RE: [nsp] Cisco DS3 Questions..

From: Daniel Golding (dgolding@sockeye.com)
Date: Fri Feb 22 2002 - 11:52:04 EST


That sub-interface numbering is useless for a point-to-point circuits.

- Daniel Golding

> -----Original Message-----
> From: Eric So [mailto:eric.so@graduate.hku.hk]
> Sent: Thursday, February 21, 2002 5:16 PM
> To: Gyorfy, Shawn
> Cc: 'nanog@merit.edu'; 'cisco-nsp@puck.nether.net'
> Subject: Re: [nsp] Cisco DS3 Questions..
>
>
> The proprietry HDLC will give you headache if you want
> to change the platform in the future.
>
> FR encap gives you sub-interface numbering which acts
> as an identifier to network devices through a proper
> indexing scheme.
>
> -e
>
> On Thu, 21 Feb 2002, Gyorfy, Shawn wrote:
>
> > 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.
> >
>



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