Business Networks Technologies

Business Networks Technologies

Question1 – Computer Network Topologies, Network Devices   

1. List four common LAN topologies and briefly describe their methods of operation by using appropriate diagrams and text. Discuss how the nodes are connected, the transfer of data, and its advantages and disadvantages.

The four main LAN topologies are Star, Bus, Ring, and Mesh topology. In star topology, a main bub or switch connects all the computers and other devices on the network (Zhang and Cai, 2016, p.38). The function of the hub or switch is to amass and distribute data flow throughout the system. It is the most popular network type used.

            Bus topology, on the other hand, requires computers and other devices organized in a manner that allows the tools to be connected to a single linear cable identified as the trunk (Zhang and Cai, 2016, p.38). The configuration results in the log b referred to as the backbone. Nevertheless, both ends of the trunk must discharge to avoid the bouncing back of the transmitted signal.

The third LAN topology is ring topology; computers and other network devices linked to a closed-loop cable. Unlike the bus topology, ring topology lacks terminating ends, the main drawback of the approach is that if one device crashes, the entire network is affected (Zhang and Cai, 2016, p.39). In other words, each computer connected to the system has the primary function of acting as a repeater. The machines charge the signal before transmitting it to the next station (Zhang and Cai, 2016, p.40). Additional information that is vital to appreciate is the fact that in the ring topology, a token utilized to send data through the network. The token works as follows; a computer seizes a token that is not carrying any data. Data is attached to the token as well as an electronic address for the recipient station (Zhang and Cai, 2016, p.39). When the recipient station receives the token, the data stripped, and the token sent back to the network

            Finally, mesh topology is a network framework where all computers and other network devices interconnected with one another. The main advantage of this approach is the reliability and level of connection (Zhang and Cai, 2016, p.41). Unlike the other topologies, all devices on this network connected, therefore in case of any system crash, data flow to different machines will not be interrupted.

1. A Star topology is to be provided that spans two buildings. Each building will have an independent star topology network, and a point-to-point link will connect a particular communications station on one system with a communications station on the other network.
   1. Explain the functions that the communications stations must perform?

            The communication stations are to provide a communication link between the two independent topologies. The communication stations are part of a star topology but connected on a universal bus that will allow tokens to be transferred from one building network to the other (Zhang and Cai, 2016, p.38).

1. At which layer would the communication stations operate in? (3 marks)

The network will utilize the tree topology; it combines aspects of both star and bus topology (Zhang and Cai, 2016, p.41). The central nodes will be connected, allowing for data to flow from one topology to the next compared to the network.

1. Describe the difference between a bridge and a router. Where would you use each of these network devices, describe the scenarios where you would use each of them

Bridges are network devices that primarily function in the data link layer; the data link layer refers to the protocol layer present on programs that handle the moving of data to and from the physical connections in the network (Denton, 2018, p.8). Therefore, bridges only forward packets amid systems that intended for another network.

Routers, on the other hand, are network devices that function in the network layer. Though both routers and bridges store and send data and information in packets, they have differences such as the number of ports (Denton, 2018, p.9). In bridges, the ports are limited to two, whereas routers can have more than two ports. Additionally, bridges connect two LANS, whereas routers connect both LAN and MAN.

Bridges are applicable when connecting various departments using different computer networks located on other floors of the same building. By extending the LAN (local area network), the network coverage increases to limits not possible through LAN (Denton, 2018, p.14). Alternatively, routers are applicable in various setups such as home connections, where it directs the data using either its either a routing table or policy.

Question 2 – Layered network Architecture, Reference Models

Explain why layering is essential in computer networking                                   (3 marks)

            Layered networking is the structure that assists in understanding the complex network interactions (White and Donohue, 2014, p.35). Currently, the most widespread approach is OSI and TCP/IP.  Its importance is appreciated when change implemented on one layer, and its effects on the other layers are minimal. Additionally, the layer definitions are separate (White and Donohue, 2014, p.35). Finally, the approach is beneficial for it institutes prearranged guidelines necessary for the interoperability between the various products developed by the multiple vendors that perform differing communication tasks.

1. The above figure shows two Ethernet LANs connected by R1. Suppose an application software running at Host A with port address 120 is sending a message to a peer application software running at host B with port 150. Using relevant diagrams and text, show the packets at each layer and only the ‘address’ related contents of the segment, datagram, and frames at the transport, network, and data link layer for each hop. [Hint: there are two hops]

The diagram above shows the related segment, network, and data link layer for every hop. From the diagram, the sheet that relates to each other directly from the two hops is the physical layer since bits are transferred from host A directly to host B (Janevski, 2015).

Question 3 – LAN, WAN Technologies

1. A common method for providing broadband Internet access over existing telephone lines is Asymmetric Digital Subscriber Line (ADSL).
   1. Why is it called asymmetric?

            ADSL is asymmetric as its design meant to exploit the one-way character of most multimedia connections where large amounts of information flow towards the user (Falk, 2018, p.46). Small quantities of interactive control information returned, thereby negating the need for Symmetric Digital Subscriber Line, where the flow of information to and from the user is equal (Falk, 2018, p.46).

1. What are other types of DSL technologies available, name at least four types

Today, there are other forms of DSL technologies; they include:

• RADSL (Rate Adaptive Digital Subscriber Line),
• HDSL (High Bit-Rate Digital Subscriber Line),
• SDSL (Symmetric Digital Subscriber Line), and
• VDSL – Very High Bit-rate Digital Subscriber Line, among others (Falk, 2018, p. 55).

1. Briefly describe how ADSL can transmit both data and telephone calls over the same twisted pair cable connecting a house to a local exchange, without the two signals interfering with each other.                                                 (2 marks)

            ADSL utilizes FDM (frequency-division multiplexing) to separate data and voice signals actively, thus forming a baseband voice, downstream and upstream data channels (Baliar and Gofaizen, 2017, p.315). Each of the channels occupies different portions of the frequency spectrum.

1. Why would users select satellite for the internet when it is expensive? (2 marks)

            When compared to dialup connections, they offer faster speeds, especially for isolated areas where line connections are not available. Additionally, satellite internet is capable of handling high bandwidth use (De Sanctis et al., 2015, p.115). Finally, with satellite internet, no phone lines are required.

1. A satellite link has about 500 milliseconds return trip latency? Will this be suitable for voice calls? Why?                                                                                                 (3 marks)

Latency refers to the delay before data transferred follows the instructions for its transmission. According to the International Telecommunication Union, callers are typically aware of voice delays when the return is more than 250ms (Janevski, 2015, p.89). The recommended maximum by the organization is 150ms latency for one-way communication (Janevski, 2015, p.89). Therefore, 500ms is beyond the recommended latency for quality service.

Question 4 – IP addresses and Routing        [20 marks]

1. A user turns on the computer and connects to the organization’s network. The user then selects a link to google.com.
   1. Describe the process of how the user is granted an IP address to access the internet.                                                             (3 marks)

All machines have unique identifiers. it is important for organizational networks that rely on IP addresses to connect computers to the network. Nevertheless, the DHCP, which is a network management protocol, dynamically assigns an IP address as well as other network parameters required (Kralicek, 2016, p.190). The action is essential as it allows computers on the network to communicate with other IP network devices.

1. Explain the difference between DHCP and DNS, including why and when they are requested.                                                                                     (5 marks)

            DHCP (Dynamic Host Configuration Protocol) is a protocol that assists users in assigning IP addresses as well as related IP information to and about the computer respectively to the network (Kralicek, 2016, p.191). DHCP is valued when it comes to IP address management. It simplifies the process by managing the addresses assigned.  Then again, DNS (Domain Name System) described as the phonebook of the internet. It maintains the various directories of names; it then translates them to IP addresses (Kralicek, 2016, p.191). The action is vital because machines rely on the IP addresses to access the webpage.

1. Explain the steps in the sequence of how the application layer to network layer resolution takes place about the above website link request. Assume the TLD name server provides the network layer address. (5 marks)

            The network access layer is the first component of our layer TCP/IP model. It defines the details about how data is tangibly through the network (WU and Irwin, 2017, p.211). The second step in the sequence is the internet layer. It is responsible for packing the data into data packets identified as IP datagrams. The datagrams contain both destination and source addresses (WU and Irwin, 2017, p.211). In other words, the second layer is liable for Routing. The third layer in the sequence is the transport layer. Its purpose is to authorize devices on both the host and destination holds to communicate (WU and Irwin, 2017, p.213). The layer defines the level of service as well as the status of the connection utilized in transporting the data. Finally, the application layer terms the TCP/IP application protocols (WU and Irwin, 2017, p.213). It is inclusive of how host programs interact with the transport layer services to utilize the network.

600. Suppose you are managing the network at a firm that has two hundred end-users in a large office block, working for a financial trading company with fast-changing financial data. You have just submitted a request to purchase a router. Your boss asks you to explain to him why you’re requesting to buy routers that use link-state dynamic Routing at $1000 when you can buy a cheaper one using distance-vector dynamic routing at $600.
     1. Explain the reasons for your recommendations. (7 marks)

Link state routing refers to the technique where routers share the information of their environment with other routers in the internetwork. It works by ensuring that the packet sent to a router copied to all other routers in the network (Zhang et al., 2018, p.37). The final outcome is every router receives the same information. The router, therefore, recommended because it utilizes routing dynamic algorithms, sharing knowledge to all other routers in the network (Zhang et al., 2018, p.37).

Additionally, any changes mandate the sharing of the packets, ensuing all routers are aware of their requirements.  Therefore, the router has information concerning the entire network, it has no count to infinity problems, and there are no persistent loops (Zhang et al., 2018, p.40). All the stated features are critical for financial trading as it can keep up with the continually changing markets.

References

Bailar, V., and Gofaizen, O., 2017, October. Quality of service for multimedia content delivery in info-communication networks based on xDSL technology. In 2017 4th International Scientific-Practical Conference Problems of Infocommunications. Science and Technology (PIC S&T) (pp. 315-318). IEEE.

De Sanctis, M., Cianca, E., Araniti, G., Bisio, I. and Prasad, R., 2015. Satellite communications are supporting the internet of remote things. IEEE Internet of Things Journal, 3(1), pp.113-123.

Kralicek, E., 2016. DNS, DHCP, IPv4, and IPv6. In The Accidental SysAdmin Handbook (pp. 189-201). Apress, Berkeley, CA.

Zhang, D.G., Zhang, T., Dong, Y., Liu, X.H., Cui, Y.Y. and Zhao, D.X., 2018. Novel optimized link-state routing protocol based on a quantum genetic strategy for mobile learning. Journal of Network and Computer Applications, 122, pp.37-49.

Denton, J., 2018. Learning OpenStack Networking: Build A Solid Foundation In Virtual Networking Technologies For Openstack-Based Clouds. 3rd ed. Birmingham: Packt Publishing.

Falk, H., 2018. IEC 61850 Demystified. Norwood, MA: Artech House Publishers.

Janevski, T., 2015. Qos For Fixed And Mobile Ultra-Broadband. Norwood, MA: Artech House Publishers.

White, R., and Donohue, D., 2014. The Art Of Network Architecture. Indianapolis, Indiana: Cisco Press.

WU, C., and Irwin, D., 2017. Introduction To Computer Networks And Cybersecurity. Boca Raton, FL. CRC Press.

Zhang, J., and Cai, N., 2016. Computer Science And Technology – Proceedings Of The International Conference. Singapore: World Scientific Publishing Company.