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6509 Access layer QOS - IOS or CatOS??

We are getting ready to deploy 6509/Sup32's and WS-X6148A-GE-TX-AF PoE modules, as our access-layer switch. These access-layer 6509's will be layer 3 connected to distribution layer 6500s, and we will be using EIGRP as our routing protocol on all 6500s.

These will be in new buildings with all IP phones, so each port will have an IP phone and a PC connected to it.

Reading through the Cisco QOS SRND 3.3 it states (pg 2-77):

"Cisco IOS.

Furthermore, at the time of writing, Catalyst 6500 IOS does not yet support AutoQoS nor the

conditional-trust feature, therefore only CatOS examples of these models are given."

Now we have many 6509s as distribution and core routers running IOS, but none running CatOS at this time.

What is Cisco's "Best Practice" when using the 6500 as an access-layer switch when needing to have QOS on it?

Should I load it up with CatOS because of the availability of AutoQoS and Conditional Trust features? Or should I stick with IOS and manually configure QOS for voice and data? (With IOS and manually configuring QOS, am I still without the ability to conditionally trust DSCP values?)

If I'm able to use IOS and manually config for VoIP and data, what is an example of a standard port with an IP phone and a PC, assuming the IP phone marks the correct DSCP values and I want to trust those values?

Also we will be using Avaya IP phones so cannot use CDP.

Consider using these parameters when sending an example of QOS in an IOS environment:

data vlan = 10

voice vlan = 910

Thanks for any and all advice!

New Member

Re: 6509 Access layer QOS - IOS or CatOS??

Here is documentation I found if anyone else is having difficulty using IOS on 6500 for VoIP configurations.

IOS is the way to go as CatOS is being phased out. But since AutoQOS is not in IOS yet, these documents describe how to manually config an access layer 6500 for VoIP.

New Member

Re: 6509 Access layer QOS - IOS or CatOS??

Heres what you need.

mls qos map cos-dscp 0 8 16 26 32 46 48 56

mls qos

(Plus the following for trunk links)

mls qos trust cos

(Plus the following for non-trunk links)

mls qos trust dscp

We ran into the same issue. It finally came down to the fact that everything is moving -away- from CatOS. So stay away from CatOS and it will save you from having to manually convert a complex config down the road. On older modules like the Sup2, newer line cards (WS-X6148A-GE-TX) are only supported in IOS.

Hope this helps.

New Member

Re: 6509 Access layer QOS - IOS or CatOS??

A good document to read for QoS on a 6000 series is - Understanding Quality of Service on Catalyst 6000 Family Switches. DOC ID 24906. Might help.



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