TMCnet - World's Largest Communications and Technology Community




Enterprise IP Fax

By: Richard "Zippy" Grigonis

Fax-over-IP (FoIP) presented a problem when it was first attempted years ago. Fax machines were devised to send documents over analog networks by transmitting certain tones (the T.30 protocol), none of which work well with the voice-optimized codecs used in enterprise VoIP phone systems, unless you’re using the ancient G.711 codec, which doesn’t really involve compression at all, just digitization.

Aside from installing an analog line just for your fax machine, or junking your fax machine and using a less expensive fax service provider, you could use a T.38-compatible gateway and fax machine, or a plug-in fax board and fax software for your PC or dedicated fax server. (The T.38 protocol is described in the Internet document, RFC 3362.)

Actually, there are two basic ITU recommendations for fax transport over IP networks: T.37 and T.38 fax. T.37 specifies how a fax image (basically a TIF file) is encapsulated in email and transported to its destination using a store-and-forward technology. The T.38 fax protocol, however, defines the more familiar method of sending a fax in real time over an IP network just as one would with analog lines and the PSTN network. It does this by placing translating “fax relay” hardware or software between each fax terminal (fax machine or PC) and the packet network.

Commetrex (News - Alert) is a company that has developed highly refined fax relay protocols over the years. Their TerminatingT38 is a combination of its ITU T.38 fax and T.30 ITU fax protocol engines, a package that gives the developer of a network-service platform or an enterprise fax server the technology necessary to terminate T.38 fax (IP network) real-time fax transmissions just as one would real-time faxes from the PSTN using analog modems. When combined with Commetrex’ stand-alone T.38 fax, a developer can now implement both terminating and standard fax-gateway functions on the same platform, combining the functions of the service platform and the gateway.

Commetrex’ TerminatingT38 is available as licensed source code for incorporation into proprietary systems. TerminatingT38 makes no assumptions regarding the connection setup, such as H.323 or SIP, nor does it assume a particular API for the application software. Interestingly, one of the legacy fax terminals (e.g. a fax machine) can be removed from a fax system and Commetrex’ TerminatingT38 substituted so that the fax terminates in the service platform rather than a fax terminal. Commetrex has developed a version of its PowerRelay T.38 fax gateway product that, rather than relaying the fax to the PSTN, terminates it in TerminatingT38’s server-based T.30 protocol engine.

In terms of hardware, Brooktrout (later called Cantata, now part of Dialogic (News - Alert)) were long the masters of fax boards. Take for example the Dialogic Brooktrout TR1034 Fax Board, a high-performance, intelligent board that offers both TDM- and IP-based fax capabilities. Available in both PCI and PCI Express (PCIe) formats, the Brooktrout (News - Alert) TR1034 can be found in various network- based fax applications and can be integrated with document management and business process automation systems to support compliance with regulations such as Sarbanes-Oxley, HIPAA, and Basel II. The board provides a migration path from traditional TDM-based fax systems to hybrid and all-IP fax systems. In addition, Dialogic works with leading IP-PBX (News - Alert) and gateway vendors to ensure fax interoperability.

The Dialogic Brooktrout SR140 is a software-only IP fax platform, providing the ability to integrate fax servers and fax document management solutions with a corporate VoIP network. The SR140 supports both SIP and H.323 and has been tested and certified with IP- PBX and VoIP gateways from leading vendors including Cisco (News - Alert), Avaya, Alcatel Lucent, and Quintum. The SR140 is suitable for a variety of fax server applications including document management, business process automation and compliance with regulations such as Sarbanes-Oxley, HIPAA and Basel II. The SR140 is available in densities ranging from 2 to 60 channels and can support up to 120 ports in a single server.

Partnerships and Alliances

The SR140’s FoIP capabilities are supported by FaxCore’s fax server, which is built on the Microsoft (News - Alert) .Net platform and conforms to a Web Services architecture. By leveraging ASP.NET Web Controls, the functionality normally associated with a fat client is available to both users and administrators through Microsoft’s Internet Explorer browser, so there’s no software to deploy and you don’t have to be at your PC to send a fax, or administer the system. Aside from the pure web browser interface, there’s also SIP integration, total Microsoft Exchange compatibility, Active Directory integration, SQL compliant database, converged IP and support for Cisco’s Call Manager that are all standard features.

AudioCodes (News - Alert) also has been heavily involved with FoIP. Their product line includes enabling technology products such as Voice over Packet chip processors, VoIP PCI and cPCI communication boards and VoIP media gateway modules (PMC form factor) and Analog Media Gateways (for 2, 4, 8 and 24 ports). In particular, their VoP Chip Processors (VoPP) are equipped with low bit rate vocoders, a state-of-the-art echo Canceller and T.38 compliant fax relay. These VoP processors are intended for high and medium density gateways, residential gateways and Integrated Access Devices (IAD), and for client applications such as small gateways and IP phones.

Also, by using AudioCodes’ MediaPack 11x media gateways, enterprises can connect existing, analog fax machines to their new VoIP network and IP PBX platforms utilizing industry standard control protocols such as H.323, MGCP and SIP. The interconnection can include thousands of faxes deployed in enterprise branches, connected to the enterprise IP network and to the PSTN. Additionally, developers can leverage the T.38 Fax-over-IP protocol and AudioCodes’ TP-260/SIP media gateway to devise advanced fax applications that can connect to existing PSTN circuits or PBX equipment. The TP-260/SIP provides the required connectivity and conversion to enable T.38-based fax applications in a range of customer deployments, avoiding expensive dedicated fax blades.

Indeed, for the past few years AudioCodes has had a strategic relationship with IP fax server solution provider Sagem Interstar (News - Alert) Corporation. To help push its products further into enterprises and call centers, AudioCodes supplies its media gateway products to Sagem Interstar to deliver VoIP media gateway solutions to Sagem (News - Alert) Interstar’s highly popular XMediusFAX T.38 FoIP fax server application and its customers. Sagem Interstar’s XMediusFAX fax server software delivers to organizations inexpensive desktop email faxing and fax broadcasting. It enables users to send and receive faxes directly from their existing email clients or networked T.37-compliant multifunction devices. Integrating AudioCodes TP-260 SIP media gateway products with XMediusFAX provides a cost-effective solution employing T.38 Fax-over-IP for organizations of all sizes. Incidentally, Sagem Interstar recently announced that its XMediusFAX Release 5.5 boardless (software-only) T.38 Fax over IP (FoIP) server solution is now rated “Avaya (News - Alert) Compliant” with Avaya’s Communication Manager 4.0.1. XMediusFAX Release 5.5 is truly boardless fax server software that interoperates with Avaya Communication Manager VoIP gateways without the added expense of fax boards and third-party software kits.

One of the legends in the fax server and FoIP business is Captaris (News - Alert), a company that came about as a result of the merger and acquisition of a bundle of companies including AVT and Infinite Technologies. The main product line, Captaris RightFax, is installed in all of the Fortune 100 and many Global 2000 companies. Captaris has taken its business far beyond simple faxing and is now a leading provider of software products that automate business processes, manage documents electronically and provide efficient information delivery. The products of Captaris and its subsidiaries Castelle (News - Alert) and Captaris Document Technologies GmbH, including Captaris RightFax, Captaris Workflow, Captaris Alchemy, the FaxPress line of products, RecoStar, DOKuStar, DOKuStar Capture Suite, Single Click Entry, ID-Star, BUSY, Invoice CENTER, Tax CENTER, and Mail CENTER are distributed globally through a network of technology partners.

Captaris also provides architectural consulting, custom deployment, integration services to third-party technologies, training and other services. These services are offered as an extension of the capabilities of the company’s channel partners.

Add IP, Mix Thoroughly

Migrating to Fax-over-IP can be done without a forklift upgrade. Multi-Tech Systems’ MultiVOIP Voice/Fax over IP gateway allows for the integration of fax onto, say, Mitel (News - Alert)’s IP communications infrastructure, such as the Mitel 3300 Integrated Communications Platform (ICP) that provides enterprise IP-PBX functionality to small, medium and large enterprises with multiple locations. The MultiVOIP gateway connects a traditional fax machine to an IP network and calls upon the T.38 protocol to provide real-time faxing over a distributed IP environment, thus reducing toll charges when faxing between inter-office locations.

“MultiVOIP” is a point-to-point solution — one is needed at each location — that merges voice/fax from traditional phone/fax equipment, onto the IP network. The sending fax machine sends a fax using traditional modem modulation to transport the T.30 protocol and image data to the MultiVOIP. This information is then encapsulated and transported across the packet network using the T.38 protocol. At the receiving end, another MultiVOIP gateway separates the fax from the IP network and sends it to the receiving fax machine. MultiVOIP allows companies to cost-effectively turn their fax machines into IP devices to provide complete inter-office communication within a distributed network environment. This solution allows a business to completely eliminate their recurring long distance charges (when faxing other locations) because their faxes ride for “free” over their data network.

Similarly, Venali (News - Alert)’s Email-to-Fax and Fax-to-Email Internet Fax Desktop Solutions, and Internet Fax Production Solutions, including Production Fax and Web Services API, can be made to integrate seamlessly with the existing infrastructure of any size enterprise. In this way Venali provides complete Internet Fax messaging solutions over secure IP. Thanks to Venali’s integration abilities, companies can immediately benefit from a fax solution that’s rapidly deployed. Their methodology also leverages your existing IT infrastructure since it avoids investment and costly upgrades of in-house hardware, software, dedicated fax lines and maintenance. Users enhance their business communications by sending and receiving faxes over their existing communications platform to anywhere an internet connection is present worldwide.

Rather than becoming extinct, fax is more important and popular than ever. IT

Richard Grigonis (News - Alert) is Executive Editor of TMC’s IP Communications Group.


The following companies were mentioned in this article:

Audiocodes (

Captaris (

Commetrex (

Dialogic (

FaxCore (

Mitel (

Multi-Tech Systems (

Sagem-Interstar (

Venali (


» Internet Telephony Magazine Table of Contents

Today @ TMC
Upcoming Events
ITEXPO West 2012
October 2- 5, 2012
The Austin Convention Center
Austin, Texas
The World's Premier Managed Services and Cloud Computing Event
Click for Dates and Locations
Mobility Tech Conference & Expo
October 3- 5, 2012
The Austin Convention Center
Austin, Texas
Cloud Communications Summit
October 3- 5, 2012
The Austin Convention Center
Austin, Texas