Fax over IP (FoIP)

Fax over IP (FoIP) enables ordinary fax machines to communicate reliably over IP networks. Fax continues to be a workhorse in the office, with a dedicated fax machine offering the simplicity of feeding a hardcopy document “as is” and transmitting the image to an unattended destination. Fax transmission is so vital that networking technologies must continue to support it, i.e. FoIP and Fax over wireless networks. FoIP enabled devices using T.38 allow Group 3 and high speed V.34 facsimile machines to send faxes over the internet by relaying calls through a VoIP service, while legacy non-FoIP enabled devices can work over IP using ATAs and VoIP adapters.

VOCAL’s Fax over IP software is optimized for performance on X86/X64 Windows and Linux servers, and leading DSP architectures from TI, ADI, AMD, Intel and other vendors. VOCAL has been producing Fax Software for more than 20 years, and has deployed millions of fax ports, currently transmitting hundreds of millions of pages a month.  Contact us to discuss your specific FoIP application requirements.

Fax over IP Methods

VOCAL offers a variety of Fax over IP methods for transmitting facsimile communications over IP networks: fax pass-through, store and forward, and fax relay. Fax over IP treats facsimile transfers as simple data, which may be packetized and transmitted in real time over IP networks. Audio is digitized at (or near) the source. The data packets are transmitted over IP networks using Fax over IP protocols, and demodulated at the destination.

The fax pass-through method transmits the facsimile signals over IP networks as voice band data (VBD) / audio  – compressed with a suitable codec, such as G.711. The relay method, on the other hand, demodulates the incoming facsimile data at the gateway and transmits the pertinent information over an IP network as T.38 Protocol data packets to the remote gateway where it can be modulated and sent directly to the remote facsimile machine. Store and forward systems, demodulate the pages locally, and send them as email or HTTP to the destination.  T.38 and V.152 protocols offer different advantages when performing facsimile transfers using FoIP. 

Fax over IP Software

VOCAL’s Fax over IP software also includes our VoIP software suite in a fully integrated and highly configurable FoIP solution with a Network Stack, SIP Stack, full-featured Telephony software, and a complete fax modulation and fax modem software library.