Like hosted VoIP providers, Whaleback Systems provides IP PBX capabilities to SMBs, with no upfront equipment costs. Customer companies simply pay monthly fees for phone service plus an array of sophisticated call-handling features. But Whaleback calls its CrystalBlue service managed VoIP. It differs from hosted VoIP in where it places the IP PBX and how it delivers the calls. And now Whaleback is offering a new version of the service for sale through carriers, namely SIP trunking providers.