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

Adam Roach <> Tue, 20 December 2016 22:49 UTC

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Subject: Re: [dispatch] Review of draft-mohali-dispatch-cause-for-service-number-12
To: Ben Campbell <>, Joel Halpern <>
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From: Adam Roach <>
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Date: Tue, 20 Dec 2016 16:49:36 -0600
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On 12/15/16 22:28, Ben Campbell wrote:
> 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.

I don't think that's true. We're talking about a registry established by 
RFC 3969, which says:

   "SIP and SIPS URI parameters and values for these parameters MUST be
    documented in a standards-track RFC in order to be registered by


   "For the purposes of this registry, the parameter for which IANA
    registration is requested MUST be defined by a standards-track RFC."

These are not ambiguous statements. We just botched our communication 
with IANA.

But I think we can do the right thing here without going back and fixing 
all of the issues with our ancestral documents. I mean, sure, maybe we 
should clean that up too, but I don't see the value in blocking new work 
on doing so.

In terms of publishing draft-mohali-dispatch-cause-for-service-number, I 
think there are two reasonable paths forward:

The first would be forming consensus that the two statements I quote 
from 3969 above -- and the reinforcing statement in 5727 -- were all 
incorrect, and that we want to explicitly (i.e., in a new document) 
reverse those statements and update the corresponding registration 
policy. Then, we publish -mohali- as informational.[1]

The second would be implicitly accepting established consensus around 
this registry, and consequently changing -mohali- to PS.

Rather than figuring out which of these is easier (clearly, the second 
is less work), I think the real question here is: do we think we got the 
registration policy for SIP URI parameters wrong?


[1] We *might* or might *not* also decide to then do something about RFC 
4458 in this case, but that's a completely separate decision.