Merit Network
Can't find what you're looking for? Search the Mail Archives.
  About Merit   Services   Network   Resources & Support   Network Research   News   Events   Home

Discussion Communities: Merit Network Email List Archives

North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

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

  • From: Iljitsch van Beijnum
  • Date: Wed Feb 20 16:30:19 2002

On Wed, 20 Feb 2002, Jon Mansey wrote:

> OMG! Arent we missing the point here? What about never running links above
> 60% or so to allow for bursts against the 5 min average, and <shudder>
> upgrading or adding capacity when we get too little headroom.

> And here we are, nickel and diming over a few MBps near to 45M on a DS3...

And why not? Obviously there is a reason why they're not upgrading,
because there is plenty of traffic to fill up a second or faster circuit
if packets are being dropped because of congestion. (Which has not been
confirmed so far.)

There shouldn't be any problems pushing a DS3 well beyond 99% utilization,
by the way. With an average packet size of 500 bytes and 98 packets in the
output queue on average, 99% only introduces a 9 ms delay. The extra RTT
will also slow TCP down, but not in such a brutal way as significant
numbers of lost packets will. Just use a queue size of 500 or so, and
enable (W)RED to throttle back TCP when there are large bursts.





Discussion Communities


About Merit | Services | Network | Resources & Support | Network Research
News | Events | Contact | Site Map | Merit Network Home


Merit Network, Inc.