"Prema" <[EMAIL PROTECTED]> asks > Hi All, > I have a doubt in incrementing cseq value in subsequent SIP request. > > What should be cseq value for BYE request, which is sent by, called party? > Initially it received INVITE with cseq value 1.
RFC 3261 says 15.1.1 UAC Behavior A BYE request is constructed as would any other request within a dialog, as described in Section 12. Further, 12.2.1.1 Generating the Request <snip> The Call-ID of the request MUST be set to the Call-ID of the dialog. Requests within a dialog MUST contain strictly monotonically increasing and contiguous CSeq sequence numbers (increasing-by-one) in each direction (excepting ACK and CANCEL of course, whose numbers equal the requests being acknowledged or cancelled). Therefore, if the local sequence number is not empty, the value of the local sequence number MUST be incremented by one, and this value MUST be placed into the CSeq header field. If the local sequence number is empty, an initial value MUST be chosen using the guidelines of Section 8.1.1.5. The method field in the CSeq header field value MUST match the method of the request. Since the called party _received_ the INVITE it'll have an empty local sequence number, so must generate one. The called party then constructs the BYE with that sequence number. If the caller sent the BYE, the caller would send a BYE with a sequence number of 2 (in this case). frank _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
