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