On Fri, 2009-12-11 at 09:47 +0100, [email protected] wrote: > A doubt about UA implementation when a 302 is received as response to an > INVTE. > How shall de new INVITE be built? Shall the UA keep the same Call-Id, the > same tags, increment CSeq, change the brach? Is this behaviour a MUST, a > SHALL, a SHOULD, a MAY?
The UA should act on a 3xx in much the same way as a proxy would. Of course, in some circumstances (especially the 300 response) the UA may want to query the user as to whether to proceed. But assuming that the UA intends to proceed with processing, the new INVITEs are just further forks of the original: They have the same Call-ID, from-tag (there is no to-tag), and CSeq. They have different branch values (in the one Via header), because each fork of a request gets its own branch value. This behavior is a MUST, both in theory and in practice, since sometimes the downstream proxy does return a 3xx (often 302) response to the UA. Dale _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
