First draft for discussion at DVB

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

The DVB Commercial Module (CM) meet on 11th October, we need
to ensure the commercial and technical modules in DVB are
aware of this list, and also seek there advice on the
future way things should develop.   

It would be very helpful to jointly prepare a document to come
before this meeting to present the case for the existence of
this mail group and the work we intend to do.  The future
of the mailing list depends on finding a suitable relationship
with DCB technical groups and other such organizations. I'd
like to suggest we co-author a document to bring before this
working group.


The following is a suggested draft outline, as offered by 
Keith Fenwick, please do suggest text, comments, or issues 
to help with
this....


best wishes,

Gorry Fairhurst

-----



Transporting IP over Satellite

Contribution to DVB-TM Meeting of 11th October 2001 presented by 
Keith Fenwick (Hughes Network Systems) and prepared by ??

<< to add list of contributors>>

Summary

This note addresses the problems of carrying IP data over DVB, 
reports on work being proposed in the Internet Engineering 
Task Force (IETF) to improve transport efficiency and proposes 
that DVB should be party to this work.

<<< What is the correct form of words for a BoF? >>>>

Background

The need for DVB systems to carry data has already been recognised. 
It has also been shown that problems exist with the current MPE 
specification, which led to an RFI being issued by DVB-IPI AHG.  
This RFI requested information on current deficiencies (with any 
solutions) for the current MPE specification.  The responses to 
the RFI are now being handled by the DVB-SI AHG.  The majority 
of the RFI responses have been concerned with the signalling of 
IP address information to the terminals.

In addition, the expertise of DVB members tends to be in delivering 
traditional broadcast services and not data delivery using IP. 


Using DVB Systems to Carry IP Traffic

DVB systems need to carry IP traffic to provide true multimedia and 
interactive services. Multi-Protocol Encapsulation has the advantage 
that it is an existing ETSI standard but has some disadvantages 
for IP services using IPv4 and IPv6 which include:
1. It may waste up to 15% capacity in unnecessary overheads (MPE Tax).
2. It is overly complex, incurring significant per-packet processing overhead.
3. It contains many options, which in practice are not required for 
many IP services, and complicate interoperability between vendors.
4. Some desirable functionality is missing, including: address 
resolution of IP addresses to MPEG2-Transport Stream (TS), Packet 
ID (PIDs), support for IPv4 and IPv6 multicast.
5. Some additional features are desirable, e.g. SNMP support.

Potential Solutions

At present, only outline solutions have been proposed, including a
leaner encapsulation.

>>> Details to be added. <<<

Recommendations

DVB supports and contributes to the work being proposed within IETF to
take 
advantage of the knowledge within that group and to align with other
transport 
systems, e.g. IP over Cable Data Networks.

>>> Details to be added. <<<