It has taken probably a decade longer than its proponents expected, but it looks as if booming demand for voice over IP (VoIP) and session initiation protocol-based (SIP) services may finally be chiming the death knell of the TDM-based PBX, in North America at least.
According to Frost & Sullivan, VoIP access and SIP trunking service revenues turned in what the researcher described as “down-turn defying” performance last year, with revenues up 22% at $717.3 million, and customer numbers up 401%.
