Technical Summary
iSCSI Extensions for RDMA provides the RDMA data transfer capability
to iSCSI by layering iSCSI on top of an RDMA-Capable Protocol. An
RDMA-Capable Protocol provides RDMA Read and Write services, which
enable data to be transferred directly into SCSI I/O Buffers without
intermediate data copies. This document describes the extensions to
the iSCSI protocol to support RDMA services as provided by an RDMA-
Capable Protocol.
Working Group Summary
This document is a minor update to RFC 5046, primarily to reflect
what has actually been done in implementations. WG Last Call turned
up several issues around relaxing RFC 5046's requirements based on what
implementations have done. These issues involved use of Send message
types that have side effects (implementations often do not use these)
and the consequences of delayed resource allocation (implementations
have run into a race condition that can terminate an iSER connection
if measures to avoid it are not taken). All of these issues have
been resolved in the current version of this document, although
the race condition avoidance is not perfect due to the need to
cope with current "running code" in implementations.
Document Quality
There are multiple implementations of the iSER protocol;
the primary purpose of this document is to reflect implementation
experience so that the iSER protocol specification matches the
"running code". Hemal Shah's review of the document resulted in
some important changes in the text describing use of versions of
the Send message. Alexander Neshinsky reported the resource
allocation problem seen in implmenetations and provided valuable
help in working out an approach that encompasses boht the "right
thing" to do going forward and necessary measures to cope with
current "running code" in implementations.
Personnel
Document Shepherd: David Black (storm WG co-chair)
Responsible Area Director: Martin Stiemerling (Transport)