Trixbox

Trixbox CE is an open telephony platform that combines the best of the open source telephony tools into one easy-to-install package. Based on an enhanced LAAMP (an open source bundle of Linux^®, Apache™, Asterisk^®, mySQL^®, and PHP), the trixbox^® dashboard provides easy to use, Web-based interfaces to setup, manage, maintain, and support a complete IP-PBX system.


Features

• Unlimited Extensions
• TDM/SIP/IAX Trunks
• Remote Extensions
• Voicemail
• Fax Support
• Voicemail to Email
• IVR Menu System
• Ring Groups
• Call Queues
• Conference Rooms
• Follow-Me
• Time-Based Routing
• Music On Hold
• Paging and Intercom
• Web Access to Voicemail
• Admin Status Screen
• Package Manager (for easy updates)
• Phone Provisioning Tool
• Network Settings Tool
• Enhanced CDR Reports
• Echo Cancellation - OSLEC (Open Source Line Echo Cancelation)

Link: http://www.trixbox.com