The BYE method is used to terminate an established media session. In telephony, it is similar to a release message. A session is considered established if an INVITE has received a success class response (2xx)or an ACK has been sent. A user agent responds with a 481 Dialog/Transaction Does Not Exist to a BYE for an unknown dialog.
It is not recommended that a BYE be used to cancel pending INVITEs because it will not be forked like an INVITE and may not reach the same set of user agents as the INVITE. The CANCEL method is used to terminate pending searches or call attempts. It can be generated by either user agents or proxy servers provided that a 1xx response containing a tag has been received, but no final response has been received. A user agent uses the method to cancel a pending call attempt it had earlier initiated. A forking proxy can use the method to cancel pending parallel branches after a successful response has been proxied back to the UAC. The CSeq is not incremented for this method so that proxies and user agents can match the CSeq of the CANCEL with the CSeq of the pending INVITE to which it corresponds. A user agent confirms the cancellation with a 200 OK response to the CANCEL and replies to the INVITE with a 487 Request Terminated response. Harpreet Juneja ---------------------------------------------- Harpreet Singh Juneja New Delhi, India --- OmPrakashTripathi 70630 <[EMAIL PROTECTED]> wrote: > Hi, > > I have a doubt regardig the Termination of the Early Dialog. > > For terminating an Early Dialog, whether a 'BYE' or a 'CANCEL' > should be used, especially when the B Party is not Responding. > > Waiting for the clarifications. > > Thanks, > Om.. > > _______________________________________________ > Sip-implementors mailing list > [email protected] > http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors > Send instant messages to your online friends http://uk.messenger.yahoo.com _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
