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 & 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.