Strike another blow to SIP fragmentation. Huzzah!
XO Communications has gotten itself certified to the SIPconnect standard, which aims to enable global interoperability between IP PBXs and service provider SIP trunks.
Because there are so many different flavors of the SIP application protocol, service providers have had to perform individual testing and certification to show interoperability with each IP PBX vendor — a costly process. Also, the lack of standardization has been an SIP trunking gating factor for nervous IT people who view vendor lock as a sketchy thing to embrace.
By attaining SIPconnect compliance, service providers can interop with any SIPconnect-compliant IP PBX, like those from Avaya Inc.