: Indicates a Cisco CallManager terminal firmware installer. 7975 : The model number for the Cisco 7975G color IP phone.
From Cisco’s internal release notes (paraphrased): cmterm7975sip942sr4zip 2021
This firmware update is typically used to enable or upgrade SIP functionality on the 7975G model, which is often necessary when connecting the phone to third-party VoIP platforms like or FreePBX . It includes: : Indicates a Cisco CallManager terminal firmware installer
The cmterm7975sip942sr4.zip archive contains the Session Initiation Protocol (SIP) firmware release version 9.4(2)SR4 designed for the Cisco Unified IP Phone 7975G. This firmware allows the phone to register with third-party SIP servers (such as Asterisk, FreeSWITCH, or 3CX) rather than the proprietary Cisco Unified Communications Manager (CUCM). cmterm7975sip942sr4zip 2021