By now we know a lot of details about why HD voice calls are better than conventional phone calls. We've heard how the PSTN cuts off much of the audio range human conversation usually employs, making it hard to distinguish between fricatives such as s and f, and to understand people with different accents. We know that straining to fill in the words and phrases we can't understand produces listener fatigue and makes conference calls an ordeal.
All this information is evidence that the HD voice promoters have done a good job of getting the word out about their favored technology. But we don't have the same kind of information about why video calling is better than voice calling. The general assumption seems to be that everyone understands the benefit of video communication intuitively. In reality, understanding is limited, because detailed information is in short supply.
Continue reading "Why Video Conferencing Needs a Better Story" »
When AT&T responded late last year to the FCC's request for comment on the transition from circuit-switched to all-IP public telephone infrastructure, it seemed to mark a turning point in the history of telecommunications. The 30-page letter the telco filed on December 21 urged the total phaseout of POTS (traditional "plain old telephone service") and the PSTN (public switched telephone network) on which it runs. It also recommended that the agency set a firm date for the transition in order to ensure that it happen as quickly as possible. Thus the company whose name is virtually synonymous with traditional telephony seemed to cast a clear vote in favor of the all-VoIP future. In reality, though, it was just as much a vote against AT&T's traditional service obligations. It was also a shrewd attempt to bind the phone company's interests to the high-profile issue of universal broadband access.
Continue reading "Does AT&T Really Want to Get Rid of the PSTN?" »
There were more advances than true innovations in the VoIP world in 2009. That's because some of the most important developments had more to do with commercial and political maneuvers than with technical creativity. Still, such maneuvers often helped spread the benefits of VoIP as much as did technical innovation. And collectively, the advances brought some already-evident trends into clearer focus. A key such trend is the increasing integration of voice with other applications and services. Another is the intensifying interest in HD voice. A third is the growing interconnection of VoIP services, in part in response to the possibilities that end-to-end HD voice offers. With such trends as background, here, in no particular order, are our top 25 VoIP advances of 2009.
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TechCrunch reported this morning that Google has bought Gizmo5 for $30 million. Gizmo5 is a SIP-based Internet phone service that competes with Skype. Such an acquisition would make sense, given the already-close relationship between Google's Voice service and Gizmo5. One little-noticed effect of that relationship is that the combined services already allow free inbound and outbound calling to and from the PSTN via Internet-connected PCs with headsets. A formal acquisition would presumably make such calling even easier.
Continue reading "Google Voice-Gizmo5 Combination Means Free Inbound, Outbound Calling" »
SIP trunking services deliver voice calls from telecom providers to companies over IP data connections. Feeding their traffic directly into IP PBXes on the companies' premises, such services can bring considerable benefits. Sprint began offering SIP trunking to companies using Microsoft's Office Communications Server 2007 R2, an IP PBX software package that runs on Office servers, in February of this year. Now it's making the service generally available to business customers.
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AT&T's recent letter to the FCC about Google Voice was obviously disingenuous. It tried to link network neutrality, a key Google crusade, with Google Voice's blocking of certain calls. In reality, there was little connection except the politics involved: The real goal of the communication was to paint AT&T as on the side of network openness, and Google as on the opposite side. But the letter did inadvertently bring to light a potentially major weakness in the Google Voice model: the fact that the free service has to pay to have its users' calls delivered to their destinations on the PSTN (public switched telephone network).
Continue reading "AT&T Call Blocking Attack Reveals Google Voice Structural Problem" »
Skype business announcements are coming fast and furious these days. One big one was the introduction of Skype for Asterisk earlier this month. Others are the result of the introduction of Skype for SIP beta service in March. ShoreTel was the first to announce certification of its IP PBXes with that service earlier this month. SIPfoundry followed with certification of its sipXecs product about a week ago, and now Skype has added the biggest name yet: Cisco.
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VoIP and cellular services alike can do a lot of things that conventional landline services can't. For example, they can transmit both voice and various other kinds of data between phones or other end devices. That capability makes possible all kinds interesting combined services, often starting with or based on the ability to detect users' presence – that is, their availability to receive calls or respond to messages.
Once those services encounter the traditional phone network, or PSTN (public switched telephone network), though, they hit a roadblock. The PSTN can transmit only voice calls and limited kinds of call-related data. That means presence and other information, not to mention the various kinds of video or other data streams themselves, can't get through. A new deal between XConnect and the GSM Association, or GSMA, attempts to circumvent that roadblock.
Continue reading "XConnect and GSMA Open Way to VoIP-Cellular Interconnection" »