Hi
This 200 OK without SDP is acceptable as the answer SDP has already been received in a reliable non-failure response. Refer RFC 3262 (Sec 5 The Offer/Answer Model and PRACK): If the INVITE contained an offer, the UAS MAY generate an answer in a reliable provisional response (assuming these are supported by the UAC). That results in the establishment of the session before completion of the call. Similarly, if a reliable provisional response is the first reliable message sent back to the UAC, and the INVITE did not contain an offer, one MUST appear in that reliable provisional response. If INVITE contains SDP, the SDP in reliable 18x shall complete the offer-answer. Regards Rohit Aggarwal Aricent -----Original Message----- From: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] On Behalf Of Harsimran Singh Sent: Monday, June 01, 2009 3:55 PM To: Sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] 200OK without SDP. Hi I am confused about the section 13.2 of RFC 3261. The description given in the RFC looks inconsistent. My call flow is as follows: INVITE with sdp & Supp 100rel -----------> 100 Trying <------------ 180 Ringing with Req 100rel & sdp <------------ PRACK no sdp ------------> 200OK for prack no sdp <------------ 200OK for INV no sdp <<is this OK>> <------------ ACK -----------> Is the above call flow correct? -------- o 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. ---------- Thanks Harsimran Singh _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu 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 Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
