Internet Technology Star Bus Topology

Question: Discuss about the Internet Technology for Star Bus Topology. Answer: 1: Advantage and disadvantage of Star, bus and mesh topology with real life example Topology Advantage Disadvantage Examples Star a. If a node in the star topology fails it does not hamper the whole system. b. Data sent from one node to the other reaches the destination through the hub. c. It is easy to add or remove new nodes in the system. d. All the nodes are connected with the central hub and thus it is easy to monitor the network (Haque et al., 2013). a. All the nodes are dependent on the central hub and thus if it fails the whole network would collapse (Jiang, 2015). b. The use of the hub, router or switch as the central device increases the cost of the network. c. Addition and performance of node in the network depends on the capacity of the central device. It is used in buildings and offices Bus a. It is the appropriate topology for small networks and LANs b. The setup of the bus topology requires less effort. c. Less cables are required and thus it decreases the cost. a. All the nodes are connected with a single cable and if it fails the whole network shut down. b. The performance of the network decreases with the addition of new nodes in the network. c. Security is much less as all the nodes can access each other. It is used for local LANs with less nodes connected in series. Mesh a. This type of network is designed to handle high traffic. b. The device of the mesh topology can communicate with different nodes at a time (Jiang, 2015). c. The data can be transmitted through different paths and thus if a path fails then the data can be transmitted using an alternative path. a. The maintenance cost of this type of network is very high as compared with the other topologies. b. Chances of redundancy in the network is also higher. c. The overall costing of this type of network is high as more cables are needed (Haque et al., 2013). The mesh topology can be use in regional offices where high speed LANs are connected to every office. 2: In case of OSI model, it is a protocol independent model that acts as a gateway between the user and the internet network. On the contrary, the TCP/IP is a protocol that governs the connection between the hosts over any network. The transport layer of OSI model guarantees the delivery of the data packets over the internet network. On the contrary the TCP model does not guarantee the delivery of the data packets from the sender to receiver (Alani, 2014). In OSI models, protocols are hidden and can be easily replaced by the other protocols with the change of the technologies, whereas replacing the protocols in TCP/IP model is not an easy task. The OSI model clearly separates the interfaces, services and communication protocols that helps the users to find out the errors in case of any failure (Alhamedi et al., 2014). On the contrary a TCP/IP model does not separate the different layers clearly which makes it complex for the user to find out the point of error in any failure. Observing all the above reasons, it can be said that OSI model is user friendly and clearly separated reference model for data transmission than the TCP/IP model. The reason behind the lesser popularity of OSI: The TCP/IP model is considered to be simpler model than the OSI model due to the lesser number layers in the whole protocol. In addition to this, TCP/IP is adopted as more credible model, since the internet was developed depending on the standards described in TCP model (Alani, 2014). On contrary, as the internet is not developed around the standards of OSI model. Therefore, the OSI model is not able to take over the TCP/IP model and remains as a guidance tool. 3: The formula for channel capacity is given by, C=B log2 (1+SNR) C=3.5*106*7.066 C=24.73Mbps. Therefore, the bit-rate is 24.73 Mbps. Signal level C = 2* Bw *log2 L log2 L=C/(2*BW) log2 L=24/ (2*3.5)=3.4285 L=10.767 4: Private addressing in IPv4 and IPv6: The private addresses are those IP addresses which are not directly connected with the internet. In IPv4, the IP addresses are 32 bit long, and are represented in dotted decimal notation. To make this address understandable to the users these addresses are broken into octets or bytes. In contrast with it, the IP addresses are 128 bit long in IPv6 addressing therefore, the space and number of IPs to assign to the users is much higher than IPv4 addressing. Therefore it would not be necessary for the network administrators to assign private addresses inside a local or organizational network. The network devices like routers do not have any functionality in networks other than the passing the data packets to the next node (Ali, 2012). This will also help in assigning IP addresses of the devices that reside inside the same network by eliminating the chances of clashes between them. Range of IPv4 and IPv6 addresses: For IPv4 the range of the addresses is 232 IP addresses. On the other hand the range of the IPv6 addresses is 2128 bits. Even though the private addresses are used several times, but this would not result into conflict, since this IP addresses are non-routable. In addition to this, when a data packet is delivered from clients router to its internet service providers gateway, then the private IP address of the client gets removed from the data packets and is replaced by the public IP of the internet service provider (Mshangi, 2014). To the outer internet network it seems that, the user is using the distinct public IP and hence the clashes between the same private IP addresses are avoided. 5: Diagram describing the stages of POP3 6: Distributed hash table: A distributed hash table can be defined as a class of distributed systems that helps in the look up services that is similar to a hash table. Data is stored in pairs of (key, value) inside a DHT (Chmaj Latifi, 2013). A node in the network can retrieve the desired value for a provided key. Mainly this algorithm is used in P2P systems, distributed file systems and web caching. The working mechanism of DHT in P2P systems: Every connected node in the network or the system handles a part of the hash table and is responsible for storing a certain number of keys. When a certain key is searched in the network as well as in the hash table, the system will return the required value related to the key. In case of DHT each connected node acts like both client and server for the requests (Fujiwara, Newman Yao, 2013). The DHT tables helps the nodes to put the get their requested files on the network. Example of Application of DHT in P2P torrent applications: Today the most successful use of the DHT is utilized in Torrent applications. In this case the IP addresses are stored in the DHT, using infohash as the related key. Therefore when a GET requested is originated for a file in the network, then this DHT algorithm searches the whole table and returns a set of IP addresses as a result of the search (Chmaj Latifi, 2013). References Alani, M. M. (2014).Guide to OSI and TCP/IP models. Springer. Alhamedi, A. H., Snasel, V., Aldosari, H. M., Abraham, A. (2014, July). Internet of things communication reference model. InComputational Aspects of Social Networks (CASoN), 2014 6th International Conference on(pp. 61-66). IEEE. Ali, A. N. A. (2012). Comparison study between IPV4 IPV6.International Journal of Computer Science Issues,9(3), 314-317. Atwell, H., McManus, D. J., Carr, H. H. (2013). The OSI Model and the Seven Chakras of Hinduism: A Comparative Analysis.International Journal of Applied,3(3). Chmaj, G., Latifi, S. (2013). Decentralization of a multi data source distributed processing system using a distributed hash table.Int'l J. of Communications, Network and System Sciences,6(10), 451. Fujiwara, K., Newman, C., Yao, J. (2013). Post Office Protocol Version 3 (POP3) Support for UTF-8. Haque, M. E., Zain, M. F. M., Hannan, M. A., Jamil, M., Johari, H. (2013). Loss monitoring of star topology sensor network based on scheduling algorithm for assessing structural health information.American Journal of Applied Sciences,10(12), 1484. Jiang, R. (2015). A review of Network Topology. Mshangi, M. (2014). Using Soft Systems Methodology and Activity Theory to Exploit Security of Web Applications against Heartbleed Vulnerability.International Journal of Computing ICT Research,8(2). Normand, J. (2013). Intrusion Detection Systems: An Investigation of Evaluation Corpora.