8/21/2007 -- The networking segment in general is in the midst of a protracted boom -- although some networking categories are hotter than others.

Consider the red-hot VoIP segment, which -- at $15.8 billion and growing -- amounts to a big enough market in its own right. According to market watcher Infonetics, VoIP revenues doubled between 2005 and 2006 and, if that isn't enough, should triple between now and 2010.

Residential services are fueling much of this growth, but business VoIP is also surging. Sales of hosted VoIP services are outstripping those of IP PBX services by a long shot, Infonetics indicates, with worldwide revenue from residential hosted VoIP services exploding by 68 percent from 2005 to 2006, while sales of managed IP PBX services grew by 45 percent.

Residential or SOHO VoIP subscription growth, in particular, is also on the rise. The number of worldwide residential/SOHO VoIP subscribers almost doubled between 2005 and 2006, approaching 50 million. Nearly half (46 percent) of these are located in the Asia-Pacific region, which has long been a hotbed of VoIP adoption.

That's changing, too. For example, Infonetics points to surging VoIP adoption in non-traditional locales.

"Asia-Pacific has been leading the VoIP services scene for a couple of years, with Japan's SoftBank pioneering the service and taking a strong lead, but the EMEA and North America regions have gained some ground at the expense of Asia in the last two years. The Latin American-Caribbean region is also posting impressive growth and gaining share," said Infonetics principal analyst Stéphane Téral in a statement.

SoftBank is the world's biggest VoIP service provider, serving almost 18 percent of VoIP subscribers. Rounding out the top five are (in order) NTT, Vonage, France Télécom and Time Warner Cable. --Stephen Swoyer