TCP-IP Data Encapsulation and Decapsulation †MyAssignmenthelp.com

Question: Discuss about the TCP-IP Data Encapsulation and Decapsulation. Answer: Introduction: In any connection, a logical pattern or structure is followed, the layout that is usually followed when connecting computers in a given network is what is known as a physical or network topology (Zandbergen, 2017). In our discussion, we will highlight three patterns; star, bus and mesh topology Management and their corresponding advantages. A topology where each and every device is connected to a central device such as a switch (Certification kits, 2017). It is the most commonly used layout as its resilient and robust in its operations, example LAN connections in offices where PCs are connected to a central server. Advantages Its a simple structure that is very easy to install. Since each device is independent (connected to the central device) there are no disruptions when devices are removed. A simple overview structure that facilitates faults detection. Disadvantages It requires extensive resources to set up i.e. cables. Susceptible to central point failures. Overall its more expensive as compared to the other models. In this topology, all devices or nodes are connected to a central cable or even network (the bus). Essentially, this bus acts as the communication medium used by devices to communicate (Omnisecu, 2017). Example classroom connection of PC tapping from a central Ethernet line. Advantages Its usually very easy to connect a device to a linear connection e.g. a bus. As compared to the star topology, it requires fewer resources to install. Disadvantages The entire network is lost if the central cable fails. Its difficult to establish the root of a problem if the network fails. It cannot be used as a standalone option Mesh A redundant topology where all devices are connected to each other using multiple connections Management . As expected its a very expensive topology but it offers the best solution to a redundant and resilient connection requirements. Example the internet. Advantages Extremely resilient and robust, failed connections do not affect the network. Adding new devices has no effect on the overall network. It can handle large amounts of traffic. Disadvantages Its very hard to manage and maintain. Moreover, it requires a lot of capital investment (Nizam, 2014). First, the TCP/IP is a layered organisation of protocols that are used in communication today particularly on the internet. Its made up of different layers whose hierarchical protocols are made of interactive modules that perform specific functionalities. Therefore, each upper layer or protocol level is supported by the functionalities and services of more than one other layer. Now, encapsulation and decapsulation are a process that is used to package data for transmission or reception. Encapsulation and decapsulation A shown below, as data moves from the upper layer to the lower layers of the TCP/IP model, each layer adds a bundle of relevant control information. This control information is known as header files and at each subsequent layer will become the wholesome data where at lower layers is repackaged to form an additional header file. This supplementary data is used at the receiving end to extract data at the intended layer. Therefore, in reverse, decapsulation will unpack the data based on the control information provided (Omnisecu, 2017). While encapsulation and decapsulation involve the addition or removal of control information (header files), multiplexing and de-multiplexing involve the transmission of actual data. In fact, multiplexing is a method used to transmit multiple signals or information streams over a single communication channel. On the other hand, de-multiplexing is the process used to recover and separate these signals at the receiving end (Nizam, 2014). Therefore, encapsulation and decapsulation will involve control data while multiplexing and de-multiplexing will have the actual data or be it multiple instances of data (data streams). Given values: Bandwidth 6.8 MHz and SNR 132 Nyquist bit rate formula: 2 x Bandwidth x Log2 Signal level (L) Using Shannon capacity formula: Capacity (Shannon capacity) = bit rate = B x Log2 (1 + SNR) = B x Log2 SNR = 6800000 x Log2 132 Bit rate = 47901880.01 = 47.9019 MHz Signal can be obtained from Nyquist formula Signal level: 47901880.01 = 13600000 x Log2 L 3.52219706 = Log2 L, therefore, L = 23.52219706 = 11.48912529 Levels The OSI (Open systems interconnection) model is a standard created to outline the division of labour in a given communication network, this division will involve both software and hardware interactions (Burke, 2017). On the other hand, TCP/IP are network standards that are used to define communication over the internet. Basically, IP defines the method computers acquire data from each other in a routed network. While the TCP defines the channels used in the communication process. As a model, the OSI model defines a broad and wider variety of functionalities as compared to the TCP/IP model that only works when dealing with the internet. Moreover, the TCP/IP was created in the 1970s to solve specific problems and not functionalities. Therefore, at the time there were minimal variables to consider as compared to when the OSI model was developed. However, many communication protocols more so, those used on the internet such as HTTP (Hypertext transfer protocol) are built on top of the TCP model. This outcome necessitates the need of the TCP/IP model which still stands in the way of the OSI model (Frenzel, 2013). Advantages and disadvantages of OSI model For one, the OSI model is a true generic model that distinguishes layers based on service, protocols Management and interfaces. Moreover, it has improved flexibility to link with any other protocol which makes it possible to support both connected and connectionless services. Finally, it has abstract operation principles thus changes in one layer never affect another. However, it does have some faults; for instance, it never defines any operation protocols. Furthermore, its difficult to introduce new protocols as it was created before the invention of protocols. In addition to this, there is extended interdependency between communication layers (Chaudhari, 2016). In general, the TCP/IP model works independently of the operation systems which makes it easy to establish connection regardless of the type of computer used. Secondly, it does support several protocols including crucial routeing protocols. Moreover, its a scalable architecture that can accommodate new concepts and standards. However, this model is also very difficult to establish due to its complex nature. Furthermore, other models such as IPX are faster as compared to it and finally, it has a higher overhead which requires extra transmission resources (Jayasundara, 2017). Values given: frame of size 5 million bits, 10 routers, queuing time of 3.5 s, processing time of 1.8 s, link length 1900 km, speed of light 2.2 x 108 m/s and bandwidth of 8 Mbps Therefore, from these parameters we can have: Delay/latency = Processing time + queuing time + transmission time + propagation time Therefore Processing time (for 10 routers) = 10 x 1.8 = 1.8 x 10-5 s Queuing time (10 routers) = 10 x 3.5 = 3.5 x 10-5 s Transmission time = Frame size/Bandwidth = 5000000/8000000 = 5/8, approximately 0.625 s Propagation time = Link length/speed of light = 1900000/2.2 x 108 = 8.636364 x 10-3 s Latency = 1.8 x 10-5 + 3.5 x 10-5 + 0.625 + 8.636364x10-3 = 0.63369 s Transmission time is dominant (bigger packet size). Whereas, Processing time and queuing time are negligible. Post Office Protocol 3 (POP3) is a mail retrieving protocol that is used to access mailboxes hosted on remote servers. These servers usually retain all the users messages until they request for them. Furthermore, unlike IMAP4 it will only receive the sent messages (mail) which outline its limited capabilities. Nevertheless, in its operation, POP3 will use three different stages or sessions to execute its functionalities, they are Closed, Authorization, Transaction and Update (Netscape Communications Corporation, 1998). In general terms, POP3 is usually defined based on a finite state machine with each corresponding session moving between three general states during its lifetime. Authorization In this state, the server will provide a go-ahead signal known as a greeting to the client. This greeting will signal the servers intent to receive subsequent operations i.e. commands. In response, the client provides the necessary authentication procedures or information to allow it to access its designated mailbox. Transaction After providing the necessary authentication, the client is given authority to conduct various activities and operation within a given mailbox. These operations will include a listing of all available messages as well as the retrieving operation. Moreover, it will outline messages that are to be deleted. Update Finally, after being done with all the activities involved, the client will issue a quit command and as a result, the overall session will enter the update state automatically. In this state, the server deletes all messages designated for deletion. In conclusion, the session is terminated and the TCP connection set between the two (client and server) is also terminated. Closed this state exists just before the authorization state when no connection exists. Its closed because no operational activities are conducted and are in fact sometimes not considered an operational session or state (Kozierok, 2015). References Burke. J. (2017). What is the difference between TCP/IP model and OSI model? Tech target. Retrieved 01 May, 2017, from: https://searchnetworking.techtarget.com/answer/What-is-the-difference-between-OSI-model-and-TCP-IP-other-than-the-number-of-layers Certification Kits. (2017). CCNA Bus, Ring, Star Mesh Topologies. Retrieved 01 May, 2017, from: https://www.certificationkits.com/cisco-certification/ccna-articles/cisco-ccna-physical-networking-concepts-layer-1/ccna-bus-ring-star-a-mesh-topologies/ Chaudhari. A. (2016). 12 Advantages and Disadvantages of OSI model Layered Architecture. CSE stack. Retrieved 01 May, 2017, from: https://www.csestack.org/advantages-disadvantages-of-osi-model-layered-architecture/ Frenzel. L. (2013). Whats The Difference between the OSI Seven-Layer Network Model and TCP/IP? Electronic design. Retrieved 01 May, 2017, from: https://www.electronicdesign.com/what-s-difference-between/what-s-difference-between-osi-seven-layer-network-model-and-tcpip Jayasundara. M. (2017). Advantages and disadvantages of TCP/IP and OSI model. Retrieved 01 May, 2017, from: https://msccomputernetworks.blogspot.co.ke/2016/08/advantages-and-disadvantages-of-tcpip.html Kozierok. C. (2005). POP3 General Operation, Client/Server Communication and Session States. The TCP/IP guide. Retrieved 01 May, 2017, from: https://www.tcpipguide.com/free/t_POP3GeneralOperationClientServerCommunicationandSe-2.htm Netscape Communications Corporation. (1998). Receiving Mail with POP3. Messaging Access SDK Guide. Retrieved 01 May, 2017, from: https://docs.oracle.com/cd/E19957-01/816-6027-10/asdk5.htm Nizam. A. (2014). Advantages and Disadvantages of Using Mesh Topology. Networking basics. Retrieved 01 May, 2017, from: https://www.networking-basics.net/mesh-topology/ Omnisecu. (2017). TCP/IP Data Encapsulation and Decapsulation. Retrieved 01 May, 2017, from: https://www.omnisecu.com/tcpip/tcpip-encapsulation-decapsulation.php Zandbergen. P. (2017). How Star, Bus, Ring Mesh Topology Connect Computer Networks in Organizations. Retrieved 01 May, 2017, from: https://study.com/academy/lesson/how-star-topology-connects-computer-networks-in-organizations.html