Wayne State University

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Knowledge Base

[VoIP] How do I call people in a different phase of the telephone upgrade?

Five-digit dialing does not function between Centrex (Wayne State University's old telephone system) and the new VoIP system. If you are calling a user who is on a different phone system, dial the full number as if you are calling a line outside of WSU.


Example: If you previously dialed 7-1234, you will now dial 9-1-313-577-1234


If you attempt to five-digit dial

  • From a Centrex number to a VoIP number: You will hear a fast busy signal.
  • From a VoIP number to a Centrex number: You will receive an error message.

NOTE: Despite the phase of the phone system update, dialing a full phone number will always function. Check the VoIP Timeline to see which buildings are functioning on Centrex or VoIP.