Cisco 7920 Administration Guide - Page 193

Chapter 9 Troubleshooting the Cisco Wireless IP Phone 7920 Resolving Voice Quality and Roaming Problems Verifying that the Phones Have Not Been Intentionally Reset If you are not the only administrator with access to Cisco CallManager, you should verify that no one else has intentionally reset the phones. Eliminating DNS or Other Connectivity Errors If the phone does not register with Cisco CallManager, check to see if you are using host names or IP addresses for Cisco CallManager servers. To eliminate DNS or other connectivity errors, follow these steps: Procedure Step 1 Step 2 Step 3 Reset the phone to factory defaults. See the "Erasing the Local Configuration" section on page 9-22 for details. Modify DHCP and IP settings: a. Disable DHCP. See the "Modifying DHCP Settings" section on page 5-4 for details. b. Assign static IP values to the phone. See the "Configuring Static Settings" section on page 5-6 for details. Use the same default router setting used for other functioning Cisco IP Phones. c. Assign a TFTP server. See the "Configuring TFTP Option" section on page 5-9 for details. Use the same TFTP server used for other functioning Cisco IP Phones. From Cisco CallManager, choose System > Server and verify that the server is referred to by its IP address and not by its host name. Note Cisco recommends that you configure IP addresses only and not host names to eliminate the DNS resolution in the phone registration process. OL-7104-01 Cisco Wireless IP Phone 7920 Administration Guide for Cisco CallManager Release 4.0 and 4.1 9-13