Bus topologies are best suited for networks that use ______________ access methods.

What is Bus Topology in Computer Networks & Its Differences

There are various communication devices are connected to a network to establish a reliable communication network. The devices connected in a communication network are known as ‘nodes’. These nodes are connected through ‘Links’. The arrangement of these elements in a communication network is given by the Network Topology. LAN is an example of network topology. Here each node is connected to the various other nodes through physical links. When these links are mapped graphically, they result in a geometric pattern which shows the physical topology of the network. This physical topology gives the placement of various network elements. Bus Topology, Ring Topology, Star Topology,etc.. are some of the examples of physical topology.

Examples of Bus Topology

Ethernet –Ethernet is the least expensive high-speed LAN alternative. It transmits and receives data at a speed of 10 million bits per second. Data transferred between wiring closets using either a heavy coaxial cable (thick net) or fiber optic cable. Thicknet coaxial still used for medium-long distances where medium levels of reliability are needed. Fiber goes farther and has more excellent reliability but a higher cost. To connect several workstations within the same room, a light-duty coaxial cable called thin net commonly used. These other media reflect an older view of workstation computers in a laboratory environment. The figure shows the scheme of Ethernet where a sender transmits a modulated carrier wave that propagates from the sender toward both ends of the cable.

Ethernet was first designed and installed by Xerox Corporation at its Palo Atto Research Center (PARe) in the mid-1970. In the year 1980, DEC Intel and Xerox came out with a joint specification which has become the de facto standard. Ethernet from this period is often called DIX after its corporate sponsors Digital, Intel, and Xerox. Ethernet as the most popular protocol for LAN technology.

Local Talk

LocalTalk is a LAN that employs bus topology. Apple Computer Corporation invented it for use with Apple’s PCs LocalTalk uses ordinary telephone wire with standard RJ-l1 telephone connectors, the same as used to plug in a telephone and modem. Each connector plugs into a LocalTalk transceiver, which connects to a PC’s LocalTalk interface card. LocalTalk transceivers that connect to a PC’s parallel port are also available. Multiple computers can connect in a daisy chain, like the way railroad cars connected on a train. Hub can also be used for the same purpose.

LocalTalk does have some limitations over Ethernet. For one, LocalTalk is slower than Ethernet. LocalTalk has a bandwidth of230.4 Kbits/second, while Ethernet has a bandwidth of 10MB per second. In practice, Ethernet runs about 4-to-5 times faster, than LocalTalk. Another limitation of LocalTalk is that it cannot run TCP/IP protocols directly.

LocalTalk significant advantages are that it is simple and very inexpensive. The hardware and software required for LocalTalk already built into every Macintosh computer to connect with a LocalTalk network except the iMac(tm). LocalTalk is also cheaper in terms of cabling than Ethernet. Many Macintosh computer owners use a printer cable to create a temporary network between two Macintosh Computers. There is no software to install beyond the Macintosh operating system itself and LocalTalk work with any current version of the Macintosh operating system as well as versions from several years ago. For cabling of a LocalTalk network, standard RJ-II phone cable is used which is cheaper than the cable used for Ethernet. Many printers on the market come with built-in LocalTalk support, making them easy to share on such a network.