IP Faxing Easily Explained
What is IP Faxing?
IP faxing occurs when fax machines, fax servers, MFP/MFD devices, PDA’s, email servers and any other fax enabled devices miscellaneous applications have the ability send or receive fax communications using an IP-based network. Existing within the backbone of the IP-based network and one or more of its gateways is the behind the scenes fax transmission communication protocols; T.30, T.37 and/or T.38.
IP Faxing with T.30
The T.30 protocol is the International Telecommunications Union (ITU) standard. This type of IP fax protocol is the primary building block used for IP fax transmission and early IP faxing solutions. The T.30 IP fax protocol defines page size, image type, transmission speed, tone frequency, communication, monitoring and validation requirements between devices and more. Additional technical detail regarding the T.30 IP fax protocol may be found here http://www.itu.int/rec/T-REC-T.30/en or http://www.soft-switch.org/spandsp-doc/t30_page.html.
IP Faxing with T.37
The T.37 protocol is the ITU standard for sending an encapsulated fax over an IP based network in a method called store and forward. The method is called store and forward because the fax document (defined by the T.30 IP fax protocol) is captured within an email format (SMTP, ESMTP, MIME) and delivered via the Internet.
One of the many reasons (besides minimum vulnerability points, virus exception, and difficult data interception) fax has survived since the explosion of the Internet is a fax sender and receiver can actually witness all phases of the fax transmission in real-time i.e. while they happen. The phases of a IP fax transmission are initiation, connection, validation, delivery, confirmation and call termination.
The creation of the T.37 IP fax protocol, improved computer technology, increased Internet bandwidth and explosion of email all contributed to the birth of IP faxing. New industry terms began to develop such as Internet fax, web faxing, faxing over the Internet and ultimately FoIP (Faxing over IP).
IP Faxing with T.38
The T.38 protocol is the ITU standard for sending a fax real-time over an IP based network. T.38 has multiple use-case scenarios for IP faxing. The T.38 IP fax protocol may be used as a gateway between two traditional T.30 fax devices where the origin of fax transmission begins over PSTN, is encapsulated by a T.38 fax gateway, converted back to T.30 by another T.38 gateway and then given back to the PSTN for fax communication and delivery purposes. T.38 may also be used directly between two T.38 enabled fax devices which by definition is true IP faxing. A third scenario includes a T.30 fax device, T.38 gateway and T.38 enabled fax device.
IP Faxing with SIP
SIP stands for Session Initiation Protocol. It is an RFC standard (RFC3261) from the IEFT. SIP is used to establishing, managing and terminating IP-based communication sessions for voice, video, instant messaging, conferencing and more. Its primary role in IP faxing is to provide a reliable transport mechanism from one IP fax enabled device or gateway to another.