> RFC 2327 specifies the origin field as : > > origin-field = "o=" username space > sess-id space sess-version space > nettype space addrtype space > addr CRLF > > Isnt it must to have "sess-version" value in > the SDP of re-invite to be different than the > value in original invite, given the reinvite > does change the session parameters > ( for ex : put a call on hold etc ). ?
No. RFC 2327 section 6 mentions the following: "the tuple of <username>, <session id>, <network type>, <address type> and <address> form a globally unique identifier for the session." And section 6 also mentions the following: "<version> is increased when a modification is made to the session data." Thus all the contents of origin line are used to identify a unique SDP. And when the <username>, <session id>, <network type>, <address type> and <address> are the same, the <version> must be incremented to indicate an update to the session data. > I am seeing a vendor implementation where > ( in o= field ) sess-id and sess-version > remain same but "addr" changes. > Should this sdp offer be treated > different than the first one ? Assuming by "addr" you mean <address> of the Origin line, the answer is yes. > Shouldnt combination of "sess-id" and > "sess-version" uniquely identify a session ? See above comments. _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
