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Execute

Timestamp:: 05/23/13 09:31:48 (12 years ago)
Author:: shuang@bbn.com
Comment:: --

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GENIEducation/SampleAssignments/OpenFlowAssignment/ExerciseLayout/Execute

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   Note that the timeout-based nature of flow removal dictates that small connection limits will be quite limiting. Keep this in mind when testing your firewall!
+  '''Question: extend the firewall.rb to take the new firewall configuration file and accept the additional parameter'''
   '''Hints: Want to get the complete firewall.rb? ask your instructor or visit here (you need a password to get it), or send an email (the solution code may be full of bugs, feel free to tweak it and report bugs/ask questions)''' [[BR]]
   You probably want to change the `rule` structure defined in function `add_rule` to add two members: `limit` and `count` to store the maximum number of active flows allowed and the current number of active flows. [[BR]]
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  - '''3.3 Load Balancing''' [[BR]]
+ - '''3.3 Load Balancing''' -- Files to download: [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/lb.rspec lb.rspec], [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer.rb load-balancer.rb], [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/netinfo.py netinfo.py] [[BR]]
  Load balancing in computer networking is the division of network traffic between two or more network devices or paths, typically for the purpose of achieving higher total throughput than either one path, ensuring a specific maximum latency or minimum bandwidth to some or all flows, or similar purposes. For this exercise, you will design a load-balancing OpenFlow controller capable of collecting external data and using it to divide traffic between dissimilar network paths so as to achieve full bandwidth utilization with minimal queuing delays. [[BR]]
  An interesting property of removing the controller from an OpenFlow device and placing it in an external system of arbitrary computing power and storage capability is that decision-making for network flows based on external state becomes reasonable. Traditional routing and switching devices make flow decisions based largely on local data (or perhaps data from adjacent network devices), but an OpenFlow controller can collect data from servers, network devices, or any other convenient source, and use this data to direct incoming flows. [[BR]]
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   '''Balancing the Load''' [[BR]]
   An example openflow controller that arbitrarily assigns incoming TCP connections to alternating paths can be found at [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer.rb load-balancer.rb]. [[BR]]
+  An example openflow controller that arbitrarily assigns incoming TCP connections to alternating paths can be found at [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer.rb load-balancer.rb] (If you have already downloaded it, ignore this). [[BR]]
   The goal of your OpenFlow controller will be to achieve full bandwidth utilization with minimal queuing delays of the two links between the OpenFlow switch and the Aggregator host. In order to accomplish this, your OpenFlow switch will intelligently divide TCP flows between the two paths. The intelligence for this decision will come from bandwidth and queuing status reports from the two traffic shaping nodes representing the alternate paths. [[BR]]
   When the network is lightly loaded, flows may be directed toward either path, as neither path exhibits queuing delays and both paths are largely unloaded. As network load increases, however, your controller should direct flows toward the least loaded fork in the path, as defined by occupied bandwidth for links that are not yet near capacity and queue depth for links that are near capacity. [[BR]]
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   '''Questions'''[[BR]]
   To help user to fetch the information about the amount of traffic as well as the queue depth (measured in number of packets) on both left and right node, we provide a script that the user can download and run on both left and right node [[BR]]
   You can download the script from [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/netinfo.py netinfo.py]. Then do the following to start monitoring network usage: [[BR]]
+  You can download the script from [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/netinfo.py netinfo.py] (If you have already downloaded it, ignore this). Then do the following to start monitoring network usage: [[BR]]
+ -
   - 1. install Twisted Web package for Python on both left and right node:
 …
 python netinfo.py
 }}}
   - 5. verify it is working by opening a web browser and typing the following URL (replacing 155.98.36.69 with your left or right node's public IP address):
+  - 5. verify it is working by opening a web browser and typing the following URL ('''replacing 155.98.36.69 with your left or right node's public IP address'''):
 {{{
 http://155.98.36.69:8000/qinfo/0
 …
+  '''If you really do not know where to start, you can find a semi-complete load-balancer.rb [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer-hint.rb HERE], you only need to complete the ''next_path'' function that prints out the statistics of each path and returns the path choice''' [[BR]]
   '''Hints: Want to get the complete load-balancer.rb? ask your instructor or visit here (you need a password to get it), or send an email (the solution code may be full of bugs, feel free to tweak it and report bugs/ask questions)''' [[BR]]
+  -