SolidPBX™ appliances deployed in multiple branch offices allow VoIP communications between the various devices connected to them, and provide DHCP, NTP, and TFTP services as well. The appliances also allow analog calls from the public telephone network to communicate with their registered devices through an FXO gateway.

The SolidPBX™ appliances communicate with each via IP networks or through the public Internet. The appliances may also pass calls to each other through the PSTN. VoIP calls pass through routers that connect the appliances in an IP network (or the Internet) and the FXO gateways can allow calls to SolidPBX™ through the public telephone network even when the internet connection is down.

The client devices registered to a SolidPBX™ appliance can include SIP phones registered through public internet or the appliance’s web-based user interface; personal computers registered through the local area network (LAN); and wireless devices registered through SolidPBX™ WiFi access points.

The diagram shows two SolidPBX™ appliances deployed in separate branch offices. The appliances provide VoIP communications for their registered devices and handle analog calls to and from the public switched telephone network (PSTN) through FXO gateways. The two VoIP deployments communicate via an IP network (the internet) or through a trunk line.