Parallel Computing Homework Assignment 1 并行计算家庭作业代写 1.In the global sum problem that we discussed in class, in lecture 1, if we assume that there is a variable called my_rank (loca...View details
CS 158A Computer Networks
Problem Set 2
计算机网络课业代做 Problem 1 Read the following statements on reinforcement learning. Indicate if the statement is True or False and write a brief justification.
Due: Tuesday, April 19 at 6 PM (BEFORE CLASS)
No late submission will be accpted to go through solutions during the class on the due date.
A submission must be made as a PDF file on Canvas.
Read the following statements on reinforcement learning. Indicate if the statement is True or False and write a brief justification.
Problem 1.1 (0.5 pt)
MAC addresses can be used in routing in the Internet.
Problem 1.2 (0.5 pt)
Suppose that Alice in Local Area Network (LAN) X sends a message to Bob in LAN Y. When Alice sends out a frame including the message, the destination MAC address in the frame is the MAC address of Bob’s machine.
Problem 2 The Link Layer: Error Detection/Correction 计算机网络课业代做
Problem 2.1 Parity bit (0.5 pt)
Suppose that a frame includes the bit pattern 1001 1010 0001 1001 and an even parity scheme is being used. What would the value of the field containing the parity bits be for the case of a two-dimensional parity scheme?
Problem 2.2 CRC (0.5 pt)
Consider C(x) = x4 + x2 + 1, and suppose that message M has the value 1001100110. What is the value of P (Original message & CRC) that will be sent?
Problem 3 The Link Layer: LAN Setup (0.1 pt each) 计算机网络课业代做
Let’s consider the operation of a learning switch in the context of a network in which 6 nodes labeled A through F are star connected into an Ethernet switch S.
1. A sends a frame to C,
2. C replies with a frame to A,
3. D sends a frame to B, and
4. C sends a frame to F.
The switch table is initially empty. Show the state of the switch table before and after each of these events. For each of these events, identify the link(s) on which the transmitted frame will be forwarded, and briefly justify your answers. (You need to show 5 table updates including the initial one.)
Problem 4 TCP: ACK 计算机网络课业代做
Host A and B are communicating over a TCP connection, and Host B has already received, from A, all bytes up through byte 121.
Suppose Host A then sends two segments to Host B back-to-back. The two segments (Segment X and Y) contain 50 and 90 bytes of data, respectively. Note that Host A sends Segment X first and Segment Y after X. In both segments, the source port number is 2001, and the destination port number is 80. Host B sends an acknowledgment whenever it receives a segment from Host A.
Answer the following questions.
Problem 4.1 (0.5 pt) 计算机网络课业代做
In the segment Y sent from Host A to B, what are the sequence number, source port number, and destination port number?
Problem 4.2 (0.5 pt)
If Segment X arrives before Segment Y at Host B, in the acknowledgment of the second arriving segment (Segment Y), what is the acknowledgment number, the source port number, and the destination port number?
Problem 4.3 (0.5 pt)
If Segment Y arrives before Segment X, in the acknowledgment of
the first arriving segment (Segment Y), what is the acknowledgment number, the source port number, and the destination port number?
Problem 5 TCP: Congestion Control 计算机网络课业代做
Consider Figure 1. Assuming TCP Reno is the protocol experiencing the behavior shown above, answer the following questions. In all cases, you should provide a short discussion justifying your answer.
Problem 5.1 (0.5 pt)
Identify the intervals of time when TCP slow start is operating.
Problem 5.2 (0.5 pt)
After the 16th transmission round, is segment loss detected by a triple duplicate ACK or by a timeout?