The 8520T voice/data terminal is used with the ISDN communication system through a 4-wire T-interface. The 8520T voice/data terminal offers the following:


  • 20 programmable buttons, ISDN terminal
  • 9 fixed feature buttons
  • Large supertwist LCD; 7-lines, 24-characters
  • Call logs keep track of 60 recent calls
  • Built-in speakerphone
  • Speakerphone which can also be optioned as a listen-only Speaker
  • Volume control
  • Improved acoustic quality with the K-type handset
  • Adjunct jack for adjunct equipment
  • Touch-tone dialing. Ten softkeys and four display control buttons located on either side of the Directory, a Call Log which lists the most recent incoming and outgoing calls, the Self-Test feature, and a personalized ringing pattern for the voice/data terminal.

System Requirements/Compatibility:

  • TN556B BRI ISDN line circuit card
  • Compatible with “custom” ISDN service from local service providers