Re: Puzzling QoS Issue

Try adjusting removing the child policy from the parent, reapply the
parent, and see if issue is still there.

If yes, try adjusting queue-limit of "class class-default" in parent policy.

Perhaps also adjust the tx-ring parameters on the interface itself.

Does the CPU go high? If yes, what process?

Perhaps try changing "bandwidth remaining" to an explicit allocation (aka
bandwidth xx) and see if that helps.

Thanks,

On Fri, Apr 19, 2013 at 2:49 PM, Joe Astorino <joeastorino1982_at_gmail.com>wrote:

> I have a 3945 ISR router connected via a GigabitEthernet link to a service
> provider that is providing 10Mbps WAN access. I wish to use CBWFQ and the
> service provider requires dot1q tagging. As such, I must shape my
> sub-interface and use a hierarchical type QoS policy...no big deal
>
> policy-map WAN-EDGE
> class VOICE
> priority percent 20
> !
> class VIDEO
> bandwidth remaining percent 60
> queue-limit 128 packets
> !
> class APPS_SIGNALING
> set dscp af21
> bandwidth remaining percent 30
> !
> class class-default
> bandwidth remaining percent 10
> !
> !
> policy-map SHAPE-OUT
> class class-default
> shape average 10000000
> service-policy WAN-EDGE
> !
> !
> int gi0/1.2
> encapsulation dot1q 2
> ip address ...
> service-policy output SHAPE-OUT
>
>
> Here is the very strange thing. Even when the TX of this WAN interface is
> barely being used, when and only when the service-policy is applied, the
> response in pings to anything behind this router increase immediately by
> 200-400ms. Immediately after removing the service-policy things return to
> normal.
>
> Investigating the output of "show policy-map interface" reveals a large
> number of output drops in the shaper class-default. So far I have tried
>
> - increasing the queue-limit to many different combinations
> - increasing the burst size
>
> I also have the exact same configuration on another remote site router
> running the same version of IOS with the same setup (10Mbps Ethernet WAN
> link) on the same platform.
>
> I'm really baffled as to what would cause this. Any insight appreciated.
>
>
>
> --
> Regards,
>
> Joe Astorino
> CCIE #24347
> http://astorinonetworks.com
>
> "He not busy being born is busy dying" - Dylan
>
>
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Received on Fri Apr 19 2013 - 15:22:53 ART