I think RFC 3312 has some examples where 18x is needed for preconditions in a mid-call session.
Sanjay. >-----Original Message----- >From: Sarkar, Uttam [mailto:[EMAIL PROTECTED] >Sent: Tuesday, October 31, 2006 2:05 PM >To: Sanjay Sinha (sanjsinh); [EMAIL PROTECTED]; >[email protected] >Subject: RE: [Sip-implementors] Query 100rel in re-INVITE > >Whole idea of 100rel is to make sure 18X message is received >by the other party so that they can be sure of exchnage any >media before session is established. >Re-INVITE is for established session. >Please correct me if I am wrong. > >-----Original Message----- >From: Sanjay Sinha (sanjsinh) [mailto:[EMAIL PROTECTED] >Sent: Tuesday, October 31, 2006 1:09 PM >To: Sarkar, Uttam; [EMAIL PROTECTED]; >[email protected] >Subject: RE: [Sip-implementors] Query 100rel in re-INVITE > >It might be useful for QoS cases. > >>-----Original Message----- >>From: [EMAIL PROTECTED] >>[mailto:[EMAIL PROTECTED] On Behalf >Of Sarkar, >>Uttam >>Sent: Tuesday, October 31, 2006 11:28 AM >>To: [EMAIL PROTECTED]; [email protected] >>Subject: Re: [Sip-implementors] Query 100rel in re-INVITE >> >>I still can't understand why 100rel is requiring to a >re-INVITE (change >>media from audio to audio and video). >>In the re-INVITE it will carry the new media. Other endpoint will >>respond back with final response (like 200 OK or 488 Not Acceptable >>Here). >>I can't imagine other end will send 18X with media and send >PRACK for a >>session that is already established. >> >>Thanks, >> >>-----Original Message----- >>From: [EMAIL PROTECTED] >>[mailto:[EMAIL PROTECTED] On Behalf Of >>[EMAIL PROTECTED] >>Sent: Tuesday, October 31, 2006 10:57 AM >>To: [email protected] >>Subject: Re: [Sip-implementors] Query 100rel in re-INVITE >> >> From: "Sarkar, Uttam" <[EMAIL PROTECTED]> >> >> 100rel does not make sense in re-INVITE as session is already >> established. UAS is expected to send final response >(2XX/4XX/5XX etc >>). >> It can send 100 trying to stop retransmission of INVITE while it's >> preparing the final response. >> It's not recommended for UAS to send 1XX response for the >re-INVITE. >> >>One can imagine scenarios where a re-INVITE might not be >instantaneous, >>and so 100rel might be a useful mechanism. For instance, if one >>endpoint wishes to upgrade an audio call to an audio-and-video call, >>the other endpoint might want to ask its user before activating the >>video camera. >> >>Dale >>_______________________________________________ >>Sip-implementors mailing list >>[email protected] >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> >>This email and any attached files herein contain information that is >>intended only for the use of the individual or entity to whom it is >>addressed and may contain information that is legally privileged, >>confidential or otherwise exempt from disclosure under >applicable laws. >>If the reader of this message is not the recipient, any disclosure, >>dissemination, distribution, copying or other use or >retention of this >>communication or its substance is prohibited. >> >> >> >>_______________________________________________ >>Sip-implementors mailing list >>[email protected] >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> > >This email and any attached files herein contain information >that is intended only for the use of the individual or entity >to whom it is addressed and may contain information that is >legally privileged, confidential or otherwise exempt from >disclosure under applicable laws. If the reader of this >message is not the recipient, any disclosure, dissemination, >distribution, copying or other use or retention of this >communication or its substance is prohibited. > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
