Re: (4 bits from PID * 24 bits from @link_sat_adress) == 28 bits.

[Ghassane Aniba <Ghassane.Aniba@sophia.inria.fr>]

Kearney wrote:
> 
>  From: "Ghassane Aniba" <Ghassane.Aniba@sophia.inria.fr>
> Sent: Tuesday, April 23, 2002 1:19 AM
> Subject: (4 bits from PID * 24 bits from @link_sat_adress) == 28 bits.
> 
> .....SNIP.
> >
> > If we take in consideration, that most of IP packet are 1500 or 576, and
> > 40 or 48, and with a simple calcul, we see that the overhead don't
> > affect.
> > One thing more, i'll present another schema of encapsulation, into
> > reduce the treatment on board the satellite.
> >
> We should not base an encapsulation design on the momentarily observed
> packet statistics - as has been pointed out by several people, this might
> change very quickly.
> Furthermore, when we start packing - and with a 184 byte payload field this
> seems advisable, then your argument
> 
> > if we use the SNDU encapsulation ( + 8 bytes for each IP packet), we
> ..... assume for example a FTP transfer of a file of 100KByte
> >
> > 152 bytes free  ----->   584 bytes (4*184 bytes)
> >
>  leads to the following comparison:
> without packing you transmit a total of 126,592 (give or take a few) Bytes,
> with packing you transfer 100,096 bytes (give or take a few, depending on
> your encapsulation)
> and that IS a significant difference.
> 

I totaly agree with you, but this encapsulation, until now, is the
unique wich give us possibility to switch mpeg2-TS. with other ther
encapsulation, we have to reassembly the fragments of packet, if we want
switching it.
It's sur that it takes a lot of places, but this propose a new
possibilities like switching onboard satellite.

> if you think that is too big - take 10KB in which case the number come out
> to 13,248/10,120.
> 
> --Horst
> 
> BTW I don't seem to get all your messages - from Gorrys replies I can see
> that I am missing some.

-- 
Ghassane ANIBA
INRIA (Projet PLANETE)             | Email :
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