This article explains how to reset your Cisco 7945, 79 IP phone to factory defaults, and how to upgrade the firmware to the latest available version.
Upgrading your Cisco IP phone firmware is a very simple process.
Special consideration must be taken into account when upgrading to the latest firmware.
From the file name, we can understand that this is firmware version 9.1.1, for Cisco 79 SCCP IP phones.
Next, the firmware must be uploaded and unpacked on our CME router.
This means that it is necessary to have Call Manager or Call Manager Express setup so that the IP phone will be able to receive the new information (phone application and configuration) after the reset procedure is complete, because it is likely the IP phone will not be usable until this information is loaded.