Aculab, a leading provider of enabling technology for the communications market

What the market needs

Even in our email dominated world, fax transmission is still a key application for many enterprises. However, the distinction between sending a fax and sending an email is blurring due to technological advances. Desktop fax, where the fax application resides on each user's PC and the fax transmissions are completed by sending/receiving the fax using standard email clients, is now commonplace.

Any fax system must offer reliability and high functionality to meet the needs of SME and corporate users at the best price. A fax server intended to replace standalone fax machines should be easy to install, require little maintenance and integrate with existing messaging clients such as Microsoft Outlook.

For enterprises migrating to IP-based PBXs but wishing to keep their existing fax machines, another problem arises - how to connect the analog based fax machines to the IP network. The solution comes in the form of a gateway to translate between the TDM and IP worlds. The gateway should seamlessly integrate the fax machines into the enterprise IP network, and offer high reliability and flexibility to interoperate with different vendors' fax machines and IP PBXs.

Aculab technology for fax solution developers

Aculab's Prosody X media processing boards and Prosody S software for host media processing architectures can provide the enabling technology for communications system developers to create solutions to integrate fax transmission with IP networks.

Specific areas where the Prosody portfolio is applicable are:

• Fax servers
• Fax-to-email servers
• T.30-to-T.38 fax gateway
• Fax broadcasting
• Fax-to-email / desktop fax
• Fax relay
• Fax over IP (FoIP)

The example shown in the figure is a hybrid solution using fax gateways to enable the re-use of existing fax machines and fax server technology to replace standalone fax machines and integrate fax and email; this example is typical of a bank or financial institution with a headquarters and multiple branch offices.

The scalability of the Prosody portfolio has also been used effectively to build hosted fax server applications. With the ability to support up to 960 fax transmit channels (512 receive channels) per board, a large scale hosted fax server application can be built in a cost and space efficient manner. For the more DSP resource intensive V.34 fax protocol, a Prosody X cPCI media processing board still supports an impressive 320 transmit channels.

Class leading interoperability

For any benchmark figure to be meaningful, a common method has to be employed in producing results. With fax, there are many legitimate reasons for a transmission to fail and these should be factored out when comparisons are sought. The most significant factor is the time of day. Many fax machines are switched off outside business hours and, at certain times, as little as 20 percent of faxes can make it through.

Also, an obvious problem is that the published number no longer exists or has changed use and is answered by a person. Additionally, network line issues, such as signal-to-noise ratio, echo cancellation and attenuation, affect the success or otherwise of any fax transmission. And finally, there is fax machine compatibility.

The T.30 fax protocol is a recommendation rather than a standard and much of it is commonly violated when implemented in fax terminals. With over 100 million fax machines in existence and many in use that are 10, 15 and even 20 years old, it is practically impossible to achieve interoperability with every conceivable machine. Indeed, industry experts suggest that a figure exceeding 80 percent is commendable.

Profitably for developers and service providers, Aculab's fax capability is second to none. In any like-for-like scenario, where compatibility is the sole issue, a fax transmission success rate of 95 percent is the interoperability challenge for competing products.

For more information see the fax application note.

For more information on the Prosody portfolio visit the DSP-based processing or host media processing pages. 

Aculab's partnership approach

When you decide to partner with Aculab, the leading-edge products are just the start of what we offer. Complementing the product range, we offer customers a solid vendor partnership in the field of professional services, ongoing development and support, based on our in-depth expertise and experience. The foundation of Aculab's approach is our industry-recognised agility and willingness to meet and exceed customer's demands.

We focus on our customers recognising that their success is our success and we are willing to listen and invest in the technology they need to achieve their goals. One of the key areas that sets Aculab apart is our ability to respond to customers near term requirements through our Request for Change (RFC) process. We were asked to add the faster V.34 fax protocol to our existing fax protocol support on the Prosody portfolio. Our target was based upon the customers' expectation that 100 channels per board would be required to meet the platform performance targets, a figure un-available from alternate solutions. We were able to far exceed all expectations by delivering 160 V.34 fax channels per board.

Visit our partners section for a list of partners offering fax platforms based on Aculab's technology.

Visit the case studies page to see how some of our customers have used Aculab products to develop fax server/gateway solutions.

Prosody media processing portfolio for fax systems:

Group 3 fax and image compression conformance

Aculab's Group 3 fax conforms to the following ITU-T and IETF specifications:

• V.21	300 bits/s for T.30 fax negotiation

• V.17	7200; 9600; 12 000; and 14 400 bits/s

• V.27ter

  2400; and 4800 bits/s

• V.29	7200; and 9600 bits/s

• V.34	up to 33 600 bits/s

• ECM	Error correction mode - transmission and reception supported

• RFC2306

  Group 3 TIFF

ITU-T data modems are also available to developers for use independently, using the TiNG architecture and the data communications API for the Prosody family.

Images can be received or transmitted in TIFF format using the following compression algorithms according to ITU-T recommendations:

• MH (1D)

  Modified Huffman data compression (ITU-T T.4)

• MR (2-D)

  Modified Read data compression (ITU-T T.4)

• MMR	Modified Modified Read data compression (ITU-T T.6); ECM only

Supported products and typical performance