Computer networks are made up of computer stations such as
personal computers,
network servers and
workstations. These stations are connected to each other via network devices such as
repeaters, bridges,
switches and
routers. A network bridge is a transmission device for carrying out bidirectional data transmission across a plurality of networks connected via ports. Bridges are devices that operate at the Data Link layer of the OSI model. Their operation is defined in the IEEE 802.1D standard. Bridges are used to connect several physical domains together. Bridges thus isolate physical segments and forward messages from one segment to the other based on the destination address of the frame. A bridge is connected to a hub by a separate local area network segment which itself requires two port interface
circuits such as LAN controllers and AUI's (generic network interfaces) with appropriate port drivers adapted for the specific media used for the bridge-hub LAN segment. A LAN bridge is used to interconnect a LAN with one or more other LANs, through an interconnecting link or links, to form a larger network in which messages can be sent from a device on one LAN to one or more devices on another LAN as if all of the devices were on the same LAN. A multi-port bridge allows simultaneous communication between nodes of the LAN by segmenting the LAN into multiple collision domains, each segment having a corresponding transmission medium.
