Question

This assessment aims to develop and gauge student understanding of the key topics covered so far by answering the following questions. Answering these questions will help you build some understanding of the next assessment items as well as for the entire subject. It is expected that answers to the assignment questions be succinct (i.e. precise and concise) with all sources of information fully referenced as per APA referencing style. You have to reference the textbook and any additional material you have used in your answers. Note that the guide for APA referencing is provided in the resources section of the Interact site of this subject. Answers MUST be written in your own words. No marks will be awarded for any answer that contains more than 10% direct quote (referenced or unreferenced). One or two sentence answers will be too short and only receive low marks. Answers longer than 1.5 pages (12 point font, single line spacing) may incur a penalty if too much non-relevant information is stated. For mathematical questions, it is expected that you show intermediate steps of your working. Just stating the correct solution will result in low marks, on the other hand, if the working is correct and you only made minor mistakes, you will still be awarded marks, even though the final answer is wrong.

Question 1 [2 Marks] What is a link-layer frame? A network layer datagram? A transport-layer segment? an application-layer message?

Question 2 [2 Marks] Is it possible for an application to enjoy reliable data transfer even when the application runs over UDP? If so, how?

Question 3 [3 Marks] Consider a router that interconnects three subnets: Subnet 1, Subnet 2, and Subnet 3. Suppose all of the interfaces in each of these three subnets are required to have the prefix 223.1.17/24. Also, suppose that Subnet 1 is required to support at least 60 interfaces, Subnet 2 is to support at least 90 interfaces, and Subnet 3 is to support at least 12 interfaces. Provide three network addresses (of the form a.b.c.d/x such as 223.1.17/24) that satisfy these constraints, and how the steps of how to obtain your answers.

Question 4 Case study [8 Marks] In this problem, you need to put together what you have learned about Internet protocols. Suppose you walk into a room outside CSU campuses, connect to Ethernet, and want to download Slides published in a Web page of the ITC 542 site in Interact 2. What are all the protocol steps that take place, starting from powering on your PC to getting the CSU Web page? Assume there is nothing in our DNS or browser caches when you power on your PC. (Hint: the steps include the use of Ethernet, DHCP, ARP, DNS, TCP, and HTTP protocols.) Explicitly indicate in your steps how you obtain the IP and MAC addresses of a gateway router.

Answer 1

Link Layer Frame:

Framing is a part of the data link layer(Second LAyer) of OSI Model.A packet in a data link layer is referred as Frame. The function of this part includes taking the packets from the network layer and encapsulates them into frames.It includes a data field in which network layer data gram is inserted and a numbr of data fields. The Structure of the frame and protocol by which frame is to be transmitted over the link is specified in those data fields.

Network Layer Datagram:

The unit of data at the newtork layer is referred to as datagram. It encapsulates transport layer segment with a network layer header.

Transport layer segment:

The unit of data or packets at the transport layer of TCP?IP model are called segments. They are sent from TCP to network layer .It consists of a header part and an application data part(packet) from the upper layer .

Application Layer Message:

It is the data which is sent to the transport layer from the application layer.They are part of the application alyer.It is used to send data over mutiple end systems. It is responsible for providing many services like file transfer,web surfing, mail transfer,etc.