Proprietary Protocols




Finally, let’s take a look at two proprietary protocols that are supported in Asterisk.

Skinny/SCCP

The Skinny Client Control Protocol (SCCP) is proprietary to Cisco VoIP equipment. It
is the default protocol for endpoints on a Cisco Call Manager PBX.† Skinny is supported

in Asterisk, but if you are connecting Cisco phones to Asterisk, it is generally recom-
mended that you obtain SIP images for any phones that support it and connect via SIP
instead.

UNISTIM

Support for Nortel’s proprietary VoIP protocol, UNISTIM, means that Asterisk is the
first PBX in history to natively support proprietary IP terminals from the two biggest
players in VoIP—Nortel and Cisco. UNISTIM support is totally experimental, and does
not work  well enough to put into  production, but the  fact  that somebody took the
trouble to do this demonstrates the power of the Asterisk platform.