The Linksys SPA3102 is an Analog Telephone Adapter or ATA with 1 FXS, 1 FXO and dual LAN/WAN RJ45 Ethernet ports. If power is lost to the unit or Internet service is down, calls can be redirected to a traditional carrier via the FXO interface.
The Linksys Wireless-G Broadband Router is really three devices in one box. First, there's the Wireless Access Point, which lets you connect both screaming fast Wireless-G (802.11g at 54Mbps) and Wireless-B (802.11b at 11Mbps) devices to the network. There's also a built-in 4-port full-duplex 10/100 Switch to connect your wired-Ethernet devices together. Connect four PCs directly, or attach more hubs and switches to create as big a network as you need.