Subject: [Sip] bug #2 in draft-ietf-sip-outbound-16 grammar

From: Florian Zumbiehl <[email-masked]>
Date: Mon, 13 Apr 2009 23:16:55 +0200

Hi,

draft-ietf-sip-outbound-16 contains (amongst others) these ABNF rules:

| message-header =/ Flow-Timer
| Flow-Timer     = "Flow-Timer" HCOLON 1*DIGIT

which, when adding them to the grammar from RFC 3261, would produce
from <SIP-message> a language that's a superset of the language that
would be produced by <SIP-message> from RFC 3261-only.

In particular, the language produced by <foo> is a subset of the
"outbound extended" language, but not of the RFC 3261-only one:

| foo = "INVITE sip:[email-masked] SIP/2.0" CRLF "Flow-Timer: 1" CRLF %x00 ":" LF

Well, seriously: <message-header> in RFC 3261 contains the final
CRLF that marks the end of a header, the newly-added alternative
<Flow-Timer> does not, I guess that it's rather obvious that that
is broken.

So, I would suggest replacing the rules quoted above by the following:

| message-header =/ Flow-Timer CRLF
| Flow-Timer     = "Flow-Timer" HCOLON 1*DIGIT

Florian