ICTContact is built over open source Asterisk PBX as back-end telephony server. It supports SIP, IAX2 and DAHDI technologies. Furthermore, ICTContact supports almost all free codecs.
![asterisk application](https://www.ictbroadcast.com/sites/ictbroadcast.com/files/ictbroadcast-sshots/images/multi-technologies.png)
Asterisk PBX supports both SIP, IAX2 and DAHDI technologies. That is why ICTContact has been designed to support all the widely used VoIP technologies with built-in support. Furthermore, ICTContact also support almost all free codecs. This feature makes ICTContact one of the best auto dialer software that support all major VoIP technologies including SIP, IAX2 and DAHDI.