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• Networks and computers are widely known and essential in today's society, where life without them is unimaginable

Introduction to Computer Networks

• Computer networking has revolutionized the world, enabling instant communication and file transfer.
• It has replaced lengthy mail correspondence with instant communication, enabling video calls and rapid sharing of documents, photos, videos, messages, and emails.
• Computer networks facilitate data transmission using computers and related devices like terminals and printers.
• It is a popular medium for data transmission, enabling communication through chatting, email, video conferencing, downloading, and FTP (File Transfer Protocol) in seconds.
• IBM introduced SNA (Systems Network Architecture) in the 1960s, linking its computers and resources, but SNA was a private network for IBM's internal use only.
• Later, many companies set up internal internets for use by their employees.

Benefits of Computer Networks

• Companies began sharing computers, printers, and storage, enabling electronic data transfer, saving time, money, and space.
• Networks that were public and based on globally accepted protocols became popular, used by any company.
• A network comprises interconnected computer hardware via wires or wirelessly for data sharing.
• Computer networks involve connecting two or more computers or hardware to share data.
• Networks use cabling like Ethernet or fiber optics, or wireless radio waves, for connectivity.
• Networking encompasses connecting, maintaining, and troubleshooting hardware

Resource Sharing

• Computer networks enable resource sharing such as internet access, printers, scanners, and file servers.
• A computer network enables connected computers to share Internet, printers, scanners, file servers, and software, maximizing resource utilization.

Definition and Operation

• A computer network conveys data among similar or different computers and peripherals through a communication medium, enabling data exchange in various formats.
• A computer network enables easy data transmission between connected systems, regardless of distance.

Wired and Wireless Technologies

• Networks can be wired, wireless, or a combination.
• Wired networks use optical fiber, coaxial cable, or copper wires.
• Wireless networks communicate wirelessly using broadcast radio, cellular radio, microwave, or satellites.

Computer Network Architecture

• Computer network architecture is defined as the software, hardware, protocols, and the physical and logical design of the data and its transmission.
• It defines how computers are organized and assigned tasks.
• Two types of network architectures are Peer-to-Peer and Client/Server.

Peer-to-Peer Network

• A peer-to-peer network gives all computers equal data processing privileges and responsibilities.
• Commonly used in small offices with fewer than 10 computers, a peer-to-peer network lacks a dedicated server.
• Each computer gets special permission to share resources and if a resouce computer goes down, problems may occur.

Advantages of Peer-to-Peer Networks

• Lower cost because there is no dedicated server.
• Computers operate independently in case of failure of other computers.
• Easy to set up and maintain because each manages itself

Disadvantages of Peer-to-Peer Networks

• Lacks centralized system, hindering data backup, it lacks data in a central place
• Less secure, due to self-management of devices

Network Communication Technologies

• Mobile computing uses packet-radio communication, cellular networks, and satellite stations.
• Allows users to send mail, access files, and connect to the internet using handheld devices.
• Slower transmission speed, about 8 to 19.2 kbps.
• Cellular technology uses towers for communication, using small antennas to connect to a wired network.
• A wireless connection doesn't require a physical medium, using air, prevents cable costs.

Types of Wireless Networks

• Wireless Personal Area Network (WPAN) is used for personal or small-scale areas like Bluetooth, radio, infrared headsets also supporting zig bee.
• WLAN (Wireless Local Area Network) connects local sources to the internet through wireless tech and provides connections for internet access
• Wireless mesh networks are created by radio nodes in mesh topology nodes, where nodes forward message to other nodes

Wireless Network benefits

Mesh networks is useful for health as it causes self healing

• Wireless Metropolitan Area Network (WMAN) connects other wireless LANs that include WiMax
• Wireless Wide Area Network (WWAN) connect large region to office branches for internet, using point-to-point communication
• Global area network, Global Area Network supports and delivers connectivity in wireless LAN communities.
• Space Network, Space networks are often used for communications between spacecraft and humans.

Content Delivery Network (CDN)

• Content Delivery Network (CDN) delivers through the Web, at various servers for the user, to speed up loading on a site.
• CDN beginnings was two years ago and has motivated academics to this day; in the area of research and design.
• The first CDN being the creation by Akamai Technologies, Inc.

Broadband Connections

• SDSL is mainly used by companies like providing video conferencing or with high bandwidth usage.
• Cable modem is given out by cable services that transmit using coxial and the user experiences both and television features.
• Fiber optics a new form, transmutes electrical signs into light also can be used with modem and DSL transmission to give fast service.
• Wireless broadband accesses customers over the radio signal or difficult terrain by an ISP; however its speed not greater.
• Satellite broadband gives good service to remote areas and has the potential to supply the world.
• Has purpose of giving service broadband worldwide.

Advantages and Disadvantages of Broadband

• The advantages of broadband are good speed for usage and is always on and never disconnect and does not rely on user and is less costly.
• The disadvantage of broadband is that there is a need month to month charges and does not work in other areas.
• Transit broadband provides the connection for buses and rails.

Client Server Network

• Client servers a model has been created the form of a new architecture.
• Consisting of one the central server (as is what is what known), is the main source which stores files, printer. and directories.
• Each client, makes contact through other main servers for permission and is an easy system of usage.

Advatanges and Disadvantages to Client Server Network

• Client server nets create high memory for usage and has is better performed, but its expense is not necessarily what is recommended in server operation.
• It requires an administrative role for usage the client with a network.

Broadband

• A broad bandwidth called and Internet access allows quicker access has has cable fibers and radio.
• It uses broadband and transmits at high speed while using new forms making better Internet accesses available.

Types of Broadband

• In Types of broadband have DLS cable models for fibers and wireless uses.
• DLS of a very fast nature and with high speed capacity.

Client-Server Network

• The Client-Server Network is a network model designed for end users (clients) to access the server (Central Computer Server).
• The server is known as a central controller, and the rest are known as clients.
• The server manages resources like files, directories, printers, etc.
• All clients communicate through the server, and the server permits communication among the clients.

Advantages and Disadvantages

• It is an expensive task to have a client server system due to memory and cost
• The clients cost very high and the system is often very high priced.

LAN (Local Area Network)

• LAN is a network in limited area that connects all computer with a set location and is within a KM (kilometers) to all communications to communicate.
• Also can be use to connect through cabling of sorts as well.

Benefits and downfalls of Networking

• Can use LAN for sharing of software via printer or server and can connect all computers at one time.
• There is easy sharing of data on another end, while switch are used for connections.

Types of Wireless

• Has LAN
• WAN (wide networks
• METROPOLITAN

The LAN, WAN, Metropolitan

• They have different variations and sizes to be used where suited for the purpose.
• Has the feature of not needed cabling but in present the WLAN's use the Ethernet Cables.
• Local Access Network with a limited area, but each the computer is placed in close limits to be connected together.

Area and Area Network

• It is possible using area and personal networks to have a wide amount of access of connection.
• The most excellent to use is a wire network and is of great importance for the function of connection.

WAN's

• WAN can also be the large, for with what it does in it and links computers while providing connection for different continents.
• Has a huge size with data and transfers.
• WAN being the type of connection it has can serve enterprise and connected enterprise that have internet connection.

WAN Network services and Advantages

It provides connection to many services and advantages such as being able to share among several users.

Network Topology

• Network topology in computer terms is how many computers interconnect with each other at points.
• This defines how node communicates among each other.

Computer Topology

• Topology describes types of computer connections.
• This defines design and method data shared
• Connections can can be connected together.

Mesh Topology

• Meshes in topology can connect through all type of topology and is cheap so its a easy choice. The amount needed is n(n-L)/S to to nodes for connectivity
• Very useful for massive data tranfer and works very easily
• Easy install of type of structure but will prove to be a slight struggle.

Topology

• Tree Topology which is very well know and connected by a wire of all the connected computers.
• The wire connect all computers to all parts.

Hybrid Topology

• The hybrid topology uses topologies to be of connection making connectivity.
• Using mesh ring and all the connectivity is available.

Ring Topology

• Using ring the data makes transfers in loops it is very easy to handle.
• The data flows in each computer due to network being set off.
• In this net, all is on all computers making the net slow.

Star Topology

• The start connects the server with server as hub.
• Every client communicates and connects through each device.
• The start with good network and data transmission.

Benefits and deficits of topologies

It is high in start but it is managed but you must maintain with cable of good transmission

Mesh

• This topology provides that the device that connected is in contact with some data transmission.
• Provides strong connections when using data.

OSI Open System

• The interconnection and model of the computer which will allow systems of communications for information.
• 7 levels of data transfer.

Description of each Level

• All modules are split in three to be divided for which is lower, higher layer for connectivity.
• Layer contains a hardware which switches data from the data.

Networking Overview

• The physical layer handles the physical and electrical aspects of the connection, converting digital signals to electrical signals.
• During data retrieval, it converts the signal from zeros and ones before transmitting them to the data link layer.
• High-Speed data transfer must also be transmitted.
• Physical connections are both required and wired or wireless must be required to access to transfer the data.

Link Layer

• Data link layer the facts and figures can describe can describe both data as must be examined to check and receive that the information.
• There had been an amount of data can must be both translated.
• The layer must function, with the data has been transfer.

Networking

• There are data the can must be received and that are transferred back and forth.
• The transport to transfer both back.
• All data be transferred to a function to be transferred.

The Session and Layer

• Devices each can communicate to be done.
• Each layer and communication must each secured for transferred for the communications.
• There all all levels for communications, but one can transfer its information for many ways.
• Windsock transfer the amount of API that's used.

Application Layer

• The application layer in OSI model allows users to access files.
• It identifies communication partners.
• It forwards and stores emails.

TCP

• TCIP are the internet protocol that has certain rules when transfer data.
• TCP/IP the true application for our model, delivers communication. virtualized

TPIC connection and model.

• There is two way or to transmit protocol to get a communication.
• Transmission is used with connectivity delivery is delivered and does does guaranteed.
• IP data has been created.