Kamis, 19 Agustus 2010

Q&A with Commetrex on FoIP

Faxes provide still the most authenticated and reliable means of electronically sending and receiving critical documentation. Yet ever wonder why you can’t use a fax machine over data lines or via cable or DSL broadband installed at small or home offices to communicate to others outside of your organization? Thereby requiring you to keep a separate old-fashioned PSTN wires at added costs, using clumsy and expensive Internet faxing, or if faxes are used infrequently, making inconvenient and productivity-diminishing trips to the local office supply store or printer?

Mike Coffee, who is President and CEO of Commetrex has the answers, and some possible solutions. His firm has long been a leading supplier of fax technologies for the transition from traditional PSTN to IP fax, featuring products such as T.38 Fax Relay and TerminatingT38(which it had invented), T.30 Protocol and the V.34 Fax Modem.
TMCnet recently interviewed Mike about Fax over Internet Protocol or FoIP, which, if it becomes widespread can finally mean the end to the other, more expensive and/or less flexible means of faxing. Much like how VoIP has relegated PSTN for voice.
TMCnet:         What specifically is FoIP? Can it be used via wireless and WiFi (News - Alert) as well as over landlines?
MC:    To really define FoIP we need to begin by answering the question of “what is a fax?” It's one of those words used every day, but causes one to pause when asked to define it. It just happens to be a question that has come before a U.S. Federal judge, who defined “facsimile” as an image transferred in real time between two terminals that follow the facsimile protocols or standards.
The ITU (International Telecommunication Union) standards define a fax terminal as a device that allows an encoded image (as specified by T.4 and T.6) to be transmitted over the switched telephone network from one communications endpoint to another using the procedures defined in ITU recommendation T.30, the standard that defines the protocol fax terminals use to control the transaction.
So, FoIP is a fax, as defined above that transits, at least in part of its journey, an IP network. Today, IP networks can be over wireless, including mobile, Wi-Fi andWiMAX ( News - Alert)/LTE, as well as all forms of landlines. This means that an e-mail with an attached image file is not a “fax” since it does not use T.30: it's an e-mail.
TMCnet:         Outline and quantify the benefits of FoIP over both PSTN-transmitted fax and Internet fax
MC:    Global telecom is converging on IP as the transport of the future, which means that eventually the legacy PSTN will be an anachronism, thereby forcing users and service providers to either move to FoIP or to bear the expense of maintaining a separate network dedicated to fax. On a smaller scale, a business that uses IP for voice and data, must either use FoIP at only incremental cost or dedicate standard phone lines to fax, at typically $40 each per month in the U.S.
Another approach is to outsource fax send-receive by engaging a hosted fax-to-e-mail/e-mail-to-fax service. This can be cost effective for some businesses where fax is used casually, but is not applicable to businesses with certain fax applications and higher volumes.
TMCnet:         What is the status of FoIP in its adoption and deployment?
MC:    Early attempts to use IP as a fax transport too often met with failure. Fax terminals use high-speed synchronous modems to send image data over the PSTN. So, these modem signals had to be converted to encoded binary data to be sent over an IP network and then decoded at the opposite side of the IP network, just as was done for voice. But packets can go missing on an IP network, so the industry quickly developed packet-loss concealment techniques that effectively masked these imperfections for voice calls since our ears did a fine job of interpolating the received signal. Yet those fax modems just couldn't handle the lack of data integrity, causing image errors and failed transactions.
In October 1998, the ITU released T.38 version 0, which was designed to render any IP network transparent to the two endpoint fax terminals. T.38 specifies a protocol that gateways, situated on either side of an interposing IP network, use to eliminate lost packets and overcome the timing problems of using a packet network to substitute for a traditional network (the PSTN) that produces a smooth flow of modem data.
Nothing is ever quick thanks to inertia when it comes to telecom infrastructure, so the industry spent the next 10 years absorbing this new technology into enterprise networks, what we call T.38 deployment Phase I. Deployment of FoIP in enterprise networks allowed businesses to go to an all-IP internal infrastructure, with gateways employed to make the transition to the PSTN at the enterprise networks’ edges. Seamless internal IP networks delivered significant cost savings to businesses, especially when multiple offices were networked.
Yet it was only a matter of time--roughly 10 years--before those businesses wanted to push the borders of their IP networks beyond their premises with SIP trunking and/or direct IP peering with service providers and IP carriers...enter T.38 Phase II. During Phase I, service providers and carriers were busy adding T.38 support to their infrastructure. And, today with Phase II enterprises, equipment vendors and carriers are busy working out the inevitable problems associated with the interconnections between users, service providers, IP carriers and their peering partners across the globe.
TMCnet:         What, if any, is the lag between VoIP usage in businesses and at homes and the growth of it and FoIP? How are businesses and consumers that have switched over to VoIP meeting their fax needs and what issues and impacts is this creating?
MC:    With the relatively large scale of carrier networks and the degree to which they are interconnected via peering connections with other carriers compared with enterprise networks, there has been a 10-year lag between Phase I and Phase II. And, even though we’ve marked the beginning of Phase II, there will actually be a Phase II.V (2.5).
Today, FoIP calls that go beyond the metro or regional networks of CLECs and regional IP carriers, to national or possibly international destinations are carried by the tier-one IP carriers, such as Global Crossing, Level(3) andXO Communications ( News - Alert). The incumbent carriers are only now beginning to get involved. The layering of the incumbent PTTs on top of the newer IP carriers will take us to Phase II.V. Unless and until the carriers of all stripes work out their peering problems enterprise users will continue to be cautious in implementing FoIP expansion   to the wide area.
TMCnet:         What is holding FoIP back from becoming widespread? What are the key issues?
MC:    The number one hurdle for global deployment is just getting the FoIP infrastructure in place. The access gateways of service providers and the tandem gateways of the carriers must support T.38. Number two is probably what we call the “slow-network-signaling problem.” Other than its effect on customer satisfaction and resource utilization, slow call-set-up times in TDM networks wasn't and isn't a major problem, that is, it doesn't make the call fail. But with T.38 in SIP networks, slow network signaling can and does all too frequently make the session fail.
TMCnet:         Outline the steps being taken to resolve these matters. When do you hope to see them settled to enable widespread FoIP?
MC:    The slow-network-signaling problem is just becoming understood due to the combined efforts of the vendor-centric SIP Forum (News - Alert) FoIP Task Group and a similar group in the carrier-centric i3 Forum. In Q2 2010, the two organizations decided to work together to fully characterize the problems that manifest in FoIP calls that transit multiple IP networks. So far, 13 carriers have signed up to do inter-carrier co-operative testing on test platforms provided by the SIP Forum membership. We hope that the testing and data-collection phase will be complete by the end of the year. Analysis and recommendations should consume much of the first half of 2011.
Independently of our work with the SIP Forum, Commetrex (News - Alert) continues to work with our customers and carriers to resolve Phase II problems. That work has led to our applying for a patent on the techniques we developed for use in BladeWare and our T.38 relay package we license to ATA and gateway OEMs. We call the technology Smart FoIP, and it gives our customers FoIP-transaction success rates comparable to multi-line PSTN fax boards.
TMCnet:         Describe how BladeWare enables FoIP and its benefits to businesses, service providers and to their customers
MC:    Smart FoIP requires that a server support both T.38 and G.711 pass-through FoIP. The essence of the “invention” is that a server or gateway must be "smart" about whether it accepts a T.38 re-Invite. And if the re-Invite to T.38 is not accepted, the call will remain in G.711 pass-through mode. In a server, this means fax modems stand between the network and the T.30 protocol engine, not a T.38 stack.
BladeWare not only supports G.711 mode, but last quarter we announced BladeWare 2.0, which supports T.38 V3, the latest version, with V.34 fax. So BladeWare supports V.34 in both T.38 and G.711 pass-through modes, an industry first. V.34 modems are twice as fast as the older V.17 modem, cutting image-transfer times in half.

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