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
Business telephone & telecommunication installation and services for Nortel phone systems, Avaya phone systems. Dallas VoIP products, services & installation