What is internetworking?
Internetworking is the process and methodology used to connect multiple independent networks, regardless of their distance.
Internetwork or Internet----Multiple independent networks that are connected and can share remote resources.
Networking----Networking is the process and methodology applied to connect multiple computers (or other devices), so that they are able to exchange information. Network: A set of interconnected computers (or other devices) sharing resources.
Middleware----Middleware is a layer of software between client and server processes. This software provides services such as identification, authentication, authorization, directories, and security.
Software: A term used in computing to refer to programs or applications.
Hardware: A term used in computing to refer to physical parts or equipment.
Main Components Of The Computer
• Motherboard or mainboard
• CPU
• Memory (RAM)
• Case, power supply
• Floppy disk drive (FDD)
• Hard disk drive (HDD)
• CD-ROM, CD-R, CD-RW or DVD-ROM
• Keyboard, mouse
• Serial port, parallel port, USB port
• Video card, monitor
• Sound card, speakers
• Network card
• Modem
What Can A Computer Understand?
Computer cannot understand human language (English, French, German, Chinese, Arabic or Italian etc).
Computer can only understand two things:
Voltage----(Current flowing through the wires -> 1)
No Voltage----(No current flowing through the wires -> 0)
Computer can only understand machine language i.e. combination of 0’s and 1’s. Human language is coded into combination of 0’s and 1’s by the Keyboard, so computer can understand human instructions. Most common coding scheme is called ASCII (American Standard Code for Information Interchange).
Overview of Networks
A communication network is an interconnection of numerous network elements, which are required to transfer voice, data, and video traffic between users. It is the network that connects the end user to virtually anywhere in the world through the use of coaxial cable, copper twisted-pair cable, fibre-optic cable, and through wireless technology such as microwave or satellite. Examples of communication networks are telephone networks; telegraph networks, radio and television broadcast networks, computer networks, cellular telephone networks and the Internet.
Telecommunications and Information Technology have been converging for the past few years. However, there is a much closer interrelationship between both at present than at any time in the past. This convergence is changing the way; carriers will carry voice, data and video signal.
Information Technology has provided new networked applications and made extensive changes to corporate needs, human life style and leisure. These networked applications are video conferencing, file transfer, world wide web browsing, electronic mail, financial transactions, database access and voice over the Internet protocol (VOIP).
This led to a massive growth of the Internet and huge bandwidth demand from customers. It resulted in the need to re-architect the traditional and oldest communication network called Public Switched Telephone Network (PSTN). Carriers are now using new technologies to carry voice, data, and integrated services, which can also interoperate with the existing PSTN infrastructure.
Now days, communication networks enable organisations to build their networks on the basis of Local Area Networks (LANs) or/and Wide Area Networks (WANs), to satisfy their communication demands. It is arguable that the very terms “Telecommunications” and “Information Technology” are losing their relevance as separate identities. It is expected that these fields will become virtually indistinguishable in the near future.
Types of Networks
A network is an interconnection of computers, network devices, printers and software through a transmission media. These networks are of different shapes and sizes. Network administrators usually classify networks according to their geographical size. Networks are predominately classified as:
- Local Area Networks (LANs)
- Wide Area Networks (WANs)
- Metropolitan area networks (MANs).
Local Area Networks (LANs)
A local area network (LAN) comprises a group of computers and network communication devices interconnected within a limited geographically area, such as a building or a campus (neighbouring buildings). LANs have the following characteristics:
- They allow communication in a limited geographical area
- They transfer data at faster speed (higher bandwidth)
- Transmission media and resources are managed by the organisation running the LAN.
Wide Area Networks (WANs)
A wide area network (WAN) interconnects different LANs across the world. A WAN allows communications within a state, a country, or anywhere else in the world.
WANs are characterized by the following:
- They allow communications in an unlimited geographical area.
- They connect multiple LANs located in same or different cities.
- They are usually slower than LANs.
- Transmission media and connections are managed by a third-party carrier like a telephone company Telstra or a cable company Optus.
WANs can be further classified into the following two categories:
Enterprise WANs: An enterprise WAN interconnects the widely separated communication resources of a single organization. An organization with several offices at distant sites can setup an enterprise WAN to interconnect these offices. An enterprise WAN comprises private and commercial network services, but it is designed exclusively for communications within a particular organization.
Global WANs: A global WAN interconnects networks of various corporations or organizations across the world.
Metropolitan Area Networks (MANs)
A Metropolitan area network (MAN) allows interconnection of LANs within boundaries of a Metropolitan. MAN usually interconnects networks within an area of 50 Km. An example of a MAN is data backup or data transfer between two campuses of a University through a telephone cable. These days MANs are overshadowed by WANs.
An example of LAN and WAN interconnection is shown in the following figure:
