Fax, modem, TTY, H.323 Clear Channel calls over H.323 IP trunks, and SIP 64K Data calls over SIP trunks

Last Updated : Sep 29, 2026 |
Prolog information
Communication Manager uses the Relay mode or the Pass-through mode to transport fax, modem, and Teletypewriter device (TTY) calls over IP interfaces. Communication Manager supports transport of the following:
  • TTY calls over the corporate Intranet and the Internet
  • Faxes over a corporate Intranet or the Internet
    Note:
    Faxes sent to non-Avaya endpoints cannot be encrypted.
  • T.38 fax over the Internet, including endpoints connected to non-Avaya systems
  • Modem tones over the Internet, including endpoints connected to non-Avaya systems
  • H.323 Clear Channel data calls over H.323 IP
  • SIP 64K Data calls over SIP trunks
  • Avaya devices are G430 and G450
Note:
Avaya no longer sells G250, G350, and G700.