Jiang Lintao: Full text of the report "CDN Technical Issues and Standardization"! The CDN market is booming

The 2017 Asia-Pacific CDN Summit was held in Beijing on April 12-13, 2017. The conference consisted of seven parts: Asia-Pacific CDN Summit, International CDN Forum, TV New Media CDN Forum, Video Cloud Forum, Future Network Forum, C Future Video Summit, and Asia-Pacific CDN Exhibition. At the Asia-Pacific CDN Summit, Jiang Lintao, Director of the Science and Technology Committee of the Telecommunication Research Institute of the Ministry of Information Industry, delivered a keynote speech entitled "CDN Technical Issues and Standardization".

1. Industry Overview: Opportunities and Challenges Coexist

Jiang Lintao started his speech with the current status of CDN industry. He believed that CDN industry has both opportunities and challenges. The rapid growth of video, game, social and other businesses has provided continuous impetus for CDN development. At the same time, the rapid maturity of emerging technologies such as cloud computing, big data, and mobile Internet has promoted the innovation of CDN technology and model. The rise of Internet of Things, Industrial Internet and 5G has provided new impetus for the development of CDN. The technical direction, business model, industrial structure and regulatory strategy are all facing in-depth adjustments.

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Pictured: Jiang Lintao, Director of the Science and Technology Committee of the Telecommunication Research Institute of the Ministry of Information Industry

However, Jiang Lintao also stressed that the CDN industry is still in a state of fierce competition. Professional CDN service providers maintain their leading position through comprehensive solutions. At the same time, telecom operators use their pipeline advantages to enter the CDN market in a big way, market traffic is divided, and Internet companies also use cloud computing to develop CDN. The entire CDN market is booming.

According to data, CDN accounts for more than 90% of the communication business volume in the network, and CDN has become the infrastructure of communication. For the CDN industry, its storage capacity is exchanged for transmission capacity, and the input-output ratio is high; the nearby service of the business can improve the business quality and user experience. CDN exists in the form of an overlapping network, between the bearer network and the business network, and its independent devices are storage devices and CDN management devices. Jiang Lintao believes that there is a consensus on the system and functions of CDN, and the standardization work of CDN is progressing smoothly.

2. CDN-related technical issues

1. CDN technical route

Traditional CDN is a layer-by-layer distribution system, which consists of a binary tree storage structure or a multi-tree storage structure, and the structural system is already complete. However, CDN with a P2P structure belongs to a single-layer plane structure, and the two-layer structure (super node and edge P2P node) is also technically mature. The technical trend of CDN is to focus on traditional CDN and supplement it with P2P. The edge storage of P2P can only reach the edge of the operator. Jiang Lintao believes that it is not advisable for user terminals to serve as P2P edge nodes, which poses operational risks; there are still problems with the security and trustworthiness of P2P, and P2P encryption (such as HTTPS, etc.) also needs further research.

2. CDN networking technology

CDN's networking technology includes physical networking and virtual networking. Physical networking includes three parts: physical storage, physical server and physical data line. Virtual networking includes virtual machines, virtual storage and service chains.

3. “Cloud computing” and “fog computing”

Can cloud computing be used in CDN? Jiang Lintao believes that cloud computing is not what most people really use. Cloud computing concentrates a large number of servers in one place, rather than in sharded places. From now on, if the servers are concentrated in one place and all communication networks are concentrated together, it is not CDN. CDN must be edge storage and intermediate distribution, so now many places, led by Cisco, have proposed fog computing. What is the difference between fog computing and cloud computing? Fog computing is that the closer is called fog, and the farther is called cloud. Fog is more dispersed. So in essence, fog is a dispersed cloud.

Jiang Lintao believes that CDN will require a large number of edge devices in the future.

4. Edge computing and CDN

Jiang Lintao explained: Edge computing specifically refers to computing power in exchange for transmission capacity (terminal capability adaptation and edge transcoding, etc.), while CDN focuses on content distribution, storage capacity in exchange for transmission capacity, etc.; IT's basic resources include computing resources, storage resources, software resources, and I/O, and cloud computing refers to pooled IT basic resources.

5. Back-to-origin technology in CDN

CDN mainly refers to content distribution, which is a one-way technology. Its essence is storage for transmission. CDN back-to-source is a two-way capability. It is essentially an end-to-end communication technology. It has no direct relationship with CDN and is the scope that data network capabilities should cover. Back-to-source technology has a lot of room for development. The problem is that the IP network is unknowable, unmanageable, and uncontrollable. In theory, it should be solved by the data network. At the current stage, IP is deified and the task is undertaken by CDN. Jiang Lintao believes that this development space is very large and may lead to the advancement of IP technology.

6. CDN and access network technology

CDN can effectively solve the problem of content distribution quality between CDN main nodes (websites and information sources) and edge storage nodes. There are two more access links that need to be considered. The first is from the website or information source to the CDN main node. Generally, it is easy to use a dedicated line. The data transmission network can provide a dedicated line with certain capacity. The second is from the user to the CDN edge storage node, such as IPTV (dedicated network), mobile video under cellular mobile network, video under IP network (fixed network, WiFi, etc.).

7. CDN and access network technology

From the perspective of user experience, the data shows that IPTV (private network) scores 3.2, mobile video under cellular mobile network scores 2.8, and video under IP network (fixed network, WiFi) scores 1.8.

From a technical analysis perspective, CDNs use the same technology and can provide the same quality; the three access methods of the access network have vastly different capabilities and must be taken seriously. A considerable number of CDN operators hold access network operating licenses and this should be taken seriously.

8. The relationship between CDN and mobile network

At present, network mobility is provided by cellular mobile networks, whose IP address allocation anchor points are very high, CDN edge devices are difficult to sink, and CDN's role in mobile networks is difficult to fully play. At the same time, network mobility needs to be provided by IP networks, but there are technical difficulties. The international community is still working hard, and mobile IP technology cannot solve all problems.

3. CDN standardization work: to attract enough attention

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First, it is necessary to realize the integration of information and communication networks: packet transmission network realizes point-to-point data dedicated line, packet data network realizes end-to-end data connection, and content distribution needs to build content distribution network (CDN); second, CDN will become the infrastructure of communication. So far, CDN has been positioned as an auxiliary network of communication network; the increase of communication volume and importance will become the infrastructure of information and communication. Third, it is necessary to put standardization work on the agenda. The convergence of technology already has the basis for standardization, and Jiang Lintao emphasized that the basic facilities of communication must be standardized.

CDN networking technology and system architecture: Jiang Lintao introduced that CDN networking technology and system architecture are divided into two parts: physical networking technology and virtual networking technology. Physical networking technology means that all devices in the network are physical devices, the network's business chain is a determined business chain, and the device backup is an independent part and cannot be shared. Virtual networking technology refers to a new networking method, in which the devices in the network are non-physical devices; the network's business chain is a non-determined business chain, generated on demand; IT resources are shared resources and are not attached to specific devices.

At the beginning of the speech, Jiang Lintao emphasized that CDN will become the infrastructure of communication. So far, the positioning of CDN has always been the auxiliary network of the communication network; the increase in communication volume and importance will become the infrastructure of information communication. The convergence of technology has made CDN have the basis for standardization; but the communication infrastructure must be standardized!