Subject: [BEHAVE] TURN: IANA registry for channel numbers

From: Philip Matthews <[email-masked]>
Date: Wed, 4 Feb 2009 22:46:37 -0500

I have received two last call comments on TURN saying "You seem to be  
missing an IANA registry for channel numbers".

Personally, I didn't think that an IANA registry for channel numbers  
was appropriate or necessary. IANA registries are usually used for  
codepoints, while here we are registering a range of allowed values.  
Channel numbers are something that get dynamically allocated within a  
range, and the allowed range is (in part) dictated by packet formats:  
specifically, the current need to distinguish ChannelData messages  
from STUN-formatted messages, and a possible future need to  
distinguish them from something else.

However, given that I have now received two last-call comments on this  
subject, I am now re-considering my position. It might be clearer to  
add one, even though it seems weird.

Comments?

- Philip

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From: Brian E Carpenter <[email-masked]>
Date: Thu, 05 Feb 2009 17:42:38 +1300

On 2009-02-05 16:46, Philip Matthews wrote:
> Personally, I didn't think that an IANA registry for channel numbers was
> appropriate or necessary. IANA registries are usually used for
> specifically, the current need to distinguish ChannelData messages from
> STUN-formatted messages, and a possible future need to distinguish them
> from something else.
> 
> subject, I am now re-considering my position. It might be clearer to add
> one, even though it seems weird.

I was one of the two, wearing my Gen-ART reviewer hat, and
what prompted my comment was this:

> > 0x8000 through 0xFFFF: These values are reserved for future use.

If there isn't an IANA registry, there's no way to find out easily
if those values have been allocated subsequently.

    Brian

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From: Matthew Kaufman <[email-masked]>
Date: Wed, 04 Feb 2009 20:55:36 -0800

Philip Matthews wrote:
> ...
Not necessary. Rewrite it to say "the high bit must be zero". Then it is 
clear that 0x0000-0x7FFF can be used for whatever this draft/RFC says, 
and that 0x8000-0xFFFF aren't allowed by this draft/RFC. A subsequent 
draft/RFC can define the behavior with the high bit set.

There isn't an IANA registry for TCP initial sequence numbers, even 
though subsequent RFCs have changed the recommendation for how they 
should be chosen.

Matthew Kaufman

---

From: Simon Perreault <[email-masked]>
Date: Thu, 5 Feb 2009 08:29:21 -0500

On Wednesday 04 February 2009 23:55:36 Matthew Kaufman wrote:
> Rewrite it to say "the high bit must be zero". Then it is

This is just playing with words, it doesn't change anything.

I also strongly support creating an IANA registry.

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