QualNet 3.6 Product Tour

Transcription

1 QualNet 3.6 Product Tour For Windows and UNIX Do not circulate without express consent of SNT, Inc.

2 Table of Contents Introduction QualNet Animator BUTTONS AND CONTROLS Runtime Controls Manual Configuration Tools Animation Filters Time Controls BASIC ANIMATOR EXPERIMENTS Modify An Existing Experiment Semi-automated Node Placement Manual Node Placement Exploring more of QualNet Animator ANTENNA ANIMATION/PROPAGATION EFFECTS BATCH EXECUTION DYNAMIC STATISTICS COLLECTION QUEUE ANIMATION Creating a Wired Model Simulating a Wired Model Comparing Queue Disciplines Queuing with FTP/Generic HIERARCHICAL DESIGN/BGP Creating a Hierarchical Network Setting up BGP MIXED (WIRED AND WIRELESS) NETWORKS QualNet Analyzer STATISTICS FROM A SINGLE EXPERIMENT STATISTICS FROM MULTIPLE EXPERIMENTS STATISTICS BY IP ADDRESS QualNet Designer SETTING UP THE PROTOCOL WITH THE GRAPHICAL USER INTERFACE Designer Toolbar VBR Overview Application Parameters Building a Skeleton Diagram Creating the VBR Statistics Variables Creating VBR Local Variable ENTERING SOURCE CODE Initial State Final State Client State Server State INCORPORATING VBR INTO QUALNET SIMULATOR Header File Body File Adding VBR to the QualNet Simulator Using the New Protocol in QualNet Animator QualNet Tracer TCP TRACE QualNet Scalability...80 Do not circulate without express consent of SNT, Inc.

3 5.1 RUN TIME COMPARISON...80 Table of Figures...89 Do not circulate without express consent of SNT, Inc.

4 Introduction The QualNet 3.6 Product Tour is designed to quickly cover the basic features of QualNet for experienced network modelers. We start with installation and move on to navigate through the product. Parts of this tour ask you to modify and recompile source code; a C/C++ compiler is required for these portions. QualNet runs on both Windows and Unix. The following is a list of software you must have to use QualNet: 1. Java 1.3 JRE or SDK 2. QualNet (filename qualnet-3.6-binary-windowsnt.exe, ) 3. QualNet license file (filename ends in.lic ) 4. *For Windows users, Visual Studio 6.0 (any edition) with Service Pack 5 5. *For UNIX users, gcc 2.x or Sun compilers (cc and CC) * On Windows, Visual Studio 6.0 is not required to evaluate QualNet; if you wish to compile new source code, however, you will need this compiler. On UNIX, users must have gcc or the Sun compilers in order to use QualNet at all. gcc 3.x is not currently supported. QualNet installation is described in the Installation Guide for Windows and the Installation Guide for Solaris SPARC / Linux. These are available from the Documentation section of the Download page: 1 QualNet Animator Now that you ve got QualNet installed, each part of the Product Tour assumes that you already have QualNet Animator running. In Windows, to start QualNet Animator, 1. Click on the QualNet 3.6 Animator icon on your Windows desktop Alternatively, you may create a DOS command prompt and type RunQualnet. Note: The default QualNet home directory (hereafter referred to as [QualNet_home]) for QualNet 3.6 is c:\qualnet\3.6, or the directory in which you installed QualNet. In UNIX, to start QualNet Animator: Do not circulate without express consent of SNT, Inc

5 2. Type the following command: cd ~/qualnet/3.6/gui/bin 3. Type the following command:./runqualnet Note: If the directory is in the PATH, simply type RunQualnet. 4. QualNet Animator should load up and look like the following image. Figure 1: QualNet Animator 1.1 Buttons and Controls Let s start by familiarizing ourselves with the controls Runtime Controls The runtime control buttons are, from left to right: Setup QualNet Parameters Do not circulate without express consent of SNT, Inc

6 Run QualNet / Action! Play Pause Stop Step Resume Design Each button has a rollover caption that explains what it is. Figure 2: Runtime Control Toolbar Manual Configuration Tools The Manual Configuration tools are (left to right, top to bottom): Move Tool Node Placement Tool Application Setup Tool Link Setup Tool Wired Network Tool (Hub/Switch) Wireless Network Tool (Cloud) BGP Link Tool Hierarchy Tool Satellite Tool Figure 3: Manual Configuration Toolbar Animation Filters The Animation Filters and animation associated with each filter are shown in the table below. Animation Filter Channel Physical / Radio MAC Type of Animation in QualNet none broadcast wired links, wired broadcast Do not circulate without express consent of SNT, Inc

7 Network packet reception (green arrows), queues Transport none Application none, except VBR Routing none Figure 4: Animation Filters Toolbar Time Controls There are three main controls for time in the QualNet Animator. Sliding speed control allows you to slow down or speed up the animation. Sim Time shows you how far along in the simulation period you are. Real Time shows how long the simulator has been running to produce the data you re watching. It s useful to see Simulation (Sim) Time and Real Time together, to gauge how efficient your particular experiment is. However, since QualNet runs much faster from the command line and in batch mode, many QualNet users opt not to see Sim Time vs. Real Time when running their experiments. Figure 5: Time Controls 1.2 Basic Animator Experiments There are three basic experiments to illustrate how to place nodes to set up a simulation. They are as follows: Modify an Existing Experiment Semi-automated Node Placement Manual Node Placement Modify An Existing Experiment First, there s the blind experiment where we just change the settings. 1. Press the Setup QualNet Parameters button. Do not circulate without express consent of SNT, Inc

8 2. Select the Traffic and Status tab. 3. Press Browse to locate the application configuration file. 4. Navigate to [QualNet_home]\qualnet\3.6\gui\bin. 5. Select one of the following files: heavy36.app, light36.app, med36.app, or one36.app. These files specify the application traffic for the experiment. 6. Press Open. Figure 6: Opening the application file in QualNet Animator 7. Press the Save button 8. Press the Close button at the bottom of the Settings window. Note: While the Settings window is open, you can see all the experiment setup options, but we won t change them now. 9. Press the Action! button (looks like a clapper). 10. Press the Play button (forward arrow) on the main window to run the model. Note: If QualNet prompts you to Select QualNet Binary, browse for it in [QualNet_home]/bin. You may have to go up a directory to find it. If QualNet is asking you for this, you may not have compiled QualNet for UNIX. For additional information on QualNet compiling in UNIX, refer to the README file also in the [QualNet_home]/bin directory. If QualNet has successfully started running, the following will be displayed: Do not circulate without express consent of SNT, Inc

9 Blue circles are radio broadcasts. The size of the circle represents the transmission range. Green arrows mean successful data packet transmission at the network layer. Figure 7: QualNet simulation showing radio broadcasts as blue circles and green arrows as successful data packet transmission Semi-automated Node Placement 1. Clear the experiment by selecting File New. Note: It is not necessary to save changes from the previous experiments. 2. Follow the steps from the previous experiment, but before step 1, from the Main Menu Bar select Experiment Automatic Node Placement 3. In the Number of Nodes field, type In the Placement Strategy pull-down menu, Uniform should be selected. Do not circulate without express consent of SNT, Inc

10 Figure 8: Automatic Node Placement 5. Open the Setup QualNet Parameters window. 6. Click Browse. 7. Select an application file like in the previous experiment. Note: The application file chosen may cause the animation displayed to vary from the examples shown. 8. Select Open. Note: A message screen may be displayed. Click OK and continue. 9. Press the Save button 10. Press the Close button at the bottom of the Settings window. 11. Press the Action! button (looks like a clapper). 12. Press the Play button (forward arrow) on the main window to run the model. This time, the application links are shown on the screen, allowing us to see who s trying to send data to whom, and even change those settings if necessary. Do not circulate without express consent of SNT, Inc

11 Figure 9: Application links for Constant Bit Rate (using light36.app) shown between specific wireless nodes Manual Node Placement 1. Clear the current experiment by selecting File New. Note: It is not necessary to save changes from the previous experiments. 2. Select the Create Node button (looks like a computer). 3. Choose the default node type 4. Click on the canvas to place 6 nodes. Do not circulate without express consent of SNT, Inc

12 5. Choose the Add Applications Type tool. 6. Select an application, such as CBR or FTP. 7. Click on a source node and drag the mouse to a destination node. Figure 10: Designation of Application links between nodes 8. Accept the default settings by clicking OK. 9. Press the Run QualNet (Action!) button. 10. Press Play to start the simulation. Note: Because of how fast this experiment can run in QualNet, users may want to slow down the speed of the simulation on the Time Control Bar to better see the detailed animation of the experiment. Do not circulate without express consent of SNT, Inc

13 Figure 11: CBR and FTP application traffic flowing between nodes Exploring more of QualNet Animator There are many other things that you can see without running a specific experiment. For example: Pop up help: Move the mouse over a variable name or button for helpful information about the variable. Coordinates: Click on Setup QualNet Parameters, then on the General tab. Switch between Cartesian and LatLonAlt coordinates and press Save to show the effect on the canvas. Changing coordinates must be done before placing nodes. Note: It is not possible to switch between Cartesian and LatLonAlt coordinates while an experiment is loaded and/or running. Background and rulers: Enable and disable this feature by selecting View Background Choose Background. One sample background included in [QualNet_home]\gui\icons is mammoth.jpg. Output Files: Select View output files. You can see the files that will be generated. Do not circulate without express consent of SNT, Inc

14 Animation Controls: While running any experiment, you can enable or disable specific animation with the Animation Filters Toolbar, or from the View menu. You can also use play, step, pause, etc. The default step size is 1 second of simulation time. Node Specific Settings: To modify these settings, users should enter design mode by clicking the Resume Design Mode (Painter s Palette) button. In design mode, right click on any node on the canvas. Select node properties from the popup. You get a miniature Settings menu, allowing you to change the characteristics of the node. Figure 12: Node Properties menu showing the parameters a modeler can set for each device or node in the model. Here, the modeler is selecting from a list of routers by manufacturer and model number. 1.3 Antenna Animation/Propagation Effects 1. Choose File New to clear the screen. Note: It is not necessary to save changes from the previous experiments. 2. Open the Setup QualNet Parameters window by clicking the button just to the left of the clapper. 3. Go to the Wireless Settings tab. 4. Scroll down to Radio/Physical Layer. 5. Set Antenna model to Switched Beam 6. Click Browse to find an Azimuth Pattern File and choose default.antenna-azimuth (from the [QualNet_home]\qualnet\3.6\bin directory). 7. Click Open. Do not circulate without express consent of SNT, Inc

15 Figure 13: Opening the switched beam antenna azimuth file 8. Under MAC Protocol section, under Directional Antenna Mode select Yes. 9. Click Save. 10. Click Close. 11. From the Main Menu bar, select Experiment Automatic Node Placement to uniformly place 16 nodes. Note: You must change the antenna model before placing the nodes. Additionally, some randomly placed nodes may occasionally land outside each other's range and may not react to the transmissions. 12. Click on the Application Setup Tool button (that has 3 CD s ) to manually set up an application connection. 13. Select CBR. 14. Click and drag the connection between two nodes. 15. Accept the default CBR settings by clicking OK. Do not circulate without express consent of SNT, Inc

16 Figure 14: Making a CBR application connection between nodes 16. Save this experiment for later by selecting File Save As from the Main Menu Bar. 17. Name it antenna.xml and save it in the [QualNet_Home]\3.6\gui\scenarios directory. 18. Prepare the simulator to run by pressing the Run QualNet (Action!) button. 19. From the View menu, choose Animation Filter By Event and enable Antenna. You should see red circles around all the nodes. The red circles indicate the direction of each node s antenna for reception. 20. Press Play. 21. To see the action more clearly, press Pause, then from the Main Menu Bar select Edit Set Step Size By Animation Command. 22. Set the value to Click OK. 24. Press Step repeatedly. Users should see the following: Do not circulate without express consent of SNT, Inc

17 a. A node broadcast, drawing a blue circle b. One by one, from closest to farthest, each node within the blue circle (and perhaps a couple just outside the blue circle) will change its pattern to maximize the gain in the direction of the broadcaster. 25. As an alternative to changing step size, simply use the speed control, which is the horizontal sliding scale to the left of Sim Time. At full speed, not all the antenna pattern changes are displayed. At slow speeds, most are. Figure 15: Nodes adjusting their directional antennas for reception of a signal 26. What s going on: a. Red circles around the nodes represent the current reception pattern. b. In this model, receivers receive omnidirectionally when idle. c. Each node transmits omnidirectionally. d. Blue transmission circles represent the transmission range if both the sender and the receiver are omnidirectional. e. When a receiver hears a signal, it switches its antenna pattern so that the maximum gain is in the direction of the signal. Do not circulate without express consent of SNT, Inc

18 f. Each antenna has eight identical patterns focused in eight directions. (N, NE, E, SE, S, SW, W, NW assuming the antenna is facing north). The maximum gain in the forward direction is 15.5db. 1.4 Batch Execution This feature can be run with any of the pre-built experiments. It is a good idea to follow up a batch execution by launching QualNet Analyzer and viewing the statistics you just produced. 1. If a model is still running in the Animator, keep it loaded up. 2. Choose Experiment Batch Experiment Setup. 3. Choose General Experiment Seed. 4. Enter the following values in each field: Start Value: 1 End Value: 5 Increment Value: 1 5. Press the Calculate No. of Runs button. Figure 16: Batch Experiment Setup tool with start, end and increment values 6. Highlight all five entries that appear in the upper right by holding down the shift key and selecting each number. Do not circulate without express consent of SNT, Inc

19 Figure 17: Selection of seed values for batch experiments Note: As an alternative to changing the seed for wireless experiments, vary the Network Protocols Routing Protocol Routing Policy Dynamic Routing Protocol and choose AODV, DSR, and LAR1. 7. Press Run. 8. When prompted to Specify a Directory for Batch, select No. They should run now. Figure 18: QualNet message window showing the status of batch experiments in execution 9. If there is a second question, answer No to it. By answering no, you are telling QualNet to create stat files in the current directory named Seedt1.stat, Seed2.stat, etc. 10. A completion window will be displayed. Select OK. You can run Analyzer now (QualNet Analyzer). 11. From the Statistics menu, you will be able to identify the stat files based on this naming scheme. Do not circulate without express consent of SNT, Inc

20 1.5 Dynamic Statistics Collection This experiment requires application traffic to produce dynamic statistics. Dynamic statistics tend to use a lot of memory, so you should start QualNet Animator fresh both before and after such an experiment. 1. Stop previous model. Or, if you have nothing loaded, load antenna.xml (from Antenna Animation/Propagation Effects) by selecting File Open. 2. Start again by pressing the Action! button (picture of a clapper). 3. We re going to disable some of the animation to speed things up. Check antenna animation by selecting View Animation Filter By Event Antenna and deselect it if it s already selected. 4. Disable radio broadcasts by making sure the top right button in the Animation Filters Toolbar is darkened (see Section Animation Filters). Disabling radio broadcast animation is not necessary; we re just doing it to speed the experiment up. 5. Press Pause. 6. Choose Statistics Dynamic System Wide Metrics. 7. Choose IP InReceives and type 100 and select milli-second for the units to indicate how often statistics are updated. Figure 19: Dynamic statistics selection for system wide data 8. A popup with a graph should appear. Size the graph and position it so that the dynamic statistics can be seen alongside the QualNet Animator window. 9. Press Play (the forward arrow). The related statistics will be displayed on the graph. 10. If you want to show a graph for just one node: a. Pause the animation b. Right-click the node and select Metrics. c. Choose a metric to display, such as IPInReceives with 100 millisecond update. Do not circulate without express consent of SNT, Inc

21 Note: The graphs shown below may not match the graphs you produce with QualNet. This is because QualNet randomly distributes nodes on the canvas in the experiment antenna.xml. Figure 20: Dynamic statistics graphs for the system as a whole and node Queue Animation These experiments highlight some of QualNet s queuing functionality and the animation that illustrates the behavior of those protocols Creating a Wired Model 1. Start a new experiment by selecting File New. 2. Place four default nodes (the squares) in a Y shape (or a divining rod shape). See Figure 23 to see an example of the Y configuration. a. Click on the Create Nodes button (top right in the Manual Configuration Toolbar). b. Place the nodes in the desired configuration. c. Activate the Link Setup Tool (right below the Create Nodes button). d. Create links between the center node and each other node by clicking on one node and dragging the mouse to the other node. Accept the default point-to-point link settings for the top of the Y. e. The link on the lonely side (the bottom of the Y) should be made very slow. Trim two zeroes off the bandwidth value. Do not circulate without express consent of SNT, Inc

22 Figure 21: Link on the lonely side of the Y being set up for a bottleneck 3. Activate the Application Setup Tool (click the button with 3 CD s). 4. Choose Constant Bit Rate (CBR). (FTP/Generic also works, but it isn t as good at illustrating queuing.) 5. Create an application link from one of the two nodes at the top of the Y to the node at the bottom of the Y. a. Change the Items to Send (number of packets) to b. Change the interval (for CBR) to 10MS (milliseconds). Note: The default unit for a time interval is seconds, not milliseconds. c. Change the Endtime of the CBR load to 2.3 seconds. d. Type of Service should equal 1 (the default). 6. Create an application link from the other of the two nodes at the top of the Y to the node at the bottom of the Y. a. Change the Items to Send (number of packets) to b. Change the interval (for CBR) to 10MS (milliseconds). Note: The default unit for a time interval is seconds, not milliseconds. c. Change the Endtime of the CBR load to 2.3 seconds. d. Change the type of service to 2 (2 indicates non real time). Do not circulate without express consent of SNT, Inc

23 Figure 22: Specifying the second CBR application traffic between remote nodes in the Y configuration Simulating a Wired Model 1. Press Action! (Run QualNet). 2. Right-click on the center node of the Y and choose Node Animation Filter By Event, and select Queue animation. a. It should display three rows of three tall skinny empty rectangles. b. The center node has three interfaces, and for each interface there are three queues. c. If you enabled queue animation for a node besides the center node, you would only see three queues, because the other nodes have only one interface. Do not circulate without express consent of SNT, Inc

24 Figure 23: Adding queue node animation to the center node 3. Press Play. 4. Two of the queues should begin filling up. a. This is because the application traffic generated by the two nodes at the top of the Y is too much for the slow bandwidth link at the bottom of the Y. b. The two applications were configured to use two different types of service (priorities), so they fill up two different queues. 5. Eventually, the two queues should begin to overflow. One queue will have higher priority and should fill up less quickly, and also empty more quickly when the application traffic ends. Do not circulate without express consent of SNT, Inc

25 Figure 24: Queues at a bottleneck filling at different speeds because of different priorities Do not circulate without express consent of SNT, Inc

26 Figure 25: Two queues overflowing at a bottleneck. The queue that fills up first will take the longest to empty Comparing Queue Disciplines 1. Press the Setup QualNet Parameters button. 2. Go to Network Protocols. 3. Change IP Queue Scheduler to Round Robin. 4. Press Save. 5. Press Close. Do not circulate without express consent of SNT, Inc

27 Figure 26: Selecting Round Robin IP Queue Scheduler 6. Run the experiment again by pressing the Action! button (the clapper) to show the different queue discipline. You will need to reselect the Queue Node Animation filter. In the case of Round Robin queuing, you can see that the queues fill up at roughly the same rate. Unlike in Strict Priority queuing, the higher priority queues are served at the same rate as the lower priority queues. Do not circulate without express consent of SNT, Inc

28 Figure 27: Round Robin queuing serves high and low priority queues at roughly the same rate Queuing with FTP/Generic The behavior in Section Comparing Queue Disciplines occurs if you use CBR as the application. If you use FTP/Generic as one of the two applications, that queue never overflows because FTP is a TCP application and TCP figures out the bandwidth of the slow link and slows down the transmissions to fit. Let s see QualNet in action. 1. Click the Resume to Design Mode button (painter s palette) on the top right of the main toolbar. 2. Right-click on one of the two CBR application links. 3. Select Cut. 4. Switch to Add Application Type and select FTP/Generic. 5. Drag an FTP/Generic application between the nodes that used to have a CBR application connection. Accept the default values. Do not circulate without express consent of SNT, Inc

29 Figure 28: Replacing one of the two CBR links with FTP/Generic 6. Click on the Run QualNet (Action!) button, enable queue animation for the center node (see Figure 23), and press Play (the forward arrow). 7. In this case, what you see is that the higher priority queue (whichever one you left as CBR) will stay more full than the lower priority queue. This is because CBR (a UDP application) sends packets as fast as it is scheduled to, regardless of the behavior at the packet destination. FTP (a TCP application) sees a growing queue size at the destination end and slows down packet transmission rates. Do not circulate without express consent of SNT, Inc

30 Figure 29: FTP/Generic traffic has a shorter queue (middle top bar) compared with CBR (right top bar) because TCP adjusts packet rates according to the capacity of the connection. 1.7 Hierarchical Design/BGP This exercise shows you how to design a hierarchical network. There is no simulation in this exercise because the network must exchange routes to stabilize itself for a while before application traffic can be sent across it. For this reason, the setup is all we show you. To watch traffic going through the network, use QualNet Animator and leave the animation running in the background. Some of the protocols, including OSPF and BGP require 30 minutes of simulation time to exchange routes. However, if the hierarchy consists of all Bellman Ford networks, routes should establish themselves much sooner. Also, application connections within a subnet should work right away. With QualNet, when the Animator runs slower than realtime, it may not reflect the fastest speed at which the simulation can run. Executed from the command line, the Simulator produces simulation data usually faster than real-time. In QualNet Do not circulate without express consent of SNT, Inc

31 3.6, you can only start watching a simulation in the QualNet Animator at the beginning of the simulation time Creating a Hierarchical Network 1. Start with a clean slate by selecting File New. 2. Select the Create Hierarchy button (the second to bottom right button) in the Manual Configuration toolbar. 3. Place one Hierarchical Component (HC) by clicking on the canvas. 4. Open the HC by moving the mouse over it and pressing the letter o key. (The letter o is for open. ) The HC should expand to cover most of the screen. Rulers and grid lines are expanded. 5. Once inside the HC, select the Create Wired Subnet button (third from the top on the left in the Manual Configuration toolbar), and place a switch by clicking on the canvas. 6. Select the Create Nodes button (top right button in Manual Configuration toolbar) and place a few default nodes. Figure 30: Selection of a node for a hierarchical network 7. Select the Create Link button (second from top on right). Do not circulate without express consent of SNT, Inc

32 8. Connect each node to the switch by clicking on the node and dragging the mouse to the switch (or vice versa). Figure 31: Connecting computers to a switch in a subnet 9. Press c to close the HC. 10. Right-click on the HC icon and choose Copy. Do not circulate without express consent of SNT, Inc

33 Figure 32: Copying of a Hierarchical Component 11. Then right click on the canvas and choose paste. This should paste a duplicate of the entire original HC. Now you have two HCs. 12. Open one HC with the o key as before. 13. Select the Create Link button again. 14. Click on a node and drag the mouse to create a link. 15. While holding down the mouse, close the HC with the c key. Make sure the cursor is still within the grid of the HC. Next, move the mouse over the other HC, and open it with the o key. 16. Drag the mouse to a node in this other HC and release. Essentially, we have just connected two networks through two gateway routers. Do not circulate without express consent of SNT, Inc

34 Figure 33: Connecting one subnet to another using hierarchical tools 17. If you want, copy another HC inside an existing HC. With QualNet, you can nest HCs inside other HCs Setting up BGP BGP requires that you designate HCs as autonomous systems, and then make a BGP link between the systems. 1. Close the HCs from the previous exercise and return to the top level. 2. Right click on an HC, and enable the Autonomous System checkbox. 3. Right click another HC and enable the Autonomous System checkbox. Do not circulate without express consent of SNT, Inc

35 Figure 34: Assigning Autonomous System status to a subnet 4. Open one of these HCs. 5. Select the BGP Link button (second from bottom left button in the Manual Configuration toolbar). 6. Click on the same node that has a link to the node in the other HC. 7. Repeat the process of making a link between this node and the one in the other HC. Note: If you have trouble opening and closing HCs, make sure your cursor is inside the grid that contains the HC. 8. On the resulting popup menu for BGP settings, designate both nodes as neighbors and enter a large number (e.g. 4000) as weights, and then click OK. Now there is a BGP connection between the two autonomous systems. Do not circulate without express consent of SNT, Inc

36 Figure 35: Assigning parameter values to the BGP speakers in Autonomous Systems To watch traffic flowing between Autonomous Systems, press the Run QualNet (Action!) button, then press Play. 1.8 Mixed (Wired and Wireless) Networks Let s set up a mixed network scenario. In mixed networks, the routing protocol must be the same throughout. That means we choose between OSPF and Bellman Ford from the current QualNet protocol library. Since OSPF takes a longer time to set up, we re going to use Bellman Ford for this exercise. 1. Start with a clean slate by selecting File New. 2. Set the global routing protocol by clicking on the Setup QualNet Parameters button (looks like a computer with software next to it). 3. Select Network Protocols Routing. Scroll down to find the Routing section and select Bellman Ford as the routing protocol. Figure 36: Selection of Bellman Ford as the network-wide routing protocol 4. Press Save and then Close. Do not circulate without express consent of SNT, Inc

37 5. Click on the button labeled Create Wired Subnet. It looks like a blue switch. 6. Click on the canvas. You have created a wired switch. 7. Add five nodes around it by clicking on the Create Nodes button (looks like a computer), selecting the default node icon, and clicking on the canvas. 8. Connect the nodes to the switch by selecting the Create Link button (looks like 2 nodes with an elbow connection between them). Each node should connect directly to the blue switch. 9. Create a wireless subnet by clicking on the Create Wireless Subnet button (looks like a cloud), and then click on the canvas. 10. Right-click on the cloud on the canvas and select Subnet Properties. Select Bellman Ford as the routing protocol. Click OK. Figure 37: Selection of Bellman Ford for the wireless subnet 11. Add five nodes around the wireless subnet (the cloud) by clicking on the Create Nodes button (looks like a computer), selecting the default node icon, and clicking on the canvas. 12. Connect the nodes to the wireless subnet (the cloud) by selecting the Create Link button (looks like 2 nodes with an elbow connection between them). Each node should connect directly to the wireless subnet. 13. Now, we need to link the wireless and wired subnets together. Click the Create Link button. Connect a node from the wireless network to a node of the wired network. 14. A box will pop up and ask you to specify the point-to-point link parameters. Press OK. Do not circulate without express consent of SNT, Inc

38 Figure 38: Point to Point link specifications for the connection between the wireless and wired subnets 15. Add some application traffic by clicking the Add Application Type button (has three CDs on it). 16. Select FTP/Generic or CBR as the application type. Make sure to connect at least one wired node to a wireless node. The purpose of this exercise is to move traffic across a mixed network. Make sure the traffic is going in both directions (i.e., from the wired subnet to the wireless, and also from the wireless subnet to the wired). Do not circulate without express consent of SNT, Inc

39 Figure 39: A mixed network with application traffic in design mode 17. Press Action! (the clapper). 18. If everything has been set up correctly, traffic should be flowing through the network. Green arrows indicate packets being delivered. Blue rings indicate wireless signals being transmitted. Do not circulate without express consent of SNT, Inc

40 Figure 40: A mixed network transmitting packets 19. If you have any trouble, select View Output Files qualnet.config. In this main configuration file, you ll see each part of the network listed by node and the corresponding network parameters. If your network isn t running, there s a good chance that some part of your network is not running Bellman Ford. Look for the ROUTING PROTOCOL tag to verify. Do not circulate without express consent of SNT, Inc

41 Figure 41: qualnet.config file for verification of routing protocols and other network parameters 2 QualNet Analyzer These experiments compare routing disciplines in wired networks. There s a bit of preparation to create the statistics to view with QualNet Analyzer, but they re very nice for illustrating QualNet s ability to graph high fidelity simulations. 1. Select File New. 2. Select File Open and browse to the [QualNet_home]\gui \scenarios directory to find and load the bottleneck-tcp.xml file. a. This is a wired network, running Bellman Ford routing, with the topology shown in cyan. Traffic is flowing from left to right. There are high-speed links connecting the outside nodes to their neighboring center node, and a bottleneck link between the two center nodes (3 and 4). b. The bottleneck link between nodes 3 and 4 has one-tenth the bandwidth, and ten times the propagation delay as the segments on either side. Do not circulate without express consent of SNT, Inc

42 c. FTP/GENERIC traffic is flowing from left to right. Specifically, node 1 is sending TCP packets to node 5 and node 2 is doing the same with node 6. Nodes 1 and 5 start talking at seconds, and continue until the end of the simulation. Nodes 2 and 6 start communicating at seconds, and also continue until the end of the simulation. In all cases, packets go through the bottleneck to their respective destinations. Right-click on any links or application connections or nodes to see the properties. Figure 42: Bottleneck.xml set up showing the application properties between nodes 1 and 5 3. Click Experiment Batch Experiment Setup to configure the experiments: a. Click on the icon to select Network Protocols Network Protocol Network Protocol IP to expand the menu selections in this area. b. Click on the entry Specify Priority wise IP Queue Type? and select No IP Queue Type. The IP queue types should be displayed on the right side of the window (FIFO, RED, etc). Do not circulate without express consent of SNT, Inc

43 c. Select FIFO and RED by holding down the control key and selecting them. Figure 43: Batch setup of a bottleneck traffic situation using FIFO and RED queuing types 4. Click the Run button in the bottom right corner of the Batch Experiment Setup window. 5. Click No to choose the default folder where your results will be stored. 6. Click OK once the batch files have run. 2.1 Statistics from a Single Experiment 1. While still running Animator, choose Statistics Run Analyzer. Note: You can also click the ε button in the bottom right corner of QualNet Animator. 2. Analyzer automatically opens all the stat files in the current directory. It s sometimes hard to tell which files are from the most recent experiment, unless you just did a local batch experiment. Local batch experiment stat files are named Qualnet_IPFIFO.stat, Qualnet_IPRED.stat, for our experiments where we varied IP queue types. 3. If the files you just created don t automatically appear in the left window, you ll want to open the data files you just created. Choose File Open. 4. Find the prepared stat files you just made. 5. Click on an experiment file name in the left window to display the list of metrics. Do not circulate without express consent of SNT, Inc

44 6. Click any metric to pop up a per-node graph, such as FIFO Packets Dequeued. The configuration has three queues at each out interfaces with priority values 0, 1, and 2, with 0 being the highest priority. The X-axis has the node IDs of the 6 nodes. This particular scenario has traffic with priorities 0 and 1 (0 used by the routing protocol control packets, 1 by the application). The 0 priority dequeued packets (in blue) are fewer and can be viewed better if enlarged (select the lower portion of the graph with a marquee). The 0,1 values on the side of the graph represents these packet priorities. Figure 44: QualNet Analyzer showing a single data set displayed in bar chart format 7. Select Option Chart Type and choose 2D Histogram. 8. Click any metric, such as the MAC tab Link Destination, to pop up a histogram. Here, the "0, 1, 2" legend represents interface index at a node. Do not circulate without express consent of SNT, Inc

45 Figure 45: Histogram of MAC layer Link Destination by node ID 9. Set the chart type back to 2D bar chart by selecting Option Chart Type 2D Bar Chart. 2.2 Statistics from Multiple Experiments 1. Click on Option Graph Visibility and select Multiple Graph. 2. Highlight more than one statistic file (e.g., IPFIFO.stat and IPRED.stat ) by holding down the shift key while selecting the file names. 3. Select the Application tab, then Gen/FTP Server Throughput (bits/s) and note the slight throughput penalty with RED as opposed to FIFO. Do not circulate without express consent of SNT, Inc

46 Figure 46: QualNet Analyzer showing Server Throughput in bits/second for FIFO (left) and RED (right) 4. Select the Network tab, then select RED Average Queue Length (bytes). Next, select Average Time in Queue. Do not circulate without express consent of SNT, Inc

47 Figure 47: RED Average Time in Queue (seconds) and Average Queue Length (bytes) 5. Select FIFO Average Queue Length (bytes). Next, select Average Time in Queue. Do not circulate without express consent of SNT, Inc

48 Figure 48: FIFO Average Time in Queue (seconds) and Average Queue Length (bytes) Notice that the RED statistics graphs in Figure 47 show that average queue delays (~1 milliseconds) and queue sizes (~400 bytes) are dramatically lower than their FIFO counterparts in Figure 48 (~5.5 milliseconds and ~800 bytes), even though their throughputs remain almost similar, as shown in Figure 46. Do not circulate without express consent of SNT, Inc

49 2.3 Statistics by IP Address 1. Load a new experiment in QualNet Analyzer by selecting queuedrop3.stat in the [QualNet_home]/gui/sample directory. 2. In the Option menu, select Compare by IP Address. All metrics but FIFO should disappear. 3. Click on one of the remaining metrics (Packets Queued works). The graph will compare statistics by IP address rather than node ID. This allows for comparison of each interface of a wired node with more than one connection. Figure 49: Statistics by IP address 3 QualNet Designer It takes about an hour to actually build a working protocol. In this section, we will walk you through the compile and add steps to incorporate new code into QualNet. IMPORTANT NOTE: If you go beyond this exercise and add other code on your own and actually go so far as to add to qualnet and compile, you should at least remove from qualnet before doing anything else, and possibly go so far as to reinstall QualNet. This precaution will allow you to continue through the Product Tour without experiencing trouble with bad code. Included with QualNet are a few sample protocol models that end in the extension.xml (Aloha.xml, vbrudp.xml). QualNet 3.1 Designer supported the Do not circulate without express consent of SNT, Inc

50 .QPD file format. The current 3.6 Designer supports an import feature that converts from.qpd models to the current.xml format. The Variable Bit Rate (VBR) protocol is included as an example of an application layer protocol model and is the model we will build from scratch in this tutorial. The ALOHA (simple) model at the MAC layer is also included as a sample Designer model. All the Designer sample models can be found in the [QualNet_home]/gui/models directory. This exercise will walk you through the creation of an application layer protocol called VBR (Variable Bit Rate). We will start by setting up the protocol states and initialization elements using the graphical user interface, then we ll continue on to cut and paste source code into each of the states, and then we ll finish with the compilation of the appended simulator. 1. Start QualNet Designer by clicking on the D button at the bottom right corner of QualNet Animator. Note: Alternatively, you can run Designer from the [QualNet_home]/gui/bin directory by typing RunDesigner.bat, so long as you ve set the path correctly. Figure 50: Start up QualNet Designer 2. In the QualNet Protocol Designer window (which can be opened by selecting File New), select the New tab. 3. For the Protocol Name field, type VBR. 4. For the Layer, select the Application checkbox. 5. Click OK. 6. In the Application Type Selection window, select UDP from the pull-down menu. Note: The current VBR model is written using UDP (version 3.1 was written with TCP). Do not circulate without express consent of SNT, Inc

51 Figure 51: Create a new protocol in QualNet Designer Do not circulate without express consent of SNT, Inc

52 Figure 52: QualNet Designer 3.1 Setting up the protocol with the Graphical User Interface Designer Toolbar The QualNet Designer Toolbar buttons are pictured and described from top to bottom below. Figure 53: QualNet Designer Toolbar Do not circulate without express consent of SNT, Inc

53 Move State/Transition Moves the state to a new position or shifts a transition to distinguish. Add a New State Creates a new state in the model. Click on this button and then click on the canvas to create and name a state. Add a New Transition Creates a transition between two states. Click the button, and then click on a source state and drag the mouse to a destination state. A pop up window will then ask for properties for the newly created transition. Add Configuration Parameters Configuration parameters are the variables associated with a protocol that must be written to the qualnet.config file used as input to the Simulator. Add Data Definitions Allows the user to define data structures that can be used to declare state variables and local variables in the protocol code. For example, #define, #include, typedef, data structure, and enumeration definition and statements are automatically generated at the top of the header file of the protocol. Add Variable Declarations Writes code to declare variables, along with some automatically generated variables. Add Utility Functions These functions are defined in the protocol code file, and can be used within the state s entry code. Add Statistics Variables Allows users to declare statistics variables for the protocol. These statistics can be accessed and modified from the state entry and utility function code. Add User Defined Event When designing a custom protocol, not all events come included with QualNet. This tool exists to allow the model to invent new events for the protocol. Set Application Parameters Similar to configuration parameters, these are the variables that appear in the application description file used as input to the Simulator. Parameters defined here pass values to application protocols in the qualnet.app file. Project Explorer Toolbar The right pane of Designer has a Project Explorer view, which lists the states. The Code View and the Design View buttons allow the user to switch between the code and design view. Note: To view the code view, the user must first select a state before using the Code View button. Figure 54: Project Explorer Toolbar Do not circulate without express consent of SNT, Inc

54 3.1.2 VBR Overview The functionality of the VBR protocol is simple. Traffic, in the form of items with a specified size in bytes, is sent at a frequency that varies depending on an exponential distribution from the client to server node. The mean interval determines the variation. The amount of traffic received is counted by the server and reported as a statistic. It turns out that VBR code does not require data definitions such as structure definitions, enumerations, #defines, or #includes due to it s simplicity. In contrast, code for more complex protocols call other C libraries and depend on various functionality outside of the protocol itself. Most of the work to build the VBR protocol lies in the design of the state diagram and the writing of the functionality that links states to one another. Specifically, we will write the functionality that defines how the protocol enters a particular state (state entry code). State entry code is the action that the protocol performs upon entering a state; state exit code is an action performed upon leaving a state. There is currently no support for state exit code in the Designer Application Parameters Application layer protocols in QualNet take in application parameters for initialization from the qualnet.app file and pass the values to the protocol function. VBR is a simple traffic generation protocol with the following parameters: Name Type Default Description Source ID NodeID Traffic source (client) node ID for VBR connection Destination ID NodeID Traffic destination (server) node ID for VBR connection Item Size int The size of each data unit to be sent in bytes. Mean Interval clocktype 1 Seconds Start Time clocktype 1 Seconds End Time clocktype 1 Seconds Table 1: Initialization parameters for the VBR protocol Mean Interval used to determine delay between data transmissions. Simulation time of when to start traffic. Simulation time of when to stop traffic. Do not circulate without express consent of SNT, Inc

55 1. To set the application parameters, click the bottom icon in the Designer toolbar. A pop up window will request the parameters above. 2. In the Name field, type Item Size. 3. In the Type pull down menu, select int. 4. Leave the default and help fields empty, and click Add. 5. Add another parameter. In the Name field, type Mean Interval. 6. In the Type menu, select clocktype. 7. In the Default field, type 1 and select Seconds from the drop down menu. 8. Leave the help field empty, and then click Add. Figure 55: Adding a default parameter value 9. Finish adding the rest of the parameters until you have all six VBR application parameters in the list, and then press Confirm All Changes. Do not circulate without express consent of SNT, Inc

56 Figure 56: All VBR parameters 10. To update the application parameters, select one of the names that show up in the list and update the required field. 11. Click Update and then Confirm All Changes. Do not circulate without express consent of SNT, Inc

57 3.1.4 Building a Skeleton Diagram Protocols are created in Designer using a finite state diagram. Users create and place states into the diagram and connect the states with transitions. States and transitions are represented as per the Unified Modeling Language (UML) state diagram notation, with some modifications to the terminology for simulation purposes. 1. Let s create an idle state by clicking the State Tool, and then clicking on the canvas. 2. Give it the name Client Idle. To move the position of this state select Move State/Transition button and move the state to the desired location. Figure 57: Creation of a new state called Client Idle Most protocols are designed so that the initial state automatically transitions to an idle state. The idle state has many event-driven triggers that branch out to all the event states in the protocol. VBR has two idle states: Client Idle and Server Idle, for when the node is sending and receiving traffic, respectively. The reason why there are two idle states is that client and server nodes behave differently in VBR. 3. Create a second main state called Server Idle by repeating step 1. The VBR protocol code must first include the functionality that checks if a node is a client node or a server node. To do this, we employ a guard, or Boolean statement, that checks what type of node it is before transitioning to idle state. 4. To specify the guard code, create a transition by clicking on the second button from the top with an arrow on it. 5. Click on the Initial State in the top left corner and drag the line onto the Client Idle state. 6. A pop up window will ask you for the guard code. Carefully type in the following C code into the text box and click OK: ip->interfaceinfo[default_interface]->ipaddress == clientaddr Do not circulate without express consent of SNT, Inc

58 Figure 58: Transition from Initial State to Client Idle state 7. Repeat steps 3 and 4 for the transition between for the Server Idle state. 8. A pop up window will ask you for the guard code. Carefully type the following code into the text box and click ok: ip->interfaceinfo[default_interface]->ipaddress == serveraddr Figure 59: Two VBR idle states with transitions There is only one state that stems from the Client Idle state in VBR. For this state that branches from the Client Idle sate, a trigger, rather than a guard is employed. The difference between a trigger and guard is that triggers invoke a Do not circulate without express consent of SNT, Inc

59 state transition based on an event delivered to the protocol, whereas Boolean guards invoke a state transition based on the result of user-coded logic. The Client state has the following properties: State Name QualNet Event Trigger What this does ClientTimerExpires MSG_APP_TimerExpired This is an event that the application sends to itself. This timer exists to notify the application to send more data when appropriate. Table 2: State names and trigger source code for client events stemming from the Client Idle state Similarly, there is one state that stems from the Server Idle state: State Name QualNet Event Trigger What this does ServerReceives MSG_APP_FromTransport This is an event from the transport layer that notifies the application protocol that there is data ready to be received. Table 3: State names and trigger source code for server events stemming from the Server Idle state Let s insert the states that stem from the Client Idle and Server Idle states. 9. Click the Add a New State button right below the 100% field. 10. Click on the canvas to make a new state in the upper right hand corner. 11. Name it ClientTimerExpires. Press OK. 12. Repeat steps 9-11 for the ServerReceives state. Do not circulate without express consent of SNT, Inc