Re: [Sip] comments on draft-barnes-sip-rfc4244bis-00.txt

["Elwell, John" <john.elwell at siemens.com>]

Part of the complexity is in the indexing mechanism. Do we really need
this?

John 

> -----Original Message-----
> From: sip-bounces at ietf.org [mailto:sip-bounces at ietf.org] On 
> Behalf Of Francois Audet
> Sent: 22 March 2009 16:11
> To: Jonathan Rosenberg; SIP IETF; Mary BARNES; 
> "B601:EXCH]"@zcars04e.nortel.com
> Subject: Re: [Sip] comments on draft-barnes-sip-rfc4244bis-00.txt
> 
> Jonathan, you are correct, we have not done too many changes so far.
> In part because we are waiting on target-URI, in part because 
> we didn't have
> enough time. And mostly, because we'd like to get agreement on how to
> proceed before. I'd like to discuss in the meeting.
> 
> The problems with HI today, IMHO, are the following:
> 
> - In order to make it work, today, people make "assumptions" 
> about HI to
>   be able to use it. Specifically, it is assumed that the first
>   retargeting is listed, and so are the 2 last ones. This is then
>   used by implementations as part of service logic and/or mapping to
>   PSTN information (Original Called Number, Redirecting Number, Last
>   Called Number). Unfortunately, HI (the spec) makes no such garantee:
>   current usage however does. Furthermore, it is assumed that 
> there are
>   no recorded "routing" entries before the first one or 
> between the last
>   retarget and the final contact. One "simplification" that I 
> would like
>   to see is rules that makes the outcome predictable. First, 
> I would like
>   to mandate that at a minimum those entries (first, last 
> two) are NEVER
>   removed by proxies, and second, that retargets proper are labeled as
>   such (as per target-URI discussion). That would greatly simplify
>   History-Info.
> 
> - There is a bug in ABNF. Corrected in current draft.
> 
> - There is a gratuitous requirement that TLS be used on each hop for
>   HI. I'd like to revisit that. Nobody enforces that, and I 
> see no reason
>   why HI would be treated differently than other similar headers (Via,
>   Record-Route).
> 
> - The examples are all wrong... They are all using Strict Routing. The
>   chances of having an implementation using HI and Strict 
> Routing in real
>   life are close to zero. It makes the reading more complex, and makes
>   HI look like some form of Record-Routing.
> 
> - There have been some editorial comments on text being repetitive and
>   wordy, and some proposals for simplification.
> 
> - Finally, and importantly, the idea would be to integrate all the
>   changes from target-URI, including the mid-path retarget 
> (as per point
>   one above), and the last-Contact replacement.
> 
> 
> 
> On Mar21 2009 08:07 , "Jonathan Rosenberg" <jdrosen at cisco.com> wrote:
> 
> > My main comment at this time, is that this bis document doesn't seem
> > much different from the original. Section 10 calls out a 
> bunch of things
> > that I would put in the 'minor' category - certainly not worth a
> > wholesale bis document if this is all we do.
> > 
> > I think it'd be worth having a high level discussion on the 
> changes we'd
> > like to make to this document, and assess whether there are 
> enough to
> > warrant a bis. For example, many have complained about the 
> complexity of
> > HI; are there changes meant to help that? So far, frankly, the few
> > comments on this draft have been suggestions for additions 
> for the most
> > part, and NOT simplifications. Is this meant as an omnibus 
> for a bunch
> > of extensions to HI?
> > 
> > Thanks,
> > Jonathan R.
> 
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