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.
TERRATEL is a company providing services of designing embedded electronic and computing systems and telecommunication equipment: a full range of customized electronic design services of any complexity.