Introduction to computer networks : Introduction to computer networks By
Md. Mudassir Rehman
Session topics : Session topics Introduction to computer networks
Types of computer networks
How computers communicate with each other
IP address
Do's and Don'ts to maintain a computer system
Slide 3 : Introduction to computer networks A computer network is a collection of computers and devices connected to each other.
The network allows computers to communicate with each other and share resources and information.
The Advanced Research Projects Agency (ARPA) designed "Advanced Research Projects Agency Network" (ARPANET) for the United States Department of Defense. It was the first computer network in the world in late 1960s and early 1970s .
The computers can be geographically located anywhere.
Types of computer networks : Types of computer networks LAN (Local Area Network)
MAN (Metropolitan Area Network)
WAN (Wide Area Network)
LAN : LAN A local area network (LAN) is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school, or an airport. Current wired LANs are most likely to be based on Ethernet technology, although new standards like ITU-T G.hn also provide a way to create a wired LAN using existing home wires (coaxial cables, phone lines and power lines).
MAN : 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. Routers, switches and hubs are connected to create a metropolitan area network.
WAN : WAN A wide area network (WAN) is a computer network that covers a broad area (i.e. any network whose communications links cross metropolitan, regional, or national boundaries ). Less formally, a WAN is a network that uses routers and public communications links.
The largest and most well-known example of a WAN is the Internet.
Network hardware : Network hardware Network interface cards
Repeaters
Hubs
Switches
Routers
Wireless Access points
Network interface cards : Network interface cards A network card, network adapter or NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network. It provides physical access to a networking medium and often provides a low-level addressing system through the use of MAC addresses.
Network Interface card(NIC) : Network Interface card(NIC)
Repeaters : Repeaters A repeater is an electronic device that receives a signal and retransmits it at a higher power level, or to the other side of an obstruction, so that the signal can cover longer distances without degradation. In most twisted pair Ethernet configurations, repeaters are required for cable which runs longer than 100 meters.
Repeaters : Repeaters
Hubs : Hubs A hub contains multiple ports. When a packet arrives at one port, it is copied unmodified to all ports of the hub for transmission. The destination address in the frame is not changed to a broadcast address.
Hubs : Hubs
Switches : Switches A switch is a device that forwards and filters OSI layer 2 datagram's (chunk of data communication) between ports (connected cables) based on the MAC addresses in the packets.[5] This is distinct from a hub in that it only forwards the packets to the ports involved in the communications rather than all ports connected. Strictly speaking, a switch is not capable of routing traffic based on IP address (OSI Layer 3) which is necessary for communicating between network segments or within a large or complex LAN.
Switches : Switches
Routers : Routers Routers are networking devices that forward data packets between networks using headers and forwarding tables to determine the best path to forward the packets. Routers work at the network layer.
Routers : Routers
Wireless Access point : Wireless Access point A wireless access point (WAP or AP) is a device that allows wireless communication devices to connect to a wireless network using Wi-Fi, Bluetooth or related standards. The WAP usually connects to a wired network, and can relay data between the wireless devices such as computers, laptops or printers and wired devices on the network.
Wireless Access point : Wireless Access point
How do computers communicate : How do computers communicate
IP address : IP address An Internet Protocol (IP) address is a numerical identification (logical address) that is assigned to devices participating in a computer network utilizing the Internet Protocol for communication between its nodes.
IP addresses are stored as binary numbers, they are usually displayed in human-readable notations, such as 192.168.1.1 (for IPv4),.
The role of the IP address has been characterized as follows: "A name indicates what we seek. An address indicates where it is. A route indicates how to get there.
Maintaining Your Computer System : Maintaining Your Computer System Do’s:
Always shut down your computer properly.
Do regular Scandisk to check the hard disk surface for damage.
Defragment the hard drive periodically.
Delete all files and programs you no longer need from your computer.
Use a anti-virus program to prevent a virus on you computer.
Back up data to floppy disks or zip disks to ensure you have a copy.
Maintaining Your Computer System : Maintaining Your Computer System Taking Care of disks
Do:
Delete all files you no longer need from your disk.
Use a anti virus program to scan for viruses on a disk.
Do prevent erasing and recording information on a disk by write-protecting it.
Don't :
Do not use magnets around a disk.
Do not take a disk apart.
Do not remove the disk while it is in use.
Do not store in extremely hot or cold locations.
Do not spill liquids on the disk.
Don not format a disk many times.
Q & A : Q & A Mail me : mudassir.rehman@gmail.com
Thank you!!! : Thank you!!!
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