NetEase Yunxin debuts at LiveVideoStackCon 2021, deconstructing the self-developed large-scale transmission network WE-CAN

Recently, LiveVideoStackCon 2021 Audio and Video Technology Conference Beijing Station was grandly held. As a technology event in the multimedia industry, many industry experts gather here, where new technologies, new products, new trends and new ideas collide and converge, constantly giving birth to new inspirations for innovation and breakthroughs.

Ji Qi, Chief Architect of NetEase Yunxin Server, was invited to participate and shared a speech with the topic "Analysis of the Core System Architecture of NetEase Yunxin's Self-developed Large-scale Transmission Network", introducing the behind NetEase Yunxin's global intelligent routing network WE-CAN The design concept received extensive attention from the guests.

WE-CAN-the cornerstone of converged communication

The word WE-CAN is a little unfamiliar to some developers. Simply understand, WE-CAN (Communications Acceleration Network) is a complex network system that is set up on the public Internet and achieves the goal of improving data transmission quality and reducing data transmission costs through intelligent scheduling of various resources.

Jiqi said that NetEase Yunxin's goal is to become the number one brand in converged communication cloud services. To achieve this goal, the transmission quality of communication data is crucial, especially in long-distance and complex network environments. In this context, WE-CAN was born and developed rapidly.

 

According to Gicci, at present, WE-CAN can transmit streaming media with high arrival and low latency, and WE-CAN can perform optional, business-transparent ARQ, FEC and other services in addition to the various QoS policies of the media itself Other redundancy strategies, these strategies are also common to all other transmission modes of WE-CAN;

WE-CAN can also distribute live video on a large scale, eliminate the bottleneck of the number of people in the room through path cascading and multiplexing, reduce bandwidth costs, achieve cost close to CDN, close to RTC in real-time, and better support low-latency live broadcast scenarios ；

WE-CAN can also reliably transmit signaling, IM or other data. The so-called "reliable transmission" means to ensure that the data will arrive and the order of data delivery;

WE-CAN's services and protocols have industry-leading decoupling and layered design, which are elegant, simple to use, and flexible. For example, it abstractly encapsulates the reliable transmission protocol and provides a minimalist interface to the outside world. We call it MessageBus. The goal of MessageBus is to provide a globally deployed distributed message queue service.

As the transmission base of NetEase Yunxin, WE-CAN is not an ordinary transmission network from the beginning, but to establish a general purpose that can send any data from any point in the world to any other corner of the world stably, quickly and efficiently. transporting network.

WE-CAN design, layering is crucial

"The realization principle of WE-CAN is not difficult, but there is a lot of work to be done to truly achieve the design goals of NetEase Yunxin." Ji Qi shared with the participants.

On the whole, the biggest challenge is how to maintain the abstraction and isolation between layers. In addition, although the ultimate goal of WE-CAN is to establish a universal software-defined transmission network covering the world, the starting point is after all to serve NetEase Yunxin RTC. , So decoupling from the upper-level business system is also a big challenge.

In this sharing, Gitch also deeply analyzed the architecture design of each layer.

 

The reason for this design, Gicci said, is based on four considerations: First, WE-CAN itself is an overlay of the public Internet, and layering can be more independent and safer; second, layering can achieve each function and system boundary Clear; third, layering can be better targeted optimization, so as to achieve different transmission optimization strategies at each layer; fourth, in order to support more transmission scenarios.

In the implementation process, WE-CAN divides the entire architecture into five layers, namely the network layer, the control layer, the transport layer, the application layer and the business layer.

Among them, the network layer is the entrance to the WE-CAN core network, which provides addressing and routing functions for messages, and is the layer with the most complex and longest processes in the entire architecture.

The control layer is mainly responsible for data routing, traffic scheduling, and congestion control. The control layer will weave the forwarding nodes into a highway network and allocate the optimal highway entrances to the access nodes.

The transport layer is responsible for message sequencing, retransmission, slicing, etc. WE-CAN has developed a set of reliable transmission mechanisms based on the UDP protocol, which can support richer application scenarios, such as flow control and fuse limit for application layer protocols Streams, etc., provide hierarchical service strategies for the application layer.

The application layer provides protocol encapsulation of Message Bus, including Topic subscription, multi-destination broadcast, and bearer RTC server signaling.

The business layer supports various applications such as RTC, IM, live broadcast on demand, and data reporting, which can effectively reduce business delays, improve communication quality, and reduce costs.

As Jiqi said, thorough layered decoupling can not only make each layer work independently without affecting each other, thereby improving the stability of the system, but also promote the rapid iteration of functions and reduce the difficulty of development. In addition, the thorough hierarchical abstraction also enables WE-CAN to provide more flexible and diversified hierarchical services. This is also the biggest difference between NetEase Yunxin WE-CAN and many manufacturers.

Not only is the pursuit of advanced architecture, WE-CAN also has a consistent pursuit of reducing transmission costs. In the process of designing WE-CAN, Gitch insists on achieving or even exceeding the quality of the dedicated line at a cost much lower than that of the dedicated line. The actual online service data also verifies this concept well. WE-CAN has a huge advantage in cross-border transmission scenarios, and it truly achieves the quality of dedicated lines using public network bandwidth.

Let every terminal have the "super power" of

Up to now, WE-CAN has spread all over China and also covers all continents of the world. Nodes are deployed in major global regions such as India, the Middle East, Europe, North America, and North Africa. WE-CAN carries business traffic including RTC, IM, and live broadcast on demand, and transmits hundreds of billions of messages and hundreds of millions of minutes of media stream data every day. The transmission quality is excellent. Among them, it can achieve a high-quality transmission rate of more than 99.9% in the domestic audio and video transmission, and an end-to-end high-quality transmission rate of more than 99%. In the cross-border communication, it can achieve the quality close to the dedicated line, and the delay is global. No more than 250ms.

WE-CAN is the most reliable and solid foundation of NetEase Yunxin. Based on WE-CAN's powerful transmission capabilities, Netease Yunxin has helped many well-known companies to deepen their domestic and overseas markets and steadily promote their global business layout.

Of course, Netease Yunxin's goal is more than that. Netease Yunxin expects that every smart terminal will have Yunxin's integrated communication capabilities.

The speech record of "Analysis of the Core System Architecture of NetEase Yunxin Self-developed Large-scale Transmission Network" will be released soon, and you are welcome to continue to pay attention.