200 lines
5.8 KiB
HTML
Executable File
200 lines
5.8 KiB
HTML
Executable File
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<!-- IP.html (C) K. J. Turner 18/12/14 -->
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<title>
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Internet Protocol
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</title>
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<link rev="made" href="http://www.cs.stir.ac.uk/~kjt/"/>
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<script type="text/javascript" language="JavaScript">
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<!--
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var simulator;
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var userMessageSize;
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var maxProtocolMessageSize;
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var maxMediumMessageSize;
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var lossRate;
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function validInteger(name, value, min, max) {
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if (!value.match("\\d+") || value < min || value > max) {
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alert("Value for " + name + " must be in range " + min + " to " + max);
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return false;
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}
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else
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return true;
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}
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function validFloat(name, value, min, max) {
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if (!value.match("\\d+\.\\d+") || value < min || value > max) {
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alert("Value for " + name + " must be in range " + min + " to " + max);
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return false;
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}
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else
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return true;
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}
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function set() {
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userMessageSize = document.settings.userMessageSize.value;
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maxProtocolMessageSize = document.settings.maxProtocolMessageSize.value;
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maxMediumMessageSize = document.settings.maxMediumMessageSize.value;
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lossRate = document.settings.lossRate.value;
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if (validInteger("User Message Size", userMessageSize, 10, 1000) &&
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validInteger(
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"Maximum Protocol Message Size", maxProtocolMessageSize, 10, 1000) &&
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validInteger(
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"Maximum Medium Message Size", maxMediumMessageSize, 10, 1000) &&
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validFloat("Loss Rate", lossRate, 0.0, 1.0)) {
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simulator.setParameter("userMessageSize", userMessageSize);
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simulator.setParameter("maxProtocolMessageSize", maxProtocolMessageSize);
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simulator.setParameter("maxMediumMessageSize", maxMediumMessageSize);
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simulator.setParameter("lossRate", lossRate);
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if (document.settings.Misordering.checked)
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simulator.setParameter("misordering","true");
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else
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simulator.setParameter("misordering","false");
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simulator.updateActionList();
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}
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}
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//-->
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</script>
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</head>
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<body background="simulator.jpeg"
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onload="simulator=document.ProtocolSimulator; set();">
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<div style="text-align: center">
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<h1>Internet Protocol Simulator</h1>
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<img src="simulator.gif" alt="Simulator Logo"/>
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</div>
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<p>
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IP (Internet Protocol) a simple connection-less protocol for transferring
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datagrams in either direction between a pair of hosts.
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</p>
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<p>
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The protocol simulation shows a time-sequence diagram with users A and B,
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protocol entities A and B that support them, and a communications medium
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that carries messages. Users request data transmissions with
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<em>DatReq(DATA<strong>n</strong>),</em> and receive data transmissions
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as <em>DatInd(DATA<strong>n</strong>)</em>. Protocol messages are sent as
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<em>DT(MID,Offset,Length)</em> that gives the message identifier
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<em>n</em>, its byte offset relative to the whole user message, and the
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length of the message (fragment). The user message size may exceed the
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maximum protocol message size, which leads to fragmentation. The maximum
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protocol message size may also exceed that for the medium, in which case
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there may be further fragmentation. Each fragment is followed by `+'
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to mean that it is not the last; the very last fragment is followed by
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`-'. (This is equivalent to the <em>More Fragments</em> flag in the
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protocol.)
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</p>
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<p>
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You may choose if the receiving protocol entity should time out a partly
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received message. Since the simulation does not run in real-time, a
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message's Time-To-Live (TTL) may expire as soon as it has been
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received in part. There is no control over fragmentation in the
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simulation; this is handled automatically based on the protocol
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parameters. Messages may also be randomly lost or misordered, based on
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the parameter settings.
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</p>
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<h2>Protocol Parameters</h2>
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<p>
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The following settings are adequate for a simple simulation. For a more
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advanced exploration, choose different options and click <em>Change
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Settings</em>.
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</p>
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<form name="settings">
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<center>
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<table cellpadding="5">
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<tr>
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<td align="right">User Message Size (10 to 1000):</td>
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<td>
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<input type="text" name="userMessageSize" value="400" size="4"/>
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</td>
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</tr>
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<tr>
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<td align="right">Maximum Protocol Message Size (10 to 1000):</td>
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<td>
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<input type="text" name="maxProtocolMessageSize" value="200"
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size="4"/>
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</td>
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</tr>
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<tr>
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<td align="right">Maximum Medium Message Size (10 to 1000):</td>
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<td>
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<input type="text" name="maxMediumMessageSize" value="100"
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size="4"/>
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</td>
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</tr>
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<tr>
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<td align="right">Loss Rate (0.0 = lose none, 1.0 = lose all):</td>
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<td><input type="text" name="lossRate" value="0.2" size="4"/> </td>
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</tr>
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<tr>
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<td align="right">Medium Message Misordering</td>
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<td align="left">
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<input type="checkbox" name="Misordering" checked="checked"/>
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</td>
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</tr>
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<tr>
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<td align="center" colspan="2">
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<input type="button" name="btnSet" value="Change Settings"
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onclick="set()"/>
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</td>
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</tr>
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</table>
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</center>
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</form>
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<h2>Protocol Simulation</h2>
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<center>
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<applet code="simulator.ProtocolSimulator.class"
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archive="ProtocolSimulator.jar" width="750" height="700"
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name="ProtocolSimulator">
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<param name="protocol" value="IP"/>
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</applet>
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</center>
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<hr/>
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<p>
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<a href="index.html"><img src="uparrow.gif" alt="Up Arrow"/></a>
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Up one level to <a href="index.html">Protocol Simulators</a>
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</p>
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</body>
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</html>
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