 they're called active). Chapter 6 Local Area Networking Passive-Passive hubs serve as connection points and do not regenerate the signal; the signal simply passes through the hub. They do not require elec- trical power to run (that's why they're called passive). Wiring panels and punchdown blocks are examples of passive hubs. Hybrid-Hybrid hubs accommodate several different types of cables. You can connect hubs to expand a hub network. The advantages of hubs are that they make it easy to change or expand wiring systems, they use different ports to accommodate different cabling types, and they centralize the monitoring of net- work activity and traffic. Hubs are also sometimes called concentrators or multista- tion access units (MSAUs). A group of transceivers can all be located in and managed by an intelligent hub. Intelligent hubs are modular and chassis based, with slots that accommodate the user's choice of interface modules-such at Ethernet, Token Ring, or FDDI-for connectivity to LANs, WANs, or other network devices. The number of ports on the NIC determines the number of users in the particular star. Intelligent hubs often provide integrated management and internetworking capabilities, as well as Simple Network Management Protocol (SNMP)-based network management. New generations also offer bridging, routing, and switching functions. Figure 6.7 shows a network that uses a combination of interconnection devices. Intelligent hubs provide connectivity between workstations that comprise Intelligent Intelligent Servers Intelligent Intelligent Backbone Backbone Router Router Campus Branch Backbone: FDDI/ Office 100BASE-T/Gigabit Ethernet Figure 6.7 Using interconnection devices LAN Interconnection and Internetworking a given cluster. An internal backbone is used to internetwork the intelligent hubs to move between different clusters. Those intelligent hubs then connect into a backbone router for purposes of WAN, or campuswide, connectivity. (Note that today switches are preferred over hubs.) LAN Switches LAN swit