From: Brennan_Murphy@NAI.com
Date: Thu Mar 06 2003 - 15:34:20 GMT-3
70-80% over what period of time? 24hrs? normal bus hrs?
does proper qos allow you to ignore the 70-80% rule?
before commenting, Id like to see what others say
-----Original Message-----
From: McCallum, Robert [mailto:Robert.McCallum@let-it-be-thus.com]
Sent: Thursday, March 06, 2003 4:04 AM
To: 'OhioHondo'; Mike Schlenger; 'Pratt, Jeremy'; 'Sam Munzani';
ccielab@groupstudy.com
Subject: RE: At what percentage of T1 utilization you should see
performa n ce degrade?
I am pretty sure that is what the design guidlines are. 70% on wan - start
looking for more bandwidth
> -----Original Message-----
> From: OhioHondo [mailto:ohiohondo@columbus.rr.com]
> Sent: 06 March 2003 01:50
> To: Mike Schlenger; 'Pratt, Jeremy'; 'Sam Munzani';
> ccielab@groupstudy.com
> Subject: RE: At what percentage of T1 utilization you should see
> performan ce degrade?
>
>
> Also note that if your utilization is at 70 or 80 percent, that is an
> average over a time period. You are probably peaking at 100%
> and using your
> output buffers to accommodate peaks at over 100%.
>
> As a general rule I would take a good, indepth look at the circuit and
> interface (buffers, drops, etc.) at 70% and plan for
> additional bandwidth.
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> Mike Schlenger
> Sent: Wednesday, March 05, 2003 4:08 PM
> To: 'Pratt, Jeremy'; 'Sam Munzani'; ccielab@groupstudy.com
> Subject: RE: At what percentage of T1 utilization you should see
> performan ce degrade?
>
>
> In my opinion to this question, there is no right or wrong answer
> essentially. In a debate of this matter, there are many
> variables that can
> and will effect saturation and performance. I would want to
> consider, off
> the top of my head, Router CPU, Interface MTU, Average packet
> size (are they
> all 1500 bytes?), corresponding serialization delay, queue
> size, etc. Its
> really an open ended question...If you had more specifics, I
> think you could
> then determine whether or not your router is actually
> dropping packets, or
> if you're saturating the pipe.
>
> Mike
>
> Michael Schlenger
> CCIE #7079
> Meridian IT Solutions
> mschlenger@meridianitsolutions.com
> 847.592.3912
>
>
>
> -----Original Message-----
> From: Pratt, Jeremy [mailto:JPratt@coh.org]
> Sent: Wednesday, March 05, 2003 11:25 AM
> To: 'Sam Munzani'; ccielab@groupstudy.com
> Subject: RE: At what percentage of T1 utilization you should
> see performan
> ce degrade?
>
>
> The 3640 can handle more than 1 full T1. You'll probably have
> to adjust the
> queue outbound and inbound queue sizes. I've got a 3640 with
> 4 T1's on it
> and no one ever has performance problems and all 4 T1's run
> very hot, 75%
> and up during peak traffic.
>
> -----Original Message-----
> From: Sam Munzani [mailto:sam@munzani.com]
> Sent: Wednesday, March 05, 2003 7:51 AM
> To: ccielab@groupstudy.com
> Subject: At what percentage of T1 utilization you should see
> performance
> degrade?
>
>
> Hi,
>
> Today we got in to a debate about T1 saturation and
> performance degradation.
> Below is 2 different opinions from my self and other engineer.
>
> What I say.
> T1 is a full duplex mechanism. So until it hits 100%
> utilization on it's
> Serial(Full T1) interface it will forward to packet and no
> packet drop will
> happen. Only the time it will do a queue drop is when the
> traffic bursts
> above 100%. This queue drop is because of Serial interface short on
> forwarding buffers. Same behavior will happen on inbound.
> Only the time this
> would be a bottleneck is if router CPU is a bottleneck. This
> is on 3640 with
> Fast switching turned on. I am assuming 3640 can handle more than 1 T1
> bandwidth.
>
> The other engineer's opinion.
> 3640 supports only 75000 pps with 64 bytes packets. His
> opinion is, your
> users will see performance problems even before T1 is hitting
> 100%(aroung 70
> to 80%).
>
> Any opinions with enough supporting proofs are most welcome.
>
> Regards,
>
> Sam Munzani
> CCIE # 6479(R&S, Security)
>
> --------------------------------------------------------------
> --------------
> --
> This message and any attachments are intended solely for the
> use of the
> individual or entity they are addressed. This communication
> may contain
> information that is privileged, confidential, and exempt from
> disclosure
> under applicable law. If the reader of this communication is not the
> intended recipient, or the employee or agent responsible for
> delivering the
> message to the intended recipient, you are hereby notified that any
> dissemination, distribution or copying of the communication
> is strictly
> prohibited. If you received the communication in error,
> please notify us
> immediately by replying to this message and then deleting the
> message and
> any accompanying files from your system. CONFIDENTIAL
> ==============================================================
> ==============
> ==
This archive was generated by hypermail 2.1.4 : Sat Apr 05 2003 - 08:51:34 GMT-3