WGLC: ULE --- Questions to this WG.

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

As the ipdvb WG Chair, let me see if I can frame some questions to the WG as a 
whole (dervied from my understanding of this mail thread)? - This isn't an 
intention to stop discussions (we should address some of the issues raised onm 
the lists in the documents we plan to write), but I am aware that we have a 
document to deliver to the IESG following the WGLC.

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My three questions are:

A) There was a proposal by a reviewer to change the TITLE of the RFC, to make 
this clearer. The currently suggested new title is:

	"Ultra Lightweight Encapsulation (ULE) for transmission of
 	IP datagrams over an MPEG-2 Transport Stream"

	Instead of the existing title:
 	"Ultra Lightweight Encapsulation (ULE) for transmission of
 	IP datagrams over MPEG-2/DVB networks"

Is the new title acceptable?

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B) I propose the following text is added to the Introduction, are these 
useful/sufficient?

The MPEG-2 specification [ISO-MPEG2] requires conformant TS
Multiplexes to provide Program Specific Information (PSI) for
each stream in the TS Multiplex. Other MPEG-2 based transmission
standards may also define Service Information (SI). This
information may allow Receivers and Re-multiplexors [draft-ipdvb-arch]
to locate a specific ULE Stream (i.e., the PID value of the TS Logical
Channel that carries a ULE Stream). The conditions under which this
information is required, and the format in which it is to be provided
is beyond the scope of this document. Addressing and mapping issues
for IP over MPEG-2 are described in [draft-ipdvb-ar].

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C) The terminology "TS Logical Channel" has already been used in another 
document that has passed WGLC. Is it now sufficiently flawed that we MUST be 
replaced in the ULE document, if so why?, If not, I propose we change the 
definition to:

   TS Logical Channel: Transport Stream Logical Channel. In this
   document, this term identifies a channel at the MPEG-2 level [ISO-
   MPEG2]. This exists at level 2 of the ISO/OSI reference model. All
   packets sent over a TS Logical Channel carry the same PID value
   (this value is unique within a specific TS Multiplex). The term
   "Stream" is defined in MPEG-2 [ISO-MPEG2]. This describes the content
   carried by a specific TS Logical Channel (see, ULE Stream). Some
   PID values are reserved (by MPEG-2) for specific signalling.
   Other standards (e.g., ATSC, DVB) also reserve specific PID values.

I propose we also add:

    ULE Stream: An MPEG-2 TS Logical Channel that carries only ULE
    encapsulated PDUs. ULE Streams may be identified by definition
    of a ULE stream_type in SI/PSI [ISO_MPEG2].


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A number of minor corrections have also been made to wording and format, as 
requested by the various reviewers and WG feedback.

The complete set of proposed changes are listed at:
http://www.erg.abdn.ac.uk/ip-dvb/ids/rfcdiff-ule-05f-04.html

Please respond whether you think this revision, is now ready, and we'll try to 
reach a conclusion on whether this document is finally ready to submit.

Gorry Fairhurst
(ipdvb WG Chair)