On Cisco 7960 IP Phones, press the information button twice (this is the "?" or the "I" button, depending on the model you are using).
This following table lists troubleshooting FAQs and recovery tips.
When the power is back up, verify that the machine comes back up properly and that the network is available.
For CTI OS, start the CTI desktop and login to the CTI OS server. For Remote Option with IP Phone configuration, the IP Phone needs to contact the TFTP server and register with Unified CM.
Note: UPS can mitigate the risk of a power failure at home by keeping the cable modem and agent's PC powered up for a certain duration.
If the internet goes down, the connection is lost and the agent goes offline.
For CTI OS, when the internet is back up, the agent must re-connect to the CTI OS server and log back in. For Remote Option with IP Phone configuration, the IP Phone will also be disconnected and needs to be reconnected with Unified CM.
Reconnection of the phone to the desktop
Connect the desktop to the IP Phone's second switch port, then connect the IP Phone to the 800 Series Router.
Agent Desktop reboot
See Power failure, above.
Agent Desktop Application restart
Restart the application and log back into the server. If a call is still in progress, do not change the state to Ready.
IP Phone registration failure
Verify that the Internet is available, followed by the network. If yes, check if the TFTP server and Unified CM are online.
VPN tunnel failure
If Internet access is available, but the connection to the corporate site is not, verify that the VPN tunnel is not misconfigured / broken. If it is broken, it will have to be reconfigured by the System Administrator.