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New Member

Auto QoS VoIP non cisco phones

I'm trying to setup QoS on L2 network.

"auto qos voip" really seams helpful and I wish to use it but I have some snom and polycom phones connected to my switches.

From what I read, "auto qos vopi cisco-phone" will create classes and policies based on CDP received from cisco-phones.

My question is, using non cisco-phone, will "auto qos" work or do I have to configure every single command.

I can always configure "auto qos" in trunks and phone access, and then change (table mapping, classes, policing,...etc) acording to those phones QoS values right?


Everyone's tags (5)
Cisco Employee

Re: Auto QoS VoIP non cisco phones

Using auto-qos will work with non-cisco phones.  As you saw, you just don't want to use the auto qos voip cisco-phone, as it will be looking for CDP.

Once you get auto-qos setup, take a look at the markings your phones are doing 'show mls qos statistics'.  This will give you a good idea if you need to change which COS/DSCP values need to go into priority queue, or if you need to trust COS vs DSCP.

New Member

Re: Auto QoS VoIP non cisco phones

thanks Chad,

so I just need to configure class-maps and policy-maps and auto-qos will take care of all the queueing and I just need to tune it right?

another fact is that polycom phones support CDP...

in this case I can use auto qos voip cisco phone right?

the question here is if CDP is used to identify phones and then apply default configurations or if CDP gets QoS (CoS/DSCP) values from the phone to build class and policy configurations?

I also want to ask you for an advise. I'm using a test lab to check configuration commands but don't have phones there. The real test will be made in production where VoIP is already implemented, and I'm not sure where to start from (core layer, access layer,...). If you know of a "step by step" implementation and/or some "good practice" links I can check, I would appreciate.

thanks for the help

Cisco Employee

Re: Auto QoS VoIP non cisco phones

So, you could create some policy maps to classify the traffic as it comes in, or if you want you can just trust dscp or cos values the phones are setting.

Now since Polycomm uses CDP I am assuming that trusting device cisco-phone will work, but I haven't personally tested it.  Give it a shot, and if needed trust DSCP/COS if that doesn't do the trick.

The switch won't build class-maps and policy maps based off this information.  I'm assuming you've done MQC style QoS like we have on our routers...the 3750s don't have that.  Check this link out for a bit more info on how QOS is handled on this platform:

If your using another platform, let me know what it is, I can comment more on that if needed.

As far as best practice links for implementation, I'm not too sure of any.  However I'd start at your access, because if we don't trust the QoS values there, then your Dist/Core won't be able to use those values to queue traffic properly.

You can check to see if packets are getting passed with the proper tags by running 'show mls qos statistics int ' to see what values we are using when  passing traffic.

New Member

Re: Auto QoS VoIP non cisco phones

Hi Chad,

I'm using Catalyst 2950, 2960 switches with IOS 12.2(52)SE Lan Base.

I tried configuring auto-qos with polycom and it works...using the "auto-qos voip cisco-phones" I can see packets getting in profile.

Because I also use Snom, Cisco...and don't know what more I'll use in the future, I will prefer to set up access interfaces the hard way .

The auto-qos voip cisco-phone configures 2 interface statements that are confusing me.

Both the "mls qos trust cos" and the "service-policy input AutoQoS-Police-CiscoPhone" are in the interface running config.


class-map match-all AutoQoS-VoIP-RTP-Trust

match ip dscp ef

class-map match-all AutoQoS-VoIP-Control-Trust

match ip dscp cs3  af31


policy-map AutoQoS-Police-CiscoPhone

class AutoQoS-VoIP-RTP-Trust

  set dscp ef

  police 1000000 8000 exceed-action policed-dscp-transmit

class AutoQoS-VoIP-Control-Trust

  set dscp cs3

  police 1000000 8000 exceed-action policed-dscp-transmit


interface FastEthernet0/5
switchport mode access
srr-queue bandwidth share 10 10 60 20
priority-queue out
mls qos trust device cisco-phone
mls qos trust cos
auto qos voip cisco-phone
service-policy input AutoQoS-Police-CiscoPhone

shouldn't it be just one of them?

witch one takes precedence over the other?

thanks for your help

Cisco Employee

Re: Auto QoS VoIP non cisco phones

When you use an ingress policy-map it will take precedence over the 'mls qos trust' statement.

I'm not sure why both are there, I didn't know we did that...mabey its new, or I haven't configured auto qos for cisco-phone in some time...both very possible .

Regardless policy-map will take precedence over the trust statement.

New Member

Re: Auto QoS VoIP non cisco phones

That's what I thought , thanks..

now for a question relating class-maps:

on cisco documentation I read:

"Only one ACL per class map and only one match class-map configuration command per class map are supported. The ACL  can have multiple ACEs, which match fields against the contents of the  packet."

but when configuring, IOS lets me do this:


class-map match-all test1

match ip dscp ef

match ip dscp cs7

match access-group 99

match access-group name VOICE2


I was expecting not to be possible to configure multiple match statements inside de class map but that doesn't seam to be true.
What am I getting wrong?
What do they mean regarding only one ACL and one match statement?
New Member

Re: Auto QoS VoIP non cisco phones


I now understand that policy-map will take precedence over the trust statement.  I was a bit confussed as well.

Thanks for clarifying for all of us others too!


New Member

Auto QoS VoIP non cisco phones

"Does anybody know if we will eventually see LLDP used as a standard way  to provide the same function as CDP regarding the "trust" boundary and  auto qos? such as using the lldp netowrk policy to set cos values?"

That is an excellent question George.  Wouldn't it be nice if Cisco actually "walked the walk" and used open standard protocols to do something useful.

I have a bunch of Yealink phones that fully support LLDP that I would like to AutoQoS to work with as it does with CDP.

Shouldn't really be that difficult for Cisco to roll into IOS.


New Member

Re: Auto QoS VoIP non cisco phones

I am also looking for a way to take advantage of auto qos for non Cisco phones.But I dont neccessarily want to trust all the traffic. I want to apply a policy map to set dscp values based on udp ports. I still want to use auto qos to set the global qos commands. The below bullets summarize what we would like to do.

  1. Use Auto qos to set the global qos settings for that switch platform. For the cos-dscp mappings the queue mapping and threshold values.
  2. Have the port behavior be as "untrusted" and use a policy map to select dscp values based on upd or tcp ports. During the transition period a port could have either a cisco phone attached or a Lync phone attached. We will selectively remark traffic based on udp/tcp ports.

Will a policy map truly override the mls trust or conditional cisco phone extended trust boundary?

Can I specify auto qos trust cisco-phone and then modify the policy map to remark dscp based on udp ports that Lync phones are using? If the policy map fully over rides the mls trust settings then would I also need to include in the modified policy cisco phone udp/tcp port settings?

Does anybody know if we will eventually see LLDP used as a standard way to provide the same function as CDP regarding the "trust" boundary and auto qos? such as using the lldp netowrk policy to set cos values?

New Member

Auto QoS VoIP non cisco phones

I am lucky enough to be using ShoreTel phones.  I am using LLDP and the network policy TLV to assign the voice vlan, don't need voice vlan commands when you use that.

Then I am using auto qos voip trust since the phones mark the traffic.  Now here is what I don't understand, depending on the model of switch and I guess potentially the software version, not all switches seem to apply the expected commands when the macro is run.

For example, on a 4500, I see that a policy map is created and applied to each interface the auto qos macro is run on.  However, on a 3750 or 3560, I dont see any indication of a policy map being created or one being applied to interfaces that are trusting cos and dscp.

I am not sure what to think of it.