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QoS on 6509 running native IOS

Hi to all,

we have a couple of Catalyst 6509 with SUP720 and SUP720B running native IOS (Version 12.2(33)SXH2) and (Version 12.2(18)SXF1)

All switches have the WS-X6748-GE-TX line cards.

Now, for the WAN connection between the branch offices i've configured the switchports as a routing-ports.

We have aprox. 40 IP phones in each location (non Cisco phones)

On layer 2 (the access layer) we have Catalyst 2950. On each switchport where the IP phones are connected, the mls qos trust dscp command is active.

Now, i also want to implement QoS on the Layer 3 ports. What i've tried till now:

class-map match-any VoiceClassMap

match ip dscp ef

match access-group 199

policy-map VoicePoliMap

class VoiceClassMap

priority 1000000

access-list 199 permit ip any

access-list 199 permit ip any

As soon as i try to bind the policy on that Layer 3 interface i get the following error:

priority 1000000 priority command is not supported in output direction for this interface Configuration failed!

So after spending couple of hours reading documetations, forum posts etc etc i'm on the verge to go crazy.

I've found out that LLQ on this linecards are not suported.

So my question is simple: how can i use QoS on these Layer 3 switchports (with the hardware mentioned above) so that VoIP traffic gets priorized to use 1Mbit of the available 100MBit Link speed.

A configuration example would be so great!!

Thank you

Hall of Fame Super Blue

Re: QoS on 6509 running native IOS


The WS-X6748-GE-TX supports a 1P3Q8T queueing structure for the transmit side so you do have a priority queue. Attached is a link to the QOS SRND covering how to configure a 1P3Q8T line card to support VOIP in the priority queue -


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