Resetting your Cisco phone is a quick and easy way to solve many issues, such as missing Transfer or Hold options, phantom voicemail indicator (voicemail light is on, but there aren't any messages), static, or inability to reach voicemail server when pressing the voicemail button: To reset a Cisco 8841/8851 (5-button desktop phone) to Factory Defaults, follow the instructions below: After that, your phone will reboot and get a new configuration file. It may take a few minutes to complete the process.