The new service called SIPphone is the latest of several SIP-based services to emerge recently, as the SIP Voice-over-IP landscape heats up. Michael Robertson has shown a knack for identifying emerging technologies that threaten established players before. MP3.COM was sued into oblivion by the RIAA for copyright violations and Lindows is currently under attack from Microsft. Now he is taking on the phone giants.
The big difference between these new services based on the IETF standard known as SIP (Session Initiation Protocol) and previous VoIP services is that users on one service can call those on other SIP-based services. The SIPphone service has already announced connectivity to and interoperability with the two other largest SIP services, Jeff Pulver’s Free World Dialup and IPTEL.ORG. FWD claims to have 43,000 subscribers world-wide.