Toshiba Phone System

Can I use VOIP on my internal network without outside service?

I need a pbx style phone system in my business but I dont have the funds for a traditional system. I have a wired/wireless ethernet system already installed throughout my business and was wondering if there was a way to use IP phones through the network internally without an outside VOIP service provider?

Public Comments

1. If you have a pbx you already have internal extensions. To run voip you would need to install a sip server, this will be very expensive.
2. Asterisk for Linux uses SIP and the proprietary AIX protocols for their servers. http://www.asterisk.org/