The network modules provide various port densities to meet customer requirements at various price points. The WAN-interface-card (WIC) option offers a single ISDN BRI port (with optional NT1). The WIC-1B-S/T-V3 inserts into a mixed-media network module or is supported on the Cisco 1700 Series, Cisco 1800 Series, Cisco 2600XM Series, Cisco 2800 Series, Cisco 3700 Series and Cisco 3800 Series routers. The ability to add BRI connectivity via a WIC enables administrators to maximize valuable slot space while providing additional connectivity options on the same module such as Fast Ethernet.