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Illinois State University

Overview of Voice over IP (VoIP)

Voice over IP (VoIP) is a communication technology that allows telephone calls to be placed using a broadband network instead of a regular analog phone line.

Voice over IP (VoIP) is one type of telephone service available in campus offices, classrooms, and other areas at Illinois State University.

Telephone Models

Four models of desktop VoIP phones are available for use on campus:

  • Cisco IP Phone 7911 – A basic VoIP phone with a small screen
  • Cisco IP Phone 7945 – Standard office VoIP phone on campus
  • Cisco IP Phone 7965 – VoIP phone with six programmable buttons
  • Cisco IP Phone 7975 – VoIP phone with eight programmable buttons and a touch screen

The 7965 and 7975 can both accept an optional sidecar which contains twelve additional buttons, and each sidecar allows for two “pages” of buttons. In effect, one sidecar can store a total of twenty-four phone numbers.

For assistance with programmable buttons on the 7965 and 7975 models, contact Telecommunication & Networking.

Reporting problems

To get help with your VoIP phone, contact the Technology Support Center to open an Incident for your problem or issue. You can contact the Support Center by phone at 309-438-4357 or by email at

You must provide the following information:

  • Your name, ULID, and a contact phone number where you can be reached (which might be different from your VoIP phone number, especially if that phone is not working properly)
  • Building and room where your VoIP phone is located
  • Port number to which your VoIP phone is connected
  • Phone number of the VoIP phone that is experiencing problems

You can also report problems with your VoIP phone through the ITHelp Support Center website. To report an issue, please complete an Incident Report Form by clicking navigating to ITHelp Portal and clicking Get Help. Please provide the same information outlined above under the Reporting Problems section.

More Information

For more information on VoIP phone service, refer to the following:



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