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 Primary Rate Interface (ISDN PRI) connectivity.The network modules provide various port densities to meet customer requirements at various price points. The many LAN connectivity modules for the Cisco 3600 platform are designed to accommodate a range of application needs in customer networks. The LAN network module family assures customers that they can choose a LAN connectivity solution that fits their requirements. Available as network modules, LAN connectivity options offer several port densities, media options, and speeds. As modular components, they are easily and inexpensively field-upgradable as customer requirements change.The new mixed media LAN/WAN network modules series offers a single network module that combines a single 10/100BaseTX interface with two ISDN/PRI or Channelized T1 to support a wide range of LAN-to-LAN, LAN-to-WAN, and dial applications in a single network module. The single-port 10/100Base-TX interface supports autosensing and autonegotiation of 10/100 Mbps, and the ISDN/PRI interfaces support most of the Cisco IOS software related dial features up to and including 11.3(4)T. The single-port 10/100BaseTX interface has one RJ-45 port. This port connects to two-pair Category 5 UTP cabling following the 100BaseTX physical layer protocol. The ISDN/PRI/Channelized T1 interfaces are available with an integrated CSUs to be connected directly to the network with an RJ-48 cable. This one 10/100 Ethernet with two ISDN/PRI or Channelized T1 with integrated CSU's network module supports speeds of up to 1.544Mbps full duplex and provides up to 24 virtual interfaces in channelized mode and up to 23 ISDN b-channels in the PRI mode.