Advantages and Disadvantages of Star Topology

Star Topology

Figure 1. STAR TOPOLOGY

Source: (created by Author)

The Advantages of the star topology are:

• In the star topology the server is located on the center and is connected to the client machines individually. Hence, the performances of the star topology is better when compare with the other topologies.
• The server in the star topology is located at the center and hence, the monitoring procedures of the network can be performed very easily and also very efficiently.
• The expansion of the network implemented in the star topology can be very easy. Any number of additional nodes can be easily attached with the already existing network.
• The client machines are detached from each other in this topology. Hence, the failure of a single node would not hamper the whole of the network.
• The disadvantages of the Star topologies are:
• As the server is located on the central node the whole system is dependent on the central node. This dependency of high level on the central node might hamper the efficiency of the system.
• Due to the over dependency on the central node the system might fail totally if the central node of the network fails for any reason.
• The topology is a bit expensive and the cost of implementation of the technology is on the higher side.
• Too much dependency on the central node.

Bus Topology

Figure 2. BUS TOPOLOGY

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The advantages of the Bus topology are:

• The implementation process and the cost of implementation of the Bus topology is very easy and very cheap.
• The expansion of the topology is very easy. More than 50 systems can be easily accommodated in the system having a bus topology.
• The design of the topology is linear and hence, the efficiency of the topology is very high.

Disadvantages of the Bus topology:

• The termination of the system requires efficient dumping of the signals.
• The maintenance cost of the system increases significantly with the increase of time.
• The topology is inefficient for the networks where the daily traffic throughout the network is very high.
• The security provide by the topology is also very inefficient as the network is accessed by all the clients in a linear structure and the data are that are send by the server to a particular client are generally available to all the clients within the network.

Mesh Topology  

Figure 3. MESH TOPOLOGY

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The advantages of the mesh topology are:

• All the clients and the servers of the mesh topology are interconnected with each other with a number of links. There is a link in between each and every server and client machines. Hence, the data transmission in the network takes place simultaneously.
• The failure of a single node or a single node does not affect the system to great extent. The data can easily flow through an alternate node or an alternate link.
• The expansion process and the modification procedure of the network when required can be dones easily. It would not require much of an alteration of the actual network that was implemented originally.

The disadvantages of the mesh topology are:

• The chances of redundancy in the mesh topology are very high.
• The cost of implementation of the mesh topology is very high and in addition to this the implementation process of the mesh topology is also very complex.
• The Mesh topology is also very hard to maintain.

Figure 4. DATA TRANSFER

Source: (created by Author) 

The data transfer in the networks takes place by transferring the data packets from one node to another. In addition to this the data packets also have through the different layers of anetwork in a single machine before they are ready to be transferred. At first in the sender machine the data packets are generated in the application layer. The data traverses the through the different layers and finally arrives at the network layer where the data would transported to the other machines. During the traversal through all the network layers, some additional bits are added to the data packets every time the data moves down from the layer to the layer below it. This process is known as the process of data encapsulation.

After the data packet is sent from the sender machine into the network, the recipient would have to receive the data packets. After the reception process is over, the data is kept in the network layer. In the recipient machine, the data travels from the network layer to the application layer. IN this machine every time the data packets move up, the extra bits that were added in each layer of the sender machine are deleted from the data packet in each layer of the recipient machine. This process of the removal of the extra bit from the data packets is known as the process of decapsulation. After the decapsulation process is completed the actual data is obtained by the application layer.

The techniques of mutilplexing and demultiplexing are dissimilar to the techniques that involve the encapsulation and the decapsulation of data. The multiplexing and the demutiplexing technique are applied on the signals of the network, while the encapsulation and the decapsulation techniques are appied to the data that is flowing through the network. In addition this, the multiplexing and the demultiplexing techniques are used for simplifying the signals of the network, whereas the encapsulationand the decapsulation techniques are usually involved with ensureing the data security within the network. They ensure that the data ment for a single machine can not be received by some other machine.

It is given that,

B= 6.8 MHz is the bandwidth.

SNR= 132 is the signal to noise ratio

C= Bit Rate.

C=B log (1+SNR) = 6.8×10⁶ log₂ (1+132) = 6.8×10⁶ log₂ 133 = 48 Mbps.

Hence, the bit rate is 48 Mbps.

Let, L be the number of signals

Therefore, C = 2 x B x log₂ (L)

0r, 48= 2×6.8xlog₂L

Or, log₂ L=48/(6.8×2)

Or, log₂ L= 3.56 0r 4 (approx)

Or, L = 2⁴= 16.

Advantages and Disadvantages of Bus Topology

There are 16 level of signals.

The OSI model and the TCP/IP model are almost similar to each other but are there are some differences in the functionality of both the models. The number layers present the OSI model are more than that of the TCP/IP model. Hence the OSI model provides more functionality and more number of options to the network. The OSI model also provides enhancement of the security of the network. The OSI model involves a number of authentication procedures due to the number of layers in the model and also some extra functions due to the presence of the extra layers in the network model.

Although the OSI model is more efficient than the TCP/IP model, yet the TCP/IP model is preferred over the TCP/IP model. This because the OSI model is efficient theoretically, but the practical implementation of the model is very difficult, and in addition to this the TCP/IP model is easier to implement practically and also the TCP/IP model is collaborated with the reputed models.

The main advantages of the OSI model are that they can interpret functions at each level of the model and also they provide with a number of options to the networks. But the main disadvantage of the OSI model is that they are very difficult to implement.

The main advantages of the TCP/IP model are that they are very easy to implement and have more preferences. But the main disadvantages of this model are that they are slow are than the other model and also the security of data is less efficient.

It is given that,

 The frame size is 5 million bits.

The propagation speed is 2.2x 108 m/s

The distance is 1900 Km.

Length of the link = 1900 Km = 1900 x 10³ meters.

Bandwidth of the network = 8 x 10⁶ bps

The queuing time is 10 x 3.5 mS = 35 mS.

The delay in processing is 1.8 x 10 mS = 18 mS.

 The transmission time is 5 x 10⁶ /8 mS = 62500 =.625 s

The propagation time = 1900 x 10³ / 2.2x 108 uS = 8 uS

Total delay time = 35 + 18 + .08 + 62500 = 62551.08 mS = .63 sec

The total delay time is .63 sec and the dominant component is the transmission delay and the negligible component is the propagation time.

Figure 5. The POP 3 State diagram

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The POP 3 protocol has four states:

Authorization: The authorization of an established connection takes place.

Transaction: The transactions of the authorized connection takes place.

Update: The transaction are updated.

Closed: After completion of the update procedure the POP 3 is closed.

Agnoloni, T., & Pagallo, U. (2014). The case law of the italian constitutional court between network theory and philosophy of information. In 2 ND INTERNATIONAL WORKSHOP ON “Network Analysis in Law” (Vol. 91, No. F1, pp. 94-9).

An, H., Zhong, W., Chen, Y., Li, H., & Gao, X. (2014). Features and evolution of international crude oil trade relationships: A trading-based network analysis. Energy, 74, 254-259.

Becker, T., Meyer, M., & Windt, K. (2013, September). A network theory approach for robustness measurement in dynamic manufacturing systems. In 17th Annual Cambridge International Manufacturing Symposium, September, Cambridge.

Deo, N. (2016). Graph theory with applications to engineering and computer science. Courier Dover Publications.

Gao, C., Sun, M., & Shen, B. (2015). Features and evolution of international fossil energy trade relationships: A weighted multilayer network analysis. Applied Energy, 156, 542-554.

Goodall, K. T., Newman, L. A., & Ward, P. R. (2014). Improving access to health information for older migrants by using grounded theory and social network analysis to understand their information behaviour and digital technology use. European journal of cancer care, 23(6), 728-738.

Groenewegen, P., & Moser, C. (2014). Online communities: Challenges and opportunities for social network research. In Contemporary Perspectives on Organizational Social Networks (pp. 463-477). Emerald Group Publishing Limited.

Haque, A., & Mantode, K. L. (2013, June). Governance in the Technology Era: Implications of Actor Network Theory for Social Empowerment in South Asia. In International Working Conference on Transfer and Diffusion of IT (pp. 375-390). Springer Berlin Heidelberg.

Kärrholm, M. (2013). Building type production and everyday life: rethinking building types through actor-network theory and object-oriented philosophy. Environment and Planning D: Society and Space, 31(6), 1109-1124.

Li, H., Fang, W., An, H., & Yan, L. (2014). The shareholding similarity of the shareholders of the worldwide listed energy companies based on a two-mode primitive network and a one-mode derivative holding-based network. Physica A: Statistical Mechanics and its Applications, 415, 525-532.

Manshaei, M. H., Zhu, Q., Alpcan, T., Bac?ar, T., & Hubaux, J. P. (2013). Game theory meets network security and privacy. ACM Computing Surveys (CSUR), 45(3), 25.

Mpazanje, F., Sewchurran, K., & Brown, I. (2013). Rethinking information systems projects using actor-network theory–perspectives from a developing country. The Electronic Journal of Information Systems in Developing Countries, 58.

Rucco, M., Castiglione, F., Merelli, E., & Pettini, M. (2016). Characterisation of the idiotypic immune network through persistent entropy. In Proceedings of ECCS 2014 (pp. 117-128). Springer International Publishing.

Siemens, G. (2014). Connectivism: A learning theory for the digital age.