This module is about the Internet
This module is about the Internet, the well-known example of a network of networks and what or where they can be used for. This topic focuses on the uses of computer networks, the network hardware and software.
The following are the intended learning outcomes:
1. To acquaint students to all the lessons of the subject.
2. Discuss the internet development, communication technology and the network challenges
3. Identify the uses of computer networks, development, users and social issues.
4. To discuss the significance of system configuration regarding equipment as the fundamental concern and the software as the structure support.
I. Orientation
• Course Outline
• Course Requirements
II. Introduction to Networking
? Internet History and Network Challenges
• In 1962, a scientist from M.I.T. and ARPA named J.C.R. Licklider proposed an answer for this issue: a “galactic system” of electronic computer that could converse with each other.
• In 1965, Lawrence G. Roberts developed a packet switching that can send information from one computer to another.
• In late 1966 Roberts went to DARPA to develop the computer network concept and quickly put together his plan for the “ARPANET”, publishing it in 1967
• In 1969, four host PCs were associated together into the underlying ARPANET and had conveyed its first message: a “hub to-hub” correspondence starting with one PC then onto the next.
• Before the end of 1970s, a computer researcher named Vinton Cerf had built up a path for the majority of the PCs on the greater part of the world’s smaller than expected systems to speak with each other. He called his creation “Transmission Control Protocol,” or TCP where “Web Protocol” was later included.
• In 1991 a PC software engineer in Switzerland named Tim Berners-Lee presented the World Wide Web.
The Internet is a network of computers that link other smaller network of computers together.
? Uses of Computer Networks
? Business Applications
• Business – for information and resources
• Companies use networks and computers for resource sharing using the client-server model
Figure 1. Client-Server Model
• A computer network be able to offer a powerful communication medium among employees
– E-mail
– Sharing and working at the same time on common documents, sheets, data, shared virtual blackboard, etc.
– ICQ, Skype, etc.
– Video conferencing
• Faster, more efficient and convenient business
• On-line support
? Home Applications
• Access to remote information
o interaction between a person and a remote database of information
o Surfing the World Wide Web for gathering data such for business, cooking, government, wellbeing and for the sake of entertainment.
• Person-to-person communication
o Email – popular used for communication and been utilized all around. It allows attaching sound, video and additionally contenting and pictures.
o Instant messaging – – got from the UNIX talk program utilized since around 1970, now with applications like Skype, ICQ, Instant Messenger, and so forth.
Figure 2. Input, Peer-to-peer communication
• Interactive entertainment
o Video on demand – select any motion picture or TV program, in any nation, and have it shown on your screen.
o game playing – multi-person real-time simulation games – such with goggles and three-dimensional continuous, photographic-quality moving pictures frame an overall shared virtual reality
• Electronic commerce
o Home shopping – users can seek in on-line catalogs of thousands of companies
o Companies also provide on-line technical support
o Banking – numerous individuals pay their bills, deal with their ledgers, and handle their investments electronically
Figure 3. Forms of e-commerce
? Mobile Users
• Mobile computers – note pad PCs, tablets, advanced mobile phones, individual computerized aides (PDAs), are one of the quickest developing sections of the PC and correspondence industry.
• Wired connection is unimaginable at a considerable measure of spots – in autos, trains, transport, planes, some remote towns, so there is a great deal and developing enthusiasm for remote systems
• Wireless PDAs can be utilized for managing an account and shopping – sort of electronic wallet, approving installments in stores, trade for money and credit card.
Figure 4. Wireless networks and mobile computing
? Social Issues
• Network neutrality – no network restrictions
o Social networking – in forums, bulletin boards, Facebook, Twitter, etc., where people can exchange messages, photos, materials and other information with like-minded individuals or representatives of organizations can bring offense to other users.
• Content ownership, e.g., DMCA takedowns
o A massive copyright violation is also carried out – music and video are digitally transmitted and companies have problems of enforcing their copyrights.
• Anonymity and censorship
o Certain materials (on specific nations or on religions, explicit entertainment, and so forth.) might be unsatisfactory in either moral or legal angle as various nations have unique and clashing laws around there.
• Privacy, e.g., Web tracking and profiling
o Numerous individuals read and compose email at work yet a few employees assert the privilege to peruse and perhaps censor employee messages – not all employees concur with this.
• Theft, e.g., botnets and phishing
o Identity theft is an expanding issue – hoodlums gather data about a casualty and can acquire Mastercards points of interest and other private information of the casualty.
Computer networks are collections of autonomous computers interconnected by a single technology, e.g., the Internet
? Network hardware
o Networks can be classified by their scale
Figure 5. Classification of network
• Personal Area Network
o Connect devices in a range of a person
Figure 6. Example of a Bluetooth (wireless) PAN
• Local Area Networks
o Connect devices in a home or office building
Figure 7. Example of an Enterprise Network
• Metropolitan Area Networks
o Connect devices over a metropolitan area
Figure 8. Example MAN based on cable TV
• Wide Area Networks
o Connect devices over a country
Figure 9. Example WAN connecting three branch offices
? Network Software
• Protocol layers
o Protocol layering is the main structuring method used to divide up network functionality.
• Design issues for the layers
o Each layer takes care of a specific issue however should incorporate systems to address an arrangement of repeating configuration issues.
• Connection-oriented vs. connectionless service
o Service provided by a layer may be kinds of either:
? Connection-oriented, must be set up for ongoing use (and torn down after use), e.g., phone call
? Connectionless, messages are handled separately, e.g., postal delivery
• Service primitives
o Hypothetical example of service primitives that may provide a reliable byte stream (connection oriented) service
• Relationship of services to protocols
o A layer provides a service to the one above vertical
o A layer talks to its peer using a protocol horizontal
