Changes between Version 24 and Version 25 of GEC21Agenda/ChoiceNet/run_tests

10/21/14 00:24:35 (5 years ago)
Hussamuddin Nasir



  • GEC21Agenda/ChoiceNet/run_tests

    v24 v25  
    6060The initial config.txt file that we provided to you encodes a desire to use low bandwidth paths at a low price point.  As a result, the iperf test you ran above ended up purchasing the low bandwidth path through the LB router in your slice.  You should have seen a throughput of less that 1 Mbps as that is the maximum bandwidth achievable over the LB path.
    62  [[Image(lb_server.png,50%)]]
    6362 [[Image(lb_client.png,50%)]]
    6464 [[Image(LB.png,50%)]]
    7070Asking for high bandwidth paths results in the PS returning a high bandwidth path passing through the router HB.  As a result, the output from iperf should now jump to be roughly 7-8Mbps.
     72 [[Image(hb_client.png,50%)]]
     74 [[Image(high.png,50%)]]
    7276= Choosing a Medium Bandwidth Path =
    7478Now repeat the test, but change the line '''hb 10 USD''' to '''hlhb 5 USD''' in the config.txt file on H2.  This will cause the path service (PS) to return a path across the high bandwidth but also high latency path.  While this path will have worse performance than the HB path, it is more cost effective.
     80 [[Image(hlhb_client.png,50%)]]
     82 [[Image(medium.png,50%)]]
    7684= Choosing a High Bandwidth Path at a Low Bandwidth Price =
    7886As a last test, change the line '''hlhb 5 USD''' to '''hb 1 USD'''.  In this case the wrapper will request a high bandwidth path, but will only pay a maximum of 1 USD for such paths.  Because the path service does not have any high bandwidth paths to sell at this cheaper price tag (1 USD), the PS will return and error and the wrapper will abort the application.  Try this yourself by changing the line to ''hb 1 USD'' and then rerunning the iperf tests.  You should see the wrapper library aborting the program because high bandwidth paths cost more than the amount allotted by the user.
     88 [[Image(hb_wrong_payment.png,50%)]]
    8390To chose (and pay for) a higher bandwidth path (and higher cost), you will need to edit the config.txt file and replace the current policy that prefers low bandwidth paths.  In particular, you will need to change the line '''lb 1 USD''' to '''hb 10 USD'''.  This tells the wrapper library that you prefer high bandwidth paths for the iperf program and that you are willing to pay 10 USD for the paths you receive.  Having changed the policies in config.txt, all you need to do is to return iperf as you did above.