nanog mailing list archives
Re: Cisco DS3 Questions..
From: "Barton F Bruce" <barton () cent net>
Date: Thu, 21 Feb 2002 19:18:07 -0500
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 middle. 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" <sgyorfy () elinkny com> To: <nanog () merit edu>; <cisco-nsp () puck nether net> Sent: Thursday, February 21, 2002 1:46 PM Subject: Cisco DS3 Questions..
Since the topic exploded, what are your opinions on encapsulation of
leased
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
encapsulation,
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
but
maybe that 15% can shrink to 10% with less overhead. Opinions or
examples
of life appreciated. Thanks shawn -----Original Message----- From: Iljitsch van Beijnum [mailto:iljitsch () muada com] Sent: Wednesday, February 20, 2002 4:28 PM To: Jon Mansey Cc: nanog () merit edu 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
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.
Current thread:
- Cisco DS3 Questions.. Gyorfy, Shawn (Feb 21)
- Re: Cisco DS3 Questions.. Christopher A. Woodfield (Feb 21)
- Re: Cisco DS3 Questions.. Justin Streiner (Feb 21)
- Re: Cisco DS3 Questions.. Barton F Bruce (Feb 21)
- Re: [nsp] Cisco DS3 Questions.. Stephen Sprunk (Feb 22)
- Re: [nsp] Cisco DS3 Questions.. Bill Woodcock (Feb 22)
- Re: [nsp] Cisco DS3 Questions.. Niels Bakker (Feb 22)
- Re: [nsp] Cisco DS3 Questions.. Jesper Skriver (Feb 22)
- Re: [nsp] Cisco DS3 Questions.. Mike Joseph (Feb 22)
- Re: [nsp] Cisco DS3 Questions.. Jesper Skriver (Feb 22)
- Re: [nsp] Cisco DS3 Questions.. Eliot Lear (Feb 25)
- Re: [nsp] Cisco DS3 Questions.. Jesper Skriver (Feb 25)
- Re: [nsp] Cisco DS3 Questions.. Robert E. Seastrom (Feb 25)
- Re: [nsp] Cisco DS3 Questions.. Jesper Skriver (Feb 25)
- Re: Cisco DS3 Questions.. Christopher A. Woodfield (Feb 21)