Re: Review of draft-mohali-dispatch-cause-for-service-number-12

On Dec 15, 2016, at 10:07 PM, Joel M. Halpern 
<jmh(_at_)joelhalpern(_dot_)com> wrote:

At this point I will defer to the relevant ADs.


+1 on that :-)

As far as I can tell, although the entry was created by an Informational RFC, 
the registry still claims that it is standards track.
And since this document is defining behavior, it behaves more like a 
standards track document than an Informational one.

But it is up to you folks.  In teh end, all I can do is raise the question, 
not decide it :-)


So the registry takes PS to change it. And by the current SIP rules, I suspect 
(not sure) that an update to 4458 would also have to be PS. So really not sure 
how one gets around this not being PS.


Yours,
Joel

On 12/15/16 11:51 PM, Ben Campbell wrote:

On Dec 15, 2016, at 10:35 PM, Joel M. Halpern 
<jmh(_at_)joelhalpern(_dot_)com> wrote:

I see your point about this adding a value to the entry created by RFC 4458.
Is there a reason this can not simply be PS?  The fact that 4458 is 
Informational does not, as far as I can tell, justify continuing the error. 
 While this is for a 3GPP usage, it appears to have been reviewed by the 
Dispatch WG sufficiently to justify PS.
One could argue that there is a down-ref issue,
but the fact that the field is in a standards-track required registry would 
seem to make that a moot point.


Do you think it makes sense to make some new values for “cause” into a 
proposed standard when “cause” itself is informational?  That seems like a 
pretty big downref issue, as such issues go. (For the record, I could be 
convinced to re-run this LC as PS, but I suspect that would lead to 
objections in the opposite direction.)

Right now, the situation is a standards-action registry with a informational 
entry. That’s clearly broken, but I’m not sure that _this_ draft is the 
place to fix it.

Also, if it makes any difference—even there there was discussion in 
dispatch, this is not a dispatch work item.

Yours,
Joel

PS: It would seem that WG discussion of that sort is something we would 
like to see in Shepherd writeups.


There’s two paragraphs on the subject in section (1) of the shepherd writeup 
:-)  (but it wasn’t a working group discussion per se.)

Thanks!

Ben.


On 12/15/16 11:28 PM, Ben Campbell wrote:

Hi Joel,

Thanks for the comments. There has been a fair amount of discussion
about the status of the draft. The situation is clearly not optimal, and
I welcome input on how to straighten it out.

The rational so far has been that this draft updates RFC 4588, which is
informational. It adds some additional values and related semantics for
the "cause" parameter from 4588. It does not register new parameters;
rather it adds itself as a reference in the existing "cause"
registration. This is mainly a courtesy to readers. (There is no
sub-registry for "cause" parameter values.) We might could get by
without that change, since in a perfect world people following the IANA
reference to 4588 would notice the "Updated by..." tag.

The gotcha is that RFC 4588 would not be possible as an informational
today; it would not have standing to register the "cause" parameter. But
at the time it was published, there was a lack of clarity around the
"standards action" policy for the SIP URI parameters registry. Making
the new values from _this_ draft standards track, when the parameter
itself is not, doesn't seem appropriate. We had some discussion about
whether we should promote 4588 to PS, but there was not consensus to do
so when it was published, and I don't see reason to expect that to have
changed.

This draft is primarily intended to meet a need in 3GPP, where I
understand they are effectively already doing this. Would it help to
more tightly scope this as "Here's something 3GPP is doing..." rather
than as a general mechanism?

Thanks!

Ben.

On 15 Dec 2016, at 21:57, Joel Halpern wrote:

Reviewer: Joel Halpern
Review result: Ready with Issues

Major:
  This document defines a new code for use in SIP, and specifies new
behavior both for the code itself and for its use in history-info.  I
am thus confused as to how this can be an informational RFC.  It looks
like it either Proposed Standard or experimental.  Yes, I see that RFC
4458, which this updates is Informational.  But just because we did it
wrong before does not make that behavior correct now.  In addition to
my understanding of the roles of different RFCs, I note that RFC 3969
and the IANA registry both state that this assignment must be made by
a standards track RFC.

Minor:
 Given our emphasis on IPv6 over IPv4, would it not make sense for
the examples to use IPv6 addresses?  (Inspired by the Id-Nits alert.)