Re: Proposed Changes to ULE text - Format descriptors for SI sign alling

[Gorry Fairhurst <gorry@erg.abdn.ac.uk>]

Art, others, I'd like to respond to the SHOULD/SHALL thread as the WG Chair.

The reason an additional paragraph was inserted, was to associate a ULE
stream with a format descriptor that had been allocated by SMPTE. This now
forms one of three paragraphs in the introduction of the ULE encapsulation
spec. Looking at the thread, I believe the term "SHOULD" in the new para is
correct in the IETF sense, in that there are cases where the ULE protocol
could function without the information (e.g. A private network). This was
also discussed on the list earlier.

I'll present a slide with this text again at the IETF meeting tomorrow, and
if there are more views, I'll make sure they are discussed on this list.

Although the *encapsulation* work is now complete, the topics of addressing
and identification of the set of TS to be used is now very much a
work-in-progress. 

The AR document (see below) is intended to describe the process of
binding/associating IPv4/IPv6 addresses with MPEG-2 Transport Streams (TS).
In this latter context, the discussion seems valuable. The AR document needs
to explain why and how to use the PMT, when you need it, when you may not do
it, and what other protocol parameters need to be set to complete the
mappings for IPv4/v6 multicast/unicast etc. This discussion thread provides
useful inputs to this document, which we will try to now include in section
4.
http://www.ietf.org/internet-drafts/draft-ietf-ipdvb-ar-00.txt

Gorry