[c-nsp] ME3750 Shaping

[Eric Van Tol]

> -----Original Message-----
> From: Brad Henshaw [mailto:brad.henshaw at qcn.com.au]
> Sent: Monday, September 15, 2008 8:31 PM
> To: Eric Van Tol; Arie Vayner (avayner); cisco-nsp at puck.nether.net
> Subject: RE: [c-nsp] ME3750 Shaping
>
> Eric Van Tol wrote:
>
> > The idea here is very simple - there are ports that receive
> > a data-only service and a ports that receive both data and voice.
>
> What do you /really/ need to achieve here? Priority for voice? Rate
> limitation of voice, data or both to a certain rate?
>
> Also how do you identify data vs. voice? VLAN? DSCP/CoS?
>
> Regards,
> Brad

I've explained the situation to both Arie and my local SE.  It looks like the 3750 is simply not able to provide what we need it to do today.

To answer your question, though, I need the switch to perform bi-directional bandwidth limiting on data-only ports at speeds of 5M, 10M, 25M, 50M, and 75M.  This can easily be accomplished with a policing configuration and using the 'srr-queue' interface option on egress.  No problems there.

The problem comes when I need to add voice to a port - one VLAN is for data and one VLAN is for voice (802.1q trunk).  I can easily perform ingress policing at any rate I need for the data VLAN.  However, I am unable to provide any bandwidth shaping on egress at speeds higher than 50Mb/s due to the limitations of the 'srr-queue bandwidth shaping' interface option, which was my original question.  You get the option to specify a weight from 0 through 65535, which correlates to a percentage of the bandwidth.  A weight of 20 will limit the queue to 5Mb/s.  A weight of 50 will limit the queue to 2Mb/s.  A weight of 2 will limit the queue to 50Mb/s.  I have nowhere to go from '2'.

I understand that I can accomplish what I need by policing upon ingress from one of the uplink GE ports.  That's not what I would call an easy and scalable solution, though.

Thanks to everyone for all the suggestions, though.  Onward I must go to test more equipment.

-evt