CHAPTER 11 - Networking devices

Abstract

Networking devices is also called networking equipment or networking components. The functionality of network devices can be specified in accordance with the Open Systems Interconnection (OSI) reference model. Hubs and repeaters work at the first, physical layer; bridges and switches are thought of as network devices working at the second, data-link layer; routers work at the third, network layer; gateways are the most complex devices with respect to the functionality and work at the fourth layer (transport layer) or the uppermost layers of the OSI reference model. This chapter illustrates the possible correspondence between these networking devices and the OSI model layers. Hubs and repeaters are network devices without intelligent networking functions, but switches, bridges, routers, and gateways have different degrees of network intelligence. Network devices also use protocols to specify the software attributes of data communications, including the structure of packets. Choices include: asynchronous transfer mode (ATM), controller area network bus (CANbus), control network (ControlNet), DeviceNet, fiber channel, fiber distributed data interface (FDDI), frame relay, integrated services digital network (ISDN), synchronous optical network (SONET), token bus and token ring, etc. Ethernet is a popular protocol that uses a bus or star typology.