> There is a connected call with dialog id as (callid1, > from tag ftag1, to tag ttag1). When BYE is received at > UA1 it responds with 200 ok and starts running Timer J > timer(32 seconds). After 5 seconds a new INVITE is > received by UA1 having same callid as previous call(callid1) > and new from tag. > > UA1 is responding with 481 response? is it correct behaviour.? > please suggest if anything is there in RFC.
In my opinion if the device doesn't want to support it, it can reject the request (although there might be a better failure response). However, there might be interoperability reasons to support it. In my opinion, you are experiencing a non-compliant reuse of Call-ID; however some vendors have interpreted RFC 3261 differently. It has been many years since I've seen the topic debated; thus I'm not sure if anyone or sipcore is currently defending such Call-ID reuse as compliant. RFC 3261 section 8.1.1.4: "In a new request created by a UAC outside of any dialog, the Call-ID header field MUST be selected by the UAC as a globally unique identifier over space and time unless overridden by method-specific behavior. All SIP UAs must have a means to guarantee that the Call- ID header fields they produce will not be inadvertently generated by any other UA. Note that when requests are retried after certain failure responses that solicit an amendment to a request (for example, a challenge for authentication), these retried requests are not considered new requests, and therefore do not need new Call-ID header fields; see Section 8.1.3.5." Some vendors have intentionally violated (or interpreted differently) the globally unique mandate for correlation reasons. For instance, they use the same Call-ID with different From tag when originating a conference or recreating a persistent call. I'm not sure if any devices violate that mandate for mischievous reasons. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
