I Have installed a NEC IPK with an IAD card and 2 ip telephones. I can connect across the internet connection using sonicwall routers with vpn set up. The quality of the communication is not good. I have taken the server and workstations off local network just leaving 1 ip phone thinking bandwidth is issue. No change. I have changed the compression from 711 to 729 and no noticable change. I need help please.

First step. Set up your IP phones at the same site with your PBX. If it works back-to-back, you've got an internet problem. If it doesn't, you've got a programming problem.

If it's an internet problem, set it up PBX --> Router ---> router ---> phone. If it works, you've got an internet problem, if not, you've got a router problem.

Etc.

are you using analog lines? If so I had the same issues. Was only resolved when the customer got digital trunks.

when they had analog lines the persons using ip phones was getting "static" issues when making outside calls, but local calls had no problems