[nsp] T3 to a 3640

[Chris Hale]

So I have a potential new customer that is a cable TV company.  They offer
cable Internet service to about 5000 customers.  He's trying to run his
traffic through a 3640, and claims to be running into a ceiling about
15-17Mbps down and 12-14Mbps up.   Current stats:

30 second input rate 13542000 bits/sec, 3298 packets/sec
  30 second output rate 12247000 bits/sec, 5124 packets/sec

This gives to 513byte packets in, 298byte packets out.

My question from him:  Is the 3640 the bottleneck?  He has a full DS-3
available to him.  My first instinct was to suggest running a 7206, even
just a non-VXR 7206.  However, even at the above throughputs, his CPU is
only at 50%, and he has over 72Mb of memory free (out of 96Mb).

Ideas?

Chris

----------------------------------------------
Chris Hale
Peak Networks, Inc.
http://www.peaknetworks.com
800-PEAK-987
chris at peaknetworks.com
Motorola ACSP, Alvarion AIR, Certified Orthogon, Redline, Cisco, Terabeam
Partners.

 
 


-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Terry Baranski
Sent: Sunday, June 06, 2004 10:12 PM
To: cisco-nsp at puck.nether.net
Subject: RE: [nsp] T3 to a 3640

> So if Cisco states the 3640 can handle 50-70 kpps, how much
> of this can you realistically expect to see?  50%? 75%?
>
> Just tell me what to expect for pps, and I'll figure out 
> how much bandwidth I can expect in my own application based 
> upon my average packet size.

It's completely dependent on traffic characteristics (e.g., packet size)
and any potential performance-reducing features (e.g., ACLs, NAT, etc)
that are enabled.  You can achieve the rated pps with 64 byte packets
and nothing but CEF enabled.  But as packet size increases and
processing-intensive features are turned on, achievable throughput tends
to decrease and there's no magic formula that can accurately predict
what performance you'll get in any given scenario.

-Terry

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