Shyam, I think that require header in ACK for 200 OK should not be included ( as indicated by the Table-2 of RFC-3261, as it has '-' which implies not applicable, which is furthur clarified as meaning that the header field MUST not be present in a request ).
Now going by the section 8.2.2.3 statement, I agree that it is not consistent with the table-2 and other RFCs. But I think the intent of the statement in this section is not to suggest that one MUST include the 'require' header in the ACK for 200OK, but I think the intent may be to suggest that if 'require' header is added for some reason in ACK for 200OK, then they should be exactly same as the ones included in the initial INVITE and there should not be any additional tokens added in the 'require' header of the ACK for 200OK ( MUST contain ONLY those ) Section 8.2.2.3: " Note that Require and Proxy-Require MUST NOT be used in a SIP CANCEL request, or in an ACK request sent for a non-2xx response. These header fields MUST be ignored if they are present in these requests. An ACK request for a 2xx response MUST contain only those Require and Proxy-Require values that were present in the initial request." Also the RFC-4028 for session timer "Require/Supported: timer" seems to point that this header should not be included in the ACK as you pointed out is also similar to the statement for token "100 rel" mentioned in RFC-3262 7.1. Generating an Initial Session Refresh Request A UAC that supports the session timer extension defined here MUST include a Supported header field in each request (except ACK), listing the option tag 'timer' [2]. Best Regards, Indresh K Singh >>-----Original Message----- >>From: [email protected] >>[mailto:[email protected]] On >>Behalf Of ext shyam >>Sent: Tuesday, August 18, 2009 3:50 AM >>To: 'soma bhargava'; 'sip-implementors' >>Subject: Re: [Sip-implementors] Require header in ACK >> >>Hi, >> >> Require 100REL in ACK does not have any meaning. >>Require Header with other parameters like timer.. or any user defined >>parameters may be present. >>Thanks, >>Shyam >> >>-----Original Message----- >>From: [email protected] >>[mailto:[email protected]] On >>Behalf Of soma >>bhargava >>Sent: Tuesday, August 18, 2009 1:03 PM >>To: sip-implementors >>Subject: [Sip-implementors] Require header in ACK >> >>Hi All, >> >>As per RFC 3261 >>sec 8.2.2.3 Require: >>An ACK request for a 2xx response MUST contain only those Require >>and Proxy-Require values that were present in the initial request. >> >>and as per section 20 of RFC3261: >> >>Header field where proxy ACK BYE CAN INV OPT REG >>Require ar - c - c c c >> >>As per RFC 3262 >>sec 4 UAC Behavior: >>A Require header with the value 100rel MUST NOT be present in >>any requests excepting INVITE, although extensions to SIP may >>allow its >>usage with other request methods. >> >>the above 3 statements contradicts each other. >>Please suggest if we need to add require header in ACK or not? >>If yes then should it contain 100rel or not? >> >>Regards, >>Soma >> >>_______________________________________________ >>Sip-implementors mailing list >>[email protected] >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> >>_______________________________________________ >>Sip-implementors mailing list >>[email protected] >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
