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Re: Cisco DS3 Questions..

  • From: Barton F Bruce
  • Date: Thu Feb 21 19:20:57 2002

If you are running frame-relay now, unless you have an asymmetrical
configuration (which cisco CAN do) where one end is configured to look
like a f/r switch, you probably have your carrier's f/r switch in the

Whoever configured it that way in the router did it because that is the
king of circuit that was ordered.

It may well be that there was a much better price especially if there
was a lot of mileage and the cir was set low.

f/r can look good sometimes.

If it is a real point to point t3, don't use f/r

----- Original Message -----
From: "Gyorfy, Shawn" <>
To: <>; <>
Sent: Thursday, February 21, 2002 1:46 PM
Subject: Cisco DS3 Questions..

> Since the topic exploded, what are your opinions on encapsulation of
> line DS3s.  We currently use Frame Relay for out Point to Point DS3
> connections.  Personally, I don't know why we use FR as our
> and so the question to all.  If you are running Cisco to Cisco, would
it be
> wise to run HDLC or PPP?  Our DS3s' here are hardly maxed out, 15% or
so, so
> I'm not complaining about the few extra bits I can squeeze out them
> maybe that 15% can shrink to 10% with less overhead.  Opinions or
> of life appreciated.
> Thanks
> shawn
> -----Original Message-----
> From: Iljitsch van Beijnum []
> Sent: Wednesday, February 20, 2002 4:28 PM
> To: Jon Mansey
> Cc:
> Subject: 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
> > 60% or so to allow for bursts against the 5 min average, and
> > 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
> 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
> if packets are being dropped because of congestion. (Which has not
> confirmed so far.)
> There shouldn't be any problems pushing a DS3 well beyond 99%
> by the way. With an average packet size of 500 bytes and 98 packets in
> output queue on average, 99% only introduces a 9 ms delay. The extra
> 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.

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