I don't agree with this.
It's not a SIP entity's job to be "SIP police" to this extent.

If you require strict 3261-compliance then ok - reject the request with
400.
If you don't, then process it normally.

I feel all the others checks are unnecessary.
For example, adding code to check for strict
RFC 2543-compliance - I can't see any purpose in that.
Checking the call-id?  Why?
If you are 3261-compliant then you won't care
if it has a @ anyway.  It's just overly officious.

And the easiest way to check for RFC3261-intended-compliance
is the from-tag in the INVITE request - if there isn't a
from-tag, it's an RFC2543 implementation.

Regards,

Attila

 

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of
Sourav Dhar Chaudhuri
Sent: 25 September 2008 07:59
To: Navneet Gupta; [email protected]
Subject: Re: [Sip-implementors] UA behaviour on recieving INVITE
withoutmax-forwards header

Hi Navneet,
          Sip UA(End Point)
behavior on receiving INVITE without max-forwards header depends on
implementation of backward compatibly with RFC 2543. 

    If the Sip UA(End Point) backward compatible with RFC 2543 then it
MUST follow step (d) said by you.
     RFC 2543 does mandate Max-Forwards in a  request.
it ia OPTIONAL header.
"Refrence RFC 2543
table 4"

Max-Forwards       
R     n     e   o  
o   o   o   o   o
Table 4: Summary of header
fields, A--O
    
But be sure remaining all the headers are following RFC 2543 strictly. 
    Example Call-ID header MUST contain "@ "symbol with other value in
that Request which is MUST condition for RFC 2543 ABNF grammar. RFC 3261
does not mandate it .
 
 ABNF of Call-ID in RFC 2543
  
  Call-ID   =  (
"Call-ID" | "i" ) ":" local-id "@" host
  local-id  =  1*uric
 
 
   
ABNF of Call-ID in RFC 3261 

   Call-ID  =  ( "Call-ID" / "i" )
HCOLON callid
    callid   =  word [ "@" word ]


  If the Sip UA(End Point) is compatible with only RFC 3261 then it MUST
follow step (b) said by you.
As table 2 of chapter 20 in RFC 3261 suggest Max-Forward is mandatory
header which is marked by "m " under all the request. 
It is not marked by "m*"

RFC 3261 chapter 20
     m: The header field is mandatory.

     m*: The header field SHOULD be sent, but clients/servers need to
           be prepared to receive
messages without that header field.


 If
any of the header like Via, From, To, Call-Id & CSeq is not present in a
request the way Sip UA(End Point) treat the request. 
The same way Sip UA(End Point)  MUST that request which does not contain
Max Forwards header. As all these headers are exactly same way
represented in the table 2 of RFC 3261 
 
Thanks
Sourav


----- Original Message ----
From: Navneet Gupta <[EMAIL PROTECTED]>
To: [email protected]
Sent: Wednesday, 24 September, 2008 3:12:05 PM
Subject: [Sip-implementors] UA behaviour on recieving INVITE without
max-forwards header

Hi
If a SIP UA (Endpoint), recieves an INVITE request which does not
contain 
the mandatory Max-Forwards header, what should the UA do? Should it -

a) respond with 483 (Too many hops) response
b) respond with 400 Bad request response
c) Stay quiet and Ignore the INVITE.
d) Process the INVITE normally.

Please help.

Regards
Navneet




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