RoCE Rocks without PFC
Alexander Shpiner, Eitan Zahavi, Omar Dahley, Aviv Barnea, Rotem Damsker, Gennady Yekelis, Michael Zus, Eitan Kuta, Dean Baram · 2017
In recent years, the usage of RDMA in data center networks has increased significantly, with RDMA over Converged Ethernet (RoCE) emerging as the canonical approach for deploying RDMA in Ethernet-based data centers. Initial implementations of RoCE required a lossless fabric for optimal performance. This is typically achieved by enabling Priority Flow Control (PFC) on Ethernet NICs and switches. The RoCEv2 specification introduced RoCE congestion control, which allows throttling the transmission rate in response to congestion. Consequently, packet loss is minimized and performance is maintained, even if the underlying Ethernet network is lossy.