The number climbs to just under 17.5 million users when 'soft-clients' like Skype and VoiceGlo are added in, according to John Bosnell, senior analyst at Point Topic.
"Japan is still the largest market by some way, [as} Yahoo Japan alone has more than 4.5 million VoIP subscribers," said Bosnell.
After Japan, the American cable sector is the most important, with around 2.1 million subscribers.
Bosnell says the major Canadian cable companies all have VoIP plans. Shaw launched in February 2005, with Rogers and Cogeco planning for the middle and end of the year respectively.