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Re: EPD and PPD Simultaneously?

  • From: "Dominic Richens" <dominicr@nospamnortelnetworks.com>
  • Date: Thu, 31 Aug 2000 11:38:06 -0400
  • Organization: Nortel Networks



Thomas Frieling <thomas.frieling@experteach.de> wrote in message
8okv48$i9o$1@nnrp1.deja.com">news:8okv48$i9o$1@nnrp1.deja.com...
> In article <8oj7bc$fo9$1@nnrp1.deja.com>,
>   albert.e.manfredi@boeing.com wrote:
> >(...)
> > So RED permits this flow regulation to be done
> > independently by each router along the path.
> > (...)
>
> Only by the router? Isn't it possible that an ATM-switch - aware of the
> fact that certain VCs carry TCP/IP-traffic - randomly discards packets
> (AAL5-PDUs) and thus resets the TCP-window size of only one connection at
> a time before its buffer situation forces to drop packets massively and
> thus resets the window sizes of all connections?

Yeah, that is kinda what I was getting at when I said that W-RED
implementation in an ATM switch was getting a little out of hand (IMHO).
PPD and EPD are generic AAL5 techniques, useful for FrATM trunks, X.25,
MPLS, IP..whatever. Whereas W-RED in specifically TCP/IP...and requires that
one layer (ATM) knows specific stuff about another layer (TCP) that is 3
layers away!

cheers!