Auto QOS SRND4 service policy

[Emil Naklicki]

Hello all,

I have a few questions regarding Auto QOS SRND4 service policies. The only policy my switch created is service-policy input AUTOQOS-SRND4-CISCOPHONE-POLICY

Is this something I would want to configure on all my trunk links or should this input service policy only be applied to PC+Phone ports? 

Also for the following command 

"class AUTOQOS_VOIP_DATA_CLASS
set dscp ef
police 128000 8000 exceed-action policed-dscp-transmit"

Does this mean that I am "carving out" 128kbps for traffic marked with dscp EF on the applied port? So if this was say a 100mpbs port and I completely saturate it with default data traffic, I still have a reserved 128kbps for incoming EF packets. 

Thank you,

[Reza Sharifi]

Hi,

For trunk ports, you need this command to trust the DSCP marking.

 "auto qos voip trust"

As for the access port, I don't think you need to rate limit them with policy unless you have issues with phones not working as expected. 

HTH

[cmarva · Accepted solution]

try searching for "campus qos design" on cisco's site. This doc has a good explanation of how to configure interswitch links vs access ports, when using auto qos. 

as the last post stated, for a trunk link when using auto qos, the command is auto qos voip trust, whereas on an access port the command is auto qos voip cisco-phone, or cisco-softphone. There are a few choices. 

In my experience, as long as you use the right command on the ports you shouldn't have much worry. also please note that there are some differences in syntax per platform.

[Emil Naklicki]

Thank you, this does clear up a few things. It appears "auto qos trust" doesn't apply the service policy whereas "auto qos voip cisco-phone" does.

So is Auto QOS voip cisco-phone treated as a macro? How does this command differ from "mls qos trust device cisco-phone?"

Thank you