hw3_sols_spring2023

Both TCP and UDP are separate protocols that may be contrasted with one another. Give us an example of two circumstances in which you, as a software architect, might choose to make use of TCP rather than UDP.

Two considerations drive the use of layered protocols.

Both TCP and UDP are separate protocols that may be contrasted with one another. Give us an example of two situations in which you, as a software architect, might choose to make use of TCP rather than UDP.

Consider an employee using their computer to send and retrieve email at their workplace.  Only Ethernet networks are used for physical connectivity, but the mail server is located on a separate network.  The employee’s network and the mail server’s network are connected by a single router which also has a connection to the Internet via the workplace’s ISP.   Explain how the employees email client sends and receives emails using the email server, indicating any protocols involved and where any encapsulation/decapsulation occurs as data travels between the client, local mail server, and remote mail servers.

The use of layered protocols is driven by two different concerns.

Computer Networks - Internet Architecture & Application Layer Please answer the question   Someone suggested to use a local file called hosts.txt on each machine instead of DNS. Discuss the advantages (at least 2) and disadvantages (at least 2) of such suggestion. What is ‘saw-tooth’ behavior in TCP, and what is causing it?

To what extent do each of the following contribute to the benefits of layered protocols? Explain what you mean by providing some examples.

For NAT Network Address Translation Scenario: Jenny Bello is a small business owner selling and making customized computer peripherals. She has been finding it difficult to track her sales and inventories, however recently after an expert's advice, she adopted a Point of Sale (PoS) server. So, she can now track her sales and inventories at the store. However, she ran into another issue, the server can only be accessed within the store, because it has been assigned a private IPv4 address, it is not publicly accessible via the Internet. a) Why is not having the PoS server accessible over the Internet a problem for the business? b) What caused this problem? c) Propose a solution for the problem and explain how the solution works.

Two distinct protocols that may be contrasted are TCP and UDP. Give two examples of situations when you, as a software architect, might choose TCP over UDP.

Chose the appropriate terminology which expresses the following concepts: (Flow control, A token-ring Network, RTT, star topology, non-persistent HTTP, persistent HTTP, Network layer, Persistent, Interconnection, bus topology, Transport services, DNS). NO Terminology Description 1 Is a deterministic network, meaning each station connected to the network is assured access for transmission of its messages at regular or fixed time intervals. 2 Multiple objects can be sent over single TCP connection between client, server. 3 Allows users to exchange information (data) with other network members. All LAN data traffic is carried over a common coaxial cable link. Value used for error checking. Response time=2RTT+ file transmission time. 10 5 6

The tunneling process entails what steps, exactly? Can you name the three protocols used for tunneling?

Non-Repudiation and Anonymity ProtocolsFor the Zhou-Gollman non-repudiation protocol discussed in the lecture on “Non-Repudiation and Anonymity Protocols”, which one of the following statements is false:a) At time point 4, both A and B can produce evidence to prove that they received Kb) At time point 2, both A and B can produce evidence to prove that they received a signed message from the other partyc) At time point 0, S cannot prove anythingd) At time point 3, B cannot produce evidence to prove that A has access to key Ke) At time point 1, A can prove that B is alivef) At time point 4, S can prove that A is aliveg) At time point 3, S can produce evidence that that A has access to key Kh) At time point 0, A is not alivei) At time point 2, A can produce evidence to prove that B is alivej) At time point 4, the protocol terminatesExplain your answer below:

The usage of layered protocols is motivated by two factors.

Provide an overview of the four abstraction layers that make up TCP/IP. ii) Speculate on a scenario where two computers are transferring a video file via an unencrypted ftp connection using a weak TCP three-way handshake.

The most common uses of layered protocols are security and performance.

What two of the following arguments are strongest in support of layered protocols?

There are two main reasons why layered protocols are used.

Kerberos is a protocol that is based around Needham-Schroeder protocol for many to many authentications. Now answer the following questions. (Use necessary diagrams to justify your answers) i) Explain why the password of the user is not sent over the network and instead session keys are generated and shared in the Kerberos protocol. ii) The information in a TGT (Ticket Granting Ticket) is encrypted so the client cannot access the information in the TGT. However, all information in the ticket is already known to the client. Why is it still necessary to encrypt it? iii) Describe the working mechanism of how a ticket is generated between the client and server by the TGS (Ticket Granting Server) and how it is used for client-server communication.

- 3 - (b) The Internet Protocol (IP) can sometimes surprise with its flexibility. Since the overall design is close enough to the principles of the OSI Protocol Model, IP is independent of the Data Link and Physical network layers. And some Norwegians indeed showed successful IP network transmission is possible with carrier pigeons. (i) If we would want to attempt to use carrier pigeons to establish a TCP connection between Canterbury and London, how long would it take to successfully establish the transmission under perfect conditions? (Assume the pigeons are perfectly reliable.) Explain how you come to your result. For the experiment, let's assume that the concrete distance between Canterbury and London is 60miles (or ca. 100km) and our pigeons fly with a speed of 60 miles per hour (or ca. 100km/h). (ii) With current technology and considering the weight a pigeon can carry, we are able to send 2TB of data on an USB stick with a pigeon. On a 4G mobile network, we can likely send about…

The use of layered protocols is supported by two main arguments. You must provide evidence for your claims.

DNS makes use of UDP rather than TCP. If a DNS packet is dropped, there is no way to recover automatically. Is this a problem, and if so, how does one go about resolving it?

IPv4’s ARP and IPv6’s Neighbor Solicitation both map an address from one space to another. In this respect they are similar. However, there are several differences. In what major ways do they differ?

A frame containing http request is sent from Computer (A) [in whichever subnet it is now, make sure to show it in your figure], to the access point it is associated with. Draw the address fields (1, 2, and 3) of the frame travelling from Computer A to AP and the source and destination addresses of the frame travelling from AP to R1. The MAC addresses of AP1, AP2, and AP3 are M1, M2, and M3 respectively, and the Router R1’s MAC address connected to this Switch/AP is MRA. IP address values are already given, and the port addresses could also be used as given. The Router’s MAC address facing WAN side is MRW.

What are the primary rationales behind the implementation of layered protocols?

I need The Answer Pure Aloha in Multiple Access Protocols should be described in three to four lines, without plagiarizing.