Internet Fax - Fax Using Voice Over IP

Fax Using Voice Over IP

Making phone calls over the Internet (Voice over Internet Protocol, or VoIP) has become increasingly popular. Compressing fax signals is different from compressing voice signals, so a new standard (T.38) has been created for this. Using a (sending) VoIP adapter and (receiving) gateway which are both T.38 compliant, most fax machines can be plugged into the VoIP adapter in the same way as to a regular phone line. Not all fax equipment claiming T.38 compliance works reliably; in particular communicating with older fax machines (before VoIP began to be used) is problematic.

• Fax machine → VoIP adapter → VoIP gateway → Phone line → Fax machine (or vice versa)

As with regular faxes, only one fax can be sent or received at a time.