Re: Antwort: Checking the backgorund to this...

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

This email was received Wed, 5 Sep 2001 09:48:14 +0100 (BST),
but failed to make the mailing list due to a local error:

---


Dear all,

thank you for installing the email reflector.

I agree with Gorry's suggestions but few remarks from my side:
- IPv6:
  security is included as issue ? (see also conditional access)
- IPv6:
  if we are focused on IPv6 is it necessary to consider IPv4 (perhaps included
or not needed anymore ?) ?
- MPLS:
   yes, not to consider protocols but a gateway function to connect DVB-IP
networks directly on an
  MPLS core/cloud, or to act as a MPLS edge router seems to be necessary in
future. To extend pure and native
  IP networks (which will be based on MPLS and optical networks) over
DVB should
be possible seamlessly.
  By the way: The Generic MPLS (GMPLS) approach could fit perfectly and
could be
expanded to DVB networks
  where PIDs could be used as labels. (You see I like the MPLS approach ;-)
- TCP/IP header compression:
   a)
   yes but why not discarding IP headers ? Means: using a MPLS like
approach -
to map IP addressed to
   broadcast channel numbers (PIDs, IP connections in dedicated PIDs)
than we
can
   reconstruct IP headers at the receiving side (using a connection or service
management). This allows also to
   route IP connections within an DVB network which operate just on PIDs (MPLS
labels !) instead of IP level.
   b)
   Why not to compress also the content, e.g. static web site (text and HMTL
compression) or to adapt compression
   standards like V.90 or others (similar the current development of compression
on ISDN) ?
- direct transmission without DSM-CC:
   seems to be needed in order to be more efficient but we should not
drop the
   DVB channel approach (the multiplex, the meaning of PIDs and the
tables to
signal the content and structure).
   The DVB has to provide a transport or baerer service and our new approach
should not influence running
   TV programs. How to solve ?
- multiple datagrams in the same MPEG-TS package:
   is already possible right now (in terms of many simultaneous IP connections
in MPEG-2 TS).
   For me: How we could use free resources, like stuffing, Null Packets
etc. and
how we could multiplex different IP
   connections without lost space (seemless IP frame packaging).
- Conditional Access (CA):
   Do we support "native" DVB CA (the encryption of MPEG-2 TS) or is IP security
an issue of higher layers (IP encryption
   using IP or higher tools) ?

Other questions:
What about easy reception vs. efficient multiplexing ?
Should we think in services and start with a top-down approach (which services
have to be supported, which traffic profiles
do we need and then how we could package IP frames) instead to change the
physical layer first ?

Best regards

Torsten Jaekel
Product Marketing Datacasting
Rohde & Schwarz FTK GmbH
Wendenschlossstr. 168, Haus 28
12557 Berlin
Germany
Phone: +49 30 65 89 1 - 103
FAX:     +49 30 65 55 02 21
email: Torsten.Jaekel@FTK.rohde-schwarz.com

PS: Is there anybody visiting the IBC 2001 in Amsterdam ? I am going to be
there, Rhode&Schwarz, Hall 8, booth 271.
You are invited to visit us and to talk about this issue IP-over-DVB.





|--------+----------------------->
|        |          Gorry        |
|        |          Fairhurst    |
|        |          <gorry@erg.ab|
|        |          dn.ac.uk>    |
|        |                       |
|        |          04.09.01     |
|        |          20:24        |
|        |                       |
|--------+----------------------->
  >----------------------------------------------------------------------------|
  |                                                                     
      |
  |       An:     ip-dvb@erg.abdn.ac.uk                                 
      |
  |       Kopie:  (Blindkopie: Torsten Jaekel/FTK)                      
      |
  |       Thema:  Checking the backgorund to this...                    
      |
  >----------------------------------------------------------------------------|





As a pre-requisite to any debate, I thought it may be useful to test
whether we are in agreement on some background assumptions.

My suggestions for the basic assumptions are:

---
The encapsulation

Supports IPv4 unicast and multicast
Supports IPv6 unicast and multicast
Does NOT consider MPLS, Ethernet bridging, and other protocols
Does include support for TCP/IP header compression schemes (e.g. ROHC)
---
Encapsulation

Direct transmission in the MPEG-2 Transport stream
This should NOT be based on DSM-CC, or a PES format
This should support section-packing (multiple datagrams in the same
MPEG-TS packet)
---

Are these all sensible starting assumptions?

Would this approach raise serious issues with conditional access?

How does this relate to data piping (specified in DVB EN 301 192)?


Gorry