Re: Self routing

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

Marie-Jose Montpetit wrote <forwarded by admin for ip-dvb>:

I would be worried to propose a scheme based on user traffic statistics of
today. Yes there are huge numbers of IPv4 ACK packets out there and yes a
ton of http: traffic too. This is April 2002. Deploy IPv6 in a grand scale
and the 40 bytes traffic will go down significantly. Non TCP or http: based
protocols will have other sizes, will they dominate? Don't know...

If we want to change MPE then the solution should be robust enough to
support the changes the other IETF groups will propose... BTW I would
recommend the group works on a draft on the requirements (look at what NSIS
did). It would foster a better discussion about what we are trying to
achieve here.

Marie-Jose



Ghassane Aniba wrote:
> 
> Hi,
> i've a remark:
> if we have 96% of traffic with 1500 or 576 bytes, and 40 or 48 bytes, we
> found this:
> 
> if we use the SNDU encapsulation ( + 8 bytes for each IP packet), we
> will have this results:
> 
> 148 bytes free  ----->  1508 bytes (9 * 184 bytes)
> 
> 152 bytes free  ----->   584 bytes (4*184 bytes)
> 
> 128 bytes free  ----->   56 bytes ( 1 * 184 bytes)
> 
> 136 bytes  free ----->   48 bytes ( 1 * 184 bytes)
> 
> this results confirm that we have enough space for adding our labels.
> Although, if we though about using a pointer, and a @ling_sat for each
> fragment of SNDU, we will have other results.
> 
> I'm thinking about adding another label, to the @link_sat_adress (I know
> that most of us, will say that's a lot of overhead, but i'm sur that it
> will be interesting).
> The name of label, will be " label_sitching". if you remember the
> descriptor which i've proposed, we foung this field.
> For each MPEG2-TS packet we will add 4 bytes, for this new label. We
> suppose that we have in maximum 32 spots. Each bit of the
> label_switching in the MPEG2-TS packet, will specify if this spot is
> concerned by this packet of not.
> So, we will eliminate the switching table from satellite, and having in
> her place, a smaller tables in each terrestrial terminal.
> 
> |---------------|------------|-----------------|------------------|
> | Mpeg2 Header  | @link_sat  | label_switching |  SNDU fragment   |
> |---------------|------------|-----------------|------------------|
>      4 bytes       3 bytes        4 bytes             177 bytes
> 
> With this new label, we will find that the nombre of MPEG2-TS packet for
> each SNDU didn't change.
> 
> Aniba.
> 
> --
> Ghassane ANIBA
> INRIA (Projet PLANETE)             | Email :
> ghassane.aniba@sophia.inria.fr
> 2004, Route des Lucioles BP 93     | Phone : +33 4 92 38 75 63
> 06902 Sophia Antipolis CEDEX France| Fax   : +33 4 92 38 79 78