Cullen Jennings skrev:
On Jun 20, 2007, at 2:09 AM, Magnus Westerlund wrote:
Hi Cullen,
Sorry, but I get confused by this message. Which issue are you discussing?
A. The policy for AVP (and by inheritance the other profiles) for
the first 16-bits in the header extension. Which currently RFC
3551 says should be managed but doesn't define a policy or a registry for.
B. Header extensions signaled using the mechanism defined in
draft-ietf-avt-rtp-hdrext. Which currently is the equivalent of
FCFS and with the addition of a registry for keeping track of RFC defined ones.
I think you are talking about B and like to have confirmation of
the WG be okay with this.
Yes - I am talking about B but A is effectively being replaced by B
for all practical purposes so they are closely related.
Thanks for the clarification.
In the case of B my personal opinion is the following:
1. Per design using URIs as signalling names, this is impossible
to control. The only way of fix this would be to change the
identifier used for a mechanism into something a registration can
keep track and assign. However that also increases the chance of
borrowing a name without registering creating issues.
I was not really asking about if we should use URI or not, I was
looking for opinion on what level of control the WG thought they
should have from 1 to 4 - once we have a better idea of that, we
can propose an appropriate mechanism. Thoughts on this?
My personal opinion is that for the URN space there should be at
least expert review and specification required. We might consider
that the bar for what is considered a specification is. I think it
must be above a white paper but any industry forum or standards body
that produce a permanent documents should be okay. That way the
ones existing in the formal registry are available to read. They
will also receive some sanity check through the expert review. Going
further to require an RFC only reduced the utility of the registry
as a common gathering point for standardized solutions.
2. I think the IANA section as currently written needs to be
improved it is not easy to understand for someone desiring to
register a name in the URN space that it is under specification
required. I think a better separation of what is the rule for
registration within the space and the details needed to have the
URN space itself created is needed.
I think there might be some benefit in changing the rules for the
URN space to Expert Review and then have the Expert reviewer
guidelines require a specification as one of the criteria for acceptance.
However, the reality is that header extensions (16-bit field) have
been totally unmanaged and been in FCFS since day one.
interesting - which extension numbers are defined?
Well, that is the issue. I don't have any bodies/specifications that
I can point at. But I have herd rumors about people using them, by
simply picking a random number.
Cheers
Magnus Westerlund
IETF Transport Area Director & TSVWG Chair
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Multimedia Technologies, Ericsson Research EAB/TVM/M
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