Yes, it is mandatory for 421 response. I guess table 3 did unjustice to 421 response :)
On Wed, May 6, 2009 at 9:37 PM, Ravi Kumar <[email protected]> wrote: > Thanks Vikram, > But is this mandatory as per the MUST clause of the section 21.4.16 > then in table a it could be mentioned as m why it is mention as c > (conditional). > Because for other header's like allow header for the 405 response for bye, > invite and option and register request is mandatory. > This way for 421 rsp why it is not mandatory. > > Please let me know if I am missing something. > > Thanks & Regards, > Ravi Kumar > > > -----Original Message----- > From: Vikram Chhibber [mailto:[email protected]] > Sent: Thursday, May 07, 2009 4:23 AM > To: Ravi Kumar > Cc: [email protected] > Subject: Re: [Sip-implementors] Require header for the 421 response > (rfc-3261) > > Table 3 says: > > Require ar - c - c c c > > where > c: Conditional; requirements on the header field depend on the > context of the message. > In your case, 421 satisfy this conditional requirement. Thus, the > Require header may be present in response/request based on the > context. > I do not think the RFC has contradicted the MUST requirement for 421 > response. It has just take a generalized approach for making this > table entry for Require header. > I do not think this table is that elaborate to accommodate every > possible case and in which case, there would have been no significance > for "c" symbol. > Thus, you have to consider this table and the rest of the RFC content > for validation. > > > On Wed, May 6, 2009 at 9:09 AM, Ravi Kumar <[email protected]> wrote: >> Hi, >> >> Thanks for response for the last query. >> >> >> I have doubt about the table 3 uses. As per the section 21.4.16 421 >> Extension Required >> The UAS needs a particular extension to process the request, but this >> extension is not listed in a Supported header field in the request. >> Responses with this status code MUST contain a Require header field >> listing the required extensions. >> >> And table 3 mention that this header field may present in all the request >> and response. >> >> So the sip entity should validate request or response based on the table 3 >> or MUST clause in rfc. Because here seems some conflict between the table > 3 >> and the section 21.4.16. >> Because this is one place I have found different behavior in rfc. >> Please correct me if I am wrong. >> >> Thanks & Regards, >> Ravi Kumar >> _______________________________________________ >> 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
