On November 14, 2018 in the Asia Pacific annual festival on CDN, senior technical experts Yao Weibin ali cloud (embraced) published “the scene of the CDN technology” speech, he believes that the current CDN, need according to the developing course of the past CDN, analysis more clearly the different needs of customers under different scenarios, the technologies used by demand point again, To design CDN products that can better serve customers.
(Text scene is the third from the left in the picture to participate in the roundtable forum)
Embraced think the CDN development course of the past few years, like the image below, from the original fixed network to the present 3 g, 4 g, and the next 5 g, from the original text, images, nearly two years to live, a short video, and then to ultra hd video and IoT, need the CDN scenarios technical characteristics are very obvious, including: High throughput, low cost and low delay are required for acceleration capability; For wan access requirements of high reliability, high fluency, IoT intervention; Security requirements WAF, anti-ddos, and elastic security defense; And, of course, the concept of edge computing has emerged in recent years.
Ali Cloud CDN began to provide external services in 2014, and now has 1500+ nodes and 120T reserve bandwidth in the world. Globalization is also developing rapidly this year, and it can provide natural self-service product capability through perfect OpenAPI. It has also built ASN: 24429 by itself, and built global IXP network scheduling based on experience first, hoping to provide the most extreme accelerated experience for Chinese customers going abroad.
In terms of product functions, Ali Cloud CDN has comprehensive coverage from DCDN and SCDN to edge computing. It charges by region globally. In high-priced and low-priced regions, it charges by volume according to different demands and provides 7×24 hours personal service.
For CDN acceleration scenarios with high throughput and low cost
From content production, transmission and CDN scheduling, we can see the evolution trend of technology in recent years from the figure below.
- In terms of content production, it supports H264, H265, VP8 and PV9 at the very beginning, as well as the narrowband HD technology developed by Ali.
- As for the bit rate, from the original 500K to the general 2M, now provides many customers with 10M transmission;
- In the server, now is also generally provide 10000 MB throughput capacity, it is expected that in two to three years, network server throughput capacity of 100 GB, now the disk is generally to SSD, a single node can provide more than several PB storage capacity;
- In terms of scheduling, ali Cloud introduced DNS scheduling for the overall heavy traffic. Based on DNS scheduling and IP scheduling, we can provide accurate IP library, and provide accurate traffic prediction for a scene like the World Cup, so as to achieve accurate user scheduling.
- At the node level, with the expansion of resource scale and the closer trend of cooperation with operators, the current CDN node scale is also developing from thousands to tens of thousands. We are also seeing a trend to work more closely with operators, including MEC’s exploration.
- As for PCDN, as the concept of HD becomes more and more extensive and the total bandwidth cost accounts for a large part of the entire content provider, PCDN also emerged to provide lower cost services in addition to the entire HD video throughput capacity.
- With regard to SDK, we can provide a complete end-to-end video solution by combining ali Cloud’s video technology for many years.
In this year, Aliyun CDN carried 70% of the traffic of the World Cup in the whole network, and then the Live broadcast of the Jakarta Asian Games was sent to broadcasters in Fiji, Cambodia and Mongolia through the Global Acceleration Network, providing the viewing experience for hundreds of millions of viewers in the Asia-Pacific region. On Tmall Double 11, which just ended last week, a series of technical solutions, such as CDN traffic prediction, real-time intelligent scheduling and PCDN, supported the hd, smooth, stable and low-delay live broadcast experience of 25 million people online. In the decade since singles’ Day, the overall bandwidth capacity has grown thousands of times.
CDN acceleration scenario with low delay
In the context of 5G and the Internet of Things, real-time requirements will be higher and higher. Therefore, for this scenario, CDN made a lot of optimization at the protocol level and proposed the concept of aQUIC. For QUIC technology stack, including now IETF is gradually changing HTTP-over-QUIC into HTTP3.0, we think that now QUIC protocol stack, in fact, can provide users with the ability to customize the protocol stack, including network packet loss in the transport layer, can also provide multiplexing, multiplexing and other capabilities. Therefore, in such an aQUIC code base, we can launch different adaptation protocols and processing methods for real-time, fluency, first package, concurrency and other scenarios of users.
This year, Aliyun Video cloud released RTC products, which are suitable for end-to-end short delay communication, video conferencing, connecting to the microphone and other business scenarios. At present, RTC helps Dingding carry 7 million enterprises around the world, connect 100 million users around the world, and ensure the stability and fluency of every real-time audio and video communication.
High reliability CDN acceleration scenario
For financial, e-commerce, office, gaming, government and enterprise users, they will attach great importance to the high reliability of business.
The high reliability solution is based on the processing capability of the Last Mile, Middle Mile, and First Mile. It optimizes end-to-end protocols for IP ports, SDKS, VPNS, and domain names, and supports dynamic link selection within nodes to achieve the optimal access path.
Wen Jing believes that the whole DCDN scene is based on user experience and can be quickly and accurately optimized and adjusted for dynamic content. This solution helps Toutiao to accelerate the dynamic content of ten million levels of QPS every day, and reduces the overall RT by 50%. Through intelligent route detection, all-carrier coverage and optimal path selection, toutiao effectively provides support for real-time data transmission, and at the same time reduces the pressure on the source site through HTTPS to HTTP mode.
CDN acceleration scenario with high security
Security capability is now an important part of CDN, covering the scenarios of customers including e-commerce, finance, government and enterprise.
Today, security capabilities can be accessed directly through CDN. HTTPS and HTTPS DNS access can prevent hijacking and tampering, and defend against flood-type attacks, including layer-4 DDos and layer-7 CC attacks. At the application layer, Ali Cloud CDN can provide WAF application layer defense capability, and can provide source station protection and offline mode for the back source part. In the whole secure access process, security Acceleration (SCDN) product realizes access, security and acceleration in one, so as to protect the whole data link.
Airasia, by virtue of aliyun’s safety acceleration capability and WAF product, can reduce crawler for users by 90% and ticket brushing by more than 90%, effectively protecting customers’ ticket purchasing resources.
Edge computing scenario
Wen Jing believes that edge computing should be divided into several scenarios, including: IoT scene at the bottom, IoT gateway at the access layer, MEC, ENS at the convergence layer, cloud machine room at the center, and cloud computing scene. The evolution of edge computing and IoT is synchronous. As data, storage, computing, network, security and other data increases in quantity, scenarios that need to be further processed on the edge emerge.
Accordingly, the left side of the figure is the data flow, and the right side is the control flow in the scenario of edge computing, the maintenance and operation of massive equipment in the distributed scenario, the optimization and simulation of collected data, and the final prediction and decision, which is the whole process. Wen Jing believes that edge computing is still in the process of continuous development and evolution. Ali Cloud has provided edge node services and is about to launch video surveillance solutions. Combining with the whole IoT suite, including the whole edge gateway processing capacity, Ali Cloud can provide complete solutions to the outside world on the whole edge computing scene.
Ali Cloud’s customer Huya live platform, combined with Ali Cloud’s edge node technology solution, guaranteed the low delay, stable flow and real-time interaction of 70 million online fans on the day of S8 final, providing smooth experience for the audience.
At the end of the sharing, Wen Jing said that with the evolution of CDN technology, the whole industry is constantly emerging new technologies, such as QUIC, SCDN and so on. Ali Cloud CDN also hopes to make the CDN industry more rich together with our customers and peers.