Re: [sipcore] WGLC: draft-ietf-sipcore-name-addr-guidance

[[e-mail] (Dale R. Worley)]

Yehoshua Gev <[e-mail]> writes:
>> > The examples of:
>> >    Refer-To: sip:123@host?Replaces=1111
>> >    Refer-To: sip:123@host;user=phone?Replaces=1111

> I believe that the examples above are not valid according to the BNF -
> that of RFC 3515, not of 3261:
>       Refer-To = ("Refer-To" / "r") HCOLON ( name-addr / addr-spec ) *
>       (SEMI generic-param)
> This BNF does not allow for a question mark after the name-addr.
> So, the interpreting the string "sip:123@host" as the addr-spec alone,
> renders the
> header non-parsable by the BNF of 3515.

Yes... but if you're only considering the BNF,
"sip:123@host?Replaces=1111" can be parsed as an addr-spec, so the
header is valid (by the BNF alone).  (Actually, even "sip:123@host"
can't be parsed as a name-addr, because it doesn't have "<...>".)

> Given so, IMHO the disambiguation rule should be stated as a normative text.

Well, in section 2 of draft-ietf-sipcore-name-addr-guidance-00, it says:

   This text from the introduction to section 20 of [RFC3261]:
     ...
   is replaced with:
     When constructing the value of any SIP header field whose grammar
     allows choosing between name-addr and addr-spec, such as those
     that use the form '(name-addr / addr-spec)', the "addr-spec" form
     MUST NOT be used if its value would contain a comma, semicolon,
     or question mark.
     ...

So, yes, the new disambiguation rule is stated as a normative text.

Dale