SAN FRANCISCO--(BUSINESS WIRE)--Voxbone today reported a 12 percent increase in conferencing provider customers, and supported 43 percent more call volume (in minutes) for these customers thus far in 2015, compared to the same period last year. Voxbone is consistently gaining traction in the segment due to its high-quality dial-in numbers (also known as DIDs), as well as its WebRTC-to-SIP service, which enables providers to implement click-to-join features without the complex software developme