Grandstream GXW4104 VoIP FXO Analog Line GatewayConstructing a high end and interoperable communications network with your analog devices is easier than ever. The GXW4104 4108 is ideal for small to medium business that are looking to integrate existing PSTN lines with an IP PBX system or with an existing traditional phone system. Specification 4 ports 2 10 100 Mbps network ports Comprehensive codec support, caller ID, flexible dial plans and security protection Advanced security protection with