Cell Relay Archive

[Andrew Peterson <andrewbp@nortelnetworks.com>]

In order to implement EPD/PPD, you'd have to examine the offset
of each ATM cell that contains the AAL5 bit designating whether
there's more cells to follow that belong to the current packet.

If the data stream is AAL5, looking at that offset position makes
sense and the EPD/PPD algorithm can correctly decide whether
to discard cells...

If the data stream isn't AAL5, I'd expect the unexpected; the
algorithm could still inspect the offset position, but in the different
adaptation layer, that offset likely has a completely different
meaning.  Erratic behavior would likely result.
-ap

Paul Koning wrote:

> Kukkonen Marko wrote:
> >
> > EPD and PPD features are used with AAL5. Is it any harm if you
> > use EPD and PPD for pvc connections that are not using AAL5 ?
> > For example, you make a pvc. Pvc is used to connect two routers
> > that use AAL5. You turn EPD/PPD on. In the future, you take
> > routers away and starts to send other atm traffic that is not AAL5.
> > You use same pvc with EPD and PPD on.
> >
> > Can EPD or PPD setting cause any harm to the connection, because it is
> > no longer AAL5.
>