physical topology of a network refers to the configuration of cables, computers

Written by Gianfranco Fracassi

What is a Topology? The physical topology of a network refers torepparttar configuration of cables, computers, and other peripherals. Physical topology should not be confused with logical topology which isrepparttar 146211 method used to pass information between workstations. Logical topology was discussed inrepparttar 146212 Protocol chapter .

Real Family Freebies

free stuff fromrepparttar 146213 USA

Best Surveys for Cah Rewards

Real Free Ringtones and Logos

Win Free Prizes withrepparttar 146214 latest free contests

Main Types of Physical Topologies The following sections discussrepparttar 146215 physical topologies used in networks and other related topics.

Linear Bus Star Star-Wired Ring Tree Considerations When Choosing a Topology Summary Chart Linear Bus A linear bus topology consists of a main run of cable with a terminator at each end (See fig. 1). All nodes (file server, workstations, and peripherals) are connected torepparttar 146216 linear cable. Ethernet and LocalTalk networks use a linear bus topology. Advantages of a Linear Bus Topology •Easy to connect a computer or peripheral to a linear bus. •Requires less cable length than a star topology. Disadvantages of a Linear Bus Topology •Entire network shuts down if there is a break inrepparttar 146217 main cable. •Terminators are required at both ends ofrepparttar 146218 backbone cable. •Difficult to identifyrepparttar 146219 problem ifrepparttar 146220 entire network shuts down. •Not meant to be used as a stand-alone solution in a large building. Star A star topology is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub or concentrator Data on a star network passes throughrepparttar 146221 hub or concentrator before continuing to its destination. The hub or concentrator manages and controls all functions ofrepparttar 146222 network. It also acts as a repeater forrepparttar 146223 data flow. This configuration is common with twisted pair cable; however, it can also be used with coaxial cable or fiber optic cable. Advantages of a Star Topology •Easy to install and wire. •No disruptions torepparttar 146224 network then connecting or removing devices. •Easy to detect faults and to remove parts. Disadvantages of a Star Topology •Requires more cable length than a linear topology. •Ifrepparttar 146225 hub or concentrator fails, nodes attached are disabled. •More expensive than linear bus topologies because ofrepparttar 146226 cost ofrepparttar 146227 concentrators.

What is a Protocol? the communications between computers on a network

Written by Gianfranco Fracassi

What is a Protocol? A protocol is a set of rules that governsrepparttar communications between computers on a network. These rules include guidelines that regulaterepparttar 146210 following characteristics of a network: access method, allowed physical topologies, types of cabling, and speed of data transfer. Seerepparttar 146211 Topology and Cabling sections

of this tutorial for more information. The most common protocols are:

Ethernet LocalTalk Token Ring FDDI ATM Ethernet The Ethernet protocol is by farrepparttar 146212 most widely used. Ethernet uses an access method called CSMA/CD (Carrier Sense Multiple Access/Collision Detection). This is a system where each computer listens torepparttar 146213 cable before sending anything throughrepparttar 146214 network. Ifrepparttar 146215 network is clear,repparttar 146216 computer will transmit. If some other node is already transmitting onrepparttar 146217 cable,repparttar 146218 computer will wait and try again whenrepparttar 146219 line is clear. Sometimes, two computers attempt to transmit atrepparttar 146220 same instant. When this happens a collision occurs. Each computer then backs off and waits a random amount of time before attempting to retransmit. With this access method, it is normal to have collisions. However,repparttar 146221 delay caused by collisions and retransmitting is very small and does not normally effectrepparttar 146222 speed of transmission onrepparttar 146223 network. The Ethernet protocol allows for linear bus, star, or tree topologies. Data can be transmitted over twisted pair, coaxial, or fiber optic cable at a speed of 10 Mbps. Fast Ethernet To allow for an increased speed of transmission,repparttar 146224 Ethernet protocol has developed a new standard that supports 100 Mbps. This is commonly called Fast Ethernet. Fast Ethernet requiresrepparttar 146225 use of different, more expensive network concentrators/hubs and network interface cards. In addition, category 5 twisted pair or fiber optic cable is necessary. Fast Ethernet is becoming common in schools that have been recently wired. Gigabit Ethernet The most recent development inrepparttar 146226 Ethernet standard is a protocol that has a transmission speed of 1 Gbps. Gigabit Ethernet is primarily used for backbones on a network at this time. Inrepparttar 146227 future, it will probably be used for workstation and server connections also. It can be used with both fiber optic cabling and copper. The 1000BaseTX,repparttar 146228 copper cable used for Gigabit Ethernet, is expected to becomerepparttar 146229 formal standard in 1999. LocalTalk LocalTalk is a network protocol that was developed by Apple Computer, Inc. for Macintosh computers. The method used by LocalTalk is called CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance). It is similar to CSMA/CD except that a computer signals its intent to transmit before it actually does so. LocalTalk adapters and special twisted pair cable can be used to connect a series of computers throughrepparttar 146230 serial port. The Macintosh operating system allowsrepparttar 146231 establishment of a peer-to-peer network withoutrepparttar 146232 need for additional software. Withrepparttar 146233 addition ofrepparttar 146234 server version of AppleShare software, a client/server network can be established. The LocalTalk protocol allows for linear bus, star, or tree topologies using twisted pair cable. A primary disadvantage of LocalTalk is speed. Its speed of transmission is only 230 Kbps.

Cont'd on page 2 ==> © 2005
Terms of Use