Just a tip, since I've had this one bit me umpteen times in the last year: If you're having one-way or no-way audio issues with SIP trunks or Teleworker SIP devices, go into your MBG settings and enable "Relax set RTP checks". It's new as of MBG release 11 I think, I've had several systems that had issues with MiCollab softphones or even SIP trunk calls (particularly to rural carriers) after upgrading from an older release.