Cell Relay Archive

[Torsten Müller <torsten@europemail.com>]

Daniel Horner wrote:
> 
> I'm wondering about the simultaneous application of EPD and PPD. Is
> there a benefit to using both of these discard policies at once? If I
> understand correctly, then PPD would still catch the tail-end of
> frames that "snuck past" the EPD threshold. Ie. the beginning of the
> AAL5 frame was transmitted when the queue was just under the EPD
> threshold.

I dont know what "snuck past" means, but EPD can still fail, if the
EPD threshold is too high (the buffer between the threshold and the
total
buffer limit is too small).
In this case PPD would be useful to discard the tails of the packets
instead
of wasting the capacity with cells, which would have to be discarded
later.

If the EPD threshold is correctly chosen, then I can see no reason to
use PPD.

Hope this helps,
Torsten