EC 301 COMPUTER NETWORKING FUNDAMENTALS

Transcription

1 EC 301 COMPUTER NETWORKING FUNDAMENTALS

2 CHAPTER 1: INTRODUCTION TO NETWORKING Prepared By: Sheila/JKE/PKB

3 CHAPTER 1 DURATION 6 HOURS (3 weeks) Lecture CLO 1 Explain the hardware and network devices to built LAN for a specific implementation (C2)

4

5 COMPUTER HARDWARE??

6 COMPUTER HARDWARE?? Processing Device Input Device HARDWARE Output Device Storage Device

7 COMPUTER SYSTEM? HARDWARE? SOFTWARE The instructions given to the computer in the form of a program which are used for different purposes.

8 COMPUTER SYSTEM?? under the control set of instructions processes Input raw data from the user an advanced electronic device gives the result Output saves In the storage space

9 COMPUTER NETWORK?? Network comprise 2 or MORE computers that have been connected A group of device, known as a node connected to media transmission.

10 COMPUTER NETWORK?? The computers can be geographically located anywhere. Enable them to communicate with each other and share resources and files.

11 BRIDGE ATM TELEKOM MALAYSIA REPEATERS SERVER ROUTER HUB HUB HUB HUB HUB BRIDGE HUB HUB WORKSTATION

12 Computer networks can be used for several purposes: Facilitating communications. Sharing hardware. Sharing files, data, and information. Sharing software. people can communicate each computer efficiently on a network and easily may via : access user may and access use hardware data and resources , Users instant connected messaging, information the to network, a network chat which such rooms, may stored as printing on other a Telephone, run application video document computers telephone programs on a on calls shared the and network. network video remote conferencing. computers. printer.

13 STAND-ALONE COMPUTER NETWORK COMPUTER

14 STAND-ALONE COMPUTER Connected to Printer / scanner individually Stored on Workstations / Pendrive / CD Connected to internet Security software installed On each computer. User keeps security software updated. Physical security typically poor Connecting teams through phone

15 STAND-ALONE COMPUTER NETWORK COMPUTER A single stand-alone computer can be very useful BUT it is when connected to other computers that it becomes possible to do some of the most powerful things.

16 Share Printer / scanner Stored on server. All files can be shared Shared internet connection Security software installed on server. Client for security software installed on workstations. Server auto updates workstations. Physical security for servers good Connecting teams through / NETWORK COMPUTER

17 2 TYPES of NETWORK P2P NETWORK CLIENT/SERVER NETWORK

18 P2P NETWORK are more commonly implemented where less then ten computers are involved and where strict security is not necessary.

19 P2P NETWORK each computer in the network act as both client or server for the other computers in the network allowing shared access to files/ with every other computer on the network and peripherals without the need for a central server

20 P2P NETWORK all computers in the network to use the same or a compatible program to connect to each other and access files and other resources found on the other computer.

21 CLIENT/SERVER NETWORK Suitable for larger network A computer network in which one centralized Powerful computer is a hub to which many less powerful personal computers or workstations are connected Clients run programs and access data that are stored on the server

22 P2P vs C/S Easy to setup. PEER-TO-PEER NETWORK Less expensive. Can be implemented on a wide range of operating systems. CLIENT/SERVER NETWORK More difficult to set up. More expensive to install. A variety of operating systems can be supported on the client computers, but the server needs to run an operating system that supports networking. More time consuming to maintain the software being used (as computers must be managed individually). Less time consuming to maintain the software being used (as most of the maintenance is managed from the server).

23 P2P vs C/S PEER-TO-PEER NETWORK Very low levels of security supported or none at all. These can be very cumbersome to set up, depending on the operating system being used. Ideal for networks with less than 10 computers. Does not require a server. Demands a moderate level of skill to administer the network. CLIENT/SERVER NETWORK High levels of security are supported, all of which are controlled from the server. Such measures prevent the deletion of essential system files or the changing of settings. No limit to the number of computers that can be supported by the network. Requires a server running a server operating system. Demands that the network administrator has a high level of IT skills with a good working knowledge of a server operating system.

24 CLIENT/SERVER NETWORK ELEMENT 11. Transmission Media 10. Topology 9. Segment 8 Backbone 6. Node 5 Network Operating System 7. Connectivity Device 1. Server 2. Client 3. Workstation 4. Network Interface Card

25 CLIENT/SERVER NETWORK ELEMENT 1. Client A computer on the network that requests resources or services from another computer on a network client could also act as a server. The term client may also refer to the human user of a client workstation or to client software installed on the workstation.

26 CLIENT/SERVER NETWORK ELEMENT 2. Server A computer on the network that manages shared resources usually have more processing power, memory, and hard disk space than clients. run network operating software that can manage not only data, but also users, groups, security, and applications on the network

27 CLIENT/SERVER NETWORK ELEMENT 3. Workstations All of the user computers connected to a network are called workstations. A typical workstation is a computer that is configured with a network interface card, networking software, and the appropriate cables.

28 CLIENT/SERVER NETWORK ELEMENT 3. Workstations 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

29 CLIENT/SERVER NETWORK ELEMENT 4. Network Interface Card (NIC) NIC provides the physical connection between the network and the computer workstation. Most NICs are internal, with the card fitting into an expansion slot inside the computer.

30 CLIENT/SERVER NETWORK ELEMENT 4. Network Interface Card (NIC) NICs are a major factor in determining the speed and performance of a network. The three most common network interface connections are Ethernet cards, LocalTalk connectors, and Token Ring cards.

31 CLIENT/SERVER NETWORK ELEMENT 5. Network Operating System (NOS) is the software that runs on a server and enables the server to manage data, users, groups, security, applications, and other networking functions.

32 CLIENT/SERVER NETWORK ELEMENT 5. Network Operating System (NOS) The network operating system is designed to allow shared file and printer access among multiple computers in a network, typically a local area network (LAN), a private network or to other networks.

33 CLIENT/SERVER NETWORK ELEMENT 5. Network Operating System (NOS) The most popular network operating systems are : Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, and Novell NetWare.

34 CLIENT/SERVER NETWORK ELEMENT 6. Node A client, server, or other device that can communicate over a network and that is identified by a unique number, known as its network addressers.

35 CLIENT/SERVER NETWORK ELEMENT 7. Connectivity device A specialized device that allows multiple networks or multiple parts of one network to connect and exchange data. A client/server network can operate without connectivity devices. However, medium- and large-sized LANs use them to extend the network and to connect with WANs.

36 CLIENT/SERVER NETWORK ELEMENT 8. Segment A network segment is a part of a computer network. The nature and extent of a segment depends on the nature of the network and the device or devices used to interconnect end stations. Device including routers, switches, hubs, bridges, or multi-homed gateways

37 CLIENT/SERVER NETWORK ELEMENT 9. Backbone The part of a network to which segments and significant shared devices such as routers, switches, and servers. A backbone is sometimes referred to as "a network of networks," because of its role in interconnecting smaller parts of a LAN or WAN.

38 CLIENT/SERVER NETWORK ELEMENT 10. Topology The physical layout of a computer network. Topologies vary according to the needs of the organization and available hardware and expertise. Networks can be arranged in a ring, bus, or star formation, and the star formation is the most common.

39 CLIENT/SERVER NETWORK ELEMENT 11. Transmission media The means through which data is transmitted and received. Transmission media may be physical, such as wire or cable, or atmospheric (wireless), such as radio waves.

40 CATEGORIES OF NETWORK

41 WIDE AREA NETWORK a A larger the group largest network of computers network than LAN that share a common connection high speed connects in a small computer area or even users in in the a particular same geographic building area or region. very expensive to setup METROPOLITAN AREA NETWORK an office or home network smaller than a WAN. connected by Ethernet cables LOCAL AREA NETWORK have high Speed connections.

42 LOCAL AREA NETWORK (LAN) Connect devices in a building

43 LOCAL AREA NETWORK (LAN) the computers are relatively close together. can be constructed only with two computers and one printer only, or can be extended in one building to include audio and video peripherals. LAN size is limited to a distance of several kilometers LANs would be within the same office, a single building, or several buildings close together. Common LAN topologies are bus, star and ring. LAN has a data rate of 4 Mbps to 100 Mbps.

44 METROPOLITAN AREA NETWORK (MAN) Connecting device between several buildings or area (city).

45 METROPOLITAN AREA NETWORK (MAN) is a network that interconnects users with computer resources in a geographic area or region LARGER than that covered by even a large LAN but SMALLER than the area covered by a WAN

46 WIDE AREA NETWORK (WAN) Can send data, audio and video at long distances around the world.

47 WIDE AREA NETWORK (WAN) A computer network that spans a relatively large geographical area. Computers connected to a WAN are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet.

48 INTERNET is a global network that links computer networks around the world Internet is from Internetworking word, that meaning of communication between networks. a network of network.

49 INTRANET A contained collection of computers and networks within an organizations connecting the organization's members and/or employees to a range of computer services, resources, and information. firewall is used to separate the Intranet from the Internet and to get permission to access the source.

50 INTERNET VS INTRANET

51 NETWORK TOPOLOGY Defines the way in which computers, printers, and other devices are connected. the layout of the wire and devices as well as the paths used by data transmissions.

52 BUS TOPOLOGY Commonly referred to as a linear bus, all the devices on a bus topology are connected by one single cable.

53 BUS TOPOLOGY Bus is a passive network. messages are usually broadcasted to every computer Computers in a network bus lines just listen in to find out whether there is data that is sent. This computer does not respond to send data to the computer next to it. If the computer fails, it does not give effect to the entire network.

54 BUS TOPOLOGY Advantages Quick, reliable in building a small network, easy to use and understand cable to connect your computer does not need much, so prices are cheap Easy to expand the bus. Two cables can be connected to become longer with BNC barrel Disadvantages make a lot of network traffic is extremely slow bus. Because any computer can send signals at any time, these interfere with each other Each barrel connector will weaken the signal, if too many connections can result in signal is not received correctly difficult to be recovered

55 STAR TOPOLOGY The star topology is the most commonly used architecture in Ethernet LANs. It connecting all the cables from the computer to a central location, where everything will be connected to a device known as a hub

56 STAR TOPOLOGY Each computer in a star topology communicate with the central hub that sends the message to the all computers (in a star network broadcast) or only to a certain destination computer

57 STAR TOPOLOGY Advantages Easier to update and add computers in the stars without disrupting network disadvantages If the central hub fails, the network fails Repairs of the network easily done in the center of the stars A damaged computer does not necessarily affect the network Requires device in the center of stars for rebroadcast, or convert (switch) network traffic higher price because of all the cables must be pulled from the center Can use several types of cables within the same network, with a hub that can accept different types of cables

58 RING TOPOLOGY circuit arrangement in which each network device is attached along the same signal path to other devices, forming a path in the shape of a ring. Each device in the network (node) handles every message that flows through the ring.

59 RING TOPOLOGY Each node in the ring has a unique address. Since in a ring topology there is only one pathway between any two nodes, ring networks are generally disrupted by the failure of a single link. Similarly in the Ring topology message can travel in only one direction i.e clockwise or anticlockwise.

60 RING TOPOLOGY The redundant topologies are used to eliminate network downtime caused by a single point of failure. It is used to produce highperformance network: the network require special bandwidth for the features such as video and audio, or high performance is required when many users access the network

61 RING TOPOLOGY Each computer receives the signal from the computer next to it and send these signals to the next computer Since each computer send the signal it receives, then the ring topology is an active network. No terminator is required because there is no end in this topology

62 RING TOPOLOGY Since the data is transferred as a sequence of the same route the possibility of the occurrence of data collisions do not occur Maintenance work for this system is somewhat similar to the star topology.

63 RING TOPOLOGY Each node can be connected to the network and can also be removed at any time without affecting the whole system directly. But one problem is if a node fails, the whole network system is likely to be affected.

64 RING TOPOLOGY Advantages As each computer is given the same to achieve the token, not a single computer can be a monopoly network disadvantages The failure of a computer will cause a network failure not easy to repair if damaged Increase or decrease the computer will disrupt the network

65 MESH/HYBRID TOPOLOGY there is only one possible path from one node to another node. If any cable in that path is broken, the nodes cannot communicate.

66 MESH/HYBRID TOPOLOGY Advantages As each computer is given the same to achieve the token, not a single computer can be a monopoly network disadvantages Durable, eg failure media is not disrupt the network when compared with other topologies It is easy to be recovered

67 NETWORK STANDARD There are several organizations in the United States and Europe that produces standards for data communications and computer networks. The role of these organizations are only suggested standards.

68 NETWORK STANDARD The organizations are: a. American National Standards Institute(ANSI) b. Electronic Industries Alliance (EIA) and Telecommunications Industry Association (TIA) c. Institute of Electrical and Electronic Engineers (IEEE) d. International Organization for Standardization (ISO) e. International Telecommunication Union (ITU) f. Internet Society (ISOC) g. Internet Assigned Numbers Authority (IANA) and Internet Corporation for Assigned Names and Numbers (ICANN)

69 NETWORK STANDARD a. American National Standard Institute (ANSI) is a private organization that coordinates all standards organizations in the United States. ANSI standards are among the organizations involved in COMPUTER AND DATA COMMUNICATIONS

70 NETWORK STANDARD b. Electronics Industries Association (EIA) is an organization representing many of expenditures in the ELECTRONICS INDUSTRY. Duties and responsibilities of EIA is more focused on ELECTRICAL STANDARD includingeia-232-d and EIA-499: important interface in the delivery / receipt of information

71 NETWORK STANDARD c. Institute of Electrical and Electronic Engineers (IEEE) is a professional organization will issue a standard in their respective fields and this standard will be adopted by consumers. In the computer world, better known in the developing IEEE standard Local Area Network (LAN) which is designated as IEEE 802.

72 NETWORK STANDARD d. Internatinal Standards Organization (ISO) is a voluntary organization with membership from several countries. ISO to work with other organizations such as CCITT and ANSI standards to create some standards such as HDLC (High-level data link control)

73 NETWORK STANDARD e. Internatinal Telecommunication Union (ITU) an intergovernmental organization through which public and private organizations develop telecommunications. The ITU was founded in 1865 and became a United Nations agency in 1947.

74 NETWORK STANDARD e. Internatinal Telecommunication Union (ITU) It is responsible for adopting international treaties, regulations and standards governing telecommunications. The standardization functions were formerly performed by a group within the ITU called CCITT, but after a 1992 reorganization the CCITT no longer exists as a separate entity.

75 PRINCIPLES OF COMMUNICATION NETWORKING SOURCE CHANNEL DESTINATIONS

76 PRINCIPLES OF COMMUNICATION NETWORKING SOURCE CHANNEL DESTINATIONS

77 PRINCIPLES OF COMMUNICATION NETWORKING SOURCE CHANNEL Message sources are people or electronic devices, that need to send a message to other individuals or devices. the media that provides the pathway over which the message can travel from source to destination. DESTINATIONS The receiver of the message

78 PRINCIPLES OF COMMUNICATION NETWORKING Most networks has one feature in common: Transmitting information by breaking the original information into a set of message (packets) Transmitting packets sequentially Reassembling packet back into original information

79 PRINCIPLES OF COMMUNICATION NETWORKING In order to make sure the original message get transmitted correctly, computer networks used a set of rules: Establish a link Issue a command and command qualifier Acknowledgement of command Dissection message Error detection and correction Termination of transmission

80 PRINCIPLES OF COMMUNICATION NETWORKING Establish a Link

81 PRINCIPLES OF COMMUNICATION NETWORKING Establish a Link

82 PRINCIPLES OF COMMUNICATION NETWORKING Establish a Link Each packet is a string of bits and have to travel along way over a bunch of different network Typically lots of computer sending and receiving information over the same network The information getting sent can often get altered during transmission

83 PRINCIPLES OF COMMUNICATION NETWORKING Issues a command and Command Qualifier The SET NETWORK command allows to control information about network services on an Open system. Each structure defines a particular network service and contains the following information: Product name Manufacturer Type of network Node name Address(es) Interface(s) (OpenVMS device driver)

84 PRINCIPLES OF COMMUNICATION NETWORKING Issues a command and Command Qualifier Vendor-specific data Status Connections Counters Start command Stop command Path to the Point-to-Point Protocol utility (PPPD) shareable image

85 PRINCIPLES OF COMMUNICATION NETWORKING Acknowledgement of Command Router receiving packets from DTE A destined for DTE B Without acknowledgment the router forwards packets to the X.25 network and then forwards acknowledgments from the network back to DTE A. With acknowledgment the router can acknowledge packets received from DTE A before it has received acknowledgments from the network for the forwarded packets.

86 PRINCIPLES OF COMMUNICATION NETWORKING Acknowledgement of Command Acknowledgment is transmitted between local hops much faster and more efficiently than between end-to-end hops.

87 PRINCIPLES OF COMMUNICATION NETWORKING Dissection Message Proxies are good firewalls because the entire packet is dissected and each section can be examined for invalid data at each layer of the OSI model.

88 PRINCIPLES OF COMMUNICATION NETWORKING Dissection Message a proxy can examine a packet for information contained in everything from the packet header to the contents of the message. Attachments can also be checked for viruses. Messages can be searched for keywords that might indicate the source of a packet.

89 PRINCIPLES OF COMMUNICATION NETWORKING Error Detection and Correction Data can be corrupted during transmission. ERROR = Data Send Data Received

90 PRINCIPLES OF COMMUNICATION NETWORKING Error Detection and Correction 2 types of ERROR Single bit Error In a single-bit error, only 1 bit in the data unit has changed. Burst Error A burst error means that 2 or more bits in the data unit have changed.

91 PRINCIPLES OF COMMUNICATION NETWORKING Error Detection and Correction

92 PARITY CHECK - ODD PARITY Parity bit will be in charge to make sure Total bit 1 for bits words must be ODD EVEN PARITY Bit = = 3 LSB MSB ODD 8 bits words

93 PARITY CHECK - EVEN PARITY Parity bit will be in charge to make sure Total bit 1 for bits words must be EVEN EVEN PARITY Bit = = 2 LSB MSB EVEN 8 bits words

94 CYCLIC REDUNDANCY CHECK Method used to detect and correct error Need to send extra bits with data Redundancy bits are added by sender and removed by the receiver Allows the receiver to detect or correct corrupted bits

95 CYCLIC REDUNDANCY CHECK Sender Receiver

96 CHECKSUM Sender Receiver Bin Dec Dec Bin ,11,12,0,6,9 9 Sum 36 Sum 45 Wrapped Sum 6 Wrapped Sum 15 Checksum 9 Checksum

97 PRINCIPLES OF COMMUNICATION NETWORKING Error Detection VS Error Correction Detecting Error Looking only to see if any error occurred. Correcting Error More difficult because need to know the exact number of bits are corrupted and more importantly the location of the message Number of error and size of message are also important factors

98 PRINCIPLES OF COMMUNICATION NETWORKING Termination of Transmission each side of the connection terminating independently. When an endpoint wishes to stop its half of the connection, it transmits a FIN packet, which the other end acknowledges with an ACK. Therefore, a typical tear-down requires a pair of FIN and ACK segments from each TCP endpoint.

99 PRINCIPLES OF COMMUNICATION NETWORKING Termination of Transmission After both FIN/ACK exchanges are concluded, the terminating side waits for a timeout before finally closing the connection, during which time the local port is unavailable for new connections; this prevents confusion due to delayed packets being delivered during subsequent connections.

100 TERMINOLOGIES IN COMMUNICATION NETWORKING

101 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Encoding The destination host receives and decodes the signals in order to interpret the message. Messages sent across the network are first converted into bits by the sending host. Each bit is encoded into a pattern of light waves or electrical impulses depending on the network media over which the bits are transmitted.

102 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Encapsulation Messages are encapsulated before being sent to the appropriate location

103 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Formatting On a network messages are formatted into frames

104 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Formatting

105 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Size Messages have size restrictions depending on the channel used Messages must be of a particular size Ethernet message sizes are limited to bytes

106 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing the amount of time from the beginning until the end of a message transmission.

107 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing Tx Msg End of Msg Rx ready to listen for ACK Time wait to Tx ACK Start Tx Msg Start listening Rx Msg Min time to wait Rx Msg Rx Msg Start ACK

108 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing Access method Determines when a message can be sent to avoid collisions Flow control Determines how much information can be sent at any given time Response timeout Determines what action to take if there is no response in a reasonable time period

109 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing

110 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing The packet transmission time in seconds can be obtained from the packet size in bit and the bit rate in bit/s as: Packet transmission time = Packet size Bit rate

111 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing Example: Assuming 100 Mbit/s Ethernet and the maximum packet size of 1526 bytes. Calculate the results in Maximum packet transmission time?

112 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Timing Example: Max packet transmission = Packet size Bit rate = 1526*8 bit (1 Mbit/s) 122 μs

113 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Patterns a network-oriented architectural pattern describes how two different parts of a message passing system connect and communicate with each other.

114 TERMINOLOGIES IN COMMUNICATION NETWORKING Message Patterns

115 TERMINOLOGIES IN COMMUNICATION NETWORKING My friend at Putrajaya want to send me a files using my PKB . After sending the she identify that the files that she has attached cannot get through the PKB server. In a given scenario, identify which terminologies can be relate to this communication problem in networking.

116 FUNCTION OF NETWORING HARDWARE Networking equipment typically refers to devices facilitating the use of a computer network. includes gateways, routers, bridges, switches, hubs, and repeaters.

117 FUNCTION OF NETWORING HARDWARE A network interface controller /network interface card is a computer hardware component that connects a computer to a computer network.

118 FUNCTION OF NETWORING HARDWARE NIC NIC provides the hardware interface between a computer and a network. A NIC technically is network adapter hardware in the form factor of an add-in card

119 FUNCTION OF NETWORING HARDWARE Various types of NIC PCI NIC PCI Express NIC PCMCIA On Board NIC Wireless NIC

120 FUNCTION OF NETWORING HARDWARE PCI NIC Peripheral Component Interconnect is an industry specification for connecting hardware devices to a computer's central processor. Both Ethernet and Wi-Fi network adapters for desktop and notebook computers commonly utilize PCI.

121 FUNCTION OF NETWORING HARDWARE PCI NIC PCI defines the electrical characteristics and signal protocol used for two devices to communicate over a computer's central bus. PCI network adapters and other devices exist in several different shapes and sizes

122 FUNCTION OF NETWORING HARDWARE PCI Express NIC It is used to connect Fast Ethernet Networks together and it is connected to a PCI Slot located on your computer's Motherboard

123 FUNCTION OF NETWORING HARDWARE PCMCIA/PC card Personal Computer Memory Card International Association is an industry organization best know for developing a standard network adapter using the PC Card form factor. PC Card form factor was designed for thinness, and PCMCIA is therefore especially used mostly in removable peripherals that connect to a laptop.

124 FUNCTION OF NETWORING HARDWARE On Board NIC A LAN connection or network connection In a desktop, NIC's, video cards, sound cards and such can be inserted into physical slots on the motherboard but in a laptop there is no room for such a configuration. All of these things are built right in to the motherboard. Some desktops integrate these things as well but still maintain the slots as described above. So, an "onboard" or integrated NIC card would not be plugged into one of these slots.

125 FUNCTION OF NETWORING HARDWARE Wireless NIC WNIC is a network interface controller which connects to a radio-based computer network rather than a wire-based network A WNIC is an essential component for wireless desktop computer. this card uses an antenna to communicate through microwaves.

126 FUNCTION OF NETWORING HARDWARE HUB/SWITCH A HUB is a device that provides a central connection point for cables from workstations, servers and peripherals.

127 FUNCTION OF NETWORING HARDWARE HUB/SWITCH multi slot concentrators which can plugged a number of multi-port cards to provide additional access as the network grows in size.

128 FUNCTION OF NETWORING HARDWARE HUB/SWITCH 2 Types of HUB 1. PASSIVE concentrators/hub No voltage supply allow the signal to pass from one computer to another without amplify the signal. 2. ACTIVE concentrators/hub Need voltage supply to electrically amplify the signal as it moves from one device to another Act like repeaters that can extend the length of a network.

129 FUNCTION OF NETWORING HARDWARE REPEATERS an electronic device that receives a signal, cleans it of unnecessary noise, regenerates and retransmits it can be separate devices or they can be incorporated into a concentrator/hub.

130 FUNCTION OF NETWORING HARDWARE REPEATERS it is necessary to regenerates the signal a signal loses strength as it passes along a long distance cable The repeater electrically amplifies the signal it receives and rebroadcasts it at a higher power level the signal can cover longer distances without degradation signal Long Distance Cable signal

131 FUNCTION OF NETWORING HARDWARE BRIDGE a device to allows segment of a large network into two smaller to reduce the amount of traffic on a networks and make the traffic more efficient. 2 nd Network 1 st Network BRIDGE

132 FUNCTION OF NETWORING HARDWARE BRIDGE BRIDGE also can filters data traffic at a network boundary. 1 st Network 2 nd Network

133 FUNCTION OF NETWORING HARDWARE BRIDGE can connect the 2 network. adding new wiring scheme into an older wiring scheme or To up-date the network BRIDGE Network New Network

134 FUNCTION OF NETWORING HARDWARE BRIDGE MONITORS the information traffic on both sides of the network so that it can pass packets of information to the correct location. 1 st Network 2 nd Network

135 FUNCTION OF NETWORING HARDWARE BRIDGE LISTEN" to the network and automatically figure out the address of each computer on both sides of the bridge. 1 st Network 2 nd Network

136 FUNCTION OF NETWORING HARDWARE BRIDGE INSPECT each message and broadcast it on the other side of the network. 1 st Network 2 nd Network

137 FUNCTION OF NETWORING HARDWARE BRIDGE MANAGE the traffic to maintain optimum performance on both sides of the network (like a traffic cop at a busy intersection during rush hour. 1 st Network 2 nd Network

138 FUNCTION OF NETWORING HARDWARE ROUTER A ROUTER translates information from one network to another it is similar to a super intelligent bridge. A ROUTER select the best path to route a message, based on the destination address and origin.

139 FUNCTION OF NETWORING HARDWARE ROUTER The ROUTER can direct traffic to prevent head-on collisions or traffic It is smart enough to know when to direct traffic along back roads and shortcuts.

140 FUNCTION OF NETWORING HARDWARE GATEWAY is a network point that acts as an entrance to another network. an internetworking system capable of joining together two networks that use different base protocols.

141 FUNCTION OF NETWORING HARDWARE GATEWAY The computers that control traffic within a company's network or at a local Internet service provider (ISP) are gateway nodes.

142 FUNCTION OF NETWORING HARDWARE GATEWAY In PKB s, a computer server acting as a gateway node and it also acting as a proxy server and a firewall server. A gateway is often associated with both a router, which knows where to direct a given packet of data that arrives at the gateway, and a switch, which furnishes the actual path in and out of the gateway for a given packet.

143 REFLECTION Tell the class, what is the function of computer network hardware? Name 2 out of 5 of the computer network hardware that u remember. Identify which computer network hardware can select the best path to bring a message, based on the destination address and origin.

144 ACTIVITIES Sketch a simple peer to peer computer network at your house to show connection between 4 individual user playing and sharing web game.

145 ACTIVITIES Construct a diagram of the local area network in JKE s Multimedia Computer Lab which include 40 connected PCs and 1 shared printer. The lab have 10 Ethernet jack. Add any network hardware to apply to the connection.

146 ACTIVITIES The network in JKE s Office includes 44 connected PCs, 2 shared printers and 4 telephones with their own Ethernet jack. If there are 2 more PCs and 1 wireless router need to be add in the office but with no more Ethernet jack available. Design the connection to show the new JKE s office network. Add any network hardware to apply to the connection.

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