Core Issue
This issue occurs when you have the hostname not configured correctly as recommended in Installing the Operating System on the Cisco IP Telephony Applications Server Guide.
For example, if the hostname has an underscore, it can cause issues since it is an invalid character for the hostname on Cisco CallManager.
Resolution
Refer to Installing the Operating System on the Cisco IP Telephony Applications Server Guide for more information.
From the document:
Computer Name
Ensure that the computer name comprises a unique network name of 15 characters or less. It may contain alphanumeric characters and hyphens (-) and must begin with an alphabetical character. Make sure that the computer name and workgroup labels follow the rules for ARPANET host names.
Labels must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphens.
- Ensure the computer name is unique to your network.
- Ensure the computer name is not longer than 15 characters.
- Do not include a space anywhere in the computer name, including leading or trailing spaces. Do not use the following characters and symbols, which are not valid entries in computer names: \ " / [ ] : | < > + = ; , ?.
As a workaround, you can also use the IP address instead of the hostname when accessing CallManager.
Refer to Cisco Unified Communications IP Telephony Release 5.0. for more information on installation and configuration checklists.
