07 Feb FoIP Presentation at ITEXPO East 2011
Here’s a summary of my talk at ITEXPO given on 2/3/11.
“Telefacsimile” went commercial 150 years ago. Seems like yesterday, doesn’t it? G3 fax, made possible by the microprocessor, is now 31. And T.38 turned 12 last October … a mere kid. So, for those of you thinking fax will soon go away, don’t hold your breath. After 150 years, it’s kinda established in the world of business and telephony. And now, it’s just beginning to work its way onto IP-carrier networks. Here’s the deal: the incumbent carriers know the global telecom network must soon transition to an all-IP transport, and that transition cannot complete unless and until real-time G3 and Super-G3 fax can be reliably transported by their IP networks.
For 13 years, T.38, the ITU standard for real-time IP fax, has been incubating in enterprise networks. It’s been used for intra-enterprise gateway connections, ATA-to-gateway routes, and to allow T.38-capable fax servers to connect with the PSTN. But the boundary of the IP T.38-based fax was the edge of the enterprise network; it didn’t venture out into the wide area. T.38 Interoperability was accelerated by Commetrex’ T.38 Interop Test Lab in 2002-2004. Then, there were numerous SIPit events sponsored by the SIP Forum. And if an interop issue did arise in the enterprise network, the customer could crack the whip and get the two vendors involved to work things out. We call this T.38 Phase I.
But here we are in Phase II. SIP trunking and direct SIP peering by mission-critical fax servers have pushed the boundaries of SIP and T.38 beyond the enterprise network and into the service-provider domain and from there to the IP carrier. Goodbye comfortable Phase I.
Some early adopters of T.38 in ITSP applications, after being frustrated by the lower-than-PSTN fax-transaction success rates, devised proprietary solutions to the problem. Early on, Cisco offered gateways with built-in fax send-receive. Clients and servers within the IP network would use non-real-time carriage, such as T.37, between the gateway and the user. Others offer ATAs that do essentially the same thing by terminating the premises fax terminal’s fax in the ATA, and e-mailing it to a hosted server. Still others have proprietary ATAs that use HTML-like protocols to convey the fax in near real time to hosted servers capable of handling the proprietary protocol. But the need for these stop-gap proprietary techniques will be obviated by a solution to the tandem-carrier signaling problems now being encountered in many Phase II deployments. This is the current goal of the SIP Forum’s FoIP Task Group (TG).
The TG, formed in September 2008 with a goal of resolving the Phase II and lingering Phase I problems, has produced proposals to the ITU, which have been accepted, that improve T.38, and have been included in the 2010 update to the standard. We have also developed the procedures necessary to move to effective T.38 V3 with V.34 support. Now, the challenge is to solve the problems encountered when several carriers are involved on a fax call and the session attempts to switch from G.711 to T.38. But, the equipment vendors, which make up the bulk of the TG membership, can’t solve the problems without the complete cooperation of the carriers; the carriers can’t solve the problems without the equipment vendors.
In 2008, 36 carriers, operating in 80 countries serving over 1.5-billion subscribers, formed the i3 Forum. The goal of the i3 Forum is to develop collaborative recommendations for the coming industry-wide transition of voice and related services to IP. According to the i3 Website: “The forum’s effort to expedite global IP-based voice implementation will enhance worldwide communications by supporting widespread access to innovative high-quality IP-based services and applications.”
At a joint I3 and SIP Forum TG meeting in Warsaw held in June 2010, the two organizations decided to work together to solve the problem. The critical agreement was to conduct joint testing to measure the extent of the problems, their cause, and, ultimately, their solution.
Commetrex agreed to provide its BladeWare telephony platform with both T.38 and G.711 pass-through support. Copia International, a fax-server OEM that bases its product on BladeWare, offered to provide its CopiaFacts server and to assist the i3 carriers in installing it to access their IP networks. Today, that has been accomplished at 14 different carrier locations. And testing has begun.
We are working to complete the initial round of tests in Q1, analysis in Q2, recommendations in Q3, and retest in Q4.
Stay tuned for more updates in the coming days.