計(jì)算機(jī)專業(yè)英語Lesson-16課件

1、Lesson 16Networking Hardware教學(xué)課件 Networking hardware includes all computers， peripherals， interface cards and other equipments needed to perform dataprocessing and communications within the network. File Server A file server stands at the heart of most networks. It is a very fast computer with a lar

2、ge amount of RAM and storage space， along with a fast network interface card. The network operating system software resides on this computer， along with software applications and data files that need to be shared.1 Workstation All user computers connected to a network are called workstations. A typi

3、cal workstation is a computer that is configured with a network interface card， networking software， and the appropriate cables.2 Workstations do not necessarily need floppy disk drives because files can be saved on the file server. Almost any computer can serve as a network workstation.back教學(xué)課件 Net

4、work Interface Card The network interface card （NIC）， also called network adapter， provides the physical connection between the network and the computer workstation. Most of them are internal， with the card fitting into an expansion slot inside the computer.3 Some computers， such as Mac Classics， us

5、e external boxes which are attached to a serial port or a SCSI port. Laptop computers can now be purchased with a network interface card built-in. The network interface card is a major factor in determining the speed and performance of a network. It is a good idea to use the fastest network card ava

6、ilable for the type of workstation you are using. They are usually purchased separately from a computer， although many computers （such as the Macintosh） now include an option for a pre-installed network interface card.back教學(xué)課件 Switch Switch， also called hub， is a device that provides a central conne

7、ction point for cables from workstations， servers， and peripherals. In a star topology， twistedpair wire is run from each workstation to a central switch/hub. Most switches are active， that is they electrically amplify the signal as it moves from one device to another.4 Switches no longer broadcast

8、network packets as hubs did in the past， they memorize addressing of computers and send the information to the correct location directly. Switches are sold with specialized software for port management.back教學(xué)課件 Repeater Since a signal loses strength as it passes along a cable， it is often necessary

9、to boost the signal with a device called a repeater.5 The repeater electrically amplifies the signal it receives and rebroadcasts it. Repeaters can be separate devices or incorporated into a concentrator. They are used when the total length of your network cable exceeds the standards set for the typ

10、e of cable being used.6 A good example of the use of repeaters would be in a local area network using a star topology with unshielded twisted-pair cabling. The length limit for unshielded twistedpair cable is 100 meters. The most common configuration is for each workstation to be connected by twiste

11、d-pair cable to a multi-port active concentrator. The concentrator amplifies all the signals that pass through it allowing for the total length of cable on the network to exceed the 100 meter limit.7back教學(xué)課件 Bridge A bridge is a device that allows you to segment a large network into two smaller， mor

12、e efficient networks. If you are adding to an older wiring scheme and want the new network to be up-to-date， a bridge can connect the two. A bridge monitors the information traffic on both sides of the network so that it can pass packets of information to the correct location. Most bridges can “l(fā)ist

13、en” to the network and automatically figure out the address of each computer on both sides of the bridge. The bridge can inspect each message and， if necessary， broadcast it on the other side of the network. The bridge manages the traffic to maintain optimum performance on both sides of the network.

14、 You might say that the bridge is like a traffic cop at a busy intersection during rush hour. It keeps information flowing on both sides of the network， but it does not allow unnecessary traffic through.8 Bridges can be used to connect different types of cabling， or physical topologies. They must， h

15、owever， be used between networks with the same protocol.back教學(xué)課件 Router Router， also called gateway in earlier days， translates information from one network to another； it is similar to a super intelligent bridge. Routers select the best path to route a message， based on the destination address and

16、origin. The router can direct traffic to prevent head-on collisions， and is smart enough to know when to direct traffic along back roads and shortcuts.9 While bridges know the addresses of all computers on each side of the network， routers know the addresses of computers， bridges， and other routers

17、on the network. Routers can even “l(fā)isten” to the entire network to determine which sections are busiestthey can then redirect data around those sections until they clear up. If you have a school LAN that you want to connect to the Internet， you will need to purchase a router. In this case， the route

18、r serves as the translator between the information on your LAN and the Internet. It also determines the best route to send the data over the Internet. Routers can direct signal traffic efficiently， route messages between any two protocols across fiber optic， coaxial， and twisted-pair cabling. back教學(xué)

19、課件Key Words & TermsAdapter 適配器Bridge 網(wǎng)橋Concentrator 集中器Configuration 配置Interface 接口Intersection 交叉點(diǎn)laptop computer 筆記本電腦optimum performance 最佳性能Peripheral 外圍設(shè)備Port 端口Repeater 中繼器Router 路由器Server 服務(wù)器Switch 交換機(jī)Topology 拓?fù)鋀orkstation 工作站back教學(xué)課件AbbreviationsNIC（Network Interface Card） 網(wǎng)絡(luò)接口卡SCSI（Small C

20、omputer System Interface） 小型（計(jì)算）機(jī)系統(tǒng)接口UTP（Unshielded Twisted Pair） 非屏蔽雙絞線back教學(xué)課件Notes 1 The network operating system software resides on this computer， along with software applications and data files that need to be shared. 本句中的介詞短語along with的意思是“連同一起”，在句中與the network operating system software作并列主語。

21、 譯文：網(wǎng)絡(luò)操作系統(tǒng)軟件連同需要被共享的數(shù)據(jù)文件和應(yīng)用軟件一起存在于這臺計(jì)算機(jī)上。 2 A typical workstation is a computer that is configured with a network interface card， networking software， and the appropriate cables. 本句表語是由that引導(dǎo)的定語從句充當(dāng)，從句中的be configured with的意思是“用配置”。 譯文：一個(gè)典型的工作站是一臺配置了一塊網(wǎng)卡、網(wǎng)絡(luò)軟件和合適電纜的計(jì)算機(jī)。 3 Most of them are internal， wi

22、th the card fitting into an expansion slot inside the computer. 句中with引導(dǎo)的短語作伴隨狀語。 譯文：大部分網(wǎng)卡是內(nèi)置的，卡適合計(jì)算機(jī)內(nèi)部的擴(kuò)展槽。back教學(xué)課件Notes 4 Most switches are active， that is they electrically amplify the signal as it moves from one device to another. 本句是由as引導(dǎo)的伴隨狀語，句中one device和another是指一臺交換機(jī)和另一臺交換機(jī)。 譯文：大部分交換機(jī)處于激活狀態(tài)

23、，也就是說它們隨著信號從一臺設(shè)備移到另一臺設(shè)備時(shí)將信號放大。 5 Since a signal loses strength as it passes along a cable， it is often necessary to boost the signal with a device called a repeater. 本句是由since引導(dǎo)的原因狀語從句，從句中又包含一個(gè)由as引導(dǎo)的伴隨時(shí)間狀語。 譯文：由于信號經(jīng)過電纜時(shí)強(qiáng)度損失，所以用一個(gè)叫中繼器的設(shè)備增強(qiáng)信號經(jīng)常是很必要的。back教學(xué)課件Notes 6 They are used when the total length

24、of your network cable exceeds the standards set for the type of cable being used. 本句是由when引導(dǎo)的時(shí)間狀語從句。 譯文：當(dāng)網(wǎng)絡(luò)線纜的總長度超過正被使用的線纜的標(biāo)準(zhǔn)設(shè)置時(shí)，中繼器被使用。 7 The concentrator amplifies all the signals that pass through it allowing for the total length of cable on the network to exceed the 100 meter limit. 本句是現(xiàn)在分詞allow

25、ing引導(dǎo)的結(jié)果狀語從句。 譯文：集中器擴(kuò)大通過它的所有信號，這樣就允許網(wǎng)絡(luò)上線纜的長度超出100米的限制。back教學(xué)課件Notes 8 It keeps information flowing on both sides of the network， but it does not allow unnecessary traffic through. 本句中的keep doing的意思是“連續(xù)不斷做某事”。 譯文：網(wǎng)橋使兩邊網(wǎng)絡(luò)的信息保持流動(dòng)，但是它不允許不需要的信息通過。 9 The router can direct traffic to prevent head-on collis

26、ions， and is smart enough to know when to direct traffic along back roads and shortcuts. 本句中的head-on的意思是“正面的”；“beadjenoughto do”結(jié)構(gòu)表示“足夠怎么樣，以至于”。 譯文：路由器能夠疏導(dǎo)交通以防止正面沖突，并且智能到知道什么時(shí)候指導(dǎo)交通沿著后路走和抄近路走。backExercisesTranslate the following phrases into English.1網(wǎng)絡(luò)硬件2文件服務(wù)器3網(wǎng)絡(luò)接口卡4最佳性能5局域網(wǎng)6信號強(qiáng)度backExercisesTranslate the following sentences into Chinese.1A bridge is a device that allows you to segment a large network into two smaller， more efficient net