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NETWORKS A network is combination of all the components (hardware and software) involved in connecting devices across small and large distances.

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Presentation on theme: "NETWORKS A network is combination of all the components (hardware and software) involved in connecting devices across small and large distances."— Presentation transcript:


2 NETWORKS A network is combination of all the components (hardware and software) involved in connecting devices across small and large distances.


4 COMPUTERS Running Operating System are responsible for providing application to the user. PC (PERSONAL COMPUTER): A PC is a general-purpose computer as well as use as a Client SERVERS: A computer on a network that manages network resources.

5 NETWORKS COMPONENTS SWITCHES & HUBS: Switches & Hubs are the devices used to connect different computers on LAN through network cables. Switches manage the flow of data across a network. Switch is a Active Device (with software) and Hub is a Passive Device (without software).

6 NETWORKS COMPONENTS MODEM: A modem (modulator-demodulator) is a device that modulates an analog signal to encode digital information and demodulates the signal to decode the transmitted information.

7 NETWORKS COMPONENTS ROUTERS: A router is a device that forwards data packets between computer networks. Connected to two or more data lines from different networks. When a data packet comes in one of the lines, the router reads the address information in the packet to determine its ultimate destination.

8 NETWORKS COMPONENTS FIREWALL: A firewall is a software or hardware-based network security system that controls the incoming and outgoing network traffic. Establishes a barrier between a internal network and another network. Operating Systems has software-based firewall.


10 PAN (Personal Area Network) LAN (Local Area Network) MAN (Metropolitan Area Network) WAN (Wide Area Network) SAN (Storage Area Network) CNs (Content Networks) VPNs (Virtual Private Network) INTRANET & INTERNET

11 NETWORKS TYPES PAN (Personal Area Network) A PAN is a network that is used for communicating among computers and computer devices (including telephones) in close proximity of around a few meters within a room It can be used for communicating between the devices themselves, or for connecting to a larger network such as the internet

12 NETWORKS TYPES PAN (Personal Area Network)

13 NETWORKS TYPES LAN (Local Area Network) Local Area Networks (LANs) are used to connect networking devices that are in a very close geographical area, such as building, or a campus environment LAN’s enable the sharing of resources such as files or hardware devices that may be needed by multiple users LAN’s can be either wired or wireless.

14 NETWORKS TYPES LAN (Local Area Network)

15 NETWORKS TYPES MAN (Metropolitan Area Network) A MAN is optimized for a larger geographical area than a LAN, ranging from several blocks of buildings to entire cities A MAN might be owned and operated by a single organization, but it usually will be used by many individuals and organization

16 NETWORKS TYPES MAN (Metropolitan Area Network)

17 NETWORKS TYPES WAN (Wide Area Network) A WAN consists of two or more local-area networks (LANs) A WAN is a network that covers a broad area that links across metropolitan, regional, or national boundaries Computers connected to a WAN are often connected through public networks, such as the telephone system. The largest WAN in existence is the Internet

18 NETWORKS TYPES WAN (Wide Area Network)


20 NETWORKS TYPES (Storage Area Network) A SAN is a network dedicated to storage that is attached to a company's communication networks. Computers with access to the SAN have a specific network interface that is connected to the SAN in addition to their traditional network interface.

21 NETWORKS TYPES (Storage Area Network)

22 NETWORKS TYPES CDN (Content Distribution Network) A CDN is a large distributed system of servers deployed in multiple data centers CDN were developed to ease users’ access to Internet resources. Distributing Internet traffic loads across multiple servers

23 NETWORKS TYPES CDN (Content Distribution Network)

24 NETWORKS TYPES VPN (Virtual Private Network) A VPN extends a private network across a public network. It enables a computer to send and receive data. This is done by establishing a point-to-point dedicated connection VPN securely and cost-effectively connect geographically disparate offices of an organization

25 NETWORKS TYPES VPN (Virtual Private Network)

26 NETWORKS TYPES INTRANET An Intranet is a computer network that uses Internet Protocol technology to share information, operational systems, or computing services within an organization Intranets can help users to locate and view information faster and use applications relevant to their roles and responsibilities


28 NETWORKS TYPES INTERNET A global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols. All the countries in the world are linked into exchanges of data, news and opinions. According to Internet World Stats, there was an estimated 2,26,72,33,742 Internet users worldwide. This represents 32.7% of the world's population.



31 When you cabling up your computers and networking devices, various types of topologies can be used. A topology define how the devices are connected. Point to Point Bus Ring Mesh Star Tree

32 NETWORKS TOPOLOGIES POINT TO POINT: A Point to Point topology has a single connection between two devices and directly communicate without interference from other devices

33 NETWORKS TOPOLOGIES BUS: A Bus topology uses a single connection or wire to connect all devices

34 NETWORKS TOPOLOGIES RING: In Ring topology, each device connects to only its immediate neighbors

35 NETWORKS TOPOLOGIES MESH: In Mesh topology, each device has dedicated point-to-point link to every device

36 NETWORKS TOPOLOGIES STAR: In Star topology, each device has dedicated point-to-point link only a central controller (Switch/Hub)

37 NETWORKS TOPOLOGIES TREE: A tree topology is a combination of a star topology and a Bus topology


39 TERMS: Data: Entities that convey meaning, or information Signals: Electric or electromagnetic representations of data Transmission: Communication of data by the propagation and processing of signals

40 DATA COMMUNICATION COMPONENTS: A data communication system has five Components: Sender Receiver Data Medium Protocols

41 DATA COMMUNICATION FUNDAMENTALS: The effectiveness of a data communication system depends on following Fundamentals: Delivery Accuracy Timelines

42 DATA COMMUNICATION DATA FLOW: Communication between two devices can be following data flow: Simplex Half-duplex Full-duplex

43 DATA COMMUNICATION DATA REPRESENTATION: In data communication, information is represented the following: Text Image Audio Video


45 GUIDED MEDIA: Guided media refers to the transmission of information within a physical boundary. The signals pass through a physical pathways such as wired transmission Coaxial cables, twisted pair and fiber optic cables are some examples of guided media.

46 GUIDED MEDIA COAXIAL CABLE: Coaxial cable conducts electrical signal using an inner conductor (usually a solid copper) surrounded by an insulating layer and all enclosed by a shield. The most common type of connector is Bayone- Neill-Conelman(BNC).

47 GUIDED MEDIA TWISTED-PAIR CABLE: A twisted-pair consists of two conductors, each with its own plastic insulation. The most common Twisted-pair used in communication unshielded twisted-pair (UTP). Twisted-pair connector is RJ-45 (Registered Jack).

48 GUIDED MEDIA FIBER-OPTIC CABLE: A Fiber-optic cable is made of glass or plastic and transmit signal in the form of light. There are three types of connectors for fiber- optic cable. SC Connector, ST Connector and MT-RJ.

49 GUIDED MEDIA SC Connector: The subscriber Channel (SC) Connector is used for cable TV. It uses a push/pull locking system. ST Connector: The Straight-tip (ST) connector is used for connecting cable to networking devices MT-RJ Connector: Mechanical Transfer Registered Jack is connector that is the same size as RJ45

50 TRANSMISSION MEDIA UNGUIDED MEDIA: Unguided media transport electromagnetic waves without using a physical conductor. All unguided media transmission are classified as Wireless Communication. Wireless transmission can be divided into three broad groups: Infrared, Radio waves and Microwave.

51 INFRARED: Infrared signals can be used for short-range communication in a close area. The Infrared Data Association (IrDA) has established standards for using these signals for communication between devices such as Keyboard, Mouse, PCs and Printers WIRELESS COMMUNICATION

52 RADIO WAVES: Radio waves use omnidirectional antennas that send out signal in all direction. The omnidirectional useful for multicasting in which there is one sender but many receiver. Example: AM, FM, Television and Cordless phone WIRELESS COMMUNICATION


54 MICROWAVES: An electromagnetic wave (A wave of energy having a frequency, consisting of electric and magnetic fields, oscillating at right angles to each other). Frequency Between 1 and 300 Gigahertz. Use unidirectional antennas that send out signals in one direction. Microwaves are used for unicast (one-to-one) communication which there is one sender and one receiver. WIRELESS COMMUNICATION


56 MICROWAVES EXAMPLES : Cellular Telephones Satellite Networks Wireless LANs TYPES OF MICROWAVES: Terrestrial Microwave Satellite Microwaves

57 WIRELESS COMMUNICATION TERRESTRIAL MICROWAVES: Terrestrial Microwaves are used to transmit wireless signals across a few miles. Terrestrial system requires that direct parabolic antennas can be pointed to each other

58 WIRELESS COMMUNICATION SATELLITE MICROWAVES: Satellite microwave transmit signals through out the world. These system use satellites in orbit about 50,000 Km above the earth. Satellite dishes are used to send the signals to the satellite where it is again send back down to the receiver satellite. These transmissions also use directional parabolic antenna.







65 The International Standard Organisation (ISO) is responsible for a wide range of standards Networks built used different hardware and software implementations The ISO recognised there was a need to create a NETWORK MODEL The ISO developed the Open System Interconnection (OSI) reference model

66 OSI REFERENCE MODEL The OSI reference model divides the process of Data transmission into SEVEN manageable functions known as LAYERING 7.Application 6.Presentation 5.Session 4. Transport 3.Network 2.Data Link 1.Physical

67 OSI REFERENCE MODEL APPLICATION: It provides user interfaces to the user’s applications To allow to access networks recourse Examples: Word processing programs, Excel sheet program or Bank terminal programs

68 OSI REFERENCE MODEL PRESENTATION: The Presentation layer is responsible for defining how information is presented To translate, encrypt and compress the data Example: Graphical info (BMP/JPG), Audio (WAV and MIDI) and video (MPEG and AVI)

69 OSI REFERENCE MODEL SESSION: The Session layer is responsible for differentiating among multiple network connection, ensuring that data is sent across the correct connection as well as taking data from a connection and forwarding it to the correct application

70 OSI REFERENCE MODEL TRANSPORT: The Transport layer is responsible for the delivery of a message from one process to another Ensures end-to-end connectivity between host applications Transport Layer protocols are TCP and UDP

71 OSI REFERENCE MODEL NETWORK: The Network layer is responsible for the delivery of individual packets from the source to destination The Network layer provides a logical Network Address (IP) Router operate at Network Layer

72 OSI REFERENCE MODEL DATA LINK: The Data link layer defines hardware (MAC) Address A MAC address is represented as hexadecimal number; it is 12 characters in length. Eg FFFF.FFFF.FFFF Switches and LAN Cards operate at this layer

73 OSI REFERENCE MODEL PHYSICAL: The Physical layer is responsible for the movement of individual bits from one hop (node) to the next The Physical layer provides physical mechanics of a network connection, which include the type of cable used for connecting devices Hubs and Modem operate at this layer

74 TCP/IP Protocol Stack TCP/IP stands for Transmission Control Protocol/Internet Protocol Initially funded and developed by DARPA (Defense Advanced Research Projects Agency) for Government use TCP/IP defines how machines on an internet work can communicate with each other

75 TCP/IP Protocol Stack The TCP/IP protocol suite is made of five layers: Application, Transport, Network, Data Link and Physical The three topmost layers in the OSI model (Application, Presentation & Session) are represented in TCP/IP by a single layer called the application layer

76 TCP/IP Protocol Stack ADDRESSING Three different levels of addresses are used in an internet using the TCP/IP protocols: Physical (link) address Logical (IP) address Port address

77 TCP/IP Protocol Stack


79 IP Address stand for Internet Protocol address IP Address is a unique identification given to Host, network device, server for data communication IP is an addressing scheme used to identify a system on a network 32 bits in length (4 bytes), broken into 4 octets 11000000. 10101000.00000001. 01100100 8bit+ 8bit + 8bit + 8bit


81 IP ADDRESSING RANG Class A: from to Class B: from 128.x.x.x to 191.x.x.x. Class C: from 192.x.x.x to 223.x.x.x Class D: from 224.x.x.x to 239.x.x.x (Multicast) Class E: from 240.x.x.x to 255.x.x.x (Reserved) The class A address 127.x.y.z is reserved for loopback testing and inter process communication on the local computer.

82 PRIVATE ADDRESSES Class A: to (1 Class A Network) Class B: to (16 Class B Network) Class C: (256 Class C Network)

83 IP ADDRESSING COMPONENTS The first address in the network shows the Network Address, it defines the organization network, it is one that the used by routers to direct the message sent to the organization from the outside. The last address in the network shows the Broadcast Address. The second address to second last address in the network shows the Host Addresses.

84 IP ADDRESSING COMPONENTS IP Address Pool To Network Address Host Addresses To Broadcast Address

85 DHCP (Dynamic Host Configuration Protocol) DHCP is a standardized networking protocol used on Internet Protocol (IP) networks for dynamically distributing network configuration parameters, such as IP addresses for interfaces and servers. With DHCP, computers request IP addresses and networking parameters automatically from a DHCP server, reducing the need for a network administrator or a user to configure these settings manually.

86 DHCP (Dynamic Host Configuration Protocol)

87 DNS (Domain Name System) The (DNS) is a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network. It translates easily memorized domain names to the numerical IP addresses needed for the purpose of locating computer services and devices worldwide. The Domain Name System is an essential component of the Internet and specifies the technical functionality of this database service.

88 DNS (Domain Name System)

89 NAT (Network Address Translation) NAT is designed for IP address conservation. It enables private IP networks that use unregistered IP addresses to connect to the Internet. NAT operates on a router, and translates the private addresses in the internal network into public addresses. A single unique IP address is required to represent an entire group of computers to anything outside their network.

90 NAT (Network Address Translation)

91 ARP (Address Resolution Protocol) ARP is a telecommunication protocol used for resolution of network layer addresses into link layer addresses. ARP is used to convert an IP address to a physical address. ARP has been implemented with many combinations of network and data link layer technologies, using IEEE 802 standards. RARP, permits a physical address, to be translated into an IP address.

92 ARP (Address Resolution Protocol)

93 IPv6

94 Limitations of IPv4 Exhaustion of the Address Space The current version of IP (IPv4) has not changed substantially since (RFC) 791, published in 1981. The recent exponential growth of the Internet and the impending exhaustion of the IPv4 address space. 32-bit address space of IPv4 allows for 4,294,967,296 addresses. Requirement for security at the Internet layer Internet Protocol Security (IPSec) is optional for IPv4 and additional security solutions.

95 Limitations of IPv4 Need for simpler configuration IPv4 implementations must be either manually configured or use a stateful address configuration protocol such as Dynamic Host Configuration Protocol (DHCP). Need for real-time delivery of data Real-Time traffic support relies on the 8 bits of IPv4 Type of Service (TOS) field. Typically using a UDP or TCP port. Unfortunately, the IPv4 TOS field has limited functionality

96 Limitations of IPv4 Network Address Translator Address or Port translation requires additional processing and software components on the NAT called NAT editors. Hyper Text Transfer Protocol (HTTP) traffic on the World Wide Web (WWW) does not require a NAT editor because all HTTP traffic requires only address and TCP port translation. NATs are typically not deployed in large-scale environments.

97 Features of IPv6 New Header Format The IPv6 header has a new format that is designed to minimize header processing. The streamlined IPv6 header is more efficiently processed at intermediate routers. IPv6 is not a superset of functionality that is backward compatible with IPv4. The number of bits in IPv6 addresses is four times larger than IPv4 addresses.

98 Features of IPv6 Large Address Space IPv6 has 128-bit (16-byte) source and destination addresses. 128 bits can express over 3.4 × 1038 possible combinations. IPv6 has been designed to allow for multiple levels of subnetting and address allocation New Protocol for Neighboring Node Interaction Neighbor Discovery replaces and extends the Address Resolution Protocol (ARP) and ICMPv4.

99 Features of IPv6 Stateless and Stateful Address Configuration IPv6 supports both stateful address configuration (presence of a DHCPv6 server) and stateless address configuration (absence of a DHCPv6 server). With stateless address configuration, hosts on a link automatically configure themselves with IPv6 addresses for the link (called link-local addresses)

100 IPv6 Addressing Address Space The size of an address in IPv6 is 128 bits, a bit- string that is four times longer than the 32-bit IPv4 address. A 32-bit address space allows for 2 32, or 4,294,967,296, possible addresses. A 128-bit address space allows for 2 128, or 340,282,366,920,938,463,463,374,607,431,768, 211,456 (3.4 × 10 38 or 340 undecillion), possible addresses.

101 IPv6 Addressing Syntax IPv6, the 128-bit address is divided along 16-bit boundaries, Each 16-bit block is converted to a 4-digit hexadecimal number and separated by colons. The 128-bit address is divided along 16-bit boundaries: 0010000000000001 0000110110111000 0000000000000000 0010111100111011 0000001010101010 0000000011111111 1111111000101000 1001110001011010 Each 16-bit block is converted to hexadecimal and delimited with colons. 2001:0DB8:0000:2F3B:02AA:00FF:FE28:9C5A

102 Syed Najam ul Hassan MCS-58644, PAF(Kiet) IT Professional, SUPARCO 0321-8901510 T H A N K S

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