Voice over IP gateway provides toll-free voice and fax communications over the Internet or Intranet. By integrating voice and fax into an existing data network, businesses can realize substantial savings on inter-office long distance toll charges. Analog model provides one port. Connects directly to phones, fax machines, CO ports on key systems, analog PBX extensions, PSTN or key system extensions to provide real-time, toll-quality voice connections to any office on a VOIP network. Features: 1 port for communication over an existing IP network or the Internet Ethernet connectivity and full IP compatibility with existing routers and WAN infrastructure PSTN fail-over automatically routes calls over the PSTN network if the IP network is congested or down Supports H.323 or SIP for sending voice over the Internet Supports H.450 supplementary services to provide for call transfer, call forwarding, call hold, call waiting and name identification Voice compression to 5.3K per call with support for multiple algorithms, including ITU G.723 and G.729 T.38 real-time fax relay for interoperability among other VOIP equipment Voice prioritization using the industry-standard Differentiated Services (DiffServ) protocol Configuration and management using a web browser or Windows Brand new in a box. This gataway is certified for use in Europe too. Includes power cord which can be used in US and Europe. Please ask any question you may have. All reasonable offers will be considered.. ... Thank you.