Call quality issues

FreePBX version: 2.9.0.9
Asterisk version: 1.6.2.20
VOIP provider: XO Communications
Service: 3MB/SIP
Issues: Inbound/outbound garble/jitter.

We’ve been struggling with our VOIP provider over QoS/CoS implementation. We do not have access to their router, and they will not give it due to security reasons, etc. They claim that QoS/CoS is properly configured, but we are having consistent call quality issues (garble/jitter) when a user initiates a download (for example). We never have more than (8) simultaneous calls going, and we are nowhere near using our bandwidth limit. Our provider claims saturation is causing this issue, but then again whats the point of QoS/CoS when voice is supposed to have priority over data?

We’ve been going back and forth with all levels of support. They keep saying that their configuration is on point, and that there is no issues with their circuit, or their hardware. Any advice or recommendations would be greatly appreciated. Thank you.

P.S. We can’t drop them yet due to contract.

What is your connection form you site to the VoIP provider? Is it over the Internet? There is no QoS on the Internet.

Hello Alan,

The service is a 3MB/SIP (two T1’s) which runs over AT&T lines. QoS/CoS is implemented at XO’s router, which is onsite. The router has an external IP, which I can ping from the outside. Does this answer your question?

Check you lan. Make sure that you are using good quality switches. We use the new Cisco switches with QOS. They work great. Think about seting up vlans. If you can’t controll their router then install one of your own and have them put the public IP on the router that you just installed. Make sure you choose a quality router that you can controll the QOS with. With a good router you can setup vlans on it so that data and voice are on different lans.