NETW320 -- Converged Networks with Lab
Lab # 2 Title: Silent Suppression – Cont.
Procedure
Start OPNET Modeler
Open the scenario
1. Select File/Open.
2. Select Project.
3. Open your f: drive. (Note: If you don’t see drive F: listed, you click on “My Computer or “Computer” first.)
4. Open your op_models directory.
5. Open your NETW 320 directory.
6. Open the Lab1_Silent.project folder.
7. Click on Lab1_Silent.prj.
8. Click OK. The project should open.
9. Choose Scenarios > Switch to Scenario > Silent_Suppression.

Results analysis
1. We are now ready to look at the results. From the tool bar, select DES > Results > View Results.
2. The Results Browser will appear. You may have to expand the items in the top left panel and click on them to get Global Statistics to appear in the bottom left panel. 3. Expand Global Statistics and select the following (4) statistics: Expand Select
DB Query Response Time (sec)
HTTP Page Response Time (sec)
E-mail Download Response Time (sec)
Voice Packet End-to-End Delay (sec)

4. You can adjust the size of the panels as you wish by hovering the cursor over the panel border until it changes to the adjust line cursor, and then hold the left mouse button to set the panel size.

5. Change the view from As Is to Time Average using the dropdown menu on the lower right-hand side. Remember, your results may not be exactly the same but they should be very similar. 6. Click Show. A graph similar to the following should appear. 7. The values for your graph many differ slightly, but overall they should be about the same as those pictured. If not, you must check your configurations before continuing, because we are going to duplicate this scenario and if you have errors in the current configurations, they will be copied over to the duplicate simulation.
Close out the graphs by clicking the X in the top right-hand side of the window. This panel should appear. 8. Just click the Delete button. We can always look at the graph again later if we choose to do so. Then close out the Results Browser.

Duplicating the scenarios
1. We now want to duplicate the scenario. In the second scenario, we are going to generate the same amount of data and VoIP traffic, but we will configure the VoIP traffic to use silent suppression.
2. Choose Scenarios > Duplicate Scenario.

3. An option menu will appear. Select the second option, Duplicate Scenario. A new screen will appear. The new screen will automatically assign the name of 1 after the present scenario name. Change it to something what is shown here. 4. Click OK. The scenario will duplicate into the new one with the new name in the top banner. Left-click on the Application Config node, and then right-click on it and select Edit Attributes.

5. Expand Application Definitions->Voice Traffic> Description. 6. Change the Voice Traffic configuration from IP Telephony to IP Telephony and Silence Suppressed.

7. Click OK to close the Application Configuration window. Go to File -> Save, to save the settings for your second scenario.
8. We are now ready to run our second simulation. Select Scenarios > Manage Scenarios.
9. We only need to run the second scenario since we ran the first scenario to test it. We have not changed any of the configurations in the first one. In the Results box next to the new scenario, change uncollected to . 10. Click OK. The second scenario will now run. It should take about three minutes or so to run. When it is finished running, close out the Simulation Sequence window.
11. We will now look at some of the results. From the tool bar, select DES >Results > View Results. In the Results Browser, note the small selector at the top of the left panels. Change Current Scenario to Current Project. You can now see the results from both scenarios in the left panels. Expand the trees until you see the view shown below.
Expand Select
DB Query Response Time 11. Once again, change the view from AS IS to time_average using the dropdown arrow next to AS IS. Also, change Stacked Statistics to Overlaid Statistics.

12. Click Show. 13. Note, your results do not have to match these exactly, but they should be very similar. You can use your mouse to zoom in on a graph once you are in the Show mode to get more granularity of a specific area, if you so desire. Zoom in on the second half of the graph in order to stay away from the start-up time oscillations.
Left-click your mouse and the graph, and draw a black box around the area you wish to zoom into. 14. When you release the mouse, you will have zoomed in. 15. Note, you can continue to zoom in as many times as you like if you feel it helps you read the statistical results better. Lab Report
You need to create a word document that answers the required questions. You must retype the questions in your lab report in order to make your answers very clear. Also, you should support your answers with graphical results. In most cases, you will be instructed to view the graph either As Is or Time Average, and it is also suggested that you might want to zoom in when necessary. However, please do not hesitate to include addition graphs in any view of your choice any time you feel those graphs may support your answer. Also, you are encouraged to use your textbook, the Internet, or any other reference material you feel will help you support your answers to the questions. However, make sure you reference any such materials at the end of your lab report.
Copying a graph to your Lab report: After you have clicked Show to view your graphical data, click anywhere on that specific graph, and then hit the (alt) and (prt scr) keys on your keyboard at the same time. If you now go to your Word document and select Edit –> Paste (or type Ctrl-V) from your tool bar, the graph will be pasted into your Word document. Some questions will require you to import specific graphs, but you should feel free to import graphical results anytime you feel it helps support your answer. Always make sure that you clearly label your graphs.
Required Lab Questions for NETW320, Silent Suppression
(This section is worth 75% of your grade for this lab.)
1. On the Results Browser, make sure you are on Current Project so you have both sets of results. Expand DB Query and Select DB Query Response Time (sec). Hit the Show button. Zoom into the last half portion of the graph for better granularity and to avoid start up oscillation time to stabilize. Copy and label this graph to your lab report and answer the following: 1. Which run has a better (lower) DB Query Response time? 2. In regard to your answer to part a, approximate how much faster (in seconds or milliseconds) of a response time the better scenario has.
2. Expand E-mail and select Download Response Time (sec). Select Show and zoom into the last half portion of the graph for better granularity and to avoid start up oscillation time to stabilize. Copy and label this graph to your lab report and answer the following: 3. Which run has a better (lower) e-mail Download Response time? 4. In regard to your answer to part a, approximate how much faster (in seconds or milliseconds) of a response time the better scenario has.
3. Expand HTTP and select Page Response Time (sec). Select Show and zoom into the last half portion of the graph for better granularity and to avoid start up oscillation time to stabilize. Copy and label this graph to your lab report and answer the following: 5. Which run has a better (lower) page response time? 6. In regard to your answer to part a, approximate how much faster (in seconds or milliseconds) of a response time the better scenario has.
4. Expand Voice and select Traffic Sent (bytes/sec). Change the view from AS IS to time_average. Copy and label this graph to your lab report and answer the following: 7. For the (2) runs used in this lab was the amount of Voice Traffic sent about the same? If not, which scenario sent more and by how much?
5. Expand Voice and select Traffic Received (bytes/sec). Change the view from AS IS to time_average. Copy and label this graph to your lab report and answer the following: 8. For the (2) runs used in this lab, was the amount of Voice Traffic received about the same? If not, which scenario received more and by how much?
6. Expand Voice and select Packet End-to-End Delay (sec). Hit the Show button. Zoom into the last half portion of the graph for better granularity and to avoid start up oscillation time to stabilize. Copy and label this graph to your lab report and answer the following: 9. Which run has a better (lower) Packet End-to-End Delay? 10. In regard to your answer to part a, approximate how much faster (in seconds or milliseconds) of an end-to-end delay the better scenario has.
7. Expand Voice and select Packet Delay Variation. Hit the show button. Zoom into the last half portion of the graph for better granularity and to avoid start up oscillation time to stabilize. Copy and label this graph to your lab report and answer the following: 11. Which run has a better (lower) Packet Delay Variation? 12. In regard to your answer to part a, approximate how much of an improved (in seconds or milliseconds) packet delay variation the better scenario has.

Required Lab Summary Report for NETW320, Silent Suppression (This section is worth 25% of your grade for this lab.)
Write a two-page Summary Report, and use the graphs you generated during this lab to support your analysis. Which graphs you decide to use is up to you. Your two-page summary report must answer the following:
1. For the network under analysis in this lab, what effect did implementing silent suppression have on the data traffic? Why?
2. For the network under analysis in this lab, what effect did implementing silent suppression have on the VoIP traffic? Why?
3. What would be a possible disadvantage to implementing silent suppression on a VoIP network?