A SIP (Session Initiation Protocol) trunk is a solution that allows businesses with an installed private branch exchange (IP-PBX) to use real-time communications including VoIP. By connecting a SIP trunk to an internal NGN (next generation network) or traditional PSTN (public switched telephone network) phone system, companies can communicate over IP outside the enterprise. A SIP-Trunking solution creates a single conduit for multimedia components including voice, video and data, all of which integrate into a company’s existing phone system. SIP-Trunking features typically include local and long-distance calling, emergency calling, directory listing and caller ID. Enterprise users with SIP solution from TTCL will be;