Plenty of business companies use free Asterisk software and place it on their server, thus creating a cut-rate IP-PBX. They use manuals provided on setting up the extensions, and occasionally there are lots of discrepancies. Finding out how to install a dial plan or call flow, the set of regulations detailing how the switch deals with inbound and outbound calls is very difficult.
PBXMate software Sip Trunk for improving Audio Quality. Removes noise originated from external mobile phones or from the call center, keeps audio level at a comfortable level and removes echo.