Re: A few questions

[Muneyb Minhazuddin <Muneyb.Minhazuddin@tip.csiro.au>]

Hi,

> Any chance that network programming will make it into the 2004 olympic 
> program :-)

Programmable networks in Athens by 2004 will be a gold medal feat by
itself. 
 
> Me wonders ... If some MPEG frames can be tossed on the floor without 
> impact, then the VOD server should selectively demote those particular 
> frames to Best Effort traffic to begin with,
this implies packet re-ordering which is a big taboo in the AF RFC. It
also implies that the VOD server should be aware of the available
codepoints that it can mark packets, which is not the intention.

> and leave the network as is 
> (i.e., vanilla DiffServ, RED, etc.), without just-in-time network 
> programming. 
We are attempting to exercise the just-in-time network programming in a
multi-domain environment with our applications. 

>I guess I don't understand why a VOD server would bother to 
> priority encode its traffic  (MPEG being such a code), and then tell the 
> network that all of the resulting encoded traffic carries above average 
> importance (i.e., AF codepoint). 

The VOD server does not tell the network to mark it to AF, the action is
taken at the Ingress based on the SLA negotiated with core or ISP or a
similar entity.

The end-user appear to be doing a sloppy 
> job here, and this conflicts with the end-user argument (i.e., perform 
> operations where the proper context lives).
> As for MPEG coding, you mention that B frames are big ... I thought I 
> remembered that the I frames are meaty, and B frames are small deltas. But 
> I've not looked at those MPEG issues in a long long time.

I am sorry my mistake, B frames are small indeed and of less importance
and I frames are meaty.

Cheers
Muneyb.
_________________________________________________________
Muneyb Minhazuddin - Telecommunications Research Engineer    
CSIRO Telecommunications and Industrial Physics                
Sydney, NSW, Australia.                                    
                                                             
Phone no. : 61 2 9372 4113
FAX       : 61 2 9372 4490          
e-mail    : mminhazu@tip.csiro.au  
Home Page : http://www-networks.tip.csiro.au/~mminhazu
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