The 4 port VoIP Gateway with Caller ID is fully both SIP and H.323 standard compliant residential gateway that provides a total solution for integrating voice-data network and PSTN. By simple installation, this revolutionary compact voice over IP (VoIP) gateway could be configured as a 4 port FXS/FXO VoIP Gateway which provides voice connectivity over the IP network and to the Public Switched Telephone Network (PSTN).The Gateway is equipped with a four port Ethernet switch and built-in NAT router function that provides Internet access using only one IP address. Besides, it provides high voice quality and optimized packet voice streaming over managed and public (Internet) IP networks. You can easily connect your existing PBX setup to use VOIP Services. All extension can enjoy low cost voip service for free voice communication between branches using SIP Server resources. Encrypt peer to peer VOIP calls can avoid VoIP blocking of internet.