Networks: Communicating and Sharing Resources. Chapter 7: Networks: Communicating and Sharing Resources

Transcription

1 Netwrks: Cmmunicating and Sharing Resurces Chapter 7: Netwrks: Cmmunicating and Sharing Resurces 1

2 Netwrks: Cmmunicating and Sharing Resurces 2

3 Objectives Understand basic netwrking cncepts. Distinguish between a WAN, LAN, MAN, CAN, HAN, and PAN. Discuss the advantages and disadvantages f netwrks. Distinguish between peer-t-peer, client/server, and virtual private lcal area netwrks (LANs). 3

4 Objectives Define tplgy and understand hw the three LAN tplgies differ. Explain the imprtance f netwrk prtcls. Name the mst widely used LAN prtcl and their versins. Identify the special cmpnents f a wide area netwrk (WAN) that differentiate it frm a LAN. 4

5 Objectives Cntrast circuit-switching and packetswitching netwrks and explain their respective strengths and weaknesses. Identify the ptins, cmpnents, cnfiguratin, and maintenance f a hme area netwrk (HAN). 5

6 Netwrk Fundamentals Netwrks Links multiple cmputer systems and enables them t share data and resurces Types f cmputer netwrks: Lcal area netwrk (LAN) Wide area netwrk (WAN) Metrplitan area netwrk (MAN) Campus area netwrk (CAN) Persnal area netwrk (PAN 6

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8 Netwrk Fundamentals LAN WAN MAN Uses cables, radi waves, r infrared signals Links cmputers in a limited gegraphic area Uses lng-distance transmissin media Links cmputer systems a few miles r thusands f miles Internet is the largest WAN Designed fr a city Larger than a LAN, smaller than a WAN 8

9 Netwrk Fundamentals CAN PAN Several LANs lcated in varius lcatins n a cllege r business campus Smaller than a WAN Use devices such as switches, hubs, and ruters Netwrk f an individual s wn persnal devices Usually within a range f 32 feet Usually use wireless technlgy 9

10 Netwrk Fundamentals Cmmunicatin devices Cnvert data int signals t travel ver a medium Cmputers Mdems Ruters Switches Hubs Wireless access pints Netwrk interface cards (NICs) 10

11 Netwrk Fundamentals Nde Lgical address Physical address Netwrk interface card (NIC) Any device cnnected t a netwrk Unique name assigned t each nde n the netwrk Unique numeric that identifies each nde n the netwrk built int the hardware Expansin bard r adapter that prvides a cnnectin between the cmputer and the netwrk Ntebk cmputers have wireless NICs 11

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13 Netwrk Fundamentals USB wireless netwrk adapter USB dngle Plugs int a USB prt Usually prvides an intuitive graphical user interface (GUI) fr easy cnfiguratin Device inserted int a USB prt that adds additinal features t the base system Examples: enabling netwrk cnnectivity and increasing RAM Wireless PC card adapter Abut the size f a credit card Inserted int a slt n the side f mst ntebks and netbks Has built-in WiFi antenna that prvides wireless capability LED lights that indicate whether the cmputer is cnnected 13

14 Netwrk Fundamentals Hub Jins multiple cmputers tgether in a single netwrk Des nt manage traffic between the cnnectins Switches Filter and frward data between ndes Are similar t ruters but wrk within a single netwrk Ruters Cnnect tw r mre netwrks Inspect the surce and target f a data package Determine the best rute t transmit data 14

15 Netwrk Fundamentals Wireless access pint (WAP) Receives and transmits radi signals Jins wireless ndes t a wired netwrk 15

16 Netwrk Fundamentals Server File server Cmputer r device with sftware that manages netwrk resurces, such as files, s, printers, databases Mst cmmn type f server High-speed cmputer that prvides prgram and data files t netwrk users Cntains the netwrk perating system (NOS) File directries fr file and resurce lcatin n the LAN Autmated distributin f sftware updates t desktp cmputers n the WAN Internet services supprt Prtectin f services and data Access t cnnected hardware by authrized users 16

17 Netwrk Fundamentals Netwrk administratr Als called netwrk engineer Installs, maintains, supprts cmputer netwrks Interact with users Handle security Trublesht prblems 17

18 Advantages and Disadvantages f Netwrking Netwrking Advantages Reduced hardware csts Applicatin sharing Sharing infrmatin resurces Data management centralizatin Cnnecting peple Disadvantages Lss f autnmy Lack f privacy Security threats Lss f prductivity 18

19 Peer-t-peer (P2P) netwrks Lcal Area Netwrks Share files withut a file server Easy t set up Best used fr hme r small ffices with n mre than 10 cmputers D nt require a netwrk perating system Can be slw if there are t many users Security nt strng 19

20 Lcal Area Netwrks Peer-t-peer (P2P) netwrks 20

21 Lcal Area Netwrks Wireless LAN Cnnects users thrugh radi waves instead f wires Use includes netwrks in: Hmes Hspitals Clleges Secured with a radi transmissin technique that spreads signals ver a seemingly randm series f frequencies. Effective inside range f between 125 and 300 feet 21

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23 Lcal Area Netwrks Client/server netwrks Made up f ne r mre file servers and clients (any type f cmputer) Client sftware enables requests t be sent t the server Wired r wireless cnnectins D nt slw dwn with heavy use 23

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25 Lcal Area Netwrks Intranet Virtual private netwrk Passwrd-prtected netwrk cntrlled by the cmpany Accessed nly by emplyees Operates ver the Internet Accessible by authrized users fr quick access t crprate infrmatin Uses secure, encrypted cnnectins and special sftware 25

26 Lcal Area Netwrks LAN tplgies Netwrk tplgy Physical design f a LAN Tplgy reslves cntentin cnflict that ccurs when tw r mre cmputers n the netwrk attempt t transmit at the same time Cntentin smetimes results in cllisins crruptin f netwrk data caused when tw cmputers transmit at the same time 26

27 Lcal Area Netwrks LAN tplgies Bus tplgy Practical fr hme r small ffice One nde transmits at a time Terminatrs signify the end f the circuit Uses cntentin management technique that specifies what happens when a cllisin ccurs Star tplgy Ring tplgy Fr ffice buildings, cmputer labs, and WANs Easy t add users Fr a divisin f a cmpany r ne flr Nt in cmmn use tday Nde can transmit nly when it has the tken special unit f data that travels arund the ring 27

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31 LAN prtcls Lcal Area Netwrks Prtcls standards used by netwrks t permit cmmunicatin between netwrk-cnnected devices Mdulatin prtcls ensure that the mdem can cmmunicate with anther mdem, even if by a different manufacturer Prtcl suite cntains the prtcls f the netwrk and specifies its netwrk architecture, r hw the netwrk wrks 31

32 Lcal Area Netwrks LAN prtcls (cn t.) Netwrk layers divide netwrk architecture fr separate treatment Each netwrk layer can perate and be gverned by its wn prtcls. Prtcl stack vertical arrangement f netwrk layers 32

33 Lcal Area Netwrks LAN technlgies Ethernet mst-used LAN prtcl Ethernet star netwrks Mst ppular versins use twisted-pair wiring and switches Sends data in a fixed-size unit called a packet WiFi Uses radi waves t prvide a wireless LAN standard at Ethernet speeds Needs a central access pint culd be a wireless ruter Ht spts public wireless access lcatins 33

34 Wide Area Netwrks Pint f presence (POP) Backbnes WAN cnnectin pint used t btain access t the WAN Wired r wireless High-capacity WAN transmissin lines gigapp (gigabits per secnd pint f presence) transfers data exceeding 1 Gbps (1 billin bits per secnd) 34

35 Wide Area Netwrks WAN prtcls Internet prtcls Transmissin Cntrl Prtcl/Internet Prtcl (TCP/IP) Prtcls that define hw the Internet wrks Transmissin Cntrl Prtcl (TCP) Defines hw Internet-cnnected cmputers can exchange, cntrl, and cnfirm messages Internet Prtcl (IP) Prvides a distinct identificatin t any cmputer cnnected t the Internet: the IP address r Internet address 35

36 Wide Area Netwrks WAN prtcls (cn t.) Circuit switching Used by the public switched telephne netwrk t send data ver a physical end-t-end circuit Prvides a direct cnnectin between devices Packet switching Used fr cmputer cmmunicatin Divides and sends utging messages as packets, which are reassembled n receipt Mre efficient and less expensive than circuit switching Latency delay intrduced when a given packet is examined by many ruters Cngestin ccurs when the netwrk is verladed, causing sme packets t be further delayed 36

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41 Wide Area Netwrks WAN applicatins , cnferencing, dcument exchange, remte database access LAN t LAN cnnectins cnnect tw r mre gegraphically separate lcatins Transactin acquisitin the instant relay f transactin infrmatin frm a pint-f-purchase sale. 41

42 Hme Netwrks Hme Area Netwrks (HANs) Wired hme netwrks Wireless hme netwrks Hybrid netwrks Cmbinatin f wired and wireless technlgy 42

43 Hme Netwrks A Wired Hme Netwrk 43

44 Hme Netwrks A Wireless Hme Netwrk 44

45 Hme Netwrks Setting up a hme netwrk Planning Select technlgy Purchase equipment and firewall sftware Cnfiguring a wired netwrk Cnnect each cmputer t the ruter Plug printer, scanner, etc., int a cmputer 45

46 Hme Netwrks Setting up a hme netwrk (cn t.) Cnfiguring a wireless netwrk Cnnect each nde t wireless ruter with a wireless adapter Cnnect DSL r cable mdem t wireless ruter Maintenance and supprt Minimal maintenance required Unplug pwer surce frm ruter and ther peripherals and restart cmputer t crrect prblems 46

47 Hme Netwrks Future f hme netwrking Cnvergence will allw yu t use hme netwrks t Cntrl husehld appliances Prtect hmes with security systems Manage hme netwrk events thrugh central cntrl units in new hmes Utilize wireless systems Cntrl entertainment, temperature regulatin, and lighting 47

48 Summary Understand basic netwrking cncepts. Distinguish between a WAN, LAN, MAN, CAN, HAN, and PAN. Discuss the advantages and disadvantages f netwrks. Distinguish between peer-t-peer, client/server, and virtual private lcal area netwrks (LANs). 48

49 Summary Define tplgy and understand hw the three LAN tplgies differ. Explain the imprtance f netwrk prtcls. Name the mst widely used LAN prtcl and their versins. Identify the special cmpnents f a wide area netwrk (WAN) that differentiate it frm a LAN. 49

50 Summary Cntrast circuit-switching and packetswitching netwrks and explain their respective strengths and weaknesses. Identify the ptins, cmpnents, cnfiguratin, and maintenance f a hme area netwrk (HAN). 50