MTG200 series Digital VoIP Gateways with 4 ports E1/T1 simply migrate your legacy PSTN networks (legacy PBX or E1/T1 service providers) , to VoIP network. Only small investment, you can enjoy the real benefits of VoIP, and retain your PSTN connectivity. It is a compact box designed for SMEs and open-source market, fully compatible with Asterisk / Elastix / Trixbox / Freeswitch and mainstream VoIP platform. With support of ISDN PRI / SS7 / R2 MFC, integrating with your legacy PBX or PSTN network is also so easy.