3Com 3C16755-US User Guide - Page 18

NETWORKING TERMINOLOGY A Network is a collection of workstations (for example, IBM-compatible PCs) and other equipment (for example, printers), connected for the purpose of exchanging information or sharing resources. Networks vary in size, some are within a single room, others span continents. A Local Area Network (LAN) is a network, usually in an office, that spans no more than a single site. Ethernet is a type of LAN, referring to the technology used to pass information around the network. It operates at 10Mbps (megabits per second). Fast Ethernet is a type of LAN that runs up to 10 times faster than standard Ethernet. It operates at 100Mbps. 10BASE-T and 100BASE-TX are the names given to the Ethernet protocol that runs over Twisted Pair (TP) cable. 10BASE-T runs at 10Mbps whilst 100BASE-TX operates at 100Mbps. The OfficeConnect hub uses RJ-45 type connectors for connecting your TP network. A Network Loop occurs when two pieces of network equipment are connected by more than one path. Your hub detects this and partitions (isolates) one of its ports to break the loop. A segment is the length of cable connected to a port. Packets are the units of information your workstations and other equipment send to each other over the network. A frame is the data part of the packet and can be unicast (sent to a single device), multicast (sent to multiple devices), or broadcast (sent to all devices). Bandwidth refers to the amount of network traffic the network can hold at any one time (information capacity) measured in bits per second (bps). Workstations or applications that use the network heavily are referred to as using high bandwidth. Fast Ethernet has a higher bandwidth than Ethernet, so it can cope with larger amounts of traffic, which results in faster operation. A half duplex link allows information to flow in either direction, but not in both directions simultaneously. Collisions are part of normal ethernet operation and occur if other network equipment attempts to transmit at the same time. A sudden sustained increase in the number of collisions may indicate a problem with the device. 18