Changes between Version 2 and Version 3 of Internal/PlanetlabOrbit
- Timestamp:
- Jun 4, 2006, 11:04:34 PM (18 years ago)
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Internal/PlanetlabOrbit
v2 v3 11 11 The objective of this demo is to show the federation of the two heterogeneous testbeds: Planetlab and ORBIT. This demonstration illustrates a typical wireless hotspot scenario with one node in the ORBIT testbed fetching video media off a remote Planetlab node and serving it to a fixed and mobile client. 12 12 13 The demo has been choreographed to use nodes 17-2 and 17-7, where 17-2 is the ''hotspot AP'' that fetches the media content off a remote Planetlab node 14 ''pli2.pa-1.hpl.hp.com'' and serves it to node17-7 as well as the robot based mobile node. 13 The demo has been choreographed to use nodes 17-2 and 17-7, where 17-2 is the ''hotspot AP'' that fetches the media content off a remote Planetlab node ''pli2.pa-1.hpl.hp.com'' and serves it to node17-7 as well as the robot based mobile node. 15 14 16 15 Bitrate (in kbps) is measured by the receiving node and reported to the ORBIT infrastructure using the OML library. 17 16 18 17 A representative picture of the scenario is shown below 18 19 19 [[Image(planetlab-orbit.png)]] 20 20 21 {{{22 Timeline SOURCES DESTINATION23 1.5Mbps UDP CBR on Wireless24 Time 0 Group 1: [1,2],[1,4],[1,8] -------------------------------> [5,4]25 Time 10 Group 2: [2,1],[2,3],[2,5] -------------------------------> [5,4]26 ...27 21 28 Time 60 Group 7: [8,1],[8,5],[8,7] -------------------------------> [5,4]29 30 Time 110 Stop Group 1 senders.31 Time 115 Stop Group 2 senders.32 ...33 Time 140 Stop Group 7 senders.34 }}}35 22 36 23 === Steps to Execute Demo === 37 24 38 1. '''Image name''' -- __ conf-room-demo.ndz__. Resides on repository2:/export/orbit/image.39 a. Log onto console. sb9.orbit-lab.org using ssh (see HowToGetStarted).40 b. Turn off all nodes using the following command:25 1. '''Image name''' -- __planetlab-biggrid.ndz__. Resides on repository2:/export/orbit/image. 26 a. Log onto console.grid.orbit-lab.org using ssh (see HowToGetStarted) 27 b. Execute the following command on console.grid. 41 28 {{{ 42 wget -O - 'http://cmc:5012/allOff' 43 }}} 44 c. Execute the following command on console.sb9. 45 {{{ 46 imageNodes atheros conf-room-demo.ndz 29 imageNodes [17,2],[17,7] planetlab-biggrid.ndz 47 30 }}} 48 31 49 2. '''nodeHandler scripts''' -- execute following command on console.sb9 32 2. Download the tarball nodehandler-planetlabdemo.tar.gz from the lnk provided at the bottom of this page 33 34 3. After extracting the tarball in your home directory, 50 35 {{{ 51 nodehandler -k test:exp:conf-room-demo 36 cd nodehandler/src/ruby 37 ruby handler/nodeHandler.rb -k test:exp:planetlab 52 38 }}} 53 39 54 40 3. '''Display machine''' 55 On the display machine, point your Internet Explorer or Mozilla Firefox browser to http://sb9.orbit-lab.org. What you expect to see is a page with three frames - one showing the topology of the smaller grid, one showing a control interface to change the packet size and offered load and the third with a link to plot the cumulative throughput at the access point (AP). 41 On the display machine, point your Internet Explorer or Mozilla Firefox browser to http://internal3.orbit-lab.org/planetlab.html. 42 This page should automatically populate the database name based on the current experiment id, and after selecting bitrate and wireless client, and clicking on Submit, you should be able to see the estimated measure of the bitrate at which the video stream is being played in kbps. Whenever the media content is relatively static, the bitrate is low, when there is more action, the bitrate is higher. 56 43 57 The frame showing the topology should initially display 64 yellow boxes representing the nodes on the grid. Once the nodes in the experiment turn ON, the corresponding yellow boxes will turn green. Once the sending and receiving applications start, the senders will turn blue and the receiver will turn red.58 44 59 Click the link for the cumulative throughput in the third frame -- the expected behavior for the curve is that initially, the throughput will rise as senders are added but beyond a certain number of senders, throughput will fall drastically. The explanation for this drop is that 45 === Prerequisites === 60 46 61 a. the current implementation of CSMA/CA fails to prevent losses from occurring in a congested environment 62 63 b. the 802.11 bit-rate adaptation algorithm, which believes CSMA/CA to be perfect, infers these losses to be due to poor channel (SNR) conditions and drops the bit-rate accordingly. This in turn makes the situation worse given that the same frame will now take a much longer time on the medium -- all senders will drop their rate to 6Mbps and the cumulative throughput will reflect this (it should be equal to the saturation throughput at 6Mbps). 64 65 === Troubleshooting === 66 67 1. The graphics displaying the topology uses [http://www.w3.org/TR/SVG/ SVG] - this is built into the latest Mozilla firefox but you will need an SVG viewer extension for Internet Explorer. This extension can be downloaded from http://www.adobe.com/svg/viewer/install/main.html. 47 1. You need to have established ssh keys with the Planetlab server that is hosting the media stream (in our case, pli2.pa-1.hpl.hp.com) 48 In order to do so, run the following from console.grid 49 {{{ 50 ssh-keygen -t rsa 51 }}} 52 This will prompt you for a passphrase and you can choose to save this key-pair to file called planetlab-rsa 53 Next 54 {{{ 55 ssh-copy-id -i ~/.ssh/planetlab-rsa.pub orbit_pkamat@pli2.pa-1.hpl.hp.com 56 }}} 57 This will transfer the keys to the Planetlib slice on the host pli2.pa-1.hpl.hp.com. You may choose to have this key copied on multiple PLanetlab nodes that belong to your slice (e.g pli2.pa-2.hpl.hp.com, pli2.pa-3.hpl.hp.com, alice.cs.princeton.edu) 58 All these nodes currently have the media stream to be served for this demo. 59 68 60 69 61 [[BR]][[BR]]
