Hi this is assesment task I want you to do this on time for me everything is mentioned in document

Part A
Question 1
The hub can be defined as a networking device which can allow us to connect multiple computer systems with a single network and the switch is used to connect multiple devices together on the single network off the computer will stop the hub is used on the physical level and the switch is used on the data link layer. The hub uses half duplex cable and switch uses full duplex cable. The hub is used as the passive device and the switch behaves as the active device. This which uses frame packets to transfer the data but how uses electronic signal orbits. They both are used in the LAN.
Features of Hub.
The hub can be used with shared bandwidth and the broadcasting. We can use the hub in anyway. The hub consist of single collision domain and one broadcast room a full stop the hub is generally operated at the physical layer of the osi model. We cannot create any virtual local area network with the help of the hub. The hub can be used to achieve the half duplex transmission mode for the communication. The hub consists of single broadcast domain as we have already discussed. Hub cannot be used for the spanning tree protocol and most of the time there is packet collision inside it.
Features of Switch.
The switch operates at the data link layer and it is a data link layer device. It consists of the fixed bandwidth and also maintains a proper MAC address table. The switch allows us to create a virtual LAN area network and also behaves as the multiport bridge. The switch generally comes with 24 to 48 ports and it also supports half and full duplex transmission modes for the communication.
Application of Hubs
The hub has different type of applications for the user. We can use house in the organizations to create the connectivity. They can be used for the small home networks also. The hub is generally used to monitor the whole network and we can create peripheral or the device which will be available throughout the network.
Applications of Switches
The switch also has multiple types of applications. We can use the switch as it will allow us to manage the whole flow of the data throughout the network. This switch has the capability to manage medium to large sized land area network which consist of multiple links. Generally, the switches are used in the small office or Home Office applications. It mostly uses the single switch for accessing the different broadband services. The switch can be used in the computer network and it can allow us to connect different devices physically. The switch can also be used to transfer the data from one device to another device using either full duplex mode or half duplex mode.
Question 2
The software development life cycle is generally followed for the development of the whole software. There are 6 phases or the stages which are followed to complete a successful software and its implementation.
1. Requirement gathering and analysis is the first stage for the development of a software. All the related information is collected in this stage from the customer and this information can be used to develop the product as per the expectation of the customer stop this stage is used to remove any ambiguity which is present in the initial stages. In this face the manager and the business analyst set up a meeting with the customer to collect all the information which is related with the software. The meeting includes what the system customer wants to build, and users for the system, purpose of the product and the deadline for implementing the whole system. Before starting with the production work it is very important to have core knowledge or understanding about the product.
2. The second stage is the design stage in which all the collected requirement is written in the software requirement specification document which can be used as the input and the software architecture will be used to implement the system development.
3. The 3rd stage is the implementation for the whole system. The developer can use the design document for the implementation of the work. The software design can be translated into the source code using any suitable language. All the components which are present in the document will be implemented in this stage.
4. The 4th state is the testing stage in which testing is performed after the completion of the code. All the modules are tested in this stage will stop the software testers are used to test the software thoroughly and if there is any defect in the system then it will be assigned to the developers to fix those defects.
Once the re work is done retesting will be performed until they find a complete software which can be handed over to the customer as per the expectation and the standard.
5. The first stage is the deployment stage in which after testing the whole system will be deployed in the environment or for the user acceptance testing. The user acceptance testing is performed to find out whether this developed system is as per the customer expectation or not. For the user acceptance testing a replica is created for the production environment and the customer will perform the testing along with the developers. If the customer finds anything unexpected in the application, then he can inform about this to the developer.
6. The 6th stage is the maintenance stage in which was the deployment of the product is done completely in the production environment the maintenance of the product is handled. If there is any issue or bug or the product needs enhancement, then the developers will take care of this thing in future.
Question 3
Synchronous time division multiplexing
Synchronous time division multiplexing allows each device to receive a same time slot for transmitting the data in the network irrelevant of the fact that the device is having any data for the transmission or not. Hence it is given the name of synchronous tdm. The synchronous tdm needs the total speed for different types of input lines which should not exceed the overall capacity of the network path. Each device which is present in the network will place its data over the link whenever its time slot arrives. Each device will get the position turn by turn. If any device is not having the data for transmission, then that time slot remains empty. Different timeslots are organised in the form of frames and each frame will have one or more dedicated time slots to transmit the data. If there are n devices, then there will be n slots for the frame which means each device will have single slot of time.
Asynchronous time division multiplexing
Another name which is given for the asynchronous time division multiplexing is the statistical division multiplexing because it does not have any fixed time slots like the synchronous tdm. It follows flexible time slots. The time slots are not fixed the device which wants to send the data will receive allotted time slot.
Question 6
1. Mono-alphabetic Cipher:
It is very easier to make predictions in the Caesar cipher which makes it the most weakest algorithm as once any key replacement about the single alphabet is known then the whole message can be decrypted and it takes only 25 attempts to break the key replacement. In this technique we can simply use the substitution method for any random key with each alphabet. For example, we can replace the a with any letter from the B to Z and then we can be changed with rest of the alphabets but not itself will stop let's say that we substitute a with their, but it does not mean that be will be replaced by F only. Mathematically there are 26 alphabets which can be used for the permutation and then we can have 4 X 1026 possibilities 2 use them as the key. In this method there is only one problem as this technique can be used only for short text. Any crypto analyst can try with different attacks on the basis of their knowledge of the English language. The English analyst can try to find out the possibility of occurrence for the letter of Pete and it is 13.3 percentage which is the highest probability as followed by Z which has 11.67 percentage and the occurrences of the letters like K, and, are or CR negligible. A crypto analyst can try multiple alphabets instead of cybertext alphabet or they can even try to find for the repeated patterns of the word so that it becomes easier for them to understand the ciphertext and then deduce it.
2. Homophonic Substitution Cipher:
The mono alphabetic substitution and the homophonic substitution are almost similar. In the plane cipher substation we replace the alphabet with the help of any key but in homophonic substitution we try to map the alphabet with the set of fixed key which means we can use multiple keys. For example we can replace a with H, OB, P&J in spite of using the key set of W, d, Z etc.
3. Polygram Substitution Cipher:
In the Polygram...