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.
Hosted PBX service provider in Canada.
http://pbx.tieus.com
Only $16.95/mo, unlimited calling to 20 major Canada Cities.
unlimited calling for your cell phone
http://www.magicnumber.ca