nanog mailing list archives

Re: Cisco PPP DS-3 limitations - 42.9Mbpbs?


From: Alex Rubenstein <alex () nac net>
Date: Wed, 20 Feb 2002 12:37:17 -0500 (Eastern Standard Time)



BTW:

  30 second input rate 13039000 bits/sec, 8055 packets/sec
  30 second output rate 45531000 bits/sec, 10021 packets/sec

Thats a pa-2t3+ on a flexwan in a 6509.



On Wed, 20 Feb 2002, Stephen J. Wilcox wrote:


Hmm, reasonable explanation..

presumably this can be improved (a little) with increased interface
buffers.. ? and possibly non fifo queuing eg custom queuing in favour of
TCP rathen than UDP/ICMP etc which wont have the backoffs

Cheers

Steve

On Wed, 20 Feb 2002, Randy Bush wrote:

we run HDLC on DS3 and we max at about 40.something too

if you're using five min (or three min) samples, and you're seeing 70%,
peaks are likely much higher and some users' packets are being dropped.
by 80%, enough packets are being dropped that users are likely to see
the effects of exponential backoff.  things do not improve above 80%.

randy


--
Stephen J. Wilcox
IP Services Manager, Opal Telecom
http://www.opaltelecom.co.uk/
Tel: 0161 222 2000
Fax: 0161 222 2008



-- Alex Rubenstein, AR97, K2AHR, alex () nac net, latency, Al Reuben --
--    Net Access Corporation, 800-NET-ME-36, http://www.nac.net   --



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