Panasonic KX-TGP500 Set Up And Usage Instructions page 6

4. Ensure you have latest Firmware
1. Download latest firmware from Panasonic
and save it to your desktop:
http://panasonic.net/pcc/support/sipphone/download/us.html
2. Log into the phone's web portal using the IP address obtained earlier
(example: http://192.168.1.10). Click the Maintenance tab, select "Local
Firmware Update." Click Browse upload the firmware files saved earlier.
3. The base station will flash red for 5 seconds. Once it turns back
to flashing amber you are ready for the final step.
Note: this step not necessary if you
ordered the phone from Voice Carrier.
6