When Cisco IP phones in a CUCM Cluster have ITL or other security settings which are out of date, invalid, or mis-matched, this can cause a number of functional and operational issues such as:
- Phones are unable to de-register from one CUCM Cluster to another
- Phones are unable to download updated TFTP configuration file
- Phones are unable authenticate via HTTPS based Authentication URL
To recover from this situation, the ITL file on the phone can be deleted or erased via the phone’s administrative menu options. This process can be different depending on type of Cisco IP phone model and the firmware version it is running.
ITL File Delete Process for Cisco 7975 IP Phone
App Load ID: jar75sccp.9-3-1ES26.sbn
Firmware Version: SCCP75.9-3-1SR4-1S
Step 1) On the phone’s home/start screen, push the Settings button.
Step 2) From the Settings menu, select Security Configuration, which should be the 4th option.
Step 3) From the Security Configuration menu, select Trust List, which should be the 5th option.
Step 4) From the Trust List menu, unlock the phone by pressing Star-Star-Pound (*-*-#) on the keypad. Once complete, you should notice the unlocked icon in the upper right of the phone as shown here.
If the phone is already unlocked and showing this icon, you can skip the unlock process, as performing this will re-lock the phone if it is already unlocked.
Step 5) From the Trust List menu, select ITL File, which should be the 2nd option.
Step 6) On the ITL File screen, select the Unlock Softkey, which should be the 2nd Softkey option.
Step 7) Select the Erase Softkey, which should be the 5th Softkey option.
Note that this is where this process differs from Cisco 7945 and 7965 IP phone models, as only the 7945 and 7965 phone models do not have a 5th softkey (only 4 exist).
The phone should then indicate that it’s delete/erasing its ITL File and will likely reset/reboot.