I've been using Twilio's SIP Support in production at Better Voicemail for a few months now. The implementation is rock solid and adds a lot of value to Twilio'

I've been using Twilio's SIP Support in production at Better Voicemail for a few months now. The implementation is rock solid and adds a lot of value to Twilio's offering especially when it comes to integrating with existing business systems. Also, supposedly outbound calls through SIP endpoints is coming "in a couple of quarters".