Business Data Communication & Security - Assignment 1 UNICAF, Essays (university) of Data Communication Systems and Computer Networks

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Assignment 1 - Essay

Student Number: R1904D

Course: Business Data Communication and Security, UU-MBA-741-ZM-

Tutor: Giorgos Georgiou Date: October 25, 2020

Table of Contents

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at the network layer that facilitate the transmission of user data are: Internet Protocol version 4 (IPv4), Internet Protocol version 6 (IPv6), Novell Internetwork Packet Exchange (IPX), and Connectionless Network Service (CLNS/DECNet) just to name a few, (OSI Network Layer, 2016). The network layer uses four main processes, these are: addressing, encapsulation, routing and decapsulation. Firstly, addressing is the process of assigning a unique identifier to a device (such as an IP address) to enable transmission of data between the clients and host on a given network. Secondly, encapsulation ensures that when a packet is created it includes information about both the source and destination address. Often time data has to be transmitted across different networks and routing enables this process by ensuring the packets traverse the correct paths towards their final destination. Finally, decapsulation involves the opening up of encapsulated data for processing by the intended recipient on a network (Science Direct: Decapsulation, 2016).

According to (Pandya, 2013), the link-layer is the protocol responsible for the accurate and efficient transmission of data across nodes on the physical layer and for granting access to upper layers through framing. The data link frame includes data which comes in the form of a packet from the network layer, a header which contains the control information from the protocol data unit (PDU) and the trailer which includes control information appended to the PDU. The data link-layer has two sub-layers, they are: the Logical Link Control (LLC) and Media Access Control (MAC). The LLC’s main priority is to manage several protocols’ flow control, synchronization and error checking features whereas the MAC handles the direct control of the media being utilized.

Question 2

Name the advantages of optical fiber over twisted-pair and coaxial cable. Please elaborate on your answer.

Optical fiber, twisted pair and coaxial cable are widely used in communication systems all over the globe. They all serve their own specific purpose depending on the requirements, environment and scope in which it’s being used. Three major advantages of optical fiber over twisted-pair, and coaxial cable are its speed, bandwidth and coverage distance. According to

(Fiber Optic Cable vs Twisted Pair Cable vs Coaxial Cable, 2020), fiber optic cables offer data transmission speeds ranging from 10/100/1000 Mbps, 10/40/100/200 Gbps, bandwidth speeds of up to 4700 MHz and can cover distances up to 80km. It is to be noted that twisted-pair cables currently offer data transmission speeds of up to 10 Gbps, bandwidth speeds of up to 4700 MHz and can cover distances of up to 100 meters (without signal loss) per cable run. On the other hand, coaxial cables are by far the least efficient with data transfer speeds of 10 mbps, bandwidth speeds of 750 MHz and can cover distances of up to 500 meters.

Fiber optic cables form the backbone infrastructure of many internet and telecommunication services provider’s networks. These cables support long distance communication between cities and states which is not possible through the use of twisted-pair or coaxial cables. Optical fiber also offers superior throughput when compared to twisted-pair and coaxial cable. This is evident in the data transmission speeds of which fiber leads its counterparts by a staggering 2000% at its maximum capacity (Addanki, Amiri & Yupapin, 2018 p.745). Another major advantage of optical fiber verses coaxial cable is its reliability. Fiber is more resilient in the open environment as it remains unaffected by changes in temperature. It is also resistant to moisture in the atmosphere which would otherwise affect the performance of coaxial cables. Optical fiber does not use electrical signals and is therefore unaffected by electromagnetic interference (EMI) that can negatively impact data transmission as opposed to unshielded twisted pair and coaxial cables which are vulnerable to this.

Question 3

What are the four generic architectural components of a public communications network? Define and elaborate on each of term.

Public communication networks are electronic communication networks designed specifically to provide publicly available electronic transmission services. This transmission is achieved through the use of various telecommunication equipment, software and data. According to (Pióro and Medhi, 2014), the four generic architectural components of a public communications network are: subscribers, subscriber line, exchanges and trunks. The end user that utilizes devices attached to a network are referred to as subscribers. Subscribers include but

reversed, it generates what is called a digital signature. This signature is used to validate the authenticity of the data sent and will confirm whether or not any unauthorized modifications were made to the data during transmission.

When Alice compiles the message intended for Bob, she will have to ensure that the public key is generated to encrypt the message before it is sent. Upon sending the message encrypted using the SHA-1 function, the private key would be received by Bob to facilitate the decryption process. Only the authorized owners of a private key will be able to decrypt the message successfully. This ensures that data integrity, confidentiality and security is maintained during and after transmission.

Question 5

Explain and elaborate on the impact that communication network applications have had on business and everyday life.

As the world continues to change, information and technology remains vital to the successful operation of businesses and everyday life worldwide. Technology has evolved very rapidly over the past two decades and the advent of network communication applications has changed the way we do business and interact in the wider society. It is to be noted that many businesses today simply wouldn’t exist without some of these communication technologies. Let us explore a few of them in detail. According to (Li, 2016 p.123), a network application is an application being run on a host that enables communication between two or more hosts within a given network. Several communication network applications include but are not limited to: Dynamic Host Configuration Protocol (DHCP), File Transfer Protocol (FTP), Simple Network Management Protocol (SNMP), and telnet. DHCP is responsible for allocating IP addresses to devices within a network such as computers, printers, switches, wireless access points, etc. Without the allocation of IP addresses, communication between these networked devices would be impossible and the flow of data would cease to exist. In our everyday business world, information needs to be communicated seamlessly and efficiently across different networks. An application utilizing FTP such as Filezilla allows for information to be easily uploaded and or downloaded locally or remotely from a business’ network resource. SNMP has been used widely

in collecting and organizing information about a business’ managed devices within their operational network. This has been very helpful to system administrators as they are able to successfully monitor and maintain these devices across the organization. Communication network applications are also useful for sending and receiving email messages. In the banking sector, technology is utilized heavily to perform online digital financial transactions. In more recent times, companies such as Tesla have integrated GPS navigation technologies in their vehicles to assist drivers by providing real time statistics on routes, traffic and weather updates. The internet is made accessible through several devices such as smartphones, tablets and laptop computers just to name a few. Users are able to access digital content through video and music streaming through services such as Netflix and YouTube respectively; furthermore, chat and voice over internet protocol (VOIP) services have also enabled businesses to reduce communication costs significantly within their operational environment.

Question 6

Why are standards important for protocols? Please elaborate.

The world of computing is very dynamic and continues to evolve as new technologies are being introduced rapidly within the industry. As such, it is imperative that devices have a set standard of which to follow that guarantees an effective exchange of data across networks. The conceptual framework of the OSI model is one such example of standardization independent of any specific manufacturers and is broken down into several different areas referred to as layers (Grami, 2016). These standards have been developed to guide and manage the functionality of protocols that form the backbone of network infrastructures. Standards exist to reinforce universally accepted processes when designing protocols. These standards also exist to assist with preventing the occurrence of errors that would otherwise affect the productivity of networked devices and or applications. Though the requirements and design of networks may vary between businesses, the underlining standard operational protocols remain the same and provide the foundation for which hardware and software are able to be identified, communicate and exchange data efficiently.

urgent pointer field, options field and data field; on the other hand a datagram consists of the source port, destination port, length and checksum (Pandya, 2013).

Question 8

Compare the network topologies (Star, Bus and Ring). What capabilities and what limitations do they have? Please elaborate on your answer.

A network topology can be defined as the logical and or physical arrangement of links, nodes, etc. that allows communication between devices on a computer network. The physical arrangement and logical configuration of devices can greatly impact the performance, reliability and security of a network. As such, the right topology should be selected based on IT best practices, the operational environment and end user needs (Lim, 2016). Network topologies can be distinguished from one another in various ways and have several advantages and disadvantages when compared to one another. Let us now explore the capabilities and limitations of the star, bus and ring network topologies:

Star Topology

Within a star topology, all devices are connected to a central hub such as a switch that facilitates transmission of data between hosts. This topology is fairly easy to install and offers good performance and reliability as failure in one node would not affect other nodes on the same network. It is also quite easy to expand this topology as adding new nodes would only require connecting to the central hub. One major disadvantage to this topology is that if a failure occurs at the central hub, the entire network would be negatively impacted thus resulting in lack of access to data and shared resources. For example, if the core switch fails on a star topology, the computers within the network would not be able to share data. In addition, there would be lack of access to any other connected devices such as Printers, IP telephones, Access Points, etc.

Bus Topology

Within a bus topology, all devices are connected through a single cable called a bus. This is usually in the form of coaxial cable. This topology is also easy to implement, extend and is less expensive to set up than other topologies. It is most suited for temporary networks and

usually requires less cabling than a star topology. It is important to note that improper termination at the end of the cable run will prevent signals from bouncing in the opposite direction, thus resulting in signal loss. Another disadvantage is that it is often times infeasible for maintaining a large networks as there will be significant loss in performance when more workstations are added. If a single node fails within the bus topology, it is more difficult to identify and troubleshoot when compared to the star topology. This topology is also less secure when compared to the star topology as all computers receive the same signal sent from the source and can be easily intercepted if a hacker gains access to the network.

Ring Topology

Within a ring topology, all nodes are connected together with two nodes on either end. Similarly to the bus topology, this forms a single channel from which data is exchanged between the networked devices. A major advantage of the ring topology when compared to the star topology is that it doesn’t have a central hub which manages the communication between nodes. It is easier to identify and isolate faults on the ring topology as opposed to the bus topology. On the other hand, a major disadvantage of this topology is that in order for data to be transferred successfully within the network, all nodes must be powered on and connected. Another downside is that the data transfer speeds between nodes are much slower when compared to that of the star topology.

Pandya, P. (2013). Transmission Control Protocol/Internet Protocol Packet Analysis. Computer and Information Security Handbook. doi:10.1016/b978- 0 - 12 - 803843 - 7.00073- 9

Pióro, M., & Medhi, D. (2014). Overview. Routing, Flow, and Capacity Design in Communication and Computer Networks, 3 - 36. doi:10.1016/b978- 012557189 - 0/50003- 2

Science Direct: Decapsulation. (2016). Retrieved from https://www.sciencedirect.com/topics/engineering/decapsulation

Vasudevan, S. K., Subashri, V., & Kothari, D. (2015). Computer networking. Retrieved from http://ebookcentral.proquest.com