Google to add SIP to Google Voice

Google is to add SIP to Google Voice to give its clients a proper Voice over IP number and integrate with other VoIP services.

Google Voice is a US-only telephone services that gives you one number for all your phones, cheap calls to landlines, text transcripts of voicemail and free calls to other users of Google Voice and GMail.

Google is rolling out a significant upgrade to the service that will add proper Voice Over IP support in the form of a SIP gateway. Using the gateway it will be possible to make calls between Google Voice accounts and VoIP services like SipGate.