IP phones located offsite from CallManager could not access services and a "Host not found" error message was received

[TCC_2]

Core Issue

The user receives this error message when attempting to use either the Information or Services buttons.

The phone service parameters under the Cisco CallManager server parameters tab are using the Network Basic Input and Output System (NetBIOS) name.

Resolution

To resolve this issue, perform these steps:

1. Verify that the phones are actually hitting the Internet Information Services (IIS) web server log files on the Cisco CallManager. A host not found error message suggests it could be a network issue where the phones are not able to reach IIS on the Cisco CallManager.    
   
2. Verify that the phones are picking up the correct URL by going into the network settings on the phone. Depending on the phone, this can be achieved by selecting settings and then 3.    
   

   Scroll down through the list to verify these options:

      
   • The Domain Name System (DNS) server (if enabled as an option in your DHCP server) is correct.        
     
   • The services URL is the same as the one you configured in the Enterprise Parameters > URL Information option in Cisco CallManager. To avoid possible DNS or NetBIOS connectivity issues (particularly for remote locations), the URLs should preferably be the Cisco CallManager's IP address and not the hostname or NetBIOS name.        
     
   • Make sure that the default gateway settings are also correct, as per your DHCP server settings.

For other possible issues causing Host not found errors when attempting to access services,When user presses the services button, the IP phone displays the "Host Not Found" message.

In this case, the problem was associated with the remote devices not having NetBIOS connectivity to the central Cisco CallManager.

To resolve this issue, perform these steps:

1. Go to the Cisco CallManager Administration page and select System > Enterprise parameters.    
   
2. Change the URL services and URL information parameters to be the IP address of the Cisco CallManager rather than the NetBIOS name.    
   
3. Restart the CTFTP services.    
   
4. Reset the affected phones.

   Note: Removal of the Host not found error message indicates that the phones are now able to reach the IIS on the Cisco CallManager to which they were registered.