International voice traffic growth declined significantly last year, likely at least in part as a result of competition by VoIP provider Skype, research shows.
TeleGeography estimates that ILD traffic growth was just 4% last year, well below the long-term average of 13% annual growth.
By contrast, cross-border Skype-to-Skype calls increased 48% during the year to around 145 billion minutes.
The 47 billion additional minutes of voice traffic represents a growth rate of more than twice as much as all the telephone companies in the world combined.
TeleGeography analyst Stephan Beckert said considering the figures, it would be hard not to conclude that Skype's growth came at the expense of operators.
“If all of Skype’s on-net traffic had been routed via phone companies, global cross-border telephone traffic would have grown 13 percent in 2011, remaining in line with historical growth rates,” he said.
On the other hand, the volume of voice traffic served by the world's telcos was still more than three times that served by Skype.
Mobile operators in particular are also showing signs of seeking to work with Skype as voice traffic becomes less important to their business models.