Hi Manolis, UAS cannot ask for a PRACK without "Require:100rel". Also RSeq is used in 1xx provisional response only. Please refer the following sections in RFC-3262.
3 UAS Behavior The provisional response to be sent reliably is constructed by the UAS core according to the procedures of Section 8.2.6 of RFC 3261. In addition, it MUST contain a Require header field containing the option tag 100rel, and MUST include an RSeq header field. 7.1 RSeq The RSeq header is used in provisional responses in order to transmit them reliably. Regards, Alok Tiwari Aricent -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Manolis Katsidoniotis Sent: Monday, September 03, 2012 7:01 PM To: [email protected] Subject: [Sip-implementors] ask for PRACK omitting Require:100rel Hello I would like to ask 2 quick questions. Can a SIP:UAS ask for PRACK using only with Rseq: 1 only? (*omitting*Require: 100rel)? *1.* SIP/2.0 180 Ringing i:0f4fec9fb0d16a5b CSeq:2 INVITE f:"+306102668000470"<sip:[email protected] >;tag=f946691a85;epid=SC2ecd4a t:<sip:[email protected] :5060;transport=udp>;tag=snl_0008348494 Record-Route:<sip:scscf32.home32.fmc.ath:5090;reg-id=JZ1346337988275455;routing_id=3353bca5f30cb3b43e7ed28a763fed15;lskpmc=SJZ;lr;interface=isc> Record-Route:<sip:10.80.151.151;routing_id=pcscf_a_side;lskpmc=PJZ;lr> v:SIP/2.0/UDP 10.85.202.17:5060;branch=z9hG4bKe29bd0793df7b8142 m:<sip:[email protected];transport=udp> Allow:REGISTER,INVITE,ACK,BYE,CANCEL,NOTIFY,REFER,UPDATE,PRACK *RSeq:1* Date:Thu, 30 Aug 2012 18:11:24 GMT l:0 i.e. *Can the server omit *Require:100rel? *2.* Is there a possibility to have *RSeq:1* for a reason not related to PRACK? I'm asking because, in practice, searching for *RSeq:1* in 1xx responses especially for testing scripts would be the same as searching for *Require: 100rel* right? thanks in advance Manolis _______________________________________________ Sip-implementors mailing list [email protected]<mailto:[email protected]> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors =============================================================================== Please refer to http://www.aricent.com/legal/email_disclaimer.html for important disclosures regarding this electronic communication. =============================================================================== _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
