Connecting the telephony of the enterprise PBX or Unified Communications (UC) system using SIP trunks instead of conventional telephone lines has been very successful in recent years. Now it is time to utilize the full power of the global IP networks and our UC terminals - PCs, laptops, fixed and mobile phones, tablet computers and telepresence systems - to extend the telephony service with high quality, full UC capability, where everyone reaches one another using both telephone numbers and email-like SIP addresses.