RNIC Interoperability
Microsoft
This document describes a mechanism for enabling RDMA Network Interface Cards (RNICs) that implement both the IETF and RDMAC versions of the DDP and RDMAP protocols to interoperate with legacy RNICs that are based on the RDMAC version of the protocols. The proposed scheme uses MPA Request/Reply Frames to negotiate the protocol version as well as MPA marker and MPA CRC. A ULP or other supporting entity must perform this negotiation on behalf of the RDMAC RNIC because RDMAC MPA does not define an MPA connection scheme using MPA Request/Reply frames. This draft also makes specific recommendations for minor changes to the IETF MPA, DDP, and RDMAP internet drafts to aid in interoperability.