Broadband Multimedia Networks TCP Variants - IT/Computer Science Assignment Help

Assignment Task:

Task:

In this lab, you will:

• Explore the characteristics of three TCP Congestion Control (CC) algorithms in FreeBSD: NewReno, CUBIC, and Vegas. See the man pages for ‘mod_cc’, ‘cc_cubic’, ‘cc_newreno’ and ‘cc_vegas’ (http://www.freebsd.org/cgi/man.cgi).

• Learn how to use Wireshark or similar packet trace analysis software and interpret output from statistical logging tools.

• Learn how to use data analysis and graphing tools. Some commonly used software: Microsoft Excel, OpenOffice Calc, Matlab, Scilab, Python, R.

II. LAB METHODOLOGY

This lab focuses on developing an understanding of various TCP congestion control algorithms. A dataset containing the trace files collected from testbed experiments is provided. You would not need to run any experiments. However, you will need to:

• Think about what the selected experiment scenarios represent.

• Interpret the output of SIFTR (Statistical Information For TCP Research) log entries.

• Use data analysis and graphing software to plot the specified TCP metrics.

• Interpret the packet capture (PCAP) output with Wireshark or other similar packet analysis software to identify the TCP options set in the headers

 A. Experiment scenarios

1) The dataset contains SIFTR log files and PCAP files for the following scenarios: Scenario Bandwidth Path RTT TCP CC algorithms A 5 Mbps 100 ms B 512 Kbps 40 ms NewReno, CUBIC, Vegas C 5 Mbps 40 ms

2) There is only one traffic flow in each direction: TCP data flow from sender to the receiver, TCP ACK flow from the receiver to the sender. The IP address and port information of the sender and receiver are as follows:

• Sender: 172.16.11.67, random port

• Receiver: 172.16.10.65, Port 5000 B. Experiment analysis with SIFTR The SIFTR man page states: "SIFTR is a kernel module that logs a range of statistics on active TCP connections to a log file. It provides the ability to make fine-grained measurements of TCP connection state, aimed at system administrators, developers and researchers." A log entry is generated for every TCP segment seen. To understand the format of SIFTR log entries see: ‘man siftr’ (http://www.freebsd.org/cgi/man.cgi?query=siftr). TCP metrics of interests are: TNE40001/TNE80003 Broadband Multimedia Networks Lab 4 – TCP Variants

• Congestion Window (cwnd)

• Sending Window (swnd)

• Receiving Window (rwnd)

• Socket send buffer occupancy (“current number of bytes in the socket send buffer”)

• Socket receive buffer occupancy (“current number of bytes in the socket receive buffer”)

• TCP RTT estimates You are required to graph a subset of TCP metrics vs time, as specified below: TCP Metrics vs time Scenario TCP CC algorithms Remarks Number of graphs cwnd & send buffer occupancy A NewReno, CUBIC, Vegas Overlay cwnd and send buffer occupancy plots on the same graph. Repeat for all CCs. 3 Smoothed RTT B, C Overlay smoothed RTT plots for the same CC in Scenarios B and C. Repeat for all CCs. 3 cwnd A, C Overlay cwnd plots for the same CC in Scenarios A and C. Repeat for all CCs.

3 C. Packet capture analysis Use Wireshark or other similar packet analysis software to identify the TCP options negotiated at the start of the data transfer. You will need to discuss the options in your report. III. GENERAL

QUESTIONS 1) What is meant by the term ‘TCP congestion control’? Provide descriptions of the basic characteristics of the CCs explored in this lab (NewReno, CUBIC and Vegas).

In addition, provide three other examples of CC algorithms that are used on the Internet today and write a short description of how they operate.

2) What is the default TCP congestion control method used in the following operating systems?

• The latest version of FreeBSD

• The latest version of MacOSX

• The latest version of the Linux kernel

• Windows XP, 7, 10 3) What are TCP options? Where and when are they transmitted? Provide short descriptions of what two of them do.

IV. LAB-BASED QUESTIONS

1) Calculate the Bandwidth Delay Product (BDP) for Scenarios A, B and C.

2) Perform data analysis as described in Section II-B. Explain and discuss what you see in your results. Some questions to consider:

a) What do Scenarios A, B and C represent? Hint: Think in terms of BDP.

b) How are socket send buffer occupancy and cwnd values relate to each other? Hint: Have a look at results from Scenario A.

c) How do you obtain the Smoothed RTT estimates? Hint: HZ=1000 & TCP_RTT_SCALE=32 d) How do Smoothed RTT estimates vary with the bandwidth? Hint: Compare results from Scenarios B and C.

The above  IT Assignment has been solved by our  IT Assignment  Experts at onlineassignmentbank. Our Assignment Writing Experts are efficient to provide a fresh solution to this question. We are serving more than 10000+ Students in Australia, UK & US by helping them to score HD in their academics. Our experts are well trained to follow all marking rubrics & referencing style.

Be it a used or new solution, the quality of the work submitted by our assignment experts remains unhampered. You may continue to expect the same or even better quality with the used and new assignment solution files respectively. There’s one thing to be noticed that you could choose one between the two and acquire an HD either way. You could choose a new assignment solution file to get yourself an exclusive, plagiarism (with free Turnitin file), expert quality assignment or order an old solution file that was considered worthy of the highest distinction.