Re: [sipcore] WGLC: draft-ietf-sipcore-callinfo-spam

[Henning Schulzrinne <[e-mail]>]

Not great, but here's my new wording:

SIP proxies or B2BUAs MUST add a new Call-Info "info" header field
instance, rather than add parameters to an existing one. Thus, there MAY be
several Call-Info header instances of purpose "info" in one request, either
as a single header with a comma-separated list or separate headers, or some
combination.

Let me know if that's sufficiently clear.

Henning

On Thu, Feb 15, 2018 at 9:37 PM, Dale R. Worley <[e-mail]> wrote:

> "A. Jean Mahoney" <[e-mail]> writes:
> > Working Group Last Call starts today for draft-ietf-sipcore-callinfo-
> spam.
>
>    3.  Overview of Operation
>
>    SIP proxies or B2BUAs MUST add a new Call-Info "info" header field
>    instance, rather than add parameters to an existing one.  Thus, there
>    MAY be several Call-Info header fields of purpose "info" in one
>    request.
>
> This is correct, but I misread it the first time.  The grammar of
> Call-Info is:
>
>     Call-Info   =  "Call-Info" HCOLON info *(COMMA info)
>     info        =  LAQUOT absoluteURI RAQUOT *( SEMI info-param)
>     info-param  =  ( "purpose" EQUAL ( "icon" / "info"
>                    / "card" / token ) ) / generic-param
>
> and the above text means that a device may not add further info-param's
> to an existing info.  But it may add additional info's to an existing
> Call-Info, rather than using separate header fields.
>
> However, it's easy to misread as meaning that the following is not
> allowed:
>
>    Call-Info: <http://wwww.example.com/
>        5974c8d942f120351143> ;source=carrier.example.com
>        ;purpose=info ;confidence=85 ;type=fraud ;reason="FTC list",
>        <data:> ;source=other.example.com
>        ;purpose=info ;confidence=20 ;type=prison
>
> Is there a way to phrase this that is less easy to misread?
>