cost is too high. Simultaneously, ONU equipment also needs to support the corresponding PON protection function, which only high-end users can afford. So, it is hardly used in actual projects.

Considering the access cost and practicability, Type B protection is more economical and practical. In Type B protection, the OLT’s two PON ports adopt independent PON MAC chips and optical modules to realize the protection of two PON ports, which is suitable for protection between any 2 PON ports of the same OLT.

2、Realization of PON Protection Switching Function

   2.1 PON Protection Group

The PON protection group consists of two access PON ports. The members of the protection group have two roles: work and protect. One is a working port, and the other is a protecting port. Under normal working conditions, the working port carries services. When the optical fiber link in the working port fails, the system automatically switches the working port’s service to the protected port to ensure service transmission.

  2.2 Status of Protection Group Member

There are two states of protection group members: active and standby. The port in the active state forwards data and the port in the standby state does not forward data.

  2.3 Type of Switching

There are two types of protection group switching: automatic switching triggered by failure and protection switching performed manually. The manual protection switching performed is also called forced switching:

(1) Automatic switching means that the OLT and ONU do not need human intervention to automatically switch the optical fiber link when the switching conditions are met.

(2) Forced switching refers to operating force-switch on the OLT so that optical link switching occurs regardless of whether the designated target member is normal.

3、 Key Points of PON Protection Switching Technology

To ensure smooth service transition after PON protection switching, the PON protection group’s initial configuration needs to be issued synchronously. The dynamic data during the operation of the protection group also needs to be synchronized. Initial configuration refers to the primary PON port’s static service configuration information in the protection group, such as VLAN, bandwidth, voice configuration, and multicast video service configuration. Dynamic data includes the MAC address learning table, multicast member group information, DHCP binding table, key information.

  3.1 Configuration Synchronization

The configuration of the same ONU on the two PON ports in the protection group must be synchronized. The key to configuration synchronization is as follows:

1)  All ONUs authenticated on the primary PON port should be synchronized to the standby PON port, allowing the ONU to update its online state structure. The active PON port module should also synchronize the configuration status information with the standby PON port module to avoid repeated configurations and affecting services.

2)  Dynamic data synchronization: Dynamic data synchronization refers to synchronizing data from the PON port in the working state to the PON port in the standby state when the data changes. It requires a host CPU for real-time data synchronization.

  3.2 Service Recovery

After performing the PON port’s active/standby switchover, the original standby PON port becomes the active port. All PON related configurations and ONU configurations under the PON port should be the same as the original working PON port. After the PON protection switch is completed, all services can be automatically restored when the new working PON port is normally available.

  3.3 PON Protection Switching of C-Data OLT Products

With more and more types of services carried by PON networks, to ensure the stability of the services in engineering applications, C-Data combines PON protection in actual engineering, considering the access cost and practicality, and has fully supported PON for protection type B. The user does not need to pay attention to which PON port of the protection group is currently working. All operations are based on the main PON port. When the protection switching is triggered, the standby port state changes to the working state and replace the main PON port to continue to carry services.

As far as we know, the PON protection function implemented by OLT of some manufacturer does not actually implement protection switching but backs up the configuration of the active port to the backup port. The result is that all ONU will be disconnected after the switching, and the service will be lost, which will cause great distress to operation and maintenance personnel. However, our OLT solutions has achieved true protection switching. When the PON port is fully loaded with ONU, ONU can be kept online before and after the switching without service interruption, ensuring network stability safely and quickly.


With the popularization of information technologies such as big data, artificial intelligence, cloud computing, and the internet of things, PON technology efficiently supports various industries’ digital development by its technical reliability and practicality and relatively reasonable price advantages. As a professional supplier of network access products, C-Data will provide reliable and stable network deployment to the industries worldwide and apply more PON protection technologies to products. At the same time, it is great for consumers to choose OLT solutions that supports the PON protection of C-Data and jointly promoting the steady development of global digital networks.


IPv6 Technology for C-Data ONU Products

The rapid development of the Internet had brought a large number of intelligent terminals to our home and increasingly exhausted the IPv4 address resources we are using. Although NAT technology helps to delay the speed of the IPv4 address consumption, the world Internet technology is still developing towards IPv6 technology which has become one of the key basic technologies required by 5G, cloud computing and Internet of things technologies.

In the past two years, the world has advocated and accelerated the deployment of IPv6 technology to meet the urgent needs of the connection of massive intelligent terminals, the innovation of technology industries, and the enhancement of network security capability. Almost all ISP/Operators are building the next generation of the Internet based on IPv6 technology.

C-Data, as a professional manufacturer in access network technology, will discuss the following related topics to help you understand IPv6 technology more comprehensively.

  • Overview of IPv6 Technology
  • Transition Technology from IPv4 to IPv6
  • Relevanceof C-Data ONU to IPv6 Technology
  • C-Data ONU products supporting IPv6 technology
  • Expectation of IPv6 Technology in The Future
  1. Overview of IPv6 Technology

1.1 What is IPv6?

IPv6 (Internet Protocol Version 6) is the next generation of the current Internet Protocol (IPv4). Composed of 128-bit binary numbers, IPv6 provides a huge resource of IP address enough for every living creature and even every grain of sand on the earth to be assigned one or more IP addresses. IPv6 is to divide the 128-bit address into segments per 16 bits, and each segment is separated by colons when converted into hexadecimal digits.

An example of IPv4 address:

An example of IPv6 address: 2002:0db8:85a3:08d3:1319:8a2e: 0370:7344

1.2 Why use IPv6 technology?

IPv4 technology is a 32-bit binary address, which can address 16 million networks and 4 billion hosts. However, with the adoption of A, B, and C addressing methods, the number of available network addresses and host machines is greatly reduced. Moreover, as the core technology and about 3 / 4 IP resources are mastered by European and American countries due to their developed Internet, many developing countries fall into the predicament of insufficient IP address resources. In fact, with the increasing number of global Internet users and the vigorous development of intelligent terminals and network technology, the lack of IP address resources will seriously restrict the application and development of the Internet in many countries around the world.

1.3 Current situation of IPv6 Technology

If to realize the complete transition from IPv4 to IPv6, it requires the network software, hardware, and terminal equipment in the global Internet infrastructure to support IPv6 protocol, which will involve a lot of transformation work. Although IPv6 technology has been proposed as early as the 2010 year, it has only been promoted by governments and major ISP/Operators in recent two years. Moreover, the long-term coexistence of IPv4 and IPv6 is still a compatibility issue that we need to consider.

1.4 What are the advantages of IPv6 over IPv4?

Compared with IPv4, IPv6 has the following advantages:

  • Larger address space. The IP address length of IPv4 is 32; that is, there are 2^32-1 addresses. While the IP address length of IPv6 is 128, that is, there are 2^128-1 addresses.
  • Smaller routing table. Compared with IPv4, IPv6 packet header contains half of the fields, and all fields are aligned with 64-bit boundaries, which greatly improves the processing speed.
  • Enhanced multicast support and streaming support. There is no terrible broadcast storm caused by the IPv4 as the multicast support, and streaming support provide a good opportunity for the development of multimedia services.
  • Higher security. Users can encrypt the data in the network layer and verify the IP message while using IPv6, which greatly enhances network security.

In view of the advantages of IPv6, IPv6 will eventually completely replace IPv4 and occupy a dominant position on the Internet after a long period of coexistence of IPv4 and IPv6.

  1. Transition technology from IPv4 to IPv6

Since IPv6 will eventually replace IPv4, how to achieve a network environment fully IPv6 compatible? The initial network transformation from IPv4 to IPv6 reveals that there is a thorough adjustment from protocol to hardware, including the client and server. Therefore, the issue of backward compatibility has been taken into account by IETF when designing IPv6 from the very beginning. The ISP/Operator will provide an intermediate node and uses DNS64 / NAT64 technologies, which are responsible for protocol conversion to connect the link between IPv6 and IPv4.

2.1. Tunnel technology for the initial transition

At the tunnel entrance between the IPv6 and the IPv4, the router encapsulates the entire IPv6 datagram into the data field of the IPv4 datagram. The source address and destination address of the IPv4 packet are respectively the tunnel entrance and exit of IPv4 addresses. At the exit of the tunnel, the IPv6 packet is taken out and forwarded to the destination node.


2.2. Dual-stack technology for IPv4 / IPv6 coexistence

Dual-stack technology is an effective technology for the transition from IPv4 to IPv6. The nodes in the network support both IPv4 and IPv6 protocol stacks. The source node selects different protocol stacks according to the different destination nodes while networking equipment according to the protocol type of the message. A dual-stack can be implemented on a single device or a dual-stack backbone. For a dual-stack backbone network, all devices must support IPv4 / IPv6 protocol stack at the same time, and the interface connecting the dual-stack network must be configured with both IPv4 and IPv6 addresses.


  1. Relevance of C-Data ONU to IPv6 Technology

The IPv6 network is divided into a backbone network and an access network. As the backbone network carries a lot of IPv6 services, most ISP/Operators have completed the deployment of the IPv6 backbone network but the access network is used for the access of terminal users. Nowadays, given that almost every family is connected with optical fiber, how to integrate IPv6 function on PON products to solve the problem of IPv6 compatibility is a difficult problem faced by many a ONU manufacturer.

In order to realize fast and easy access to IPv6 network in FTTH and adapt to the needs of global IPv6 network development, C-Data has spared no effort to make ONU support IPv6 service, and a graphical interface is released for end-users to use IPv6 on C-Data ONU easily. Furthermore, C-Data ONU supports IPv4 / IPv6 dual-stack transition technology and has revived the Anatel certification to meet the IPv6 networks in most of the countries. Some countries’ networks have used C-Data ONU as IPv6 network access.

There are two IPv6 network scenarios of C-Data ONU discussing as follows:

Scenario 1: transparent transmission of IPv4 / IPv6 services by ONU bridge mode

This scenario is mainly used for PPPoE or IPoE of IPv4 / IPv6, with user computers attached to ONU devices or wireless routers attached to ONU devices. Both OLT and ONU during transmission act as middle transmission devices, and only bridge mode is configured to transparently transmit IPv4 / IPv6 services. It is worth noting that whether the intermediate OLT and ONU devices support transparent IPv6 services needs to be considered because there are many OLT and ONU devices on the market that do not support transparent transmission of IPv6 services.


Scenario 2: ONU routing mode carries IPv4 / IPv6 services

In this scenario, the routing mode on ONU should support PPPoE or IPoE services of IPv4 / IPv6, and then allocates IPv4 / IPv6 address to the attached user computer or wireless router through DHCPV4 / DHCPv6 to realize the network access of IPv4 / IPv6. It is available for the OLT devices and the transparent transmission of IPv4 / IPv6. In this scenario, many manufacturers’ ONU products are difficult to implement. However, a lot of ONU manufacturers fail to apply their products to this scenario as there is a couple of issues to figure out, such as the compatibility of IPv6, the implementation of IPv6 Routing, the coexistence of IPv4 and IPv6, and the distribution of IPv6 address.



  1. C-Data ONU Products Supporting IPv6 Technology
No. ONU Form ONU Models Function Description
1 EPON&GPON&XPON 1GE/1GE+CATV FD511G&FD701G Series 1. Support PPPoE / IPoE, DHCPv6, IPv4 / IPv6 dual stack functions of IPv4 and IPv6 in routing mode;

2. Support transparent transmission of IPv4 / IPv6 service in bridge mode.

2 EPON&GPON&XPON 1GE+wifi/1GE+1FE+wifi/


FD511GW&FD512XW&FD702XW&FD604GW&FD804GW Series 1. Support PPPoE / IPoE, DHCPv6, IPv4 / IPv6 dual stack functions of IPv4 and IPv6 in routing mode;

2. Support transparent transmission of IPv4 / IPv6 service in bridge mode.



FD50X&FD704X&FD504G Series 1. Only transparent transmission of IPv4 / IPv6 service in bridge mode.



  1. Expectation of IPv6 Technology in the Future
  • The global network will build new information technology facilities based on IPv6 and give priority to the use of IPv6 in 5G, the Internet of things, and the industrial Internet.


  • Technical standards such as IPv6 + and SRv6 will be derived from IPv6 single stack. The application mode will be innovated to increase the pilot and commercial applications under the coordination with industrial chains.


  • Intelligent ultra-wide, intelligent connection and intelligent operation and maintenance are the main characteristics of the future IP network. IPv6 is the best choice for an intelligent IP network.



AI, big data, cloud computing, and the Internet of things technologies have an important connection with TCP / IP protocol. IP is the network layer protocol standardizing the exchange and routing of Internet packet information. As an infrastructure, IPv6 will construct a new Internet era.


As a professional FTTH broadband access product supplier, C-Data will accelerate the deployment of the IPv6 network together with the global ISP/Operators and apply more IPv6 technologies to the products. If you are interested in IPv6 technology, C-Data welcomes the chance to provide C-Data ONU for you and discuss IPv6 technology together.


Passive Optical LAN(POL) and application prospect

Preface:At present,most enterprise networks use traditional copper wire LAN, which are showing more and more drawbacks. With the rapid development of cloud computing, big data, and 4K video, more and more businesses are gradually migrating to cloud data centers. Followed by changes in traffic and architecture, the majority of traffic has shifted from a local switching architecture to a cloud switching architecture. On the other hand, with the explosive development of video, IoT, and the Internet, these applications have increasingly higher requirements for high bandwidth and low latency. In the age of digital transformation, enterprises urgently need a network that can carry all “things” access, and the POL network is the best choice.

I. POL Introduction

1.1 POL overview

POL is an enterprise LAN based on PON technology that provides users with integrated data, voice, video and other services through optical fibers. It is not a new technology, but applies the PON network technology that has been proven for a long time in the ISP network to the enterprise network. POL can bring great value to customers, at the same time, it will not change the existing business planning and customers network connection mode, and can provide all the functions provided by the traditional LAN network.

1.2 POL topology

POL provides a Layer 2 transmission network, adopts PON technology to provide gigabit access to user, and uses a single optical fiber to converge sevaral services such as video, data, wireless, and voice.

POL toplogy:


1.3 Comparison between POL and traditional LAN

In the POL network, the aggregation switch in the traditional LAN will be replaced by the OLT, the copper cable will be replaced by the optical fiber, and the access switch will be replaced by the passive optical splitter. The ONU provides Layer 2/Layer 3 functions and provide data, voice and video services by wired or wireless.
The downstream of PON network adopts the broadcast mode: the optical signal is sent by the OLT and divided into multiple optical signals to each ONU with the same information through the optical splitter. The ONU selectively receives its own packages according to the tags carried in the message and discard the packages that tags are not match.

The upstream of PON network: the OLT uniformly allocates a time slice to each ONU. The ONU strictly transmits signals according to this time slice window.ONU will shutdown the optical port when the time slice does not belong to its own time slice. The upstream time window scheduling mechanism is highly dependent on the PON distance measurement technology.
An understanding of PON technology principles will help us to apply this technology more proficiently in network design,In particular, the passive (no power supply required) characteristics of its optical distribution network, and the point distribution planning and design caused by the difference from traditional switches require special attention.To ensure the traffic packets in both directions are forwarded on a single-core fiber, PON uses wavelength division to process two-way signal transmission at the same time. Upstream and downstream signals use different wavelengths, but are transmitted on the same fiber. The direction from OLT to ONU/ONT is the downstream direction, and vice versa is the upstream direction. The downstream direction uses 1490nm and the upstream direction uses 1310nm.
Line structure comparison:


Device selection comparison::

Subsystem Name Traditional solution equipments POL solution equipments
1 Device room/machine house system ODF、Voice distribution frame ODF,Splitter (centrally placed)
2 Backbone wiring/vertical wiring subsystem Most copper cables or indoor multimode optical cables Indoor single-mode optical fiber
3 Floor management/floor machine house system Rack/cabinet, copper cable distribution frame, optical fiber distribution frame Floor distribution box, optical fiber connector, optical splitter (dispersing device)
4 Horizontal wiring subsystem Twisted pair, indoor multi-mode optical cable Butterfly fiber
5 Work area subsystem Copper module, copper panel, copper cable Fiber and fiber connectors

II. POL advantage analysis

Through the comparison between POL and traditional LAN in the previous section, we can find the challenges of traditional LAN and the unique advantages of POL.

Challenges of traditional LAN:

A large number of switches occupy the space of the computer room, high power consumption, and difficult heat dissipation.

The connection between aggregation routers is complicated,and it takes up pipeline space, making wiring and maintenance difficult.

Switch locations are scattered,management is complicated, and a large maintenance team is required.
Transmission distance limitation.
It is complicated to add new network equipment.

It is difficult to upgrade and expand network.

Whether its transmission distance,smooth network upgrades,high reliability,flexible networking,easy deployment,and simplified operation and maintenance,the traditional integrated wiring system has completely lagged behind POL. The POL integrates the transmission of traditional integrated wiring with fiber to the desktop, fiber to user unit, and fiber to the public area and turns the original L3 network into a flat L2 architecture.Enterprises can integrate different systems such as data,voice,video security,and wireless into a single optical fiber network, which has incomparable advantages over traditional integrated wiring.

POL advantage analysis:

Advanced architecture:POL network uses single-mode fiber,with almost unlimited bandwidth potential, and smooth broadband upgrades on demand.

Safe and reliable:Full optical fiber transmission,anti-detection,anti-electromagnetic interference, PON device provides strong DoS defense capabilities, reducing network attacks.

Converged bearer: The POL solution can bear data, voice, video and other services on one network.

Space saving: The POL solution is super convergent. The park only needs to provide a core computer room and don’t need many floor computer rooms.

Wide coverage: Covered distance is 20km,meeting the coverage requirements of super-high buildings and super-large parks.

Green and energy-saving: The POL solution uses passive optical splitters to replace convergence equipment of the traditional network,and the equipment room does not require air conditioning,which is more energy-efficient.

Convenient maintenance: PON technology adopts a centralized management method to avoid the disadvantages of decentralized management of traditional schemes and reduce the difficulty of operation and maintenance.

Cost advantage: Based on past experience, using 1000 points as a sample, choosing POL’s FTTD (Fiber To The Desktop) method will save 15% cost compared to traditional switch networks, and choosing FTTO (Fiber To The Office) will save cost more than 58% compared to switch networks.

III. Prospects of POL Development

POL is in the early development stages currently, and the current utilization rate is not high, but significant changes will occur in the next five years. The degree of POL solutions selection by enterprise users is not high enough,but manufacturers and social groups have been vigorously promoting this technology,and the IoT demand will become an important driving force to promote POL.

When it comes to POL applicable scenarios,most people may think of places such as corporate offices,education parks,and hotels.It cannot be denied that these places are the most widely used places,but from the unique advantages of POL,we can see that POL helps reduce energy consumption and operating costs.The IoT is the key to truly promoting the adoption of POL technology by enterprises. In the IoT application solution,a large number of terminal devices scattered in various places need to be connected to the network,Traditional LAN cannot meet such demand, and POL can serve as a bridge to eliminate the gap in this demand.Therefore,POL will find greater applications in the urban infrastructure, manufacturing,processing,solar,wind,and smart energy fields.The reason is that the current cable lines in these industrial facilities usually extend several miles,while POL can extend a long distance,and nodes can be deployed along the line through multi-fiber co-cables and optical splitters.Take the manufacturing industry as an example,it involves sensors such as flow meters, filters,or temperature,these devices need to be connected to the Internet,and traditional LAN are difficult to meet their networking needs.What is needed is to be able to operate stably in the working environment of these sensor devices.And does not produce electromagnetic interference or radiation.POL is just such a technology.It has a long transmission distance,can be networked through an optical splitter,does not produce electromagnetic interference and radiation,and can be used for the connection of most equipment.It has great needs in manufacturing and processing industries.Play a role in the large area and wide coverag application scenarios.

POL is an amazing technology because it is based on optical fiber transmission,has a simple network structure,is easy to manage,and has certain advantages in both construction and operation and maintenance costs.With the continuous development of enterprises,users put forward higher requirements for bandwidth, and the use of optical fibers will become more and more common,expanding from campus networks,backbone networks to the access field.IT users try to accept it,and good technology will prove its value through time.But I have to admit that there is still huge resistance to POL’s promotion.Enterprises that have invested heavily in traditional LAN may not change to POL,at least not immediately.For small organizations,POL solutions may be not a good idea.Compared with twisted-pair copper-based networks,user may not use all the capacity that POL can provide,and the solution may become very expensive. Therefore,these two technologies may coexist in the future,and POL will be used to make up for the functions that traditional LAN cannot achieve.Moreover,for those who familiar with traditional network technology, it takes time to gradually learn, adapt, master and apply POL technology.


With the intelligentization of cities,the application of cloud computing and big data,and the popularization of IoT,more and more enterprise applications will become cloud-based in the future.For enterprise networks,the digital transformation is imperative,which requires a simple network.POL have the characteristics of one network with multiple services,cost-effectiveness, simplicity, flexibility,safety and reliability,effectively supports enterprise digitization.So it is becoming the best choice for digital transformation in education,hotel,electric power, transportation,smart security,industry and other fields.With the gradual improvement of customer recognition,the ecology is also growing. I believe that the POL will continue to grow rapidly in the future.



Security Policy Configuration Guide For FD11xx EPON OLT

Preface:C-Data FD11xx Pizza-Box EPON OLT series products is 1U high 19 inch rack mount product. The features of the OLT are small, convenient, flexible, easy to deploy, high performance. It is appropriate to deploy in an compact room environment. This article proposes security suggestions based on experience and actual user scenarios in the OLT side to enhance the security of the access network.

1.Security configuration suggestions

1.1 Configuration suggestion for username and password

The first time when you log in to the device, please modify the user name and password, including ordinary accounts and super users. The user password must meet the password complexity principle: the length is between 8-12 digits, and the combination of numbers,uppercase and lowercase letters is used,and continuous numbers or continuous numbers are avoided.Do not use phone,birthday,personal name,ID and other information known to others as passwords,and change the password regularly

Case:Add new user test9,user role is superuser,password is Dscn@#0247



Case:Modify new password of user test9 as Wsdf#$9345



1.2 Configuration suggestion for SNMP

If you do not use ems, web and other network management platforms that use the snmp protocol, it is recommended not to open the snmp protocol. If you need to enable snmp, do not configure the two well-known communities, public and private, and customize the random read-write community;

Case:Config OLT SNMP read community is Pdfrd34#,wirte community is Yosjd34@



1.3 Configure management VLAN

The configuration of management VLAN can effectively isolate the device from other VLANs to achieve more secure protection.

Case:config inbind management vlan is 200

epon# system ipconfig mgmt-vlan 200

1.4 Enable OLT access control

The FD11xx series OLT version which built time is 200601 or later, Access control can be based on ip and mac address. For login security, it is recommended to configure this function, only add the ip or mac address of the administrator, and restrict other ip or mac to log in to the device .

Case:Only allow device which ip is login OLT,Note:epon# system access-control admin enable must in the behind of the command of system access-control …



1.5 Disable web service

If you don’t use web to manage OLT,please disable web service,command as follows:

epon olt7

Summary:The FD11xx OLT has been used to IP Camera, Enterprise LAN and IOT applications.

The EPON OLT is popular used in ISP network, campus network, enterprise network. Since the users have different networking and application scenarios, this article proposes security recommendations on the EPON OLT side for users who lack an upper-level firewall or expose the OLT on the public network, in order to reduce the risk of hacker attacks.

optical network unit

Development and prospect of PON

What is pon

PON is a typical passive optical fiber network, which means that the optical distribution network does not contain any electronic devices and electronic power supplies, ODN is all composed of passive devices such as optical splitters and does not require expensive active electronic equipment. A passive optical network includes an optical line terminal (OLT) installed in the central control station, and a number of matching optical network units (ONUs) installed in the user’s premises. The industry has always believed that the passive optical network (PON) is the future development direction of the access network. On the one hand, because the bandwidth it provides can meet the needs of various broadband services now and in the future, it is generally optimistic about solving the problem of broadband access; On the other hand, its expenses are both in terms of equipment cost and operation and maintenance management overhead. Both are relatively low. Comprehensive economic and technical analysis shows that PON is the main technology for FTTB/FTTH.

The development of the PON

PON(Passive Optical Network) is a point-to-multipoint passive optical access technology, which originated in the 1990s.From the development of narrowband PON to various broadband PON technologies,the development of PON technology has gone through several stages.

Narrowband PON technology is the earliest proposed PON technology, which can only provide narrowband services such as POTS or ISDN with service access rates below 2Mbit/s. However, due to the inconsistent specifications of various manufacturers and the inability to reach agreement at that time, there is still no unified and complete standard for narrowband PON technology. In the era of continuous development of the Internet, narrowband PON has long withdrawn from the stage of history, and then APON technology appeared in the mid-1990s. APON used the ATM protocol, which was considered to be able to provide various types of communications at that time, as the bearer protocol, and the transmission rate has been greatly improved. Later, with the rapid development of Ethernet technology, APON is basically no longer applicable, so the concept of broadband passive optical network BPON appeared. BPON is an enhancement after the APON standard, and is also based on the ATM protocol, and the uplink and downlink rates have been greatly improved. ITU-TG.983.1, the first international standard for PON systems released in 1998, is also generally referred to as the BPON standard.

Since entering the 21st century, with the decline of ATM technology and the rapid rise of Internet IP technology, the high-cost deployment of BPON technology seems a bit outdated. At this time, the industry hopes to develop a new PON system to replace the outdated BPON technology. In this context, IEEE and ITU-T successively initiated the standardization of EPON and GPON in 2000 and 2001, and respectively issued the completed standards in 2004, laying the foundation for the large number of applications of EPON and GPON in the current network today. The EPON standard was completed by IEEE’s EFM (Ethernet in the First Mile) working group, and was approved by the IEEE as the IEEE 802.3ah standard in September 2004. The GPON standard is standardized by ITU-T Study Group 15. The GPON-related standards include G.984.1-G.984.6 six standards, covering the GPON system architecture, physical media related layers, transmission convergence layer, ONU control management Protocols and regulations for enhanced wavelength usage and distance extension. Compared with the BPON system, the upstream and downstream rates of EPON and GPON have been greatly improved. The upstream and downstream bandwidth of EPON is 1.25 Gbit/s, while the downstream bandwidth of GPON is 2.5 Gbit/s and the upstream bandwidth is 1.25 Gbit/s.

With the rapid development of IP business volume and the continuous increase in the number of users, 10GEPON and XG-PON supporting higher split ratio and higher bandwidth have also emerged. Beginning in 2005, IEEE and ITU have successively carried out standardization studies on the next-generation PON system. IEEE established a project in 2006 and began to formulate the standard IEEE 802.3av for EPON systems with a rate of 10 Gbit/s. In this standard, 10G EPON is divided into 2 types. One is the asymmetric method, that is, the downstream rate is 10 Gbit/s, but the upstream rate is the same as EPON and is still 1 Gbit/s. The second is the symmetrical approach, that is, the uplink and downlink rates are both 10 Gbit/s. As the first mature next-generation PON technology, 10GEPON technology is in line with network development trends. It has the advantages of large bandwidth, large optical splitting ratio, compatibility with EPON, unified network management, and smooth upgrade. ITU started the study of the next-generation GPON standard in 2008 and confirmed it in 2010. It is currently called the XG-PON standard. The XG-PON standard ITU-T G.987 series have been released one after another. The physical layer rate currently specified by XG-PON is asymmetric, that is, the downstream rate is 10 Gbit/s and the upstream rate is 2.5 Gbit/s. In 2015, the XGPON symmetrical solution that was cancelled in 2013 was restarted again and adopted the new name XGSPON. Unlike XGPON, the XGSPON upstream and downstream rates are both 10Gbit/s, and the ITU officially passed G.9807 in 2017. XGSPON international standard. In recent years, Internet applications such as video and games have developed rapidly, and users have a strong demand for network broadband, which has further stimulated the maturity of the 10GPON industry chain. Commercial deployment of 10G PON has begun in some cities in China.

After the establishment of the XGPON standard, FSAN started the study of NG-PON2. Its key requirements are mainly 40G downlink and 40G/10G uplink, achieving 20km transmission distance and 1:64 splitting. At that time, mainstream alternative technical solutions for NG-PON2 included high-speed TDMA-PON, TWDM PON, OFDM-PON and WDM-PON. After analysis and comparison, in April 2012, FSAN decided to adopt TWDM PON technology as the implementation plan of NG-PON2, and started to formulate the G.989.x series of standards, which was finally completed in 2015. The IEEE started NG-EPON research in 2013, and started the formulation of the 100G-EPON standard in July 2015, named IEEE802.3ca, and plans to release it within this year.

optical network unit

The future of the PON

It is not difficult to imagine that in the future, we need a PON technology with larger bandwidth, more users and higher efficiency. 25G/50G/100GPON has already been put on the agenda of the standards organization. In February 2018, China’s optical access network industry successfully promoted the establishment of the 50G TDM-PON standard, marking a key step taken by ITU-T in the field of next-generation PON standard research. Although IEEE did not accept the establishment of a single-wave 50G PON project, it at least clarified the future technological evolution route of PON. For the future 100G PON technology, China’s communication equipment vendors are actively investigating 100G PON technology to jointly promote standard formulation and maturity of the industry chain. The application of 100G PON is only a matter of time.

With the development of the times and the continuous advancement of science and technology, 200G/5OOG/1000G and even higher PON technologies will be slowly realized. However, in addition to studying the next generation of PON technologies, the industry is still paying close attention to a very important issue. That is, the convergence of the two technical schools of ITU-T and IEEE. EPON and GPON coexist for a long time, which is actually very unfavorable to the industry. On the one hand, it brings difficulties to the technical decisions of operators and equipment; on the other hand, it also increases the cost of the industrial chain, and industrial chain enterprises need to invest in two lines. Especially for the huge optical access network market like China, the influence of the differentiation of PON technology factions is even greater, and more waste of resources. In recent years, under the active promotion of domestic and foreign industries, ITU-T and IEEE have also made some positive “shows”, including issuing joint statements, forming working groups, and establishing liaison letter mechanisms. But for now, it will take a long time to truly realize the final integration.



Whether GPON will replace EPON in the future

What is PON?

PON refers to passive optical fiber networks.In other words, there are no electronic devices or electronic power sources in the optical distribution network, and ODN is composed of passive devices such as optical splitters, without the need for valuable active electronic equipment.A passive optical network consists of an optical line terminal (OLT) installed at a central control station and a number of ancillary optical network units (ONUs) installed at the user site.The optical distribution network (ODN) between OLT and ONU consists of an optical fiber and a passive spectrometer or coupler.At present, passive optical network PON is considered as the future development direction of access network.On the one hand, because the bandwidth it provides can meet the needs of all kinds of broadband services now and in the future, it is generally favored to solve the problem of broadband access.On the other hand, the cost is relatively low in both equipment cost and operation and maintenance management.Comprehensive economic and technical analysis shows that PON is the main technology to realize FTTB/FTTH.

What is EPON?

EPON means Ethernet Passive Optical Network. As the name implies, it is a PON technology based on Ethernet.It adopts point-to-multi-point structure, passive optical fiber transmission and provides multiple services over Ethernet.The EPON system is mainly composed of optical line terminal (OLT), optical distribution network (ODN) and optical network unit (ONU).In the EPON system, OLT is both a switch or router and a multi-service provider platform that provides fiber interfaces for passive fiber networks.

As an emerging broadband access technology, EPON achieves integrated data, voice and video service access through a single fiber optic access system with good economy.It is widely believed in the industry that FTTH is the ultimate solution for broadband access and EPON will become a mainstream broadband access technology.Due to the characteristics of EPON network structure, the special advantages of broadband access, and the organic combination with computer network, experts all over the world agree that passive optical network is the best transmission medium to realize the integration of “three networks” and solve the “last kilometer” of information superhighway.

In the EPON system, the downlink data flow adopts time division multiplexing (TDM) technology and the uplink data flow adopts time division multiple access (TDMA) technology. In this way, when the ONU receives the data packet, each ONU extracts the data packet according to the specific address information and there is no interference between ONU, which can avoid transmission conflicts.EPON technology combines low-cost and high-bandwidth Ethernet equipment with low-cost fiber network technology, which has the advantages of good compatibility, low construction and maintenance cost and high access reliability.However, it has the disadvantages of poor scalability and low cost advantage.

What is GPON?

GPON refers to gigabit-passive Optical Networks.GPON technology is the latest generation of broadband passive optical integrated access standard based on ITU.TG.984.x standard. It is regarded by most operators as an ideal technology to realize broadband and integrated transformation of access network services.GPON technology adopts the same network topology as EPON, which is mainly divided into ONU, ODN and OLT.OLT provides the interface between the network side and the core network, and connects with each ONU through ODN.As the core functional equipment of the PON system, OLT has the functions of centralized bandwidth allocation, control of ONU, real-time monitoring, operation, maintenance and management of the PON system.ONU provides user-side interface for access network, and provides access to voice, data, video and other multi-service streams and ODN, which is controlled centrally by OLT.The branch ratio supported by the system is 1:16/32/64. With the development and evolution of the optical transceiver module, the branch ratio supported will reach 1:128.

The transmission mechanism of GPON is completely the same as that of EPON. Single fiber bidirectional transmission mechanism is adopted. WDM technology is used to transmit upstream and downstream data with different wavelengths on the same optical fiber.On the same optical fiber, GPON can realize two-way signal transmission using WDM technology.Based on the traditional tree topology, the PON protection structure can be used to improve the network survivability.GPON has three major advantages, namely, longer transmission distance, higher bandwidth and strong spectral characteristics.But the technology is relatively complex and the equipment cost is high.

Comparison between EPON and GPON

The main difference between GPON and EPON is the use of completely different standards.On application,GPON has a bigger bandwidth than EPON, its business carrying more efficient, spectral ability stronger, can transmit more bandwidth business, achieve more users access, pay more attention to business and QoS guarantee, but more complex, so cost is responsible for its relative EPON is higher, but with the large-scale deployment of GPON technology, EPON and GPON is diminishing cost differences.EPON aims to be compatible with the current Ethernet technology. It is the continuation of 802.3 protocol in optical access network, fully inheriting the advantages of Ethernet, such as low price, flexible protocol, mature technology, etc., it has a wide market and good compatibility.GPON, on the other hand, is positioned as the telecommunications industry’s demand for multi-service, QoS guaranteed all-service access, and strives to seek an optimal solution that supports all services and has the highest efficiency, and proposes to “completely and completely reconsider the openness of all protocols”.EPON and GPON have different technical characteristics, which are as follows:

The technical features of EPON are as follows:

  • Ethernet is the best carrier for IP service
  • Easy to maintain, easy to extend and easy to upgrade
  • EPON equipment is mature and available. Millions of lines of EPON have been laid in Asia. The third-generation commercial chip has been launched
  • The EPON protocol is simple and has low implementation cost and low equipment cost. The most appropriate technology, rather than the best technology, is needed for urban access network
  • More suitable for domestic, metropolitan area network without ATM or BPON equipment burden
  • More suitable for the future, IP hosts all services, Ethernet hosts IP services

The technical features of GPON are as follows:

  • Access network for telecom operation
  • High bandwidth: line speed, 2.488GB /s downstream, 1.244GB /s upstream
  • High transmission efficiency: 94% down (actual bandwidth up to 2.4g) 93% up (actual bandwidth up to 1.1g)
  • Full service support: The G.984.x standard strictly defines the full service (voice, data, and video) that supports the telecommunications level
  • Strong management ability: rich functions, sufficient OAM domain is reserved in frame structure, and OMCI standard is established
  • High quality of service: a variety of QoS levels, can strictly guarantee the bandwidth and delay requirements of the service
  • Low comprehensive cost: long transmission distance, high spectral ratio, effective allocation of OLT cost, reduce user access cost

Due to different technical characteristics, EPON and GPON technology are actually two different market applications. EPON technology is more suitable for Internet access application type, while GPON technology is more suitable for full business operation and three-network integration application type.From the perspective of business, these are actually two market segments, but from the perspective of end users, both EPON and GPON are actually invisible to users, especially in the FTTB construction mode. Users’ terminal devices in their homes only see Ethernet interfaces and telephone interfaces, so there is no need to think about GPON and EPON.


GPON and EPON have their own features, with different application scopes and overlapping application scenarios, such as FTTB for residential users.Looking to the future of the broadband access market may not be who replaces who, should be complementary coexistence.For customers with high bandwidth, multi-service, QoS and security requirements and ATM technology as backbone network, GPON will be more suitable.For cost-sensitive, QoS and security requirements are not high customer base, EPON became the dominant.


The difference between Wireless AP and wireless Router

Wireless AP, which is wireless access point. In simple terms is the wireless switch in the wireless network. It is an access point for mobile terminal users to enter a wired network and is mainly used for home broadband and intra-enterprise network deployment. The wireless coverage distance is tens to hundreds of meters. At present, the main technologies For the 802.11x series. A typical wireless AP also has an access point client mode, which means that APs can wirelessly link to each other so as to expand the coverage of the wireless network.

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