Re: AW: AW: Extension of conference procedures

On Sep 5, 2007, at 6:10 AM, DRAGE, Keith ((Keith)) wrote:

> So this is a convenient way to bring us back to the
other half of  
> the issue which we do not seem to have discussed yet.
When the  
> syntax was defined that allowed ?headers:
>
>       Headers: Header fields to be included in a
request constructed
>          from the URI.
>
>          Headers fields in the SIP request can be
specified with  
> the "?"
>          mechanism within a URI.  The header names and
values are
>          encoded in ampersand separated hname = hvalue
pairs.  The
>          special hname "body" indicates that
the associated hvalue is
>          the message-body of the SIP request.
>
> What usage did the SIP WG envisage for this, and thus
what  
> semantics did they define for that usage.
>
> Is it appropriate to assign new semantics to such
usage?
>

I believe we were confused about the differences between
headers and  
URI parameters and didn't quite get the "?"
notation used with HTTP  
cgi-bin.

But that's just where it started. "?" notation has
since been fairly  
widely used as a way to "flatten" elements of a
SIP request for  
expression on a single (if somewhat long) line, which has
been shown  
to be somewhat useful in both REFER and in retargeting
proxies that  
allow one-line configuration of a target URL.


--
Dean



_______________________________________________
Sip mailing list  https://ww
w1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementorscs.columbia.edu for questions on current
sip
Use sippingietf.org for new developments on the application of
sip

It looks to me like we could usefully have some
informational text
drafted on the usage of "?", i.e. what it can be
used for and what it
cannot.

Further, can any implementation use it, or does it need
specification 

Any volunteers.

Regards

Keith 

> -----Original Message-----
> From: Dean Willis [mailto:dean.willissoftarmor.com] 
> Sent: Thursday, September 06, 2007 1:20 AM
> To: DRAGE, Keith (Keith)
> Cc: Huelsemann, Martin; eburgerbea.com; sipietf.org
> Subject: Re: AW: AW: [Sip] Extension of conference
procedures
> 
> 
> On Sep 5, 2007, at 6:10 AM, DRAGE, Keith ((Keith))
wrote:
> 
> > So this is a convenient way to bring us back to
the other 
> half of the 
> > issue which we do not seem to have discussed yet.
When the 
> syntax was 
> > defined that allowed ?headers:
> >
> >       Headers: Header fields to be included in a
request constructed
> >          from the URI.
> >
> >          Headers fields in the SIP request can be
specified 
> with the 
> > "?"
> >          mechanism within a URI.  The header names
and values are
> >          encoded in ampersand separated hname =
hvalue pairs.  The
> >          special hname "body" indicates
that the associated 
> hvalue is
> >          the message-body of the SIP request.
> >
> > What usage did the SIP WG envisage for this, and
thus what 
> semantics 
> > did they define for that usage.
> >
> > Is it appropriate to assign new semantics to such
usage?
> >
> 
> I believe we were confused about the differences
between 
> headers and URI parameters and didn't quite get the
"?" 
> notation used with HTTP cgi-bin.
> 
> But that's just where it started. "?"
notation has since been 
> fairly widely used as a way to "flatten"
elements of a SIP 
> request for expression on a single (if somewhat long)
line, 
> which has been shown to be somewhat useful in both
REFER and 
> in retargeting proxies that allow one-line
configuration of a 
> target URL.
> 
> 
> --
> Dean
> 
> 


_______________________________________________
Sip mailing list  https://ww
w1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementorscs.columbia.edu for questions on current
sip
Use sippingietf.org for new developments on the application of
sip

On 9/5/07 7:19 PM, Dean Willis wrote:
>
> On Sep 5, 2007, at 6:10 AM, DRAGE, Keith ((Keith))
wrote:
>
>> So this is a convenient way to bring us back to the
other half of the 
>> issue which we do not seem to have discussed yet.
When the syntax was 
>> defined that allowed ?headers:
>>
>>       Headers: Header fields to be included in a
request constructed
>>          from the URI.
>>
>>          Headers fields in the SIP request can be
specified with the "?"
>>          mechanism within a URI.  The header names
and values are
>>          encoded in ampersand separated hname =
hvalue pairs.  The
>>          special hname "body" indicates
that the associated hvalue is
>>          the message-body of the SIP request.
>>
>> What usage did the SIP WG envisage for this, and
thus what semantics 
>> did they define for that usage.
>>
>> Is it appropriate to assign new semantics to such
usage?
>>
>
> I believe we were confused about the differences
between headers and 
> URI parameters and didn't quite get the "?"
notation used with HTTP 
> cgi-bin.

I'm not certain there was any actual confusion here when we
settled on 
that syntax originally. RFC 2396 (which was current at the
time, 
although it has been superseded by RFC 3986) describes this
portion of a 
URI as nothing more than: "The query component is a
string of 
information to be interpreted by the resource." I think
SIP's use is 
consistent with that.

Additionally, RFC 2368 gives clear and strong precedent for
precisely 
this interpretation of the query component of URIs.

/a


_______________________________________________
Sip mailing list  https://ww
w1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementorscs.columbia.edu for questions on current
sip
Use sippingietf.org for new developments on the application of
sip