Network of Networks Vineeth Nagumantri Roll No MBA(P)-B

UNIT-II Technical Aspects of EC A Network of Networks TCP/IP Hyper Text Transfer Protocol Web Browsers Web Servers Commercial Web Servers Intranet Extranet EDI

LEARNING OUTCOMES A Network of Networks Internet Define Computer Networks Define Communication State Importance of Computer network and communication Network classification Types of networks Comparison of different networks TCP/IP Hypertext Transfer Protocol

Internet A network formed by the co-operative interconnection of a large no. of computer networks. Since Internet is formed by the interconnection of no. of networks, sometimes its also called as network of networks

COMPUTER NETWORK What is…

Computer network A computer network is a system of interconnected computers and peripheral devices. For example, it may connect computers, printers, scanners and cameras.

COMMUNICATIONS What is…

Communications Communications is about the transfer of information from a sender, across a distance, to a receiver. Communication is an act of transmitting messages.

Computer network communication We transmit information or data by using two types of signals, namely analog and digital. Computers communicate with digital signals. The older forms of communications technology, such as telephones and radios, use analog signals.

Network Classification Connection method Computer networks can also be classified according to the hardware and software technology that is used to interconnect the individual devices in the network, such as Optical fiber, Ethernet, Wireless LAN, HomePNA, Power line communication or G.hn. Scale Based on their scale, networks can be classified as Local Area Network (LAN), Wide Area Network (WAN), Metropolitan Area Network (MAN), Personal Area Network (PAN), Virtual Private Network (VPN), Campus Area Network (CAN), Storage Area Network (SAN), etc.(LAN) (WAN)(MAN)(PAN) (VPN)(CAN)(SAN) Functional relationship (network architecture) Computer networks may be classified according to the functional relationships which exist among the elements of the network, e.g., Active Networking, Client-server and Peer-to-peer (workgroup) architecture. Network topology Computer networks may be classified according to the network topology upon which the network is based, such as bus network, star network, ring network, mesh network, star-bus network, tree or hierarchical topology network.network topology

Types of Networks Local area network(LAN) Metropolitan area network(MAN) Wide area network(WAN) Personal area network (PAN) Campus area network (CAN) Global area networks (GAN) Virtual private network (VPN)

LOCAL AREA NETWORK (LAN) Smallest network compared to the other two networks. The simplest form of LAN is to connect two computers together. LAN is operated within a limited physical area, such as at home, school, a single building or several buildings. A network which consists of less than 500 interconnected devices across several buildings, is still recognised as a LAN.

METROPOLITAN AREA NETWORK (MAN)  A metropolitan area network (MAN) is a network that connects two or more local area networks or campus area networks together but does not extend beyond the boundaries of the immediate town/city. MANs provide Internet connectivity for LANs in a metropolitan region, and connect them to wider area networks like the Internet  A MAN is made from switches or routers connected to one another with high-speed links (usually fibre optic cables).  Metropolitan Area Networks (MANs) are networks that connect LANs together within a city.

WIDE AREA NETWORK (WAN) The largest network of all network types. Internet is the largest WAN in the world. WAN generally covers large distances such as states, countries or continents. This is network which covers a large geographical area, and use communications circuits to connect the intermediate nodes. In other words this is in contrast to both the local area network and the metropolitan area network, which provides communication within a restricted geographic area. WAN is a group of MANs or LANs or the mixture of both networks.

Comparison of LAN, MAN, WAN

Personal area network A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that are used in a PAN are printers, fax machines, telephones, PDAs and scanners. The reach of a PAN is typically about feet (approximately 6-9 meters), but this is expected to increase with technology improvements.

A campus area network (CAN) is a computer network made up of an interconnection of local area networks (LANs) within a limited geographical area. It can be considered one form of a metropolitan area network, specific to an academic setting. A global area networks (GAN) specification is in development by several groups, and there is no common definition. In general, however, a GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. A virtual private network (VPN) is a computer network in which some of the links between nodes are carried by open connections or virtual circuits in some larger network (e.g., the Internet) instead of by physical wires.

Network architecture Overall design of a computer network that describes how a computer network is configured and what strategies are being used. mainly focuses on the functions of the networks. Also known as network model or network design. They are two types – Client / Server Network – Peer-to-peer or P2P Network

CLIENT/SERVER NETWORK A client/server network is a network in which the shared files and applications are stored in the server but network users (clients) can still store files on their individual PCs. A server is a computer that shares information and resources with other computers on a network. A client is a computer which requests services or files from a server computer.

Network architecture Peer-to-peer or P2P It is a network with all the nodes acting as both servers and clients. A PC can access files located on another PC and can also provide files to other PCs. All computers in the peer-to-peer network has equal responsibilities and capabilities to use the resources available on the network. With peer-to-peer network, no server is needed; each computer in the network is called a peer.

Differences

Network topology Computer networks may be classified according to the network topology upon which the network is based, such as bus network, star network, ring network, mesh network, star- bus network, tree or hierarchical topology network. network topology bus networkstar networkring networkmesh networkstar- bus networktree or hierarchical topology network Network topology signifies the way in which devices in the network see their logical relations to one another.

Bus Topology Click on picture to play video

Star Topology Click on picture to play video

Ring Topology Click on picture to play video

Basic hardware components Network Interface Card Repeaters Hub BridgesSwitchesRouters

TCP/IP (Transmission Control Protocol/Internet Protocol)  TCP/IP (Transmission Control Protocol/Internet Protocol) is the basic communication language or protocol of the Internet.  It can also be used as a communications protocol in a private network (either an intranet or an extranet).intranet extranet  When you are set up with direct access to the Internet, your computer is provided with a copy of the TCP/IP program just as every other computer that you may send messages to or get information from also has a copy of TCP/IP.  TCP/IP is a two-layer program.  The higher layer, TCP, manages the assembling of a message or file into smaller packets that are transmitted over the Internet and received by a TCP layer that reassembles the packets into the original message.  The lower layer, Internet Protocol, handles the address part of each packet so that it gets to the right destination.  The TCP/IP model consists of four layers, From lowest to highest, these are the Link Layer, the Internet Layer, the Transport Layer, and the Application Layer

TCP/IP Click on picture to play video

Hypertext Transfer Protocol  HTTP (Hypertext Transfer Protocol) is the set of rules for transferring files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web.  As soon as a Web user opens their Web browser, the user is indirectly making use of HTTP. HTTP is an application protocol that runs on top of the TCP/IP suite of protocols.browserprotocolTCP/IP  HTTP development was coordinated by the World Wide Web Consortium and the Internet Engineering Task Force (IETF)World Wide Web ConsortiumInternet Engineering Task Force  HTTP/1.1, the version of HTTP in common use  HTTP is a request/response standard between a client and a serverclientserver  When the browser user enters file requests by either "opening" a Web file (typing in a Uniform Resource Locator or URL) or clicking on a hypertext link, the browser builds an HTTP requestURLhypertextlink  It establishes a Transmission Control Protocol (TCP) connection to a particular port on a host (port 80 by default; see List of TCP and UDP port numbers) and sends it to the Internet Protocol address (IP address) indicated by the URL.Transmission Control ProtocolportList of TCP and UDP port numbersIP address  Upon receiving the request, the server sends back a status line, such as "HTTP/ OK", and a message of its own, the body of which is perhaps the requested resource, an error message, or some other information.

Network to HTTP Click on picture to play video

How a Computer Network Works? Click on picture to play video