Just helped someone last night who had had their box changed. They apparently had the old Insight phone service and were switched to the new Arris box like pictured. I didn't realize it at first but this box does a lot - it's a cable modem, phone modem, wired and wireless router.
There's was model TG862. It has four Ethernet ports on the back. Anything plugged in to one of the ports will be handed an address like 192.168.0.2 or higher. The box was preset (apparently) for WiFi and was broadcasting an SSID like ARRIS-1127 and security was turned on.
I changed the wireless settings by going to »192.168.0.1
The default username is "admin" and the default password is "password".
So, this box is pretty nice. It's could be all you need.