Re: [Sip-implementors] Require header in ACK request
Sumant, > Does it serve any purpose if we send Require/Proxy-Require header in the ACK > request? If we have Require/Proxy-Require in Initial Invite, we can have the same (or) subset of tags in the ACK. It will not server any purpose in sending new tags in Require/Proxy-Require in the ACK Request. The Reason is ACK cannot be rejected. Its good not to add these headers in ACK as they serve no purpose. This Text could have been worded better in 3261 : not to include these headers in ACK (as mentioned in Table2.) -Sreeram. -Original Message- From: Sumant Gupta [mailto:sumantgu...@gmail.com] Sent: Tuesday, May 14, 2013 3:26 AM To: sip-implementors@lists.cs.columbia.edu Subject: [Sip-implementors] Require header in ACK request Hi All, As per 3261 "An ACK request for a 2xx response MUST contain only those Require and Proxy-Require values that were present in the initial request". As per table 2 (rfc 3261) require header is not applicable in ACK request. Does it serve any purpose if we send Require/Proxy-Require header in the ACK request? Any reason why it is mentioned in RFC as older posts on this forum does not provide any concrete answer? Regards Sumant ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
Re: [Sip-implementors] Require header in ACK
soma bhargava wrote: > 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. I think that is less than ideal wording. It would have been better worded as: "An ACK request for a 2xx response MUST NOT contain any Require or Proxy-Require values that were not present in the initial request." There is no purpose to Require or Proxy-Require in ACK. Including Require values that were not present in the INVITE is an invitation for the ACK to be rejected, which it should not be. In practice you would be best to include *no* Require or Proxy-Require values in the ACK regardless of what ones were included in the INVITE. Thanks, Paul > 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 > Sip-implementors@lists.cs.columbia.edu > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
Re: [Sip-implementors] Require header in ACK
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: sip-implementors-boun...@lists.cs.columbia.edu >>[mailto:sip-implementors-boun...@lists.cs.columbia.edu] 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: sip-implementors-boun...@lists.cs.columbia.edu >>[mailto:sip-implementors-boun...@lists.cs.columbia.edu] 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 >>Sip-implementors@lists.cs.columbia.edu >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> >>___ >>Sip-implementors mailing list >>Sip-implementors@lists.cs.columbia.edu >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors >> ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
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: sip-implementors-boun...@lists.cs.columbia.edu [mailto:sip-implementors-boun...@lists.cs.columbia.edu] 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 Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors ___ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
