ATM QoS

Corey OBrien · ‎07-14-2010

I am wondering what my options are for QoS on an ATM DS3 link (NM-1A-T3). I cannot apply a service policy to the ATM interface or the pvc on that interface like I normally do.

When I attempt to apply to the VC, it accepts the command but once I exit out, the command is not applied.

amahendi · ‎07-17-2010

Hi Corey,

What is the PVC configured for in terms of ATM shaping..? If its set for ubr / ubr+, the policy won't be taken. In case that is configured correctly, check if you exceeding allocating more than the rate the PVC is configured for in the QoS policy.. If the IOS is any 12.4 M release (or) any T release below 12.4(20)T, the bandwidth estimation for QoS is based on 75% of the PVC configured rate - if you exceed this, then the policy will not be taken, use the 'max-reserved-bandwidth' command to modify this behavior and then try applying the policy.

- Abhi

Corey OBrien · ‎07-19-2010

That was exactly it. I was allocating 80% so it wouldn't accept the config. Thanks.