ITEE ITEE-1 | Page 271

Reference LAN analyzer A “LAN analyzer” is a piece of software or hardware that monitors the packets (data) that are carried over a LAN, and analyzes the traffic (volume of data). 10BASE 2 Lightweight coaxial cable Terminator LAN board LAN board LAN board Hub 10BASE-T Twisted pair cable LAN board LAN board ●Relay device Various types of relay devices are used to expand a network. The main types of relay devices are summarized below. Device Repeater A device that amplifies an electrical signal carried over a cable to extend the transmission distance. Connects the first layer (physical layer) in the OSI model. Bridge (bus) A device that connects multiple LANs. The bridge remembers the MAC address for the LAN board in each computer, and can be configured to reduce traffic (data over the network) by not carrying data that is unnecessary to the LAN and unrelated to communications. Connects the second layer (data link layer) in the OSI model. Switching hub (star) A hub that provides functions for transferring packets only to LAN ports that have a destination MAC address. To provide this function, the switching hub has the ability learn the MAC address for each LAN port. Unlike a repeater hub, there are no limitations on the number of intermediary hubs that can be used. Reference MAC address A “MAC address” is a 48-bit number that is assigned to a LAN board at the time of manufacturing. MAC address is assigned in order to identify each computer within the LAN. Reference Default gateway A “default gateway” is a piece of equipment such as a computer or router that is used when accessing a computer located outside the network. The equipment acts as a gateway to enable communications. Reference OSI Refer to “Chapter 9-4-2 Communications protocols.” 265 Characteristics