This is a Voice over Internet Protocol (VoIP) and streaming media service based on the Session Initiation Protocol (SIP) by which Internet telephony service providers (ITSPs) deliver telephone services and unified communications to customers equipped with SIP-based private branch exchange (IP-PBX) and Unified Communications facilities
Level 3 (Nasdaq: LVLT) is an international communications and information services company and is headquartered in Broomfield, Colorado. The company operates one of the largest communications and Internet backbones in the world.