Set up a Cisco 8800 phone
Register a 8811, 8841, 8845, 8851, 8861 and 8865 phone to your phone system.

These steps cover the 8811, 8841, 8845, 8851, 8861 and 8865. If your phone system supports auto-provisioning, use that instead.
Steps
- Go to Settings → Status → Network status to find the IP address.
- Open the IP in a browser, click Admin Login, then Advanced.
- Go to Voice → Ext 1 and enter the proxy, user ID and password.
- Click Submit All Changes.
- Set an admin password under Voice → System.