> -----Original Message----- > From: Arunachalam Venkatraman [mailto:[EMAIL PROTECTED]] > Sent: Friday, April 13, 2001 1:58 PM > To: [EMAIL PROTECTED] > Subject: [Sip-implementors] ReUse same Call Id > > > If an INVITE gets a non-SUCCESS final response (>2xx), can a > subsequent > INVITE use the same call id? > In section 6.35.1 of rfc2543-bis-02, two values 401 and 484 > are identified > as candidates for this scenario. > What about 415 Media Type Unsupported? > What other values allow the callid to be re-used? In general, when the request is a re-submission of a previous for the same call attempt. This would include 415, and also 420 and a few others. > > Also, can an OPTIONS use the same callid as a preceding or subsequent > INVITE? If an OPTIONS is sent with the same callid as an existing call-leg, its a mid-call request. Thats fine. If an OPTIONS is sent, and then later an INVITE, there is no purpose in reusing the call-id (in fact, you probably shouldn't). > If a subsequent OPTIONS method is sent (An application level > keep-alive > mechanism in some applications), can it re-use the callId > from a previous > OPTIONS request? In this case, its a mid-call request. Thats fine. Note that this will NOT give you a keepalive. The response to OPTIONS is not dependent on whether its within a call or not. Thus, you cannot tell whether the call is up or down, only whether the UAS is alive. > > What is the life of the CallId for non-call requests like OPTIONS, > SUBSCRIBE, NOTIFY etc. For requests that have no session created by them, such as OPTIONS, the lifetime is just that transaction. For requests that initiate a "session" in some way (which is right now things like SUBSCRIBE, REGISTER, INVITE), its the duration of this session. I will need to clarify that in the bis draft. -Jonathan R. --- Jonathan D. Rosenberg 72 Eagle Rock Ave. Chief Scientist First Floor dynamicsoft East Hanover, NJ 07936 [EMAIL PROTECTED] FAX: (973) 952-5050 http://www.jdrosen.net PHONE: (973) 952-5000 http://www.dynamicsoft.com _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
