The Edge-Core VoIP Starter Kit provides the most cost effective solution for Small to Medium Businesses to easily build up VoIP networks. The VoIP Extension Server VES3302-12, is a SIP Registrar and Proxy Server that supports up to 12 extensions. IP phones can be located anywhere in the world with internet to make calls to each other. This enables frequent business travelers and overseas branch offices to call their main office by simply dialing an extension number, consequently, eliminating telephone bills and limitations of distance. The VoIP Trunking Gateway, VTG3306C, offers IP PBX functions. With 4 FXO ports, communication between the PSTN (Public Switched Telephone Network) and VoIP network becomes effortless. IP phones can call out to the PSTN, or vice versa. Anywhere there is Trunking Gateway, international calls become local.Calls from one country can cross oceans via the internet to a VTG3306C and out to the PSTN of that country, saving money. The VPN Router VR-50 supports NAT function. All devices within its network can use private IPs and have firewall protection. In addition, VPN encrypts calls for further protection that companies may demand. IP phones, VP3302, require only internet connection to become plug and play, making them quick with high mobility. Furthermore, users can expand VoIP networks by purchasing additional IP phones.