Understanding SRR shape and limit

stretchlad · ‎07-13-2009

I just want to know if I have understood this correctly. If I have a port connected at 100Mb Full duplex with the following config:

srr-queue bandwidth shape 0 2 0 0

srr-queue bandwidth limit 18

Would this limit bandwidth to 18Mbit and also limit Queue 2 to 50% of 18Mbit which would be 9Mbit?

stretchlad · ‎07-14-2009

I have tested this in a lab and bot bandwidth shape and limit work off the physical speed rather than shape working off what limit is set at so my config was wrong. No need for a response now.

d.calton · ‎09-28-2009

So, to clarify, when you tested, did you get 18M, because the srr-queue bandwidth shape cmd was 50% and the srr-queu bandwidth limit command was only 18%, or did the shape command override the limit cmd?

stretchlad · ‎09-29-2009

The shape command in this scenario as it is allows 1/2 or 50% of the physical bandwidth which was 100Mb so 50Mb. As I have a limit of 18Mb it would peak at 18Mb when in relaity I only wanted it to use 9Mb.

So bandwidth shape 0 11 0 0 would give 9Mb for queue 2 which is what I wanted to achieve. I still used the bandwidth limit to limit the overall port utilisation to 18Mb but wanted a cap on an individual queue also.