Hi
Since an answer has not been sent yet by the UAS, the UAS should ignore this new offer received in PRACK. The UAC is misbehaving in this scenario. Refer RFC 3261 13.2.1 Creating the Initial INVITE .. .. 1. The initial offer MUST be in either an INVITE or, if not there, in the first reliable non-failure message from the UAS back to the UAC. In this pecification, that is the final 2xx response. 2. If the initial offer is in an INVITE, the answer MUST be in a reliable non-failure message from UAS back to UAC which is correlated to that INVITE. For this specification, that is only the final 2xx response to that INVITE. That same exact answer MAY also be placed in any provisional responses sent prior to the answer. The UAC MUST treat the first session description it receives as the answer,and MUST ignore any session descriptions in subsequent responses to the initial INVITE. 3. If the initial offer is in the first reliable non-failure message from the UAS back to UAC, the answer MUST be in the acknowledgement for that message (in this specification, ACK for a 2xx response). 4. After having sent or received an answer to the first offer, the UAC MAY generate subsequent offers in requests based on rules specified for that method, but only if it has received answers to any previous offers, and has not sent any offers to which it hasn't gotten an answer. 5. Once the UAS has sent or received an answer to the initial offer, it MUST NOT generate subsequent offers in any responses to the initial INVITE. This means that a UAS based on this specification alone can never generate subsequent offers until completion of the initial transaction. Regards, Tarun Aricent Mobile +91.981.171.9672 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Krishna Rao Gurram Sent: Thursday, April 30, 2009 1:50 PM To: [email protected] Subject: [Sip-implementors] What is the server side behavior if PRACK withnew SDP receives (Urgent!!!!!!) Scenario:- UAS receives Invite with SDP. Application above UAS sends 100 Trying Application now sends 180 without SDP and with 100 rel. UAS receives PRACK with SDP for 180. Here what is the behavior of UAS? How to handle this PRACK at the UAS end. Please find the messages. INVITE sip:[email protected] SIP/2.0 Via: SIP/2.0/UDP 172.16.107.21:51594;branch=z9hG4bK629348334-18296 From: Alice<sip:[email protected]:51594>;tag=abc123def To: Bob<sip:[email protected] > Call-ID: [email protected] Cseq: 1 INVITE Contact: sip:[email protected]:51594 Max-Forwards: 70 Accept: application/sdp Supported: 100rel, replaces <------------------------------ Require:100rel Content-Type: application/sdp Content-Length: 131 v=0 o=ICF 12345 787 IN IP4 10.203.154.44 s=Session c=IN IP4 10.203.154.44 t=0 0 m=audio 4568 RTP/AVP 0 b=AS:128 a=ptime:20 SIP/2.0 100 Trying Via: SIP/2.0/UDP 172.16.107.21:51594;branch=z9hG4bK629348334-18296 From: Alice<sip:[email protected]:51594>;tag=abc123def To: Bob<sip:[email protected]>;tag=ICF_4168957464-5666 Call-ID: [email protected] ---------------------> CSeq: 1 INVITE Supported: timer Contact: Bob<sip:[email protected]:51591> Content-Length: 0 SIP/2.0 180 Ringing Via: SIP/2.0/UDP 172.16.107.21:51594;branch=z9hG4bK629348334-18296 From: Alice<sip:[email protected]:51594>;tag=abc123def To: Bob<sip:[email protected]>;tag=ICF_4168957464-5666 - - ---------------> Call-ID: [email protected] CSeq: 1 INVITE Supported: 100rel,replaces,precondition,timer Require: 100rel RSeq: 2 Contact: Bob<sip:[email protected]:51591> Allow: INVITE,ACK,CANCEL,BYE,OPTIONS,UPDATE Content-Length: 0 PRACK sip:[email protected] SIP/2.0 Via: SIP/2.0/UDP 172.16.107.21:51594;branch=z9hG4bK629348334-18296 From: Alice<sip:[email protected]:51594>;tag=abc123def To: Bob<sip:[email protected] >;tag=ICF_4168957464-5666 Call-ID: [email protected] Cseq: 1 PRACK Contact: sip:[email protected]:51594 RAck: 2 1 INVITE <---------------- Max-Forwards: 70 Accept: application/sdp Expires: 3600 Supported: replaces,100rel Require:100rel Content-type: application/sdp Content-Length: 131 v=0 o=ICF 12345 788 IN IP4 10.203.154.44 s=Session c=IN IP4 10.203.154.44 t=0 0 m=audio 4568 RTP/AVP 8 b=AS:128 a=ptime:20 "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error,please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus." _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ________________________________ "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error,please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. Aricent accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus." _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
