Hi Attila, See my reply with >>>> in your attached mail
But whatever I have given comments is strict implementation of RFC. To make call it can be neglected. But then it cannot be claimed as a full Compliance of RFC Thanks Sourav ----- Original Message ---- From: Attila Sipos <[EMAIL PROTECTED]> To: Sourav Dhar Chaudhuri <[EMAIL PROTECTED]>; Navneet Gupta <[EMAIL PROTECTED]>; [email protected] Sent: Thursday, 25 September, 2008 1:52:29 PM Subject: RE: [Sip-implementors] UA behaviour on recieving INVITE withoutmax-forwards header >> If a request does not contain From tag that does not means it is RFC 2543 compliant request. If it doesn't have a From tag then it isn't RFC3261. If I am wrong, can you give me an example of where RFC3261-compliant UAs send requests without a From tag. >>>> I am not saying a request without From tag is 3261 request. I am saying it is not 3261 request. but it does not mean it is a definitely RFC 2543 request. For cosidering a request as a RFC 2543 request you have to verify the request with ABNF grammar of RFC 2543 >>You have to then verify the Call-ID of the request to check it follows ABNF grammar of RFC 2543. If you believe "a request that does not contain From tag does not means it is RFC 2543 compliant request." then checking the call-ID will not help either. You could have an RFC3261-compliant UA which legally uses a call-ID of the form [EMAIL PROTECTED] . Then your detection principle does not work. So, using your beliefs, it is not possible to determine RFC2543-compliance. >>>>.As per RFC 3261 compliant UA(here UAS we are talking about UAS only) it MUST has to accept any request with or without "@" symbol in Call-ID header for any 3621 request. UAS wise it is RFC 3261 non compliant. ABNF grammar of Call-ID in RFC 3261.here [EMAIL PROTECTED] ] i.e it is optional for UAC to generate in "@" in Call-ID. So UAS cannot implement [EMAIL PROTECTED] as a Call-ID validation & can claim RFC 3261 compliant Call-ID = ( "Call-ID" / "i" ) HCOLON callid callid = word [ "@" word ] As per RFC 2543 compliant UA(here UAS we are talking about UAS only) it MUST has to accept any request at least with a "@" symbol in Call-ID header for any 2543 request. other wise UAS is RFC 2543 non compliant. ABNF grammar of Call-ID in RFC 2543 Call-ID = ("Call-ID" | "i" ) ":" local-id "@" host local-id = 1*uric So any request came without From tag & with "@ " symbol in Call-ID can be considered as RFC 2543 request if the UAS implemetation of RFC 2543 So any request came without both From tag & "@ " symbol in Call-ID then the request MUST not be considered as neither as a RFC 2543 request nor RFC 3261 request. My logic is simple any time you are considering any request as RFC 2543 instead of a RFC 3261 request then Call-ID grammar MUST be validated with ABNF of RFC 2543 Regards, Attila _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
