Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

Voice over ATM/Frame

Hello, I am trying to find out about doing centralized voice mail over my WAN.

I currently have a Frame to ATM network. With this there is no ability for QoS. I am taking a Frame connection and pointing it to ATM over IMA.

Is voice feasible over this kind of connection? Are any of you doing this?

New Member

Re: Voice over ATM/Frame

You can do this.

You can use frame relay fragmention and rtp header compression on the frame-relay side. This will dice up the frame relay packets into whatever size you wish. The ATM is already a nice 53 bytes. The rtp header compression you can do on both the ATM and frame sides. You can then map your COS (layer 2 packets) with DSCP values and then map that to an access-list. All of this will allow you to mark VOIP traffic and call control traffic and prioritize in/out the WAN ports. The ATM side sees the physical T-1s as one logical IMA interface so that really does not matter.