Cisco offers a wide variety of connectivity, expansion and upgrade modules to accommodate the range of application needs in customer networks. The network modules assure customers that they can choose a connectivity solution that fits their requirements. As modular components, they are easily and inexpensively field-upgradeable as customer requirements change.Cisco 1600 series routers are a family of small desktop routers that link small-to-medium remote Ethernet LANs to regional and central offices over multiple WAN connections.