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Cat-6504-E service-policy output priority not supported??

I have a 6504 with sup720 with these mods and IOS:

ROC-6504-DW-A#sh mod

Mod Ports Card Type Model Serial No.

--- ----- -------------------------------------- ------------------ -----------

1 2 Supervisor Engine 720 (Active) WS-SUP720-3B SAD1023090E

2 24 CEF720 24 port 1000mb SFP WS-X6724-SFP SAL1034YSL8

4 48 SFM-capable 48 port 10/100/1000mb RJ45 WS-X6548-GE-TX SAL10403B0X

Mod MAC addresses Hw Fw Sw Status

--- ---------------------------------- ------ ------------ ------------ -------

1 0017.944a.5ec4 to 0017.944a.5ec7 5.2 8.4(2) 12.2(18)SXF7 Ok

2 0018.b916.f028 to 0018.b916.f03f 2.4 12.2(14r)S5 12.2(18)SXF7 Ok

4 0018.b9e7.b348 to 0018.b9e7.b377 11.1 7.2(1) 8.5(0.46)RFW Ok

Mod Sub-Module Model Serial Hw Status

---- --------------------------- ------------------ ----------- ------- -------

1 Policy Feature Card 3 WS-F6K-PFC3B SAD102501U9 2.3 Ok

1 MSFC3 Daughterboard WS-SUP720 SAD102501AA 2.6 Ok

2 Centralized Forwarding Card WS-F6700-CFC SAL1032XPTJ 2.0 Ok

The QOS classes and service policy I have defined are:

class-map match-any Call-Control

match ip dscp cs3

class-map match-any Video

match ip dscp af41

class-map match-any Voice

match ip dscp ef



policy-map QOS_classes_330voice

class Voice

priority 30000

class Call-Control

bandwidth 500

class class-default



I need to apply priority queueing to some of the interfaces to prioritize our voice traffic that is going to be routing through this switch -- 330 G-711 voice calls so I'm setting up a priority queue of 30MB.

Here is the error I get when I apply the service policy to an interface:

ROC-6504-DW-A(config)#int g2/1

ROC-6504-DW-A(config-if)#service-policy output QOS_classes_330voice

priority command is not supported in output direction for this interface

Configuration failed on:


This errors also on the 48-port line card as well as in the input direction.

How do I prioritze my voice if the line card won't take an output service policy, or am I not doing the service policy right?

Hall of Fame Super Blue

Re: Cat-6504-E service-policy output priority not supported??


I think the interface you try and apply a service-policy output statement on must be either a layer 3 interface or a vlan interface. Is gi2/1 a switchport ?

From cisco doc:

PFC QoS supports the output keyword only with PFC3 and only on Layer 3 interfaces (either LAN ports configured as Layer 3 interfaces or VLAN interfaces). With PFC3, you can attach both an input and an output policy map to a Layer 3 interface.

Here is the full link to doc.


Re: Cat-6504-E service-policy output priority not supported??


According to the following document both the line cards, WS-X6724-SFP & WS-X6548-GE-TX, that you are using support one strict priority queue for TX traffic. However, the size of queue is limited to 175k & 182k respectively.

Try this. Configure 'priority' under the class and do not specify the bandwidth and apply the service policy to the interface.



Community Member

Re: Cat-6504-E service-policy output priority not supported??

You're treating it as a routed port. You need to think of it in terms of a switch port. Ie, you map DSCP to COS, specify output queue bandwidth/priorities on the interface and then map COS to output queues on the interface.

The catalyst 6500 line cards have different queueing mechanisms and so you need to do a little digging about your specific interface type.

Here's a place to start:



Community Member

Re: Cat-6504-E service-policy output priority not supported??

I opened up a TAC case and the engineer was very helpful. He mentioned that by turning on global MLS QOS, and then at the interface 'mls gos trust dscp' (which we want to do), that that was enough to set up the queuing to ensure that all voice packets - packets marked with COS 5 or DSCP 46 - would be serviced in the priority queue of each interface.

The default queuing settings are enough to insure that anytime a packet is placed in the priority queue, that packet will be serviced before any other packet, so I don't need to worry about setting up 'percent' or 'bandwidth' parameters like on a router.

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