Cisco 7940/7960 IP phones can support either the Skinny Call Control Protocol (SCCP) to run with Cisco CallManager, the Session Initiation Protocol (SIP) (refer to <XRef URL="http://ftp.isi.edu/in-notes/rfc2543.txt" Exit="yes">RFC 2543), or...More
Cisco 7940/7960 IP phones can support either the Skinny Call Control Protocol (SCCP) to run with Cisco CallManager, the Session Initiation Protocol (SIP) (refer to <XRef URL="http://ftp.isi.edu/in-notes/rfc2543.txt" Exit="yes">RFC 2543), or the Media Gateway Control Protocol (MGCP), but not more than one simultaneously.