LAN CPE is the collection of LAN communications devices, which include the following:
Hubs
Bridges
Routers
Switches
Each of these items is discussed in the following sections.
Hubs are multiport repeaters that connect devices on a shared LAN. Because only two devices can be connected with LAN cables, a hub is needed to interconnect two or more devices on a single LAN. Hubs repeat every LAN signal received on a single port out all ports, propagating the signal to every device on the LAN. The cable termination points are the hub and the LAN device (host).
Bridges connect LAN segments, lengthening the diameter (across a distance) of the LAN as well as segmenting, or breaking up, collision domains. These are the four types of LAN bridges:
Transparent Used in Ethernet LAN environments only
Source-Route Used in Token Ring LAN environments only
Source-Route Translational (Mixed-Media) Used to mix Ethernet and Token Ring LAN environments
Source-Route Transparent Used to mix Ethernet and Token Ring LAN environments
Routers enable communications between LANs and/or wide-area networks (WANs). Routers are protocol specific in that they must support the network-layer protocol used by each data packet. For example, for a router to support Internet connections, the router must be able to support Internet Protocol (IP) traffic. To support of a Novell Netware implementation, the router must support IPX.
Switches carry network traffic by receiving data frames from a source host (connected to a switch port) and forwarding these frames through a different switch port (based on the frame header information).