Cisco Systems, Inc. is the worldwide leader in networking for the Internet. Cisco products include routers, LAN and ATM switches, dial-up access servers and network management software. These products, integrated by the Cisco IOS software, link geographically dispersed LANs, WANs and IBM networks. Cisco offers a variety of expanding modules for Cisco routers to upgrade its abilities in order to meet growing demands of modern networking communications. The astonishing versatility of the Cisco router 3600 series is highlighted by its broad support of Integrated Services Digital Network Basic Rate Interface (ISDN BRI) connectivity.The network modules provide various port densities to meet customer requirements at various price points. This 8-port ISDN BRI network module connects to an ISDN WAN through an external NT1 device (also known as an S/T interface). This module is also referred to as the 8-port BRI S/T network module.