VoIP & AutoQoS & frame/atm

[ciscosupport99]

I have 2 remote locations connected via frame/atm links currently with no QoS configs and potentially running VoIP. Is AutoQoS the simpliest and/or best solution, for voip communication across the WAN(frame/atm) if no other QoS is required ?

Thanks for your consideration -

[paolo bevilacqua]

No, I would recommend you manually configure QoS only after you have determined there is an actual need for it.

[Joseph W. Doherty]

" Is AutoQoS the simpliest and/or best solution, for voip communication across the WAN(frame/atm) if no other QoS is required ? "

"Simpliest", probably yes, "best", probably not.

For a fixed bandwidth inteface, such as a LAN port or WAN dedicated p-2-p port, a very simple QoS that prioritizes VoIP payload packets and guarantees bandwidth for signally packets, might be fine, but FR/ATM/MPLS WAN circuits often have other issues that AutoQoS won't likely deal with.

[Nicholas Matthews]

I'll admit that I haven't used AutoQoS on a WAN link, and definitely not on a FR/ATM interface.

I normally associate appropriate use of the AutoQoS command with L2 switchports, since the queueing on the switches is much more complex.

For routers, it's very simple, and there is a wider variance in how people use it.

In a very bare-bones scenario, you can get away with this:

class-map match-all voice

match protocol rtp audio

policy-map LLQ

class voice

priority percent 50

class class-default

fair-queue

int s0/0

service-policy out LLQ

You could make it more well rounded by matching on your VoIP signaling and other high priority traffic, but that's specific to your needs.

-nick