A Lightweight Routing Layer Using a Reliable Link-Layer Protocol

Abstract: In today's data centers, the performance of interconnects plays a pivotal role. However, many of the underlying technologies for these interconnects have a history of several decades and existed long before data centers came into being.To better cater to the requirements of data center networks, particularly in the context of intra-rack communication, we have developed a new interconnect. This interconnect is based on a lossless link layer protocol, named RIFL. In this work, we designed and implemented RIFL Layer 2, a scalable network that supports up to multi-hundred Gbps communication. RIFL Layer 2 includes the RIFL switch and RIFL NIC. By utilizing a simple Batcher Banyan and iSLIP RIFL switch, we effectively keep the typical intra-rack latency under 400 nanoseconds. Moreover, for a 32-port 100Gbps network, under both Bernoulli arrival and bursty arrival traffic patterns, we ensure that the 99\% tail latency does not exceed 12microseconds.