Use fax on a VoIP service
Voice over internet protocol (VoIP) services are often not compatible with fax machines unless the
provider explicitly states that it supports fax over IP services.
If the product experiences problems getting a fax to work on a VoIP network, verify that all cables and
settings are correct. Decreasing the fax-speed setting might allow the product to send a fax over a VoIP
network.
If the VoIP provider offers a "Pass through" mode for the connection, that will offer better fax
performance on VoIP. Also if the provider has "comfort noise" added to the line, fax performance can
be enhanced if this feature is not enabled.
If faxing problems continue, contact the VoIP provider.