If the header grammar is wrong, you must tell the vendor. They should fix it.
All SIP headers should be parsed according to their grammar. But since the User-Agent header is not very signficant, if you find an error in the header and it isn't serious enough to affect the parsing of any other headers then maybe you can just ignore the error. (and now I will argue against this...) The problem with this approach though is that your parser might know there's some kind of error but how will it know if the error is serious? So then you're left with adding extra conditions to your parser. And you have to make a judgement of what to allow and what not to allow. A whole load of extra work! It's just better if everyone complies to the grammar. The other problem is that if you make your UA/Proxy more tolerant then you are encouraging the "others" to get away with sloppy grammar and so they could work ok with you but they might have interop problems with other equipment. So by making a UA/Proxy tolerant, you are partly encouraging general interop problems. So again... It's just better if everyone complies to the grammar. Regards, Attila -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Agarwal Manish-A19715 Sent: 23 August 2007 12:46 To: [email protected] Subject: [Sip-implementors] Regarding User-Agent Header Hi, User-Agent header has its own grammar. However this header does not have much semantic significance other than display. May I know your views on if User-Agent header value has some deviations (like a LWS is missing etc ) from grammar. Can the deviations be accepted? or we must strictly follow the grammar. Any inputs on how other servers/clients handle this would be great. Regards Manish _______________________________________________ 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
