Networking

SYSTEM ESSENTIALS

AN ASSIGENMENT ON:-

1. BASIC OF NETWORKING 2. INTRODUCTION TO NETWORK TYPES 3. INTERNET AND INTRANET

SUBMITTED TO: SUBMITTED BY: Prof. Sanjana Adlakha

Networking Basics:In the world of computers, networking is the practice of linking two or more computing devices together for the purpose of sharing data. Networks are built with a mix of computer hardware and computer software.

Area networking:-

One way to categorize the different types of computer network designs is by their scope or scale. For historical reasons, the networking industry refers to nearly every type of design as some kind of area network. Common examples of area network types are: •

LAN - Local Area Network

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WAN - Wide Area Network

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WLAN - Wireless Local Area Network

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SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network

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MAN - Metropolitan Area Network

What is Networking? Networking is the practice of linking computing devices together with hardware and software that supports data communications across these devices.

Network Design:Computer networks also differ in their design. The two types of high-level network design are called client-server and peer-to-peer. Client-server networks feature centralized server computers that store email, Web pages, files and or applications. On a peer-to-peer network, conversely, all computers tend to support the same functions. Client-server networks are much more common in business and peer-to-peer networks much more common in homes.

A network topology represents its layout or structure from the point of view of data flow. In so-called bus networks, for example, all of the computers share and communicate across one common conduit, whereas in a star network, all data flows through one centralized device. Common types of network topologies include bus, star, ring and mesh.

Network Protocols:In networking, the communication language used by computer devices is called the protocol. Yet another way to classify computer networks is by the set of protocols they support. Networks often implement multiple protocols to support specific applications. Popular protocols include TCP/IP, the most common protocol found on the Internet and in home networks. Network protocols include mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols also support message acknowledgement and data compression designed for reliable and/or high-performance network communication. Hundreds of different computer network protocols have been developed each designed for specific purposes and environments.

Wired vs Wireless Networking:Many of the same network protocols, like TCP/IP, work in both wired and wireless networks. Networks with Ethernet cables predominated in businesses, schools, and homes for several decades. Recently, however, wireless networking alternatives have emerged as the premier technology for building new computer networks. Below we compare wired and wireless networking in three key areas: •

Reliability Ethernet cables, hubs and switches are extremely reliable, mainly because manufacturers have been continually improving Ethernet technology over several decades. Loose cables likely remain the single most common and annoying source of failure in a wired network. When installing a wired LAN or moving any of the components later, be sure to carefully check the cable connections.

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Total cost Ethernet cables, hubs and switches are very inexpensive. Some connection sharing software packages, like ICS, are free; some cost a nominal fee. Broadband routers cost more, but these are optional components of a wired LAN, and their higher cost is offset by the benefit of easier installation and built-in security features.

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Security For any wired LAN connected to the Internet, firewalls are the primary security consideration. Wired Ethernet hubs and switches do not support firewalls. However, firewall software products like ZoneAlarm can be installed on the computers themselves. Broadband routers offer equivalent firewall capability built into the device, configurable through its own software.

Introduction to Network Types One way to categorize the different types of computer network designs is by their scope or scale. For historical reasons, the networking industry refers to nearly every type of design as some kind of area network. Common examples of area network types are: •

SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network

•

LAN - Local Area Network

•

WLAN - Wireless Local Area Network

•

WAN - Wide Area Network

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PAN - Personal Area Network

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DAN - Desk Area Network

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MAN - Metropolitan Area Network

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CAN - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network

LAN and WAN were the original categories of area networks, while the others have gradually emerged over many years of technology evolution.

LAN - Local Area Network A LAN connects network devices over a relatively short distance. A networked office building, school, or home usually contains a single LAN, though sometimes one building will contain a few small LANs (perhaps one per room), and occasionally a LAN will span a group of nearby buildings. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet. In addition to operating in a limited space, LANs are also typically owned, controlled, and managed by a single person or organization. They also tend to use certain connectivity technologies, primarily Ethernet and Token Ring.

WAN - Wide Area Network As the term implies, a WAN spans a large physical distance. The Internet is the largest WAN, spanning the Earth. A WAN is a geographically-dispersed collection of LANs. A network device called a router connects LANs to a WAN. In IP networking, the router maintains both a LAN address and a WAN address. A WAN differs from a LAN in several important ways. Most WANs (like the Internet) are not owned by any one organization but rather exist under collective or distributed ownership and management. WANs tend to use technology like ATM, Frame Relay and X.25 for connectivity over the longer distances.

MAN - Metropolitan Area Network Metropolitan Area Network(MAN) is a computer networks usually spanning a campus or a city, which typically connect a few local area networks using high speed backbone technologies. A MAN often provides efficient connections to a wide area network (WAN). There are three important features which discriminate MANs from LANs or WANs: 1. The network size falls intermediate between LANs and WANs. A MAN typically covers an area of between 5 and 50 km range. Many MANs cover an area the size of a city, although in some cases MANs may be as small as a group of buildings. 2. A MAN (like a WAN) is not generally owned by a single organisation. The MAN, its communications links and equipment are generally owned by either a consortium of users or by a network service provider who sells the service to the users. 3. A MAN often acts as a high speed network to allow sharing of regional resources. It is also frequently used to provide a shared connection to other networks using a link to a WAN.

INTERNET AND INTRANET INTERNET The Internet, sometimes called simply "the Net," is a worldwide system of computer networks - a network of networks in which users at any one computer can, if they have permission, get information from any other computer (and sometimes talk directly to users at other computers). It was conceived by the Advanced Research Projects Agency (ARPA) of the U.S. government in 1969 and was first known as the ARPANET. The original aim was to create a network that would allow users of a research computer at one university to be able to "talk to" research computers at other universities. A side benefit of ARPANet's design was that, because messages could be routed or rerouted in more than one direction, the network could continue to function even if parts of it were destroyed in the event of a military attack or other disaster. Today, the Internet is a public, cooperative, and self-sustaining facility accessible to hundreds of millions of people worldwide. Physically, the Internet uses a portion of the total resources of the currently existing public telecommunication networks. Technically, what distinguishes the Internet is its use of a set of protocols called TCP/IP (for Transmission Control Protocol/Internet Protocol). Two recent adaptations of Internet technology, the intranet and the extranet, also make use of the TCP/IP protocol. For many Internet users, electronic mail (e-mail) has practically replaced the Postal Service for short written transactions. Electronic mail is the most widely used application on the Net. You can also carry on live "conversations" with other computer users, using Internet Relay Chat (IRC). More recently, Internet telephony hardware and software allows real-time voice conversations. The most widely used part of the Internet is the World Wide Web (often abbreviated "WWW" or called "the Web"). Its outstanding feature is hypertext, a method of instant crossreferencing. In most Web sites, certain words or phrases appear in text of a different color than the rest; often this text is also underlined. When you select one of these words or phrases, you will be transferred to the site or page that is relevant to this word or phrase. Sometimes there are buttons, images, or portions of images that are "clickable." If you move the pointer over a spot on a Web site and the pointer changes into a hand, this indicates that you can click and be transferred to another site.

Using the Web, you have access to millions of pages of information. Web browsing is done with a Web browser, the most popular of which are Microsoft Internet Explorer and Netscape Navigator. The appearance of a particular Web site may vary slightly depending on the browser you use. Also, later versions of a particular browser are able to render more "bells and whistles" such as animation, virtual reality, sound, and music files, than earlier versions.

INTRANET Intranet is the generic term for a collection of private computer networks within an organization. An intranet uses network technologies as a tool to facilitate communication between people or workgroups to improve the data sharing capability and overall knowledge base of an organization's employees. Intranets utilize standard network hardware and software technologies like Ethernet, WiFi, TCP/IP, Web browsers and Web servers. An organization's intranet typically includes Internet access but is firewalled so that its computers cannot be reached directly from the outside. A common extension to intranets, called extranets, opens this firewall to provide controlled access to outsiders. Many schools and non-profit groups have deployed them, but an intranet is still seen primarily as a corporate productivity tool. A simple intranet consists of an internal email system and perhaps a message board service. More sophisticated intranets include Web sites and databases containing company news, forms, and personnel information. Besides email and groupware applications, an intranet generally incorporates internal Web sites, documents, and/or databases. The business value of intranet solutions is generally accepted in larger corporations, but their worth has proven very difficult to quantify in terms of time saved or return on investment. Also Known As: corporate portal, private business network.