Types & Characteristics of Computer Networks: Advantages, Disadvantages & Devices, Summaries of Network Design

Download Types & Characteristics of Computer Networks: Advantages, Disadvantages & Devices and more Summaries Network Design in PDF only on Docsity! Introduction The network can be defined as the set of groups or organizations where different ideas and information can be shared. In the context of computers, a computer network can be defined as the set of groups of multiple computers connect to share data, files, hardware, application, information, and many other purposes. For the communication or sharing of these data, computers should be connected to a network. For the connection of the computer’s different types of wire or wireless devices are used. To understand the network among the computers we need to know networking principles. Those main principles help user to deliver their ideas and experience about the computer network with others. Along with the principles, a network must follow some network protocols. Therefore, Network protocols are the set of policies and plans, which contains some formats and rules for making possible communication between computers over a network. Similarly, Networking devices are also required, Networking devices are those physical devices, which are required communication and interaction between hardware on a computer network. These networking devices connect various networks using different types of networking protocols. Similarly, the Network topology is the process of arranging elements present in a communication network that can be depicted physically or logically. Fig no.1: computer network Source: https://1.bp.blogspot.com/-FBc_Q-tj2oA/XoIBk69CkKI/AAAAAAAAAnk/5P7PVJHTc0MQSzhA-dQGNh9gXuROmk6pwCLcBGAsYHQ/w1200-h630-p-k-no- nu/Pengertian-Komunikasi-Daring.jpg 1 | P a g e RUBYN-NETWORKING  Advantage of a computer network:  It helps to share an internet connection. Using a home network or office, multiple devices can be connected to access the internet without having to pay for an ISP for multiple accounts.  Devices like network printers, scanners, webcams, and CD burners can be shared.  Files like audio, photos, videos, text can be shared.  Multiple online and popular games can be played with different people from different places at the same time.  Storage capacity also can be increased. Having the better advantage of computer networks there is some limitation of computer networks.  Limitations of computer network  The major drawback of computer networks is security issues. If a computer is on a network, computer hackers can get unauthorized access by using different tools.  The rapid spread of computer viruses. Viruses get spread on a network easily because of the interconnection of the workstation. Viruses make our computer slow, can also delete important files.  Network faults can cause loss of data.  Purchasing the network cabling and file servers can be expensive.  Managing a large network is complicated, requires training and a network manager usually needs to be employed. These are the advantages and disadvantages of computer networks. As we know there are different types of computer networks. So, the different types of computer networks there use, advantages, and disadvantages are now discussed below. Types of computer networks are: i. PAN (Personal Area Network) ii. LAN (local area network) iii. MAN (metropolitan area network) iv. WAN (wide area network) v. WLAN (wireless local area network) 2 | P a g e RUBYN-NETWORKING Now, here are the important characteristics of a LAN network:  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. 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 in 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. Drawbacks of LAN:  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 the 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 a centralized data repository.  Local Area Network requires a constant LAN administration as there are issues related to software setup and hardware failures. Fig no.4: Local Area Network (LAN) Sources: http://4.bp.blogspot.com/-xZM7NSPBaBM/T_sO-DTRiAI/AAAAAAAAAAc/WhqTfq2c_Bk/s1600/Local-Area-Network.jpg MAN (Metropolitan area network) 5 | P a g e RUBYN-NETWORKING MAN stands for metropolitan area network. It is a large computer network that usually spans a vast geographical area and is used in large companies and university campuses. For example, MAN is used to link the various buildings such as academic colleges or departments, libraries, student residence halls, etc. located within a university campus. A Metropolitan Area Network (MAN) is a large computer network on a large geographical area that includes several buildings or even the entire city (metropolis). The geographical area of the MAN is larger than LAN but smaller than WAN. MAN includes many communication devices and provides Internet connectivity for the LANs in the metropolitan area. MAN is used to combine into a networking group located in different buildings into a single network. The diameter of such a network can range from 5 to 50 kilometers. MANs rarely extend beyond 100 KM and frequently comprise a combination of different hardware and transmission media. Now, here are important characteristics of the MAN network:  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. Benefits of MAN network:  It offers fast communication using high-speed carriers, like fiber optic cable.  It provides excellent support for an extensive size network and greater access to WANs.  The dual bus in the 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. Drawbacks using the MAN network:  You need more cable to establish a MAN connection from one place to another.  In MAN network it is tough to make the system secure from hackers. 6 | P a g e RUBYN-NETWORKING Fig no.5: MAN (Metropolitan Area Network) Source: https://4.bp.blogspot.com/RrRe9jtXpw8/XMse7IpOyoI/AAAAAAAAAvU/g8zIba_ucMYJ1XNvWkkJjauEjiRv5sZrQCLcBGAs/s1600/metropolitan%2Barea%2Bnetwork.png WAN (Wide Area Network): WAN stands for Wide Area Network. A WAN is a network that spans more than one geographical location often connecting separated LANs. WANs are slower than LANs and often require additional and costly hardware such as routers, dedicated leased lines, and complicated implementation procedures.  Wide area networks are implemented to connect a large number of LANs and MANs. Due to this reason, it is possible to see a large number of heterogeneous components in a wide area network. Different communication media are used, and the network spreads across several national boundaries. Computers connected to a WAN are often connected to a public network. They can also be connected through leased lines or satellite links. The government or large concerns mostly use WAN because of the considerable investment made to implement them. Now, here are the characteristics of WAN:  The software files will be shared among all the users; therefore, all can access the latest files.  Any organization can form its global integrated network using WAN. The benefits of WAN:  WAN helps you to cover a larger geographical area. Therefore, business offices situated at longer distances can easily communicate. 7 | P a g e RUBYN-NETWORKING Fig no.7: WLAN (Wireless Local Area Network) Source: http://accoladewireless.com/wp-content/uploads/2015/05/wlan41.jpg These are the different types of networks, now we are going to discuss the different network systems, their advantages, and disadvantages. So, the different types of the network system are: I. Peer-To-Peer Network II. Client-Server Network III. Cloud Network IV. Cluster Network V. Virtualized Network VI. Centralized Network I. Peer-To-Peer Network: A Peer-to-Peer network is defined as a network of computers, which does not consist server and is mostly used by small organizations, which allows sharing of certain files and folders to every user or selected user. Small organizations, having peer-to-peer networks uses a dedicated file server. In such networks, files and folders can only be configured to allow the users for copying them. Those files and folders cannot be placed/altered in their original location. This is done for the safety of files and folders. Characteristics of a Peer-to-peer network are similar to small local area networks (LAN). Computers involved in a peer-to-peer network use the same set of networking rules and regulations and the same software. The router provides centralized Internet. In these types of networks, computers are connected directly. This kind of network is mostly used in small organizations like schools, colleges, and small government offices where there is no need for security. It is mostly used for sharing data and information. 10 | P a g e RUBYN-NETWORKING Fig no.8: Peer-To-Peer Network Source: https://th.bing.com/th/id/R.e5b30376cbdb01c1b8a9714050109b91?rik=ivjgFC6ATT8jbQ&riu=http%3a%2f%2f2.bp.blogspot.com%2f-5HkiC8bwPWU %2fUal0MvjajyI%2fAAAAAAAAEpo%2fpT6-xz6ksRY%2fs1600%2fpeer_to_peer.jpg&ehk=8%2bUDxmP%2fYAE6QYr0FixCjD5HeUywFfbeXpUzeCGEp9w %3d&risl=&pid=ImgRaw&r=0  Benefits of peer-to-peer network: I. Easy to set up and manage. II. Less chance of hacking and cracking. III. No requirement of skilled manpower. The first benefit of a Peer-to-Peer Network is that the computers can be easily be configured in their workgroups allowing the sharing of files, printers, and other resources across all the devices. The data and information can be shared in both directions in such networks. Those data and information can be downloaded to the computer and can be uploaded from the computer. The Peer-to-Peer network is cheap compared to other networks. Configuration and implementation of the peer-to-peer network can be easily done in less time. The next important feature of such a network is that it is responsible to distribute load across many computers. A peer-to-peer network helps to share the files having a high volume from one computer to another. They are more resilient than client-server networks whenever a failure occurs. Peer-to- Peer network is easier to set up and install. P2P has the advantage that if one peer does not work properly or faces failure then also it does not affect the functioning of other peers. That is why it is very reliable. The network does not get affected even though the server goes down. There is no specific network administrator in such networks. Users can control the resources that they have shared.   Constraint of peer-to-peer network: I. Not suitable for the large organization but can be best for small organizations. II. Less security but chances of hacking and cracking is low. III. Cannot be managed centrally. 11 | P a g e RUBYN-NETWORKING As a peer-to-peer network does not rely on a central server and it does not have a specific administrator, the whole system is decentralized and it is difficult to control. In such networks, a specific person cannot have the right to determine the whole accessibility setting of the network to handle it properly. One of the main drawbacks is that it is not secure. Security is very poor because of which viruses and malware can easily be transmitted over its architecture. Once the data gets lost from this type of network, it cannot be recovered, or even if it is recovered, it takes a lot of time and hard work. A computer in this network must have a backup system. A peer-to- peer network is a technology, which is mostly used in torrents. In torrents, it is used to transfer a lot of movies, music, and other copyrighted files. It slows down the performance of users because others or anyone in this network can access each computer. II. Client-Server Network: Client-server Network is the complex type of network containing a server that is mostly used by many large organizations such as banks, telecom, etc. In a client-server network, the client computer must request a service with the server program of another computer before accessing the data of that computer. If the server computer accepts the request, then only the client computer can continue its further processes in the computer. It is an important idea in a network. In a network, the client/server computer is responsible to provide a convenient way of interconnecting the programs. A client-server network is one of the central ideas of computing. It is very beneficial for business purposes so, most of the business applications are performed using this type of network. Both client programs and server programs of this network are usually a part of a larger application. For example, on the internet, a web browser acts as a client computer that sends requests to a Web server in another computer located somewhere on that internet. In this type of network, one server supports many clients. Multiple servers can also be networked together in a pool to handle the increasing number of clients if required. This type of network can differentiate between devices and applications. Here, a device that acts as a server for one application simultaneously acts as a client to other servers for different applications. In this network, all computers are connected to a powerful computer for data sharing and data use. It is a centralized network that is more secured and advanced than a peer-to-peer network. Fig no.8: Client-Server Network source: https://www.itrelease.com/wp-content/uploads/2021/05/Client-server-network-1.jpg 12 | P a g e RUBYN-NETWORKING  Benefits of cloud computing: i. Reduced cost. ii. Increased storage. iii. Flexibility Cloud computing enables the user to deploy the service just in fewer clicks. The resources required for the system can also be gained quickly within fewer minutes. The data and information stored in the cloud can be accessed anywhere and at any time. Therefore, it helps to avoid delays in the work of the company. It is also easy to get them back- up and recover the data from the cloud network. This helps in saving our time to perform and complete other activities. Without cloud computing, it is not possible to run any business in a more reliable and manageable way. Cloud computing also helps in focusing on keeping up or being updated about the business competition by offering access to the most trending and in-demand applications. Cloud network helps the users to perform all the manual work of installing and maintaining the applications that they require. Cloud computing is an emerging technology in which almost every company switches for better performance in the company. Cloud computing is a necessity for every company to rise to the business competition. The biggest reason for a company to switch their technology with cloud computing technology is that it is considerably cheap than on- premise technology. Enabling cloud computing in the companies maintains enormous storage space to store the resources, which directly helps to save the money of the company as the company. Cloud computing is also responsible to manage the server by eliminating the need for IT infrastructure updates and maintenance. It takes care of all the maintenance and management of IT services.  Constraint of cloud computing: i. Data replication ii. Vulnerability to attack iii. Downtime problem. So, security should be made a core aspect of all IT operations. The constraint that cloud computing holds is that it does not have a proper security system because of which there is a chance of loss of data and information in such a network. The server can crash easily and at any time, which may cause huge losses to the company. The clients working with a server containing cloud computing may be stuck in many difficult situations. As cloud infrastructure is entirely owned and managed by the service provider, the clients have only limited control over the cloud services and the company cannot have the level of control as they want over its back-end infrastructure. This does not let the clients be updated about all the data and information of the company. The data that gets stored in the cloud is all online-based which is a great risk for a company because it can be easily hacked or theft by hackers. Thus, it is a serious challenge for a company to share data through cloud networking. Thus, Cloud computing completely depends on the internet so, the company must be able to maintain good connection speed and bandwidth for the business to run it properly and it is also a quite risky decision for a company to store all the data 15 | P a g e RUBYN-NETWORKING through the internet. Therefore, though advanced security measures are deployed on the cloud, storing confidential data in the cloud is quite risky. There is also the chance of loss of power, low internet connectivity, etc. in such networks. The server of the company may face various technical problems or issues because of the cloud networking. IV. Cluster Network: Cluster computing can be described as a fusion of the fields of parallel, high-performance, distributed, and high-availability computing. Clustering involves establishing a connection between two or more computers to make them appear as a single resource. There’s a complexity in doing so that typically requires additional costs. Maintenance and monitoring can be challenging as well. Cluster computing has become a hot topic of research among the academic and industry community including system designers, network developers, language designers, standardizing forums, algorithm developers, graduate students, and faculties. A computer cluster consisting of a set of loosely or tightly connected computers that work together to be viewed as a single system in different situations is called a cluster network. This network enables the high availability of a group of servers and resources. A cluster network integrates the resources of two or more computing devices to work for a certain common purpose. A cluster computer network is linked through LAN, which makes it more powerful. This single-core technology or network with multiple computers enables high performance, larger storage, better data, and wider resources availability. Cluster network computer consists of each node set to perform the same tasks, which are controlled and scheduled by software. Many of the companies use cluster networks broadly in computer networking. It helps a user to be able in referring to several different implementations of shared computing resources. Fig no.12: Cluster Network Source: https://th.bing.com/th/id/R.ba5d35560fbdacc650c018ae5fe193c7?rik=lMeQjokc78SIcg&riu=http%3a%2f%2fwww.techyv.com%2fsites%2fdefault%2fusers%2fImages- Folder%2fcluster-computing-300x208.jpg&ehk=U1BU8TyBXkwoikuJQj%2btmhFyvvMLhUMUa9S2%2bq3HJiM%3d&risl=&pid=ImgRaw&r=0&sres=1&sresct=1 16 | P a g e RUBYN-NETWORKING  Benefits of cluster computing: i. Clustering servers is completely a scalable alternative. You can add resources to the cluster afterward. ii. If a server in the cluster needs maintenance, you can do it by stopping it while handing the load over to other servers. iii. It is reliable and easy to configure. Installing a cluster network is beneficial because the cluster techniques are much cheaper than installing a mainframe on a server. In a cluster network, multiple computers having high-speed work together so, it can provide higher processing speed to a server of the company. As, multiple server computers work together, in case of default or error in one server, the other server from the cluster takes over the server having an issue handling the situation or a load. Therefore, a server from the cluster can stop working anytime whenever it requires maintenance. This behavior of cluster networks ensures the high availability of web applications. It aims of providing unified processing to the system. The cluster network is flexible because the users can add an extra component to the system and upgrade itself easily. Resources are added to the clusters accordingly. The server is designed under a cluster network is for the high availability of solutions. The servers that are clustered can be configured and managed easily without any trouble. To sum up, a cluster network is very reliable and easy to configure.  Constraint of cluster computing: i. Cost is expensive. Since the cluster needs good hardware and a design, it will be costly compared to a non-clustered server management design. Being not cost-effective is the main disadvantage of this particular design but it is a complete server solution. ii. Since clustering needs more servers and hardware to establish one, monitoring and maintenance are hard. Apart from the benefits of this network, it also has some constraints. As multiple computers are connected in such a network, it requires more servers and hardware to manage and monitor. This directly increases the infrastructure in the system. This network design does not support many of the applications. As it does not support most of the applications, it needs to be designed in a proper way that may cost quite a lot. Since the cluster needs good hardware and a design, it is costly compared to a non-clustered server management design. Usually, some web-hosting providers can only afford it. The cluster network is flexible but not as much as it needs to be because this network can cluster not every server type. 17 | P a g e RUBYN-NETWORKING environment. Therefore, an individual or company requires a hybrid system to function properly. The system can still save time and money in the long run, but because some vendor stops supporting the network after initially starting it, there is always a level of uncertainty while fully implementing this type of network system. This network also has some security problems. As the information of a company is very important for it to reach success, it is quite risky to share data and information using this type of network because hackers can mostly target it. There may also occur the availability issue of resources or assets in the network. There is a chance that a company can face the problem of not being able to connect to their data for an extended period. Therefore, this causes the company to struggle in competing with other companies in the business industry. In addition, as all the availability chances are controlled by third-party providers, there is no control over anyone to stay connected. VI. Centralized Network: A type of network where all users connect to a central server, which is the acting agent for all communications. This server would store both the communications and the user account information. Most public instant messaging platforms use a centralized network. Also called centralized server structure. “A type of network where all users connect to a central server, which is the acting agent for all communications. This server would store both the communications and the user’s account information. Most public instant messaging platforms use a centralized network” (webopedia, n.d.). The focus of this network is to control, for example, managing effectively the speed of the network, setting a policy for customers, flexibility, and reorganization of the network. A centralized network implies a central focus of control. In other words, the focus of a centralized network is control. For example, through effective management, a centralized network can control speed, customer service, flexibility, and reorganization within the network. While centralization does have benefits, this type of network also poses several significant disadvantages. Centralized computing is a type of computing architecture where all or most of the processing/computing is performed on a central server. Centralized computing enables the deployment of all of a central server's computing resources, administration, and management. The central server, in turn, is responsible for delivering application logic, processing, and providing computing resources (both basic and complex) to the attached client machines. Centralized computing is a kind of computing architecture where all or most of the processing is performed on a central server. It enables the deployment of all of a central server's computing resources, administration, and management. It is used for data integrity maximization and has many more features, advantages, and disadvantages. 20 | P a g e RUBYN-NETWORKING Fig no. 14: Centralized Network Source: https://th.bing.com/th/id/OIP.l3cPXziUjxd4XK-TU4fiDwHaE8?pid=ImgDet&rs=1  Benefits of centralized computing: i. Data integrity is maximized data redundancy is minimized and every information can be supplied to every place at the same time ii. Better data preservation than other types of databases due to the often-included fault- tolerant setup. iii. easier data portability and data administration. Installing centralized networks is an instant messaging platform. It can easily provide information, ideas, and concepts to the computers or clients connected within its boundary. The central server hosts the resources so that any user within its boundary can access the data easily. It is advantageous to maintain centralized management of the server or network because it is the key to the consistency, efficiency, and affordability of the system. The centralized network can minimize the cost and expenses that are required for a system to run. The network is responsible to maintain all the responsibilities and duties of the system. The central server can handle all the defaults and errors occurring in the system. It can make a decision make direct and clear decisions regarding any matter of the system. The users who work under the centralized management system can train themselves for performing very specific and dedicated tasks. As the central server governs all the tasks, the clients do not have to worry about handling the activities, which saves their time and energy to invest in some other activities of the company. A company can be operated as a unified company by management of this network that centralizes knowledge and decisions of the system.  Constraint of centralized computing: i. It is highly dependent on an internet connection, if the nets go slow data access will take more time, so data speed must be high. 21 | P a g e RUBYN-NETWORKING ii. There is minimal to no data redundancy, if a set of data is unexpectedly lost it is very hard to retrieve it back, in most cases, it would have to be done manually. The demerit that a company faces by installing or executing a centralized network is that there is a chance of loss of data stored in this network if any disaster like water damage or electric blackout occurs. A single Operating system is used for the entire network. It is difficult for multiple users to maintain flexibility by using a centralized network because the users accessing this network may have different needs but the centralized systems only allow the user to access information on the network uniformly using the same processes. As all the data and information are directly sent to the central server by every source of information, in case of damage to this network, the whole data packets and information of the company will be lost. In such a case, there will be no chance of any data being preserved or saved and the company will surely face a huge loss. Similarly, the cost of installation or repairing the network is also quite high. There is also a risk of hacking in this network. Being the main server, this network has to face many errors and defaults. However, with the maintenance of security level in the network, the hackers can attack it often. Furthermore, the network may also limit the diversity within the network and can prevent some users from accessing the network. 22 | P a g e RUBYN-NETWORKING  Switch  Bridges  Modem  Network interface card  Firewall Network cables: Network cable is one way of transmission media that can transmit communication signals. The wired network topology uses a special type of cable to connect computers to a network. Some of the networking cables are, unshielded twisted pair (UTP), shielded twisted pair (STP), coaxial cable, fiber optical cable, etc. Routers: The router is a communication device or networking device which is used to connect two logically and physically different networks. The router is used to distribute the data packets to their destination based on their IP addresses. Hub: Hub is a networking device that connects computers or other network devices through its connecting points and transmits the data packet to all computers on the network when it receives a data packet at one of its ports. Hub usually comes with 4, 8, 16, and 24. There are two types of hubs i.e., active hub and inactive hub. Active hub checks and regenerates signal where passive hub serves only as a physical connection point for computer devices. Switch: A switch is a networking device that connects computers, network devices, and network segments through its ports. It forwards the data packet directly to the destination node when it receives a data packet at one of its ports. A switch has many ports that can be used to connect different network segments. A switch conserves the bandwidth and offers greater performance than a hub. It can be sued in LAN, MAN, and WAN. Bridges: Bridges are similar to repeaters and network hubs. A bridge is a device that filters data traffic at a network boundary. Bridge also reduces the amount of traffic on LAN by dividing it into two segments. Bridges have memory buffers to queue packets. It is intelligent, only forwards packets to the correct output 25 | P a g e RUBYN-NETWORKING Modem (modulator and demodulator) : A modem is a device that modulates an analog carrier signal to encode digital information and also demodulates such a carrier signal to decode the transmitted information. The modem is more useful in connecting LAN with the internet. The main function of the modem is data correction, compressing data, flow control. Modern modem work at 56 thousand bits per second or higher data transfer speeds perform automatic error correction and allow voice and fax communications. Network interface card (NIC): Network interface cards are the devices that enable computers to connect to the network. It provides a low-level addressing system through the use of MAC addresses. A network interface card is used to connect a computer to an Ethernet network. The card provides an interface to the media. There are two types of networking cards i.e. External network and internal network cards. Firewall: A firewall is a hardware-based network security system that controls the incoming and outgoing network traffic based on the applied rule set. Firewalls protect internal networks from forming public networks; they are also used to control access between specific network segments within a network. Firewalls are essential since they can provide a single block point where security and auditing can be imposed. 26 | P a g e RUBYN-NETWORKING