Intel® Ethernet 800 Series Linux Flow Control
Configuration Guide for RDMA Use Cases
Overview
Congestion control in RDMA networks provides dynamic, end-to-end traffic throttling to reduce network congestion and improve performance as networks scale up. Each RDMA transport (iWARP and RoCEv2) supports a different set of congestion control algorithms, each with different characteristics. The best algorithm for a given network will depend on network topology, workload, and traffic patterns.
Congestion control can operate at the same time as flow control. Congestion control is end-to-end (in other words, the sender and receiver can communicate across multiple switch hops), whereas flow control operates point-to-point (like between an adapter port and its neighboring switch port).
CVL supports ECN with these protocols:
- RoCEv2 DCQCN
- RoCEv2 DCTCP
- RoCEv2 TIMELY
- iWARP DCTCP
- iWARP TCP New Reno plus ECN
- iWARP TIMELY
For DCQCN and DCTCP, ECN is a required sub-component of the overlying congestion control algorithm.