Internet Router traffic shaping

Darren Sasso · ‎05-11-2010

We have a temporary 3560 in place with a 100MB Internet link and we are starting to oversubscribe the link. I'd like to start shaping the traffic which I'm assuming will help with some of the latency and upload/download issues we see when we get close to 100MB. I'm pretty sure I can't use a service policy on a 3560 and it looks like egress shaping will have to be done by using the 'srr-queue' command. I've read some of the documents and I'm wondering if this is the correct way to shape traffic since I'm not prioritizing traffic any differently everything is best effort.

I've hard coded the gigabit interface to 100MB and would like to shape just to smooth out the bursts.

It seems the highest i can shape to would be 2 0 0 0 (i believe the 2 would shape to 50MB of traffic and then everything else would be shared)

srr-queue bandwidth shape 2 0 0 0 

What would happen if i set it to 0 0 0 0 would it shape any traffic or all traffic?

Can i shape like below?  Will both queues transmit 50MB at the same time?

srr-queue bandwidth shape 2 2 0 0

Thanks in Advance.

Giuseppe Larosa · ‎05-12-2010

Hello Darren,

you can get a shaping effect with

srr-queue bandwidth limit weight1

see

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_46_se/configuration/guide/swqos.html#wp1253412

Specify the percentage of the port speed to which the port should be limited. The range is 10 to 90.

By default, the port is not rate limited and is set to 100 percent.

Hope to help

Giuseppe