In the asterisk (www.asterisk.org) world the same $15,000 used for one sysmaster can get you two seperate systems with 8 T1/E1s each for a total of 16 E1/ T1s both systems with the following:
Heterogeneous Voice over IP gateway (MGCP, SIP, H.323, IAX)
Private Branch eXchange (PBX)
Custom Interactive Voice Response (IVR) server
Softswitch
Conferencing server
Number translation
Billing
Calling card application
Predictive dialer
Call queuing with remote agents
Remote offices for existing PBX
Voicemail server
Use regular phones, IP Phones, softphones, or all three
We dont have dongles that keep our systems from functioning.
IAX and SIP work flawlessly behind NAT. There is no one size fits all, if you need something custom built to fit YOUR specific needs the source code is INCLUDED so if you can’t find what you need, you can either have us build it or you can build it yourself!
Welcome to Open Source.
http://www.digium.com
http://www.asterisk.org
http://www.nufone.net