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Version 4 (modified by Nilanjan Paul, 9 years ago) ( diff )

17. Wimax Measurement Experiment: multiple traffic generators and single receiver

Description

The experiment runs multiple traffic generators on up to 7 (client) wimax nodes and single traffic receiver. The number of clients can be varied to study the wimax interface's ability to handle traffic at different loads. The traffic generated is UDP, the number of packets and the bit rate can be varied as well.

Hardware utilized

  1. Sandbox 4 node1-1 - node1-7: runs otg2 as generator.
  2. Sandbox 4 node1-8: runs otr2 as receiver.
  3. RF-attenuator matrix: this used prior to running the experiment to attenuate the air interface between the wimax base station and nodes.

Software / scripts worth mentioning

  1. baseline-iperf.ndz: disk image that's loaded onto the nodes. This image is loaded with otg2 / otr2.
  2. oml2-server: server running on sandbox 4 which collects measurement data from oml2-iperf and stores in a database file.
  3. sqlite3: command line interface for accessing the contents in a database file.
  4. mclient.rb: the experiment script. Click here to view file.
    1. The script takes the following parameters as arguments:
      1. nClient - number of client nodes to use, nClients = [1..7]
      2. packetsize - packet size (byte) from the sender node, packetsize max = 1024
      3. bitrate - bitrate (bit/s) from the sender node
    2. Example usage:
      1. omf-5.2 exec mclient.rb — —nClients 8 —packetsize 512 —bitrate 16000

Set up

Getting started, ssh into the console of sandbox 4.

  • Verify the oml2-server is running:
    • $ ps -elf | grep oml2-server
      nilanjan@console.sb4:~/exp/dl-iperf/5.2$ ps -elf | grep oml2-server
      4 S oml2       948     1  0  80   0 -  2471 poll_s Feb02 ?        00:00:16 /usr/bin/oml2-server -l 3003 --logfile=/var/log/oml2-server.log --user=oml2 --group=oml2
      0 S nilanjan  1259 27360  0  80   0 -  1002 pipe_w 10:59 pts/1    00:00:00 grep oml2-server
      

Before the experiment, the BS parameters can be changed. The following are a few examples commands to control the MCS:

For other details on changing BS parameters please refer to Basic Support Services under http://wimax.orbit-lab.org/wiki

Although the experiment script can vary the attenuator values, the details on manually changing attenuator values can be found in RF Matrix Control Services under http://wimax.orbit-lab.org/wiki

Usage

  • Start clean, turn off all the nodes:
    • $ omf-5.2 tell offh all
      nilanjan@console.sb4:~/exp/dl-iperf/5.2$ omf-5.2 tell offh all
      
       INFO NodeHandler: init OMF Experiment Controller 5.2.408
       INFO Topology: Loading topology 'system:topo:all'.
      ---------------------------------------------------
       Testbed : sb4.orbit-lab.org - Command: offHard
       Node n_1_2 - Ok
       Node n_1_7 - Ok
       Node n_1_1 - Ok
       Node n_1_6 - Ok
       Node n_1_5 - Ok
       Node n_1_9 - Ok
       Node n_1_4 - Ok
       Node n_1_8 - Ok
       Node n_1_3 - Ok
      ---------------------------------------------------
      
  • Query the status of the nodes. Wait until all nodes are in POWEROFF state.
    • $ omf-5.2 stat.
      nilanjan@console.sb4:~/exp/dl-iperf/5.2$ omf-5.2 stat
       INFO NodeHandler: init OMF Experiment Controller 5.2.408
      -----------------------------------------------
       INFO Topology: Loading topology 'system:topo:all'.
       Testbed : sb4.orbit-lab.org
       Node n_1_1 - State: POWEROFF
       Node n_1_2 - State: POWEROFF
       Node n_1_3 - State: POWEROFF
       Node n_1_4 - State: POWEROFF
       Node n_1_5 - State: POWEROFF
       Node n_1_6 - State: POWEROFF
       Node n_1_7 - State: POWEROFF
       Node n_1_8 - State: POWEROFF
       Node n_1_9 - State: POWEROFF
      -----------------------------------------------
      
  • Load image onto node1-1 through node1-8:
    • $ omf-5.2 load [1,1..8] baseline-iperf.ndz
      LOAD IMAGE HERE
      
  • After loading the image, the nodes are turned off. Turn these nodes back on:
    • $ omf-5.2 tell on [1,1..8]
      nilanjan@console.sb4:~/exp/dl-iperf/5.2$ omf-5.2 tell on [1,1..8]
      
       INFO NodeHandler: init OMF Experiment Controller 5.2.408
      ---------------------------------------------------
       Testbed : sb4.orbit-lab.org - Command: on
       Node n_1_1 - Ok
       Node n_1_2 - Ok
       Node n_1_3 - Ok
       Node n_1_4 - Ok
       Node n_1_5 - Ok
       Node n_1_6 - Ok
       Node n_1_7 - Ok
       Node n_1_8 - Ok
      ---------------------------------------------------
      
  • Query the status of the nodes until they are in POWERON state: > omf-5.2 stat
  • Now run the experiment script:
    • $ omf-5.2 exec mclient.rb — —nClients 4 —packetsize 512 —bitrate 1024000
      RUN EXPERIMENT HERE
      

A few words on post processing

This experiment generates a sqlite3 database file named with the experiment id and this file is automatically copied to the current directory. The .sql file will have several tables: _experiment_metadata, _senders, otg2_udp_out, otr2_udp_in.
In particular, otr2_udp_in table contain information about the received packets from the various senders.

The following will display the tables in the file:

  • $ sqlite3 udp_n4_p512_br1024000.sq3 ".tables"
    TABLES
    

The following will display the contents of the udp_otr2_in table:

  • $ sqlite3 -header udp_n4_p512_br1024000.sq3 "select * from otr2_udp_in"
    TABLES
    

For a rough calculation on bandwidth… each line in otr2_udp_in display data pertinent to a client node (identified by the IP address in column 17) with the correspond time stamps (column 4), packet received (column 14).

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