The Basics and Understanding of Computer Networking.pptx

The Basics of Computer Networking

1.0 The Computer Network Arguably, the greatest advancement in technology and communication over the past 20 years has been the development and advancement of the computer network . From emailing a friend to on-line bill paying to downloading data off the Internet to e-commerce, networking has made our world much smaller and changed the way we communicate forever.

1.1 What is a Computer Network ? net·work: [net- wurk ] – noun , a system containing any combination of computers, computer terminals, printers, audio or visual display devices, or telephones interconnected by telecommunication equipment or cables: used to transmit or receive information.

1.1 What is a Computer Network ? … A computer network is a group of two or more interconnected computer systems. You can establish a network connection using either cable or wireless media. Every network involves hardware and software that connects computers and tools.

1.1 What is a Computer Network ? … A computer network is a set of devices connected through links. A node can be computer, printer, or any other device capable of sending or receiving the data. The links connecting the nodes are known as communication channels . Computer Network uses distributed processing in which task is divided among several computers. Instead, a single computer handles an entire task, each separate computer handles a subset .

1.1 What is a Computer Network ? … Computer networks share common devices, functions, and features including servers, clients, transmission media, shared data, shared printers and other hardware and software resources, network interface card(NIC), local operating system(LOS), and the network operating system (NOS).

1.2 Advantages of a Computer Network Here are the fundamental benefits/pros of using Computer Networking : Helps you to connect with multiple computers together to send and receive information when accessing the network . Helps you to share printers, scanners, and email. Helps you to share information at very fast speed Electronic communication is more efficient and less expensive than without the network .

1.3 Uses of Computer Network Resource sharing : Resource sharing is the sharing of resources such as programs, printers, and data among the users on the network without the requirement of the physical location of the resource and user. Server-Client model : Computer networking is used in the server-client model. A server is a central computer used to store the information and maintained by the system administrator. Clients are the machines used to access the information stored in the server remotely.

1.3 Uses of Computer Network … Communication medium : Computer network behaves as a communication medium among the users. For example, a company contains more than one computer has an email system which the employees use for daily communication. E-commerce : Computer network is also important in businesses. We can do the business over the internet. For example, amazon.com is doing their business over the internet, i.e., they are doing their business over the internet.

2.0 Clients and Servers An important relationship on networks is that of the server and the client . A server is a computer that holds content and services such as a website, a media file, or a chat application. A good example of a server is the computer that holds the website for Google’s search page : http://www.google.com . The server holds that page, and sends it out when requested. A client is a different computer, such as your laptop or cell phone, that requests to view, download, or use the content. The client can connect over a network to exchange information. For instance, when you request Google’s search page with your web browser, your computer is the client .

2.0 Clients and Servers … In the example below, two computers are connected together with an Ethernet cable. These computers are able to see each other and communicate over the cable. The client computer asks for a website from the server computer. The website is delivered from the server, and displayed on the client’s web browser.

2.0 Clients and Servers …

2.0 Clients and Servers … Most requests and content delivery on networks are similar to, or are based on, a client to server relationship. On a network, the server can be located almost anywhere, and if the client has the address, it can access the content on the server. Activity: What is one real world example of a client and server relationship: Example: client : radio receiver in your car server : radio station Client: _________________ Server:_________________

3.0 Components of Computer Network

3.0 Components of Computer Network … Switches : Switches work as a controller which connects computers, printers, and other hardware devices to a network in a campus or a building. It allows devices on your network to communicate with each other, as well as with other networks. It helps you to share resources and reduce the costing of any organization.

3.0 Components of Computer Network … Routers : Routers help you to connect with multiple networks. It enables you to share a single internet connection with multiple devices and saves money. This networking component acts as a dispatcher, which allows you to analyze data sent across a network. It automatically selects the best route for data to travel and send it on its way.

3.0 Components of Computer Network … Servers: Servers are computers that hold shared programs, files, and the network operating system. Servers allow access to network resources to all the users of the network. Clients: Clients are computer devices which access and uses the network as well as shares network resources. They are also users of the network, as they can send and receive requests from the server.

3.0 Components of Computer Network … Transmission Media / Cables and connectors:

3.0 Components of Computer Network … Transmission Media / Cables and connectors: Transmission media is a carrier used to interconnect computers in a network, such as coaxial cable, twisted-pair wire, and optical fiber cable. It is also known as links, channels, or lines. Cable is a transmission media that transmits the communication signals. There are three types of cables: Twisted pair cable : It is a high-speed cable that transmits the data over 1Gbps or more.

3.0 Components of Computer Network … Transmission Media / Cables and connectors: Coaxial cable: Coaxial cable resembles like a TV installation cable. Coaxial cable is more expensive than twisted pair cable, but it provides the high data transmission speed. Fiber optic cable: Fiber optic cable is a high-speed cable that transmits the data using light beams. It provides high data transmission speed as compared to other cables. It is more expensive as compared to other cables, so it is installed at the government level.

3.0 Components of Computer Network … Access points: Access points allow devices to connect to the wireless network without cables. A wireless network allows you to bring new devices and provides flexible support to mobile users. Shared Data: Shared data are data which is shared between the clients such as data files, printer access programs, and email.

3.0 Components of Computer Network … NIC(National interface card) NIC is a device that helps the computer to communicate with another device. The network interface card contains the hardware addresses, the data-link layer protocol use this address to identify the system on the network so that it transfers the data to the correct destination. There are two types of NIC: wireless NIC and wired NIC . Wireless NIC: All the modern laptops use the wireless NIC. In Wireless NIC, a connection is made using the antenna that employs the radio wave technology. Wired NIC: Cables use the wired NIC to transfer the data over the medium.

3.0 Components of Computer Network … Local Operating System: A local OS which helps personal computers to access files, print to a local printer and uses one or more disk and CD drives which are located on the computer. Network Operating System: The network operating system is a program which runs on computers and servers. It allows the computers to communicate via network.

3.0 Components of Computer Network … Protocol: A protocol is the set of defined rules that allows two entities to communicate across the network. Some standard protocols used for this purpose are IP, TCP, UDP, FTP, etc. Hub: Hub is a device that splits network connection into multiple computers. It acts a distribution center so whenever a computer requests any information from a computer or from the network it sends the request to the hub through a cable. The hub will receive the request and transmit it to the entire network.

3.0 Components of Computer Network … LAN Cable: Local Area Network(LAN) cable is also called as Ethernet or data cable. It is used for connecting a device to the internet. OSI: OSI stands for Open Systems Interconnection. It is a reference model which allows you to specify standards for communications.

3.1 Unique Identifiers of Network Hostname: Every device of the network is associated with a unique device, which is called hostname. IP Address: IP (Internet Protocol) address is as a unique identifier for each device on the Internet. Length of the IP address is 32-bits. IPv6 address is 64 bits.

3.1 Unique Identifiers of Network… DNS Server: DNS stands for Domain Name System. It is a server which translates URL or web addresses into their corresponding IP addresses. MAC Address: MAC (Media Access Control Address) is known as a physical address is a unique identifier of each host and is associated with the NIC (Network Interface Card). General length of MAC address is : 12-digit/ 6 bytes/ 48 bits

3.1 Unique Identifiers of Network… Port:

3.1 Unique Identifiers of Network… Port: Port is a logical channel which allows network users to send or receive data to an application. Every host can have multiple applications running. Each of these applications are identified using the port number on which they are running.

3.2 Other Important Network Components ARP : ARP stands for Address Resolution Protocol, which helps network users to convert the IP address into its corresponding Physical Address. RARP : Reverse Address Resolution Protocol gives an IP address of the device with given a physical address as input.

3.3 Uses of Computer Networks Helps you to share resource such as printers. Allows you to share expensive software's and database among network participants. Provides fast and effective communication from one computer to another computer. Helps you to exchange data and information among users via a network.

3.4 Disadvantages of using Computer Networks Investment for hardware and software can be costly for initial set-up. If you don't take proper security precautions like file encryption, firewalls then your data will be at risk. Some components of the network design may not last for many years, and it will become useless or malfunction and need to be replaced. Requires time for constant administration. Frequent server failure and issues of regular cable faults.

3.5 Features of Computer Network A list Of Computer network features is given below. Communication speed File sharing Back up and Roll back is easy Software and Hardware sharing Security Scalability Reliability

3.5 Features of Computer Network … Communication speed Network provides us to communicate over the network in a fast and efficient manner. For example, we can do video conferencing, email messaging, etc. over the internet. Therefore, the computer network is a great way to share our knowledge and ideas. File sharing File sharing is one of the major advantage of the computer network. Computer network provides us to share the files with each other.

3.5 Features of Computer Network … Back up and Roll back is easy Since the files are stored in the main server which is centrally located. Therefore, it is easy to take the back up from the main server. Software and Hardware sharing We can install the applications on the main server, therefore, the user can access the applications centrally. So, we do not need to install the software on every machine. Similarly, hardware can also be shared. Security Network allows the security by ensuring that the user has the right to access the certain files and applications.

3.5 Features of Computer Network … Scalability Scalability means that we can add the new components on the network. Network must be scalable so that we can extend the network by adding new devices. But, it decreases the speed of the connection and data of the transmission speed also decreases, this increases the chances of error occurring. This problem can be overcome by using the routing or switching devices. Reliability Computer network can use the alternative source for the data communication in case of any hardware failure.

4.0 Types of Computer Network There are various types of computer networks available. We can categorize them according to their size as well as their purpose. The size of a network should be expressed by the geographic area and number of computers, which are a part of their networks. It includes devices housed in a single room to millions of devices spread.

4.0 Types of Computer Network …

4.1 Types of Computer Network : PAN (Personal Area Network)

4.1 Types of Computer Network : PAN (Personal Area Network) PAN is a computer network formed around a person. It generally consists of a computer, mobile, or personal digital assistant. PAN can be used for establishing communication among these personal devices for connecting to a digital network and the internet.

4.1 Types of Computer Network : Examples of PAN Body Area Network: Body Area Network moves along with a person like a smartphone or a watch that moves with a person. He can also connect with other people to interlink the device for sharing the data. Offline Network: The offline network can be deployed inside the house which is also called a home network. It is planned to connect with television, printers which are not accessible to the internet. Small Home Office: Small Home office is used to link the devices to cyberspace via a VPN that is a virtual private network.

4.1 Types of Computer Network : PAN … Characteristics of PAN: It is mostly personal devices network equipped within a limited area. Allows you to handle the interconnection of IT devices at the surrounding of a single user. PAN includes mobile devices, tablet, and laptop. It can be wirelessly connected to the internet called WPAN. Appliances use for PAN: cordless mice, keyboards, and Bluetooth systems.

4.1 Types of Computer Network : PAN … Advantages (pros / benefits) of PAN: PAN networks are relatively secure and safe It offers only short-range solution up to ten meters Strictly restricted to a small area Disadvantages (cons / drawback )of PAN It may establish a bad connection to other networks at the same radio bands. Distance limits.

4.2 Types of Computer Network : LAN (Local Area Network)

4.2 Types of Computer Network : LAN … A Local Area Network (LAN) is a group of computer and peripheral devices which are connected in a limited area such as school, laboratory, home, and office building. It is a widely useful network for sharing resources like files, printers, games, and other application. The simplest type of LAN network is to connect computers and a printer in someone's home or office. In general, LAN will be used as one type of transmission medium. It is a network which consists of less than 5000 interconnected devices across several buildings.

4.2 Types of Computer Network : LAN … Characteristics of LAN: It is a private network, so an outside regulatory body never controls it. LAN operates at a relatively higher speed compared to other WAN systems. There are various kinds of media access control methods like token ring and Ethernet.

4.2 Types of Computer Network : LAN … Advantages (pros / benefits) of LAN: Computer resources like hard-disks, DVD-ROM, and printers can share local area networks. This significantly reduces the cost of hardware purchases. You can use the same software over the network instead of purchasing the licensed software for each client in the network. Data of all network users can be stored on a single hard disk of the server computer. You can easily transfer data and messages over networked computers. It will be easy to manage data at only one place, which makes data more secure. Local Area Network offers the facility to share a single internet connection among all the LAN users.

4.2 Types of Computer Network : LAN … Disadvantages (cons / drawback )of PAN LAN will indeed save cost because of shared computer resources, but the initial cost of installing Local Area Networks is quite high. The LAN admin can check personal data files of every LAN user, so it does not offer good privacy. Unauthorized users can access critical data of an organization in case LAN admin is not able to secure centralized data repository. Local Area Network requires a constant LAN administration as there are issues related to software setup and hardware failures.

4.3 Types of Computer Network : WAN (Wide Area Network)

4.3 Types of Computer Network : WAN … WAN (Wide Area Network) is another important computer network that which is spread across a large geographical area. WAN network system could be a connection of a LAN which connects with other LAN's using telephone lines and radio waves. It is mostly limited to an enterprise or an organization.

4.3 Types of Computer Network : WAN … Characteristics of WAN: The software files will be shared among all the users; therefore, all can access to the latest files. Any organization can form its global integrated network using WAN .

4.3 Types of Computer Network : WAN … Advantages (pros / benefits) of WAN: WAN helps you to cover a larger geographical area. Therefore business offices situated at longer distances can easily communicate. Contains devices like mobile phones, laptop, tablet, computers, gaming consoles, etc. WLAN connections work using radio transmitters and receivers built into client devices.

4.2 Types of Computer Network : WAN … Disadvantages (cons / drawback )of WAN The initial setup cost of investment is very high. It is difficult to maintain the WAN network. You need skilled technicians and network administrators. There are more errors and issues because of the wide coverage and the use of different technologies. It requires more time to resolve issues because of the involvement of multiple wired and wireless technologies. Offers lower security compared to other types of networks.

4.4 Types of Computer Network : MAN (Metropolitan Area Network)

4.4 Types of Computer Network : MAN … A Metropolitan Area Network or MAN is consisting of a computer network across an entire city, college campus, or a small region. This type of network is large than a LAN , which is mostly limited to a single building or site. Depending upon the type of configuration, this type of network allows you to cover an area from several miles to tens of miles.

4.4 Types of Computer Network : MAN … Characteristics of MAN: It mostly covers towns and cities in a maximum 50 km range Mostly used medium is optical fibers, cables Data rates adequate for distributed computing applications.

4.4 Types of Computer Network : MAN … Advantages (pros / benefits) of MAN: It offers fast communication using high-speed carriers, like fiber optic cables. It provides excellent support for an extensive size network and greater access to WANs . The dual bus in MAN network provides support to transmit data in both directions concurrently. A MAN network mostly includes some areas of a city or an entire city.

4.4 Types of Computer Network : MAN … Disadvantages (cons / drawback )of MAN You need more cable to establish MAN connection from one place to another. In MAN network it is tough to make the system secure from hackers

4.5 Other types of Computer Networks Apart from above mentioned here, are some other important types of networks: WLAN (Wireless Local Area Network) Storage Area Network System Area Network Home Area Network POLAN- Passive Optical LAN Enterprise private network Campus Area Network Virtual Area Network Let's see all of them in detail:

4.5 Other types of Computer Networks … 1) WLAN WLAN (Wireless Local Area Network) helps you to link single or multiple devices using wireless communication within a limited area like home, school, or office building. It gives users an ability to move around within a local coverage area which may be connected to the network. Today most modern day's WLAN systems are based on IEEE 802.11 standards. Functioning like a LAN , WLANs make use of wireless network technology, such as Wi-Fi . Typically seen in the same types of applications as LANs , these types of networks don’t require that devices rely on physical cables to connect to the network.

4.5 Other types of Computer Networks … 2) Storage-Area Network (SAN) A Storage Area Network is a type of network which allows consolidated, block-level data storage. It is mainly used to make storage devices, like disk arrays, optical jukeboxes, and tape libraries. As a dedicated high-speed network that connects shared pools of storage devices to several servers, these types of networks don’t rely on a LAN or WAN . Instead, they move storage resources away from the network and place them into their own high-performance network. SANs can be accessed in the same fashion as a drive attached to a server. Types of storage-area networks include converged, virtual and unified SANs .

4.5 Other types of Computer Networks … 3) System-Area Network (also known as SAN) System Area Network is used for a local network. It offers high-speed connection in server-to-server and processor-to-processor applications. The computers connected on a SAN network operate as a single system at quite high speed. This term is fairly new within the past two decades. It is used to explain a relatively local network that is designed to provide high-speed connection in server-to-server applications (cluster environments), storage area networks (called “ SANs ” as well) and processor-to-processor applications. The computers connected on a SAN operate as a single system at very high speeds.

4.5 Other types of Computer Networks … 4) Passive Optical Local Area Network (POLAN) POLAN is a networking technology which helps you to integrate into structured cabling. It allows you to resolve the issues of supporting Ethernet protocols and network apps. POLAN allows you to use optical splitter which helps you to separate an optical signal from a single-mode optical fiber. It converts this single signal into multiple signals. As an alternative to traditional switch-based Ethernet LANs, POLAN technology can be integrated into structured cabling to overcome concerns about supporting traditional Ethernet protocols and network applications such as PoE (Power over Ethernet) . A point-to-multipoint LAN architecture, POLAN uses optical splitters to split an optical signal from one strand of single-mode optical fiber into multiple signals to serve users and devices.

4.5 Other types of Computer Networks … 5) Home Area Network (HAN): A Home Area Network is always built using two or more interconnected computers to form a local area network (LAN) within the home. For example, in the United States, about 15 million homes have more than one computer. This type of network helps computer owners to interconnect with multiple computers. This network allows sharing files, programs, printers, and other peripherals.

4.5 Other types of Computer Networks … 6) Enterprise Private Network (EPN) : Enterprise private network (EPN) networks are build and owned by businesses that want to securely connect numerous locations in order to share various computer resources. These types of networks are built and owned by businesses that want to securely connect its various locations to share computer resources.

4.5 Other types of Computer Networks … 7) Campus Area Network (CAN):

4.5 Other types of Computer Networks … 7) Campus Area Network (CAN): A Campus Area Network is made up of an interconnection of LANs within a specific geographical area. For example, a university campus can be linked with a variety of campus buildings to connect all the academic departments. Larger than LANs, but smaller than metropolitan area networks (MANs, explained below), these types of networks are typically seen in universities, large K-12 school districts or small businesses. They can be spread across several buildings that are fairly close to each other so users can share resources.

4.5 Other types of Computer Networks … 8) Virtual Private Network (VPN):

4.5 Other types of Computer Networks … 8) Virtual Private Network (VPN): A VPN is a private network which uses a public network to connect remote sites or users together. The VPN network uses "virtual" connections routed through the internet from the enterprise's private network or a third-party VPN service to the remote site. It is a free or paid service that keeps your web browsing secure and private over public Wi-Fi hotspots . By extending a private network across the Internet, a VPN lets its users send and receive data as if their devices were connected to the private network – even if they’re not. Through a virtual point-to-point connection, users can access a private network remotely.

5.0 What does Network Topology mean? Network topology refers to the physical or logical layout of a network. It defines the way different nodes are placed and interconnected with each other. Alternately, network topology may describe how the data is transferred between these nodes. There are two types of network topologies : physical and logical . Physical topology emphasizes the physical layout of the connected devices and nodes, while the logical topology focuses on the pattern of data transfer between network nodes.

5.0 What does Network Topology mean? … Computers in a network have to be connected in some logical manner. The layout pattern of the interconnections between computers in a network is called network topology . You can think of topology as the virtual shape or structure of the network. Network topology is also referred to as 'network architecture .' Devices on the network are referred to as 'nodes.' The most common nodes are computers and peripheral devices. Network topology is illustrated by showing these nodes and their connections using cables.

5.0 Different types of Physical Topologies are: P2P Topology Bus Topology Ring Topology Star Topology Tree Topology Mesh Topology Hybrid Topology

5.0 Different types of Physical Topologies are:

5.1 Point to Point (P2P) Topology

5.1 Point to Point (P2P) Topology … Point-to-point topology is the simplest and easiest of all the network topologies. In this method, the network consists of a direct link between two computers. This is faster and more reliable than other types of connections since there is a direct connection. The disadvantage is that it can only be used for small areas where computers are in close proximity.

5.1 Point to Point (P2P) Topology … Advantages: This is faster and highly reliable than other types of connections since there is a direct connection. No need for a network operating system. Does not need an expensive server as individual workstations are used to access the files. No need for any dedicated network technicians because each user sets their permissions.

5.1 Point to Point (P2P) Topology … Disadvantages: The biggest drawback is that it only be used for small areas where computers are in close proximity. You can't back up files and folders centrally. There is no security besides the permissions. Users often do not require to log onto their workstations.

5.2 BUS Topology

5.2 BUS Topology … Bus topology is a network type where every device is connected to a single cable that runs from one end of the network to the other. This type of network topology is often referred to as line topology . In a bus topology , data is transmitted in one direction only. If the bus topology has two endpoints then it is referred to as a linear bus topology . Smaller networks with this type of topology use a coaxial or RJ45 cable to link devices together. However, the bus topology layout is outdated and you’re unlikely to encounter a company using a bus topology today.

5.2 BUS Topology … Advantages (pros/benefits): Cost of the cable is very less as compared to other topology, so it is widely used to build small networks. Famous for LAN network because they are inexpensive and easy to install. It is widely used when a network installation is small, simple, or temporary. It is one of the passive topologies. So computers on the bus only listen for data being sent, that are not responsible for moving the data from one computer to others.

5.2 BUS Topology … Disadvantages (cons/drawbacks): In case if the common cable fails, then the entire system will crash down. When network traffic is heavy, it develops collisions in the network. Whenever network traffic is heavy, or nodes are too many, the performance time of the network significantly decreases. Cables are always of a limited length.

5.3 RING Topology

5.3 RING Topology … In a ring network , every device has exactly two neighboring devices for communication purpose. It is called a ring topology as its formation is like a ring . In this topology, every computer is connected to another computer. Here, the last node is combined with a first one. This topology uses token to pass the information from one computer to another. In this topology, all the messages travel through a ring in the same direction .

5.3 RING Topology … Advantages (pros/benefits): Easy to install and reconfigure. Adding or deleting a device in-ring topology needs you to move only two connections. The troubleshooting process is difficult in a ring topology . Failure of one computer can disturb the whole network. Offers equal access to all the computers of the networks Faster error checking and acknowledgment.

5.3 RING Topology … Disadvantages (cons/drawbacks): Unidirectional traffic. Break in a single ring can risk the breaking of the entire network Modern days high-speed LANs made this topology less popular. In the ring, topology signals are circulating at all times, which develops unwanted power consumption. It is very difficult to troubleshoot the ring network. Adding or removing the computers can disturb the network activity.

5.4 STAR Topology

5.4 STAR Topology … In the star topology , all the computers connect with the help of a hub. This cable is called a central node , and all other nodes are connected using this central node . It is most popular on LAN networks as they are inexpensive and easy to install. In star topology , each computer is connected to a central hub using a point-to-point connection. The central hub can be a computer server that manages the network, or it can be a much simpler device that only makes the connections between computers over the network possible.

5.4 STAR Topology … A star topology is a topology where every node in the network is connected to one central switch. Every device in the network is directly connected to the switch and indirectly connected to every other node. The relationship between these elements is that the central network hub is a server and other devices are treated as clients . The central node has the responsibility of managing data transmissions across the whole network and acts as a repeater . With star topologies , computers are connected with a coaxial cable, twisted pair, or optical fiber cable.

5.4 STAR Topology … Advantages (pros/benefits): Easy to troubleshoot, set up, and modify. Only those nodes are affected, that has failed. Other nodes still work. Fast performance with few nodes and very low network traffic. In Star topology , addition, deletion, and moving of the devices are easy.

5.4 STAR Topology … Disadvantages (cons/drawbacks): If the hub or concentrator fails, attached nodes are disabled. Cost of installation of star topology is costly. Heavy network traffic can sometimes slow the bus considerably. Performance depends on the hub's capacity A damaged cable or lack of proper termination may bring the network down.

5.5 TREE Topology

5.5 TREE Topology … As the name suggests, a tree topology network is a structure that is shaped like a tree with its many branches. Tree topologies have a root node that is connected to another node hierarchy. The hierarchy is parent-child where there is only one mutual connection between two connected nodes. As a general rule, a tree topology needs to have three levels to the hierarchy to be classified this way. This form of topology is used within Wide Area Networks to sustain lots of spread-out devices.

5.5 TREE Topology … Tree topologies have a root node, and all other nodes are connected which form a hierarchy. So it is also known as hierarchical topology . This topology integrates various star topologies together in a single bus, so it is known as a Star Bus topology . Tree topology is a very common network which is similar to a bus and star topology.

5.5 TREE Topology … Advantages (pros/benefits): Failure of one node never affects the rest of the network. Node expansion is fast and easy. Detection of error is an easy process It is easy to manage and maintain

5.5 TREE Topology … Disadvantages (cons/drawbacks): It is heavily cabled topology If more nodes are added, then its maintenance is difficult If the hub or concentrator fails, attached nodes are also disabled.

5.6 MESH Topology

5.6 MESH Topology … The mesh topology has a unique network design in which each computer on the network connects to every other. It is develops a P2P (point-to-point) connection between all the devices of the network. It offers a high level of redundancy, so even if one network cable fails, still data has an alternative path to reach its destination.

5.6 MESH Topology : Types of Mesh Topology Partial Mesh Topology: In this type of topology, most of the devices are connected almost similarly as full topology. The only difference is that few devices are connected with just two or three devices.

5.6 MESH Topology : Types of Mesh Topology Full Mesh Topology: In this topology, every nodes or device are directly connected with each other.

5.6 MESH Topology … Advantages (pros/benefits): The network can be expanded without disrupting current users. Need extra capable compared with other LAN topologies. Complicated implementation. No traffic problem as nodes has dedicated links. It has multiple links, so if any single route is blocked, then other routes should be used for data communication. P2P links make the fault identification isolation process easy. It helps you to avoid the chances of network failure by connecting all the systems to a central node.

5.6 MESH Topology … Disadvantages (cons/drawbacks): Installation is complex because every node is connected to every node. Dedicated links help you to eliminate the traffic problem. A mesh topology is robust. Every system has its privacy and security It is expensive due to the use of more cables. No proper utilization of systems. It requires more space for dedicated links. Because of the amount of cabling and the number of input-outputs, it is expensive to implement. It requires a large space to run the cables.

5.7 HYBRID Topology

5.7 HYBRID Topology … Hybrid topology combines two or more topologies. You can see in the above architecture in such a manner that the resulting network does not exhibit one of the standard topologies. For example, as you can see in the above image that in an office in one department, Star, Ring and Bus topology is used. A hybrid topology is always produced when two different basic network topologies are connected.

5.7 HYBRID Topology … Advantages (pros/benefits): Offers the easiest method for error detecting and troubleshooting Highly effective and flexible networking topology It is scalable so you can increase your network size

5.7 HYBRID Topology … Disadvantages (cons/drawbacks): The design of hybrid topology is complex It is one of the costliest processes

5.8 Network Topology : Summary

6.0 Work Group Computing and Groupware Workgroup: Term used to describe a collection of computers or other hardware connected to a network that are all related. For example, a workgroup may be dedicated to only the marketing department within a company.

6.1 Work Group Computing A workgroup is a collection of individuals working together on a task. Workgroup computing occurs when all the individuals have computers connected to a network that allows them to send e-mail to one another, share data files, and schedule meetings. Sophisticated workgroup systems allow users to define workflows so that data is automatically forwarded to appropriate people at each stage of a process.

6.1 Work Group Computing … Workgroup computing refers to any computer system that replicates the manual work process. Anytime two or more people work together sharing information on a computer system it can be defined as group computing . It is a way to electronically process human transactions. The focus is on information sharing, coordination and collaboration. When two people manually send letters or memos to each other, it is called a workgroup process . When two people send the same letters or memos using e-mail, it is referred to as workgroup computing . Any software that supports workgroup computing can be labeled as groupware .

6.2 Levels of Work Group Computing Workgroup computing is about working with other people in an electronic work environment. This collaboration can take place in offices located next to each other or in different parts of the world. There are three different levels of group computing : Individual level Coordinated effort Collaborating

6.2 Levels of Work Group Computing … Individual level – On this level the members individually work toward a group goal but there is no group coordination. Members use word processors, spreadsheets and databases, but do not coordinate their efforts. Here, we find duplication and lack of sharing of work that oftentimes produces inconsistent results.

6.2 Levels of Work Group Computing … Coordinated effort – On this level, the members coordinate and actively manage the flow of work by structuring work processes. It goes beyond individual automation and provides a structured work environment. The structures are the processes that need to be completed for a legal function. It focuses on the communication in the transmitting and receiving of messages. The basic tool for information sharing is e-mail. There are no time and place barriers. It pushes information to others. Other tools that support these coordinated efforts are schedulers, project managers, shared databases, and workflow automation software. This may require some development or customization of commercial software packages.

6.2 Levels of Work Group Computing … Collaborating – Members here make concerted efforts for information sharing, discussions, and obtaining other information as needed. It pulls information from many different data storage areas for use by all the team members. It is a “virtual” workplace that allows collaborative information exchanges without the constraints of time and space. Shared whiteboards, electronic brainstorming, shared editors, electronic conferencing, and electronic voting are technology tools that are supportive of this group dynamic.

6.3 Types of Work Group Computing Teleconferencing is a meeting among people in different geographical locations using the telephone. Computer teleconferencing is a keyboard conference among several users at computers linked through a network or the Internet. Document conferencing participants not only see and hear each other, but work on text and graphic projects at the same time. Application sharing is allowing all the participants to run a software program that is located on one user’s machine. Application viewing is similar, but only one person can edit the documents involved but everyone can see the document. Videoconferencing is where two or more people are sharing video of each other or others.

6.4 Work Group Software A workgroup is a collection of individuals working together on a task. This could be a formal unit in an organization, such as a department, or a temporary group working together on a specific project. Specialized workgroup software makes it possible for workgroup members to share data files, to schedule meetings, or to define workflows where files are automatically forwarded to the right people at each stage of a process.

6.4 Work Group Software … Many personal applications extend into workgroup applications . For example, if everyone in a group is using the same online calendar to schedule their meetings, then shared access can be set up to create a common scheduling tool. However, there are also applications specifically developed for workgroups . Workgroup software applications are also referred to as collaborative software or groupware . There are several categories of workgroup applications , including electronic communications, electronic conferencing, and scheduling and coordination tools.

6.4 Work Group Software … Increasingly, workgroup applications have become Web-based, meaning you can access the applications using a Web browser. This makes it easier to work in groups of any size in geographically separate locations.

6.5 Electronic Communications : Email Electronic communication applications send messages, documents, and files between people on different computer systems. This includes tools like email, voicemail, instant messaging, and wikis. Email is short for electronic mail . It allows for the exchange of digital messages between one sender and one or more recipients. There are a few strategies to make email more effective for workgroups . One approach is to set up a group in your contacts. You only have to do this once, and then if you want to email the entire group, you only have to enter the group name.

6.5 Electronic Communications : Email … If many different individuals will be sending emails to the group, another approach is to set up an electronic mailing list , or listserv . Individuals are added to this list, and messages sent to the listserv address are sent out to all list members. This is particularly useful for very large groups and groups whose membership constantly changes. Many organizations have an electronic mailing list of all their employees so that one email message can reach everyone.

6.5 Electronic Communications : Email … Voicemail makes it possible for users to receive, send, and store spoken messages. Voicemail is mostly used for you to record a message if someone is not able to answer their phone, but some voicemail systems can be set up for you to reach a group of people with one message. Voicemail can be cumbersome to work with if you have a large number of messages, since it may not always be immediately clear who has called and what the message is. Using a voicemail-to-text service , you can have your voicemail translated into text and converted to an email message.

6.5 Electronic Communications : Chat Instant messaging , or IM , is a widely-used form of online chat, which refers to text-based communication over the Internet in real time. This is similar to sending text messages on your mobile phone. IM uses a software application to compose, send, and receive messages. This sounds like email, but the difference is that IM occurs in real time, so your messages appear instantaneously and you can see who is online.

6.5 Electronic Communications : Chat … The software application for IM typically shows up as a small window floating on top of your other applications. This makes it possible to keep an eye on your messages while continuing with your other tasks. Quite a few companies have an online chat option on their website. Click on the link, and you actually get to chat with a live person.

6.5 Electronic Communications : Electronic Conferencing Electronic conferencing applications consist of software that makes it possible to have meetings in real time without being physically in the same location. This includes audio conferencing, video conferencing, and electronic meeting systems. Audio conferencing allows for simultaneous two-way audio transmissions between multiple parties. This is also referred to as a conference call . Typically, one party sets up the conference call, allowing others to call in. This allows any number of participants to be part of the call. Audio conferencing typically relies on regular telephone lines for the connection, but it requires at least one telephone that is specifically set up for this purpose.

6.5 Electronic Communications : Electronic Conferencing Video conferencing uses interactive communications technology to enable simultaneous two-way video and audio transmissions. This has also become very popular for personal use through services such as Skype and FaceTime, but it is also widely used by organizations. Video conferencing can reduce travel time and costs and provides a more personal connection between team members relative to other communications means. A relatively fast Internet connection is required to obtain acceptable video and audio quality.

7.0 What is a Virtual Office and What is telecommuting? Many experts say that excessive traffic congestion on roads and surging infrastructure costs in almost all the major business cities of the world are forcing companies to adopt “ virtual office ” models in order to telecommute to work.

7.0 What is a Virtual Office and What is telecommuting? … According to Wikipedia “A virtual office is a combination of off-site live communication and address services that allows users to reduce traditional office costs while maintaining business professionalism. Frequently the term is confused with ‘ office business centers ’ or ‘ executive suites ’ which demand a conventional lease, whereas a true virtual office does not require that expense.” One problem with the Wikipedia explanation is that the author of the Wiki is mistakenly trying to compare a virtual office Toronto to a Toronto office business center, when the top Toronto virtual office locations operate out of an office business center. Without having your virtual office run from a business center, there is no physical address for clients or customers to send courier packages or meet with you in person.

7.0 What is a Virtual Office and What is telecommuting? … Let’s first look at how large companies are using Toronto virtual office solutions. Companies who do not have a local Toronto office space, but require a prestigious Toronto address for employees who work remotely, will use a virtual office address and telephone service to maintain a corporate presence. All mail is sent to the Toronto virtual office location where it can be picked up or forwarded to private homes of the workers. When a client or customer phones the local exchange telephone number, their calls are routed through the central receptionist who handles the calls in a manner that the client has requested. Calls to their Toronto virtual office can re-direct to individual employees home or cell numbers, or sent to voicemail for them to pick up at their convenience.

7.0 What is a Virtual Office and What is telecommuting? … When smaller businesses are looking to get started, the budget for office space is low, so most entrepreneurs choose to run their business out of their home. While this may save them money, it could also be costing them credibility and potential customers. Without a professional appearance that comes with having a business address, customers may overlook dealing with them in favor of going with a provider who has a proper business address. Having a virtual office Toronto with a Toronto mail service address at a business center demonstrates to customers that you have a proper Toronto business address.

7.0 What is a Virtual Office and What is telecommuting? … Telecommuting is a work arrangement in which full or part-time employees enjoy flexibility in working location and hours. They are able to avoid the daily commute to the office and work remotely using telecommunications technology and access to a centralized work space. Many Toronto virtual office users find themselves working from home or other locations where they are able to get work done as well as have internet access. A person who telecommutes is known as a “ telecommuter ”.

7.0 What is a Virtual Office and What is telecommuting? … Toronto virtual offices are often used as mini hubs for larger companies without a local office who has telecommuters and wants to maintain the privacy of its workers who work out of their homes – by having a business address that is not the home address of the workers. This is especially good for companies with multiple Telecommuting workers. When a group of workers needs to get together for an in-person meeting, they can reserve a boardroom and only pay a daily or half day price. This saves the company money by not having to pay monthly rent on a meeting space that is only used on an occasional basis.

7.0 What is a Virtual Office and What is telecommuting? … No matter what size the company, a virtual office Toronto can be a great solution for those who are working from non-tradition office spaces. There are plenty of other benefits available to Toronto virtual office clients at Telsec , including access to boardrooms, Toronto meeting rooms, large conference rooms and day offices.

7.1 How is a ‘ Virtual Office ’ different than telecommuting or co-working ? Access Office Business Center’s Virtual Office packages are similar to co-working or telecommuting but not the same. Although co-working, telecommuting , and virtual offices all are ways to save on the hard costs of leasing a space and hiring staff, a virtual office package with Access Office Business Center portrays your business as professional and polished through services such as a trained receptionist, a private phone number with remotely accessible voicemail, and mail and package handling.

7.1 How is a ‘ Virtual Office ’ different than telecommuting or co-working ? … Similar to telecommuting , virtual offices offer the ability for you to work anywhere, anytime. However, as a telecommuter you have no administrative staff or a receptionist to deal with phone calls, mail, and meetings. With a virtual office , instead of connecting directly to your personal cell phone, your calls will be answered by an operator with a customized company greeting. In addition, your mail will be handled by administrative staff and you may reserve our professionally decorated meeting room and conference room for important appointments.

7.1 How is a ‘ Virtual Office ’ different than telecommuting or co-working ? … Although co-working instead of telecommuting adds the ability to have a specific space for working, these organizations often strive to maintain a casual, free-flowing vibe that may not be appropriate for the professional attitude you want to portray to your clients. With a virtual office package, you are able to depict your business as well-established, professional, and polished – exactly what you need to grow your company.

7.2 Virtual Office Assistants : Advantages and Disadvantages Gone are the days when office meant a specific location where people gathered to work but with modern advancement in thinking and technology, t elecommuting or virtual office have come into vogue. While many vouches for traditional office settings, there is a considerable population that believes that any means is good enough as long as the goal is achieved. In the last decade or so, there has been a huge increase in virtual office s and it has worked well both for employers as well as employees. A virtual office has both advantages and disadvantages and while it works well for some organizations, it might not be the case for others.

7.2 Virtual Office Assistants : Advantages and Disadvantages … S.no Advantages Disadvantages 1 It can make environment smile A greater chance of jobs being outsourced 2 Enhanced productivity A chance of losing out on promotions 3 Work-Life Balance They may not be accessible that promptly 4 Improved retention rate in the number of employees The danger of being labelled as unprofessional 5 Decrease in the number of leaves Lack of social interaction 6 Saves office space Security related concerns 7 A variety of candidates to choose from Lesser productivity 8 Saves time Less professionalism 9 Virtual office assistants or workers are a boon for small and upcoming firms Chances of miscommunication are higher 10 Relocation issues do not exist Too much dependence on technology 11 Helps scale up the business Being isolated 12 Cost cutting in many areas Many do not get the recognition and respect they deserve 13 A Virtual office assistant or worker means a dedicated professional Not all can become virtual office assistants or workers 14 Efficient but physically handicapped people can be hired Team work takes a backseat with virtual office assistants or workers 15 Virtual office assistants or workers are better at time management Scheduling Conflicts

8.0 Introduction to Network Security Network security is the security provided to a network from unauthorized access and risks. It is the duty of network administrators to adopt preventive measures to protect their networks from potential security threats. Computer networks that are involved in regular transactions and communication within the government, individuals, or business require security . The most common and simple way of protecting a network resource is by assigning it a unique name and a corresponding password.

8.0 Introduction to Network Security … Network security is a broad term that covers a multitude of technologies, devices and processes. In its simplest term, it is a set of rules and configurations designed to protect the integrity, confidentiality and accessibility of computer networks and data using both software and hardware technologies. Every organization, regardless of size, industry or infrastructure, requires a degree of network security solutions in place to protect it from the ever-growing landscape of cyber threats in the wild today.

8.0 Introduction to Network Security … Today's network architecture is complex and is faced with a threat environment that is always changing and attackers that are always trying to find and exploit vulnerabilities. These vulnerabilities can exist in a broad number of areas, including devices, data, applications, users and locations. For this reason, there are many network security management tools and applications in use today that address individual threats and exploits and also regulatory non-compliance. When just a few minutes of downtime can cause widespread disruption and massive damage to an organization's bottom line and reputation, it is essential that these protection measures are in place.

8.0 Introduction to Network Security … We live in an age of information. Businesses these days are more digitally advanced than ever, and as technology improves, organizations’ security postures must be enhanced as well. Now, with many devices communicating with each other over wired, wireless, or cellular networks, network security is an important concept. Network security is the process of taking preventative measures to protect the underlying networking infrastructure from unauthorized access, misuse, malfunction, modification, destruction or improper disclosure.

8.0 Introduction to Network Security … The Internet has undoubtedly become a huge part of our lives. Many people in today’s generation rely on the Internet for many of their professional, social and personal activities. But are you sure your network is secure ? There are many people who attempt to damage our Internet-connected computers, violate our privacy and make it impossible to the Internet services. Given the frequency and variety of existing attacks as well as the threat of new and more destructive future attacks, network security has become a central topic in the field of cybersecurity . Implementing network security measures allows computers, users and programs to perform their permitted critical functions within a secure environment.

8.0 Introduction to Network Security … Computer network security consists of measures taken by business or some organizations to monitor and prevent unauthorized access from the outside attackers. Different approaches to computer network security management have different requirements depending on the size of the computer network. For example, a home office requires basic network security while large businesses require high maintenance to prevent the network from malicious attacks. Network Administrator controls access to the data and software on the network. A network administrator assigns the user ID and password to the authorized person.

8.0 Introduction to Network Security … Information security is the process of securing information data from unauthorized access, use, modification, tempering, or disclosure. With the increased use of electronics media in our personal lives as well as businesses, the possibility of security breach and its major impact has increased. The theft of personal identity, credit card information, and other important data using hacked user names and passwords have become common these days. In addition, the theft of confidential business data may lead to loss of business for commercial organizations.

8.0 Introduction to Network Security … Network security is an organization’s strategy that enables guaranteeing the security of its assets including all network traffic. It includes both software and hardware technologies. Access to the network is managed by effective network security , which targets a wide range of threats and then arrests them from spreading or entering in the network.

8.1 How can we ensure network security ? We must ensure that the passwords are Strong and Complex everywhere- within the network too, not just on individual computers within an org. These passwords cannot be simple , default and easily guessable ones. This simple step can go a long way toward securing your networks .

8.2 Why is security so important? Information security performs key roles such as: The organization's ability to function without any hindrance Enabling the safe operation of applications implemented on the organization's IT systems Protecting the data the organization collects and its uses

8.3 What is Network security attack? A network attack can be defined as any method, process, or means used to maliciously attempt to compromise network security . Network security is the process of preventing network attacks across a given network infrastructure, but the techniques and methods used by the attacker further distinguish whether the attack is an active cyber attack , a passive type attack , or some combination of the two. Let’s consider a simple network attack example to understand the difference between active and passive attack .

8.3 Network security attack : i ) Active Attacks An active attack is a network exploit in which attacker attempts to make changes to data on the target or data en route to the target.

8.3 Network security attack : i ) Active Attacks … Meet Alice and Bob . Alice wants to communicate to Bob but distance is a problem. So, Alice sends an electronic mail to Bob via a network which is not secure against attacks. There is another person, Tom , who is on the same network as Alice and Bob . Now, as the data flow is open to everyone on that network, Tom alters some portion of an authorized message to produce an unauthorized effect. For example, a message meaning “ Allow BOB to read confidential file X ” is modified as “ Allow Smith to read confidential file X ”.

8.3 Network security attack : i ) Active Attacks … Active network attacks are often aggressive, blatant attacks that victims immediately become aware of when they occur. Active attacks are highly malicious in nature, often locking out users, destroying memory or files, or forcefully gaining access to a targeted system or network.

8.3 Network security attack : ii) Passive Attacks A passive attack is a network attack in which a system is monitored and sometimes scanned for open ports and vulnerabilities, but does not affect system resources. Let’s consider the example we saw earlier:

8.3 Network security attack : ii) Passive Attacks … Alice sends an electronic mail to Bob via a network which is not secure against attacks. Tom , who is on the same network as Alice and Bob , monitors the data transfer that is taking place between Alice and Bob . Suppose, Alice sends some sensitive information like bank account details to Bob as plain text. Tom can easily access the data and use the data for malicious purposes. So, the purpose of the passive attack is to gain access to the computer system or network and to collect data without detection.

8.3 Network security attack : ii) Passive Attacks … So, network security includes implementing different hardware and software techniques necessary to guard underlying network architecture. With the proper network security in place, you can detect emerging threats before they infiltrate your network and compromise your data.

8.4 How does network security work ? There are many layers to consider when addressing network security across an organization. Attacks can happen at any layer in the network security layers model, so your network security hardware , software and policies must be designed to address each area. Network security typically consists of three different controls: Physical, Technical and Administrative.

8.4 How does network security work ? … a) Physical Network Security Physical security controls are designed to prevent unauthorized personnel from gaining physical access to network components such as routers, cabling cupboards and so on. Controlled access, such as locks, biometric authentication and other devices, is essential in any organization.

8.4 How does network security work ? … b) Technical Network Security Technical security controls protect data that is stored on the network or which is in transit across, into or out of the network. Protection is twofold; it needs to protect data and systems from unauthorized personnel, and it also needs to protect against malicious activities from employees.

8.4 How does network security work ? … c) Administrative Network Security Administrative security controls consist of security policies and processes that control user behavior, including how users are authenticated, their level of access and also how IT staff members implement changes to the infrastructure.

8.5 Types of network security Network Access Control (NAC) Antivirus and Antimalware Software / Application Security Firewall Protection Virtual Private Networks (VPNs) Behavioral Analytics Wireless Security Intrusion Prevention System

8.5 Types of network security … i) Network Access Control (NAC) To ensure that potential attackers cannot infiltrate your network, comprehensive access control policies need to be in place for both users and devices. Network access control (NAC) can be set at the most granular level. For example, you could grant administrators full access to the network but deny access to specific confidential folders or prevent their personal devices from joining the network. To keep out potential attackers, you should be able to block unauthorized users and devices from accessing your network. Users that are permitted network access should only be able to work with the set of resources for which they’ve been authorized.

8.5 Types of network security … ii) Antivirus and Antimalware Software / Application Security Antivirus and antimalware software protect an organization from a range of malicious software, including viruses, ransomware, worms and trojans. The best software not only scans files upon entry to the network but continuously scans and tracks files. Application security includes the hardware, software, and processes that can be used to track and lock down application vulnerabilities that attackers can use to infiltrate your network.

8.5 Types of network security … iii) Firewall Protection Firewalls , as their name suggests, act as a barrier between the untrusted external networks and your trusted internal network. Administrators typically configure a set of defined rules that blocks or permits traffic onto the network. For example, Forcepoint's Next Generation Firewall (NGFW) offers seamless and centrally managed control of network traffic, whether it is physical, virtual or in the cloud. A firewall is a device or service that acts as a gatekeeper, deciding what enters and exits the network. They use a set of defined rules to allow or block traffic. A firewall can be hardware, software, or both.

8.5 Types of network security … iv) Virtual Private Networks (VPNs) Virtual private networks (VPNs) create a connection to the network from another endpoint or site. For example, users working from home would typically connect to the organization's network over a VPN . Data between the two points is encrypted and the user would need to authenticate to allow communication between their device and the network. Forcepoint's Secure Enterprise SD-WAN allows organizations to quickly create VPNs using drag-and-drop and to protect all locations with our Next Generation Firewall solution. A virtual private network encrypts the connection from an endpoint to a network, often over the Internet. This way it authenticates the communication between a device and a secure network, creating a secure, encrypted “tunnel” across the open internet .

8.5 Types of network security … v) Behavioral Analytics You should know what normal network behavior looks like so that you can spot anomalies or network breaches as they happen. Behavioral analytics tools automatically identify activities that deviate from the norm. Vi) Wireless Security Wireless networks are not as secure as wired ones. Cybercriminals are increasingly targeting mobile devices and apps. So, you need to control which devices can access your network.

8.5 Types of network security … vii) Intrusion Prevention System These systems scan network traffic to identify and block attacks, often by correlating network activity signatures with databases of known attack techniques. So, these are some ways of implementing network security. Apart from these, you’ll need a variety of software and hardware tools in your toolkit to ensure network security, those are: Firewalls Packet crafters Web scanners Packet sniffers Intrusion detection system Penetration testing software

8.6 Network security for businesses and consumers Network security should be a high priority for any organization that works with networked data and systems. In addition to protecting assets and the integrity of data from external exploits, network security can also manage network traffic more efficiently, enhance network performance and ensure secure data sharing between employees and data sources. There are many tools, applications and utilities available that can help you to secure your networks from attack and unnecessary downtime. Forcepoint offers a suite of network security solutions that centralize and simplify what are often complex processes and ensure robust network security is in place across your enterprise.

9.0 Introduction of Firewall in Computer Network Access to e-mail and other Internet resources is very much a necessity for conducting business and accessing information. However, along with the convenience that network connectivity brings, it also raises serious security concerns. With always-on connections such as cable modems and DSL lines, Internet users need to be increasingly vigilant of security issues, as network traffic coming into the computer can cause damage to files and programs even when the user is away from the computer and the computer is idle.

9.0 Introduction of Firewall in Computer Network … In a system that is not protected with any security measures, malicious code such as viruses can infect systems and cause damage that may be difficult to repair. Unscrupulous characters on the Internet are always snooping around trying to find open computers from which they can steal personal files, personal information or create other forms of mischief. The loss of financial records, e-mail, customer files, can be devastating to a business or to an individual. In conjunction with other security measures, firewalls can help to prevent this devastation.

9.0 Introduction of Firewall in Computer Network … Would-be busters are capitalizing on modern technology to exploit businesses for financial gain and espionage. Cyber crime is an increasingly prolific and profitable option. It is the single greatest risk to most companies today. If you’re not already aware of the scope of the threat: 73% of organizations do not have sufficient network security in place ( Hiscox ) Cyber-attacks have seen a 67% increase since 2014. Malware is the more common attack and the most expensive to resolve. ( Accenture ) Almost half of the cyber attacks in the US were directed at SMBs ( CNBC )

9.0 Introduction of Firewall in Computer Network … More than 4.1 billion records were exposed in data breaches, just through the first half of 2019 ( Risk Based Security ) The average cost per cyber attack against an American company in 2018 came out to more than $500,000 ( Hiscox ) The U.S. is predicted to account for more than half of breached data by 2023 ( Norton ) The cost of cybercrime comes from business disruption, information loss, revenue loss, and equipment damage. Firewalls are a crucial front line of defense against these threats, but not all firewalls deliver the kind of security at the locations you most need it.

9.1 What are Firewalls ? Firewalls are tools that can be used to enhance the security of computers connected to a network, such as a LAN or the Internet. A firewall separates a computer from the Internet, inspecting packets of data as they arrive at either side of the firewall ? inbound to, or outbound from, your computer ? to determine whether it should be allowed to pass or be blocked. Firewalls act as guards at the computer’s entry points (which are called ‘ports’) where the computer exchanges data with other devices on the network. Firewalls ensure that packets that are requesting permission to enter the computer meet certain rules that are established by the user of the computer.

9.1 What are Firewalls ? … Firewalls operate in two ways, by either denying or accepting all messages based on a list of designated acceptable or unacceptable sources, or by allowing or denying all messages based on a list of designated acceptable or unacceptable destination ports. Although they sound complex, firewalls are relatively easy to install, setup and operate.

9.1 What are Firewalls ? … A firewall is a network security device , either hardware or software-based, which monitors all incoming and outgoing traffic and based on a defined set of security rules it accepts, rejects or drops that specific traffic. Accept : allow the traffic Reject : block the traffic but reply with an “unreachable error” Drop : block the traffic with no reply

9.1 What are Firewalls ? … A firewall establishes a barrier between secured internal networks and outside untrusted network, such as the Internet.

10.0 Wireless Network vs Wired Network Increasingly, the needs of modern homes and work spaces are for greater and more versatile internet coverage than just having a single PC, or group of PCs wired up to a router with ethernet cables. Wireless networks enable multiple devices to use the same internet connection remotely, as well as share files and other resources. They also allow mobile devices, such as laptops, tablets and mobile phones to move around within the network area freely and still maintain a connection to the internet and the network .

10.0 Wireless Network vs Wired Network … There are also disadvantages to wireless networks , however, especially when you compare them with wired networks , which generally maintain a faster internet speed and are more secure. Below, I have listed all of the above points, plus the other main advantages and disadvantages of a wireless network vs wired network.

10.1 Wired Network In computing terminology, the term " wired " is used to differentiate between wireless connections and those that involve cables. A wired setup uses physical cables to transfer data between different devices and computer systems. The cables can be copper wire, twisted pair or fiber optic. Wired network is used to carry different forms of electrical signals from one end to the other. Most wired networks use Ethernet cables to transfer data between connected PCs. Ethernet works or operates in a narrow range and it is little bit difficult to configure as compared to wireless networking technologies.

10.1 Types of Wired Connections 1) Twisted pair: Consists of a pair of wires that are twisted together. The twisting reduces noise on the wires by cancelling out, to a certain extent, the amount of electromagnetic interference from the environment and between transmit and receive.

10.1 Types of Wired Connections … 2) Coaxial Cable: Coaxial cables consist of a cylindrical wire running down the middle of an insulating sheath. Surrounding the insulating sheath is a conductive sheath, acting simultaneously as a shield and a return path for the signal. Coax cables are highly resistant to noise due to the shielding which keeps most of the EM energy inside the surrounding conductive sheath.

10.1 Types of Wired Connections … 3) Fiber Optic Cable: A fiber optic cable consists of a very long thin fiber of glass down which light pulses can be sent. The data rates supported by fiber optic networks are incredibly fast. So fast in fact that most people involved in fiber optic development now say that in relation to network speeds, computers are hopelessly slow, and so we must try to avoid computation at all costs.

10.2 Wireless Connections Wireless communication involves no physical link established between two or more devices, communicating wirelessly. Wireless signals are spread over in the air and are received and interpreted by appropriate antennas. When an antenna is attached to electrical circuit of a computer or wireless device, it converts the digital data into wireless signals and spread all over within its frequency range. The receptor on the other end receives these signals and converts them back to digital data. A little part of electromagnetic spectrum can be used for wireless transmission.

10.2 Types of Wireless Connections 1) RADIO TRANSMISSION Radio frequency is easier to generate and because of its large wavelength it can penetrate through walls and structures alike. Radio waves can have wavelength from 1 mm – 100,000 km and have frequency ranging from 3 Hz (Extremely Low Frequency) to 300 GHz (Extremely High Frequency). Radio frequencies are sub-divided into six bands. Radio waves at lower frequencies can travel through walls whereas higher RF can travel in straight line and bounce back. The power of low frequency waves decreases sharply as they cover long distance. High frequency radio waves have more power.

10.2 Types of Wireless Connections … 2) MICROWAVE TRANSMISSION Electromagnetic waves above 100 MHz tend to travel in a straight line and signals over them can be sent by beaming those waves towards one particular station. Because Microwaves travels in straight lines, both sender and receiver must be aligned to be strictly in line-of-sight. Microwaves can have wavelength ranging from 1 mm – 1 meter and frequency ranging from 300 MHz to 300 GHz.

10.2 Types of Wireless Connections … 3) INFRARED TRANSMISSION Infrared wave lies in between visible light spectrum and microwaves. It has wavelength of 700-nm to 1-mm and frequency ranges from 300-GHz to 430-THz. Infrared wave is used for very short range communication purposes such as television and it’s remote. Infrared travels in a straight line hence it is directional by nature. Because of high frequency range, Infrared cannot cross wall-like obstacles.

10.2 Types of Wireless Connections … 4) LIGHT TRANSMISSION Highest most electromagnetic spectrum which can be used for data transmission is light or optical signaling. This is achieved by means of LASER . Because of frequency light uses, it tends to travel strictly in straight line. Hence the sender and receiver must be in the line-of-sight. Because laser transmission is unidirectional, at both ends of communication the laser and the photo-detector needs to be installed. Laser beam is generally 1mm wide hence it is a work of precision to align two far receptors each pointing to lasers source.

10.3 What is Difference b/w Wired & Wireless Network ? ... PARAMETER WIRED WIRELESS Communication Medium Copper, Fiber etc. Air Standard IEEE 802.3 802.11 family Mobility and Roaming Limited Higher Security High Lower than Wired. Also easy to hack Speed / Bandwidth High Speed upto 1 Gbps Lower speed than Wired Network Access to Network Physical Access Required Proximity Required Delay Low High Reliability High Lower than Wired Flexibility to change Less flexible to changes More flexible configuration Working principle CSMA/CD, operates by detecting the occurrence of a collision. CSMA/CA , hence reduces possibility of collision be avoiding collision from happening

10.3 What is Difference b/w Wired & Wireless Network ? PARAMETER WIRED WIRELESS Interference and Fluctuations vulnerability Very Less High Installation activity Cumbersome and manpower intensive Less labor intensive and easy Installation Time Takes longer time to perform Very less deployment time Dedicated / Shared Connection Dedicated Shared Installation Cost High Low Maintenance (Upgrade) cost High Low Related equipment Router, Switch , Hub Wireless Router, Access Point Benefits * Greater Speed * Higher noise immunity * Highly reliable * Greater Security * No Hassles of Cable * Best for mobile devices * Greater mobility * Easy installation and management

11.0 Generations of Mobile Networks Much of the conversation in the mobile industry at the moment is around the benefits of 5G and when we can expect to see a roll-out. But many consumers will remember when 2G, 3G and 4G were the latest innovation in mobile connectivity. Each generation of network brought with it a significant milestone in the development of mobile communications, the benefits of which we’ve outlined below.

11.0 Generations of Mobile Networks … First Generation (1G) First generation mobile networks were reliant upon analog radio systems which meant that users could only make phone calls, they couldn’t send or receive text messages. The 1G network was first introduced in Japan in 1979 before it was rolled out in other countries such as the USA in 1980. In order to make it work, cell towers were built around the country which meant that signal coverage could be obtained from greater distances. However, the network was unreliable and had some security issues. For instance, cell coverage would often drop, it would experience interference by other radio signals and due to a lack of encryption, it could easily be hacked. This means that with a few tools, conversations could be heard and recorded.

11.0 Generations of Mobile Networks … Second Generation (2G) The 1G network was not perfect, but it remained until remained until 1991 when it was replaced with 2G . This new mobile network ran on digital signal, not analog, which vastly improved its security but also its capacity. On 2G , users could send SMS and MMS messages (although slowly and often without success) and when GPRS was introduced in 1997, users could receive and send emails on the move.

11.0 Generations of Mobile Networks … Third Generation (3G) Third generation mobile networks are still in use today, but normally when the superior 4G signal fails. 3G revolutionized mobile connectivity and the capabilities of cell-phones. In comparison to 2G , 3G was much faster and could transmit greater amounts of data. This means that users could video call, share files, surf the internet, watch TV online and play online games on their mobiles for the first time. Under 3G , cell-phones where no longer just about calling and texting, they were the hub of social connectivity.

11.0 Generations of Mobile Networks … Fourth Generation (4G) The introduction of 4G went one step further than the revolutionary 3G . It’s five times faster than the 3G network – and can in theory provide speeds of up to 100Mbps. All mobile models released from 2013 onwards should support this network, which can offer connectivity for tablets and laptops as well as smartphones. Under 4G , users can experience better latency (less buffering), higher voice quality, easy access to instant messaging services and social media, quality streaming and make faster downloads.

11.0 Generations of Mobile Networks … Fifth Generation (5G) The 5G network is yet to be released but is widely anticipated by the mobile industry. Many experts claim that the network will change not just how we use our mobiles, but how we connect our devices to the internet. The improved speed and capacity of the network will signal new IoT trends, such as connected cars, smart cities and IoT in the home and office. Mobile network operators claim that 5G will be available by 2020 but nothing is certain just yet.

11.0 Comparison of Mobile Networks Parameters 1G 2G 3G 4G Image Name 1st Generation Mobile Network 2nd Generation Mobile Network 3rd Generation Mobile Network 4th Generation Mobile Network Introduced in year 1980s 1993 2001 2009 Location of first commercialization USA Finland Japan South Korea Technology AMPS (Advanced Mobile Phone System), NMT, TACS IS-95, GSM IMT2000, WCDMA LTE, WiMAX Multiple Address/Access system FDMA TDMA, CDMA CDMA CDMA Switching type Circuit switching Circuit switching for Voice and Packet switching for Data Packet switching except for Air Interface Packet switching Speed (data rates) 2.4 Kbps to 14.4 kbps 14.4 Kbps 3.1 Mbps 100 Mbps Special Characteristic First wireless communication Digital version of 1G technology Digital broadband, speed increments Very high speeds, All IP

11.0 Comparison of Mobile Networks … Parameters 1G 2G 3G 4G Image Name 1st Generation Mobile Network 2nd Generation Mobile Network 3rd Generation Mobile Network 4th Generation Mobile Network Features Voice only Multiple users on single channel Multimedia features, Video Call High Speed, real time streaming Supports Voice only Voice and Data Voice and Data Voice and Data Internet service No Internet Narrowband Broadband Ultra Broadband Bandwidth Analog 25 MHz 25 MHz 100 MHz Operating frequencies 800 MHz GSM: 900MHZ, 1800MHz CDMA: 800MHz 2100 MHz 850 MHz, 1800 MHz Band (Frequency) type Narrow band Narrow band Wide band Ultra Wide Band Carrier frequency 30 KHZ 200 KHz 5 MHz 15 MHz Advantage Simpler (less complex) network elements Multimedia features (SMS, MMS), Internet access and SIM introduced High security, international roaming Speed, High speed handoffs, MIMO technology, Global mobility Disadvantages Limited capacity, not secure, poor battery life, large phone size, background interference Low network range, slow data rates High power consumption, Low network coverage, High cost of spectrum licence Hard to implement, complicated hardware required Applications Voice Calls Voice calls, Short messages, browsing (partial) Video conferencing, mobile TV, GPS High speed applications, mobile TV, Wearable devices

The Basics and Understanding of Computer Networking.pptx

About This Presentation

Slide Content

Tags

Categories

Download

Quick Actions

Statistics

Related Slideshows

The Basics and Understanding of Computer Networking.pptx

About This Presentation

Slide Content

Slide 1

Slide 2

Slide 3

Slide 4

Slide 5

Slide 6

Slide 7

Slide 8

Slide 9

Slide 10

Slide 11

Slide 12

Slide 13

Slide 14

Slide 15

Slide 16

Slide 17

Slide 18

Slide 19

Slide 20

Slide 21

Slide 22

Slide 23

Slide 24

Slide 25

Slide 26

Slide 27

Slide 28

Slide 29

Slide 30

Slide 31

Slide 32

Slide 33

Slide 34

Slide 35

Slide 36

Slide 37

Slide 38

Slide 39

Slide 40

Slide 41

Slide 42

Slide 43

Slide 44

Slide 45

Slide 46

Slide 47

Slide 48

Slide 49

Slide 50

Slide 51

Slide 52

Slide 53

Slide 54

Slide 55

Slide 56

Slide 57

Slide 58

Slide 59

Slide 60

Slide 61

Slide 62

Slide 63

Slide 64

Slide 65

Slide 66

Slide 67

Slide 68

Slide 69

Slide 70

Slide 71

Slide 72

Slide 73

Slide 74

Slide 75

Slide 76

Slide 77