QOS Question

johnakeating · ‎03-22-2009

I have a T1 that is handed off with ethernet. I need to do QOS on the line for bandwidth sharing of two servers. I

have configured the fa0/0 with a few policies but they all seem to be using the 100mpbs to base the QOS on. I have set the bandwidth command on the interface but still nothing.

here is my config.

so you don't need to download

http://www.learnios.com/viewtopic.php?f=72&t=304

Thanks for looking.

royalblues · ‎03-23-2009

can you post the output of "sh policy-map interface FastEthernet0/0"

However when you have an ethernet handoff, the best way to configure the QoS is to use nested policy

policy-map WAN-parent-policy

class class-default

shape average 1500000

service-policy ScrewTheMedia

policy-map ScrewTheMedia

class WEBSERVERTRAFFIC

priority percent 75

HTH

Narayan

Joseph W. Doherty · ‎03-23-2009

As Narayan shows, a hierarchal policy is what you need to do. The parent policy's shaper value corresponds with the downstream bottleneck, 1.5 Mbps (T1) in this example.

One thing to note, shapers don't regulate traffic exactly as a physical interface. What they do is regulate the traffic over an average bandwidth utilization over a time period. If you need to more closely emulate the physical interface, there's additional shaper parameters that can be used. Also, if possible, slowing the Ethernet interface to 10 Mbps will also help more closely emulate a T1.

For non real-time traffic, defaults values may be "good enough", and there may be no need to slow the Ethernet to 10 Mbps.