The recent news that some regional operators have rectified personal PCDN services has caused repercussions in the industry. Affected users said that the upload bandwidth was suddenly limited to less than 5Mbps without any notification, which seriously affected the Internet experience. So the question is, what is PCDN? Who is providing PCDN services to users? Why do operators want to rectify it?
Based on P2P+CDN, the past and present life of PCDN
P2P content distribution network (English name: P2PCDN, referred to as PCDN) is a low-cost, high-quality content distribution network service based on P2P technology and constructed by mining and utilizing massive fragmented idle resources of telecom edge networks. After integrating PCDN SDK (hereinafter referred to as SDK) to access this service, customers can obtain distribution quality equivalent to (or slightly higher than) CDN, while significantly reducing distribution costs. Suitable for business scenarios such as video on demand, live broadcast, and large file downloads.
The industry knows that the basic principle of CDN is reverse proxy, which deploys cache servers to regional networks where user access is relatively concentrated. When a user accesses the website, global load technology is used to direct the access to the nearest cache server, which directly responds to the user's needs. PCDN is a low-cost, high-quality content distribution network service built on edge computing based on P2P+CDN technology.
An industry insider told TechWeb that the PCDN business can be understood as the expansion and supplement of the CDN business. The two jointly serve the target customer groups and jointly ensure end-user services. The difference lies in the nature of the resources and technical solutions used.
The PCDN business introduces terminal computing resources, builds a terminal computing network, and realizes point-to-point content transmission, thereby reducing CDN construction costs, including equipment costs, bandwidth costs, electricity bills, etc. It is very cost-effective for Internet companies and has certain advantages in terminal edge network transmission speed.
Ensuring the business stability of the terminal computing resource itself is the first prerequisite, and then it can fully utilize the idle resources. Therefore, PCDN needs to control the upper limit of usage, match different resources according to different business attributes, and be equipped with a flexible scheduling system and a complete monitoring and alarm system. At the same time, such resources often have usage restrictions such as limited ports, limited storage, and limited speed, which have certain technical requirements for users.
Take a video website as an example. It adds a cache between the server and the user, and this cache will be distributed across the country. Assuming that Zhang San is in Beijing, then he will hit the cache server in Beijing first, and then the cache server will check whether the movie is available. If so, it will directly pass the resource to Zhang San. If not, it will go back to the source to the server of the video website to pull a copy. This greatly reduces the pressure on the video website server and provides faster network services.
Later, if we go a step further, if every user is organized (individuals provide network services), wouldn't the CDN node be closer to the user, the consumption of resources during circulation will be less, and the distribution will be more efficient. Suppose Zhang San is watching a movie in his own community, and his neighbor Li Si is a node. Wouldn't it be more efficient for Zhang San to directly pull resources from his neighbors (of course it will also be accompanied by the problem of Li Si's instability). Because Li Si has provided services, he will receive a portion of the proceeds as a reward. Then unite more John Doe to form PCDN.
As a result, platforms such as video websites began to encourage individual users to deploy specific software (provided by the platform) on idle equipment, or directly purchase the platform's hardware equipment (including hardware and software environments, out-of-the-box, suitable for novice users), and then provide uplink network bandwidth (own bandwidth), join a large PCDN network, as a node in the network, provide network traffic services to users around this node, and then the platform settles fees based on the traffic provided, and the amount of the fee depends on the network bandwidth.
Large-scale application of PCDN will destroy the business model of broadband services
Currently, the network design of the broadband services provided by the three major operators is inherently asymmetrical in uplink and downlink. Ordinary users mainly need large downlink instead of large uplink.
Excessive uplink traffic will overload the operator's network, which will lead to increased maintenance costs for the access network and backbone network. If PCDN service usage is too high, it will have a great impact on other users in the community.
From the perspective of regulatory compliance, whoever accesses the network is responsible for domestic compliance. For users who use PCDN services, operators are responsible for legal disputes.
Therefore, operators will thoroughly investigate the PCDN business, but currently the PCDN business is a gray area, and there is no explicit provision that prohibits its use. As for the operation of stopping users, some experts believe that it is possible. The legal aspect mainly depends on whether there is any explanation in the agreement.
Independent telecommunications analyst Fu Liang told TechWeb that operators adopt different models for individual users and enterprise users when pricing broadband services.
At the individual user level, the uplink and downlink rates are asymmetric, large uplink broadband services are not supported, and the tariff is low.
At the enterprise user level, the uplink and downlink speeds are equal, but the tariff is higher.
Because they have different pricing strategies, operators clearly stipulate that personal broadband cannot be used as a content distribution node to make profits.
"PCDN is a typical application of P2P in the telecommunications industry. It even predates the well-known Internet loan P2P for more than ten years in the past two years. It uses personal broadband services to distribute users' idle traffic through P2P. Now there are also companies providing computing power support," Fu Liang said.
Fu Liang believes that if the industry uses PCDN technology on a large scale, it will destroy the business model of broadband services, cause operators' broadband service costs to increase sharply, and broadband tariffs will rise in the future.
PCDN suppliers, users and operators, the unclear triangular interest relationship
When it comes to the application of PCDN, according to relevant media reports, some Zhihu netizens reported that their TVs will continue to have upload speeds of 1-5M/s when the screen is in a sleep state, and will only stop when the power is completely cut off. According to reports, he bought a new TV and only installed the iQiyi TV version app. After it was forced to shut down, the upload speed became 0.
In view of this situation, he contacted iQiyi customer service, who said that this was a method of acceleration and had no impact on daily use, and provided an operation method to turn off the HCDN switch.
Check iQiyi's official website, which states that "HCDN (HybridCDN) is a large-scale hybrid architecture online video data distribution technology developed by iQiyi's technical team. This technology uses a hybrid CDN and P2P node scheduling architecture." The "iQiyi Service Agreement" mentions that in order to improve users' service experience, they will adopt a series of technical measures to optimize products and/or services, including improving CDN node distribution and scheduling, using proprietary HCDN peer-to-peer networks and other technical measures to improve the quality of video distribution.
Although the names are different, from a technical perspective, iQiyi’s HCDN is the PCDN we mentioned above.
In fact, iQiyi is not the only one to do this. In fact, some netizens revealed that similar things are commonplace on video platforms. Similar technologies and terms of use have appeared in iQiyi, Youku, and Mango TV. It is not even limited to video platforms. There are many similar cases in the entire Internet field, involving different platforms and technologies, such as Xunlei Netxin Cloud, Wanke Cloud, Money Making Treasure, JD Cloud Wireless Treasure, and a large number of hardware are also products of the PCDN model.
Take Xunlei NetXin Cloud as an example. According to its official website, NetXin Technology has created a distributed edge computing platform model for monetizing traffic resources and has become the industry's leading edge computing service provider. C-end users access various types of intelligent hardware through the Netcenter Cloud open platform and share idle computing, storage, broadband and other resources. Netcenter Technology provides users with cash returns and connects thousands of households into an edge computing network through Starfield Cloud, providing B-end enterprises with high-quality and low-cost edge computing services.
As before, there was also a "User Incentive Program" hidden in the PC version of Baidu Netdisk, which claimed to improve the PC user experience and reward corresponding points based on the user's activity and usage, which can be redeemed for different prizes. However, Baidu did not inform users that this reward program will occupy up to 1MB/s of upload bandwidth for transferring files to other users, and will also occupy up to 5GB of local space. It is enabled by default and will not bring any speed-up effect to users' downloads.
In addition to the above, in order to encourage users, JD Cloud Wireless Bao will give points that can be redeemed for Jingdou and JD E Cards, while Wanke Cloud will give money more simply and crudely.
Video websites and PCDN companies save money while users make money. Behind the seemingly win-win situation, the losers are the operators who fundamentally provide broadband access and services.
As we mentioned in the above article, my country's home broadband is super cheap and inclusive. Currently, the cost of fixed broadband has dropped to the third lowest in the world. The support behind this low price is the high fees that operators charge B-end users. This is the so-called local loss and external compensation, which naturally makes video websites pay expensive bandwidth fees every year.
Take iQiyi as an example. In 2017, its expenditure on bandwidth costs was about 2.17 billion yuan, but it only increased by 230 million yuan in 2020. This is closely related to the launch of PCDN. However, from the perspective of operators, the part saved by video websites is equivalent to their own losses. In other words, the more PCDN used by video websites, the greater the losses for the corresponding operators.
For users, there has been constant controversy about personal PCDN services recently. In addition to making "small money" as mentioned above, there are individual users who use idle broadband or corporate users who have not applied for relevant qualifications to expand broadband in batches, and then deploy specific software or hardware equipment on the network to provide data storage and uplink network bandwidth for content network distribution.
Although the above practices are not illegal, they violate the agreement with the operator. Usually the home broadband user agreement clearly stipulates that no profit-making activities are allowed, otherwise the operator has the right to stop the user's use of the broadband.
According to relevant media reports, it is not technically difficult for operators to tell whether users have used PCDN, because PCDN frequently uses uplink bandwidth. If a broadband with an uplink speed of no less than 30M can upload 300GB of data in a day, it is obviously hundreds of times that of ordinary users.
TechWeb learned from an industry insider that to carry out personal PCDN business, you need to purchase home bandwidth services and purchase equipment to connect to the network. The equipment can be ARM boxes, routers, NAS devices, etc. Different equipment characteristics determine the type of adapted business. Then, you need to maintain long-term stable online, and finally you need to register the equipment according to the requirements of different PCDN manufacturers.
Then here comes the problem. Some users may use a relatively large amount of the network due to special reasons such as work. It would be unfair if they are judged as PCDN users and have speed limits. After all, most domestic broadband packages have unlimited traffic. It is unreasonable and illegal for operators to limit speeds on users because of high traffic on suspicion of illegal activities.
The advantage of PCDN technology is that the business can achieve the purpose of reducing costs, whether it is the construction cost of the operator, the procurement cost of the CDN manufacturer, or even the operating cost of the target customer.
"At present, the CDN industry is becoming more and more transparent, and the market competition is fierce. How to reduce costs and achieve revenue is a common problem faced by all CDN manufacturers; the video industry is becoming more and more standardized, and video content is becoming more and more high-quality, and low-cost and high-quality services are the common hope of video industry customers." An industry practitioner said.
The development of new things always goes through a process from imperfection to perfection. As a newly developing industry, PCDN has many participating companies with different scales and different capabilities, but the overall development is towards scale and standardization. It is undeniable that the development of PCDN has a certain impact on IDC, but PCDN also has certain existential significance. How to create a healthy CDN+PCDN ecosystem is an issue that participants, especially operators, need to consider.
In summary, PCDN providers, including video websites, individual users, and operators have entangled interests. Each has its own advantages and difficulties. How to balance the relationship between the three in the future will undoubtedly be a challenge.
TechWeb text/Bian Haichuan