面向HPC互连网络的低延迟前向纠错编码研究与实现

当前主流高性能互连网络的端口速率已达到100~400 Gbps，其单通道速率已达到25~50 Gbps。在这种高速率的网络上传输数据，前向纠错编码是提高其可靠性的必要技术。以太网国际规范IEEE 802.3采用的前向纠错编码为RS(528,514)和RS(544,514)，但是这2种码型难以满足高性能互连网络在低延迟方面的性能需求。首先，分析了RS的编码和译码结构，并定量研究了RS码型参数与编解码延迟之间的关系。接着，提出了一种面向当前高性能互连网络的新型低延迟编码—RS(271,257)，并比较了该码型在占用带宽和纠错能力等方面的优缺点。最后，实现了基于RS(271,257)的低延迟网络编码子层，并对其进行了资源消耗评估和延迟性能模拟。综合考虑资源消耗、纠错能力和延迟性能3方面因素，RS(271,257)是一种理想的低延迟前向纠错码型，可满足当前面向HPC的低延迟高性能互连网络的编码子层的设计需求。

Research and implementation of low latency forwarderror correction coding for HPC interconnection network

At present, the port rate of the mainstream high performance interconnection network reaches 100~400 Gbps, and the single channel rate reaches 25~50 Gbps. For the data transmission at this rate, Forward Error Correction (FEC) coding is a necessary technology to improve the reliability. The Ethernet international standard IEEE 802.3 uses Forward Error Correction codes RS(528,514) and RS(544,514), but these two code types are difficult to meet the performance requirements of high performance interconnect networks in terms of low latency. Firstly, this paper analyzes the encoding and decoding structures of RS code and quantitatively studies the relationship between RS code type parameters and encoding and decoding delays. Secondly, a new coding type RS(271,257) for low latency high performance interconnection network is proposed, and its advantages and disadvantages in bandwidth consumption and error correction capability are compared. Finally, based on RS(271,257), this paper implements the network coding sub layer and performs the resource consumption evaluation and delay performance simulation. Considering the factors of resource consumption, error correction ability and delay performance, RS (271,257) is an ideal low latency forward error correction coding type, which can meet the design requirements of the current HPC oriented low latency high performance interconnection network coding sub layer.