حل واجبات الجامعة العربية المفتوحة
اتصل : O544321455 - OO966544321455
واتس اب: 966544321455+
ايميل : a_al_shora@hot mail.com
سكايبي : a_al_shora
حل واجب 0.5.4.4.3.2.1.4.5.5 الجامعة العربية المفتوحة
حل واجبات الجامعة العربية المفتوحة O54.4.3.2.1.4.5.5 - OO96654.4.3.2.1.4.5.5
ايميل : a_al_shora @ h.o.t.m.ail.c.o.m
سكايبي: a_al_shora
واتس اب: OO96654.4.3.2.1.4.5.5
Arab Open University
T324: Keeping ahead in ICTs
Tutor-Marked Assignment, Fall 2013 2014
Cut-Off Date: Week 11, Dec. 11 Total Marks: 100
Q1. Investigating socio-technical system
You have studied in block three of the course materials the socio-technical system approach for investigating system failures. To demonstrate your understanding of this part of the course, answer to the following questions:
Select a socio-technical system that you use in your daily life.
Draw the system map that you think representative for the selected system.
Present briefly two processes of the selected system.
Discuss the major criteria of failure of such system.
From your point of view, what is the major reason(s) that may lead such system to failure?
d on your answer in the previous part, which system questions can be regarded as counterparts to these?
Explain briefly how investigating the system questions of the previous part could help in avoiding failure or identifying its reasons.
Q2. Innovation in IEEE 802.11
IEEE 802.11ac is the fifth generation of WiFi which is faster and more scalable version of 802.11n. IEEE 802.11ac couples the freedom of wireless with the capabilities of Gigabit Ethernet. Using the AOU e-library and Internet resources, you are asked to write an essay presenting an overview on the standard IEEE 802.11ac while providing its major physical layer specifications (e.g., throughput, RF bandwidth, channel bonding, number of MIMO spatial streams, modulation technique). Your essay should contain at least 500 words and the list of references. It should not include unapproved sites as Wikipedia or like citation. Marks will be deducted in case of essay lacking reliable references or containing errors in syntax, structure, and style.
Q3. Sniffing wireless traffic using Wireshark
Wireshark is the world’s most popular network protocol analyzer. It is used for troubleshooting, analysis, development and education. The software and its user guide could be downloaded from its home page (i.e., http://www.wireshark.org/). In this question, you will investigate the 802.11 wireless network protocol using this passive measurement tool. For more information on 802.11 management frame types, you can find many references as for example “Understanding 802.11 Frame Types” by Jim Geier (i.e., http://www.wi-fiplanet.com/tutorials...le.php/1447501).
Unfortunately, most of the device drivers for wireless 802.11 NICs (particularly for Windows operating systems) don’t provide the hooks to capture/copy received 802.11 frames for use in Wireshark. Therefore, we will provide you in this question a trace of captured 802.11 frames to analyze; assume in the following questions that you are using this trace. If you are able to capture 802.11 frames using your hardware settings, we encourage you to train on this software using your proper tests. An alternative solution for packet capture that you can use in your upcoming projects is to use a small USB device, AirPcap, (i.e., http://www.cacetech.com) that captures 802.11 frames and provides integrated support for Wireshark under Windows.
To start the experiment, open in Wireshark the trace Wireshark_802_11.pcap which is attached to the TMA files. You can load the trace into Wireshark using the File pull down menu, choosing Open, and then selecting the Wireshark_802_11.pcap trace file. The resulting display should look just like Figure 1.
Figure 1: Wireshark window, after opening the Wireshark_802_11.pcap file
For answering the following questions, you should look at the details of the IEEE 802.11 frame and subfields in the middle Wireshark
1. Given that beacon frames are used by an 802.11 AP to advertise its existence. What are the SSIDs of the two access points that are issuing most of the beacon frames in this trace?
2. What are the intervals of time between the transmission of the beacon frames from the
linksys_ses_24086 access point? From the 30 Munroe St. access point? (Hint: this interval of time is contained in the beacon frame itself).
3. What (in hexadecimal notation) is the source MAC address on the beacon frame from 30 Munroe St?
4. What (in hexadecimal notation) is the destination MAC address on the beacon frame from 30 Munroe St?
5. What is the BSS ID of 30 Munroe St?
6. The beacon frames from the 30 Munroe St access point advertise that the access point can support four data rates and eight additional “extended supported rates.” What are these rates?
7. What is the Channel number used for WiFi communication?
8. Consider the first PROBE REQUEST and the soonest subsequent PROBE RESPONSE PAIR occurs after t = 2.0 seconds in the trace. When these frames sent and what are the sender, receiver and BSS ID MAC addresses for these frames? What is the purpose of these two types of frames?
حل واجبات الجامعة العربية المفتوحة
اتصل : O544321455 - OO966544321455
واتس اب: 966544321455+
ايميل : a_al_shora@hot mail.com
سكايبي : a_al_shora
حل واجب 0.5.4.4.3.2.1.4.5.5 الجامعة العربية المفتوحة
حل واجبات الجامعة العربية المفتوحة O54.4.3.2.1.4.5.5 - OO96654.4.3.2.1.4.5.5
ايميل : a_al_shora @ h.o.t.m.ail.c.o.m
سكايبي: a_al_shora
واتس اب: OO96654.4.3.2.1.4.5.5
