Technical Summary
RFC4976 describes how to use MSRP over special purpose MSRP relays, in order
to traverse NATs and firewalls, and to allow network policy enforcement.
However, many networks use other middleboxes for this purpose for other
SIP-signaled media, and would like to use the same middleboxes for MSRP.
This draft describes an extension to MSRP to make it easier for them to do
so.
Working Group Summary
The goal of the draft that this one replaced
(draft-ietf-simple-msrp-sessmatch) was controversial in the SIMPLE work
group. The authors of RFC4975 and 4976 initially objected to the
modification of the protocol to make it more friendly to non-standardized
middleboxes such as SBCs. However, those objections were generally secondary
to security related objections that the older draft interfered with some TLS
use cases. The working group has a consensus that the security issues do not
apply to the current draft.
In summary, draft-ietf-simple-msrp-cema-03 still extends the MSRP protocol
to make it more friendly to middleboxes such as SBCs. The work group
believes it does no incremental harm when compared with the case of using
MSRP as defined in RFC4975 in the presence of such middleboxes--which would
either result in communication failure, or the failure to anchor media at
the middlebox.
Document Quality
Multiple participants have implemented or indicated an intent to implement
it.
Personnel
The document shepherd for this document is Hisham Khartabil.
The responsible Area Director is Gonzalo Camarillo.