I wanted to make a quick response to one part of this discussion--see below: On Aug 31, 2010, at 12:39 PM, Christer Holmberg wrote: >>>> To highlight one particular aspect, RFC 4975 does not require >>>> session-ids to be present, a fact noted both in the ABNF and in this >>>> text: >>>> >>>> 4. The session-id part is compared as case sensitive. A URI without >>>> a session-id part is never equivalent to one that includes one. >>>> >>>> A matching scheme which relies on a URI section which is not >>>> guaranteed to be present has some interesting problems ahead of it. If >>>> this effectively makes their use mandatory, that requires a change to >>>> the fundamental ABNF and text. >>> >>> An MSRP URI in an SDP offer or answer for an MSRP session MUST include a >>> session-id part, so I believe the comment is >>> based on incorrect assumptions. >> >> This is not indicated in the URI matching section > > We will clarify that sessmatch conformant UAs do not use MSRP URI matching in > order to perform MSRP session matching. In fact, RFC4975 does require an MSRP URI in and SDP offer or answer to include a session ID part. Unfortunately, it does so rather obliquely. Section 6 contains the following language: > The MSRP URI authority field identifies a participant in a particular > MSRP session. If the authority field contains a numeric IP address, > it MUST also contain a port. The session-id part identifies a > particular session of the participant. The absence of the session-id > part indicates a reference to an MSRP host device, but does not refer > to a particular session at that device. Section 8.2, in the last paragraph, says the following about the rightmost URI placed in a path attribute in the SDP (Note that 4975 does not specify MSRP relay behavior, so only the rightmost URI is in scope) > It MUST be assigned for this particular session, and MUST NOT duplicate > any URI in use for any other session in which the endpoint is > currently participating. It SHOULD be hard to guess, and protected > from eavesdroppers. This is discussed in more detail in > Section 14. > This, taken together, create a requirement for a session-ID for MSRP URIs used to identify a session in the SDP. I agree this should have been more strongly worded. An errata entry is probably in order. Thanks! Ben. _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf