manual update
This commit is contained in:
Craig Dowell
@@ -16,6 +16,7 @@ this is the tracing subsystem.
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* Tracing Motivation::
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* Overview::
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* Using the Tracing API::
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* Using the Tracing Helpers::
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* Tracing implementation details::
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@end menu
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@@ -339,5 +340,835 @@ core of the simulator;
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sinks.
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@end itemize
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@node Using the Tracing Helpers
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@section Using the Tracing Helpers
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The @code{ns-3} trace helpers provide a rich environment for configuring and
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selecting different trace events and writing them to files. In previous
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sections, primarily ``Building Topologies,'' we have seen several varieties
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of the trace helper methods designed for use inside other (device) helpers.
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Perhaps you will recall seeing some of these variations:
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@verbatim
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pointToPoint.EnablePcapAll ("second");
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pointToPoint.EnablePcap ("second", p2pNodes.Get (0)->GetId (), 0);
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csma.EnablePcap ("third", csmaDevices.Get (0), true);
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pointToPoint.EnableAsciiAll (ascii.CreateFileStream ("myfirst.tr"));
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@end verbatim
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What may not be obvious, though, is that there is a consistent model for all of
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the trace-related methods found in the system. We will now take a little time
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and take a look at the ``big picture''.
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There are currently two primary use cases of the tracing helpers in @code{ns-3}:
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Device helpers and protocol helpers. Device helpers look at the problem
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of specifying which traces should be enabled through a node, device pair. For
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example, you may want to specify that pcap tracing should be enabled on a
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particular device on a specific node. This follows from the @code{ns-3} device
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conceptual model, and also the conceptual models of the various device helpers.
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Following naturallyu from this, the files created follow a
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<prefix>-<node>-<device> naming convention.
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Protocol helpers look at the problem of specifying which traces should be
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enabled through a protocol and interface pair. This follows from the @code{ns-3}
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protocol stack conceptual model, and also the conceptual models of internet
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stack helpers. Naturally, the trace files should follow a
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<prefix>-<protocol>-<interface> naming convention.
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The trace helpers therefore fall naturally into a two-dimensional taxonomy.
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There are subtleties that prevent all four classes from behaving identically,
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but we do strive to make them all work as similarly as possible; and whenever
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possible there are analogs for all methods in all classes.
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@verbatim
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| pcap | ascii |
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-----------------+------+-------|
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Device Helper | | |
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-----------------+------+-------|
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Protocol Helper | | |
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-----------------+------+-------|
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@end verbatim
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Let say at this point that @code{mixins} would probably be the best way to
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approach the kind of class hierarchy found in @code{src/helper/trace-helper.h}
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but our Python bindings generator does not support multiple inheritance and so
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this choice is excluded for now. We were forced to linearize the inheritance
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tree and use single inheritance for the trace functionality. This results in a
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somewhat odd arrangement of classes, an unusual naming convention and implies
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a hierarchy of functionality avialable in those classes. This isn't really a
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concern for users of this functionality, but it does make our discussion here
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a bit more difficult in some cases.
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Let's take a quick look at all four of these cases.
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@subsection Pcap Tracing Device Helpers
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The goal of these helpers is to make it easy to add a consistent pcap trace
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facility to an @code{ns-3} device. We want all of the various flavors of
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pcap tracing to work the same across all devices, so the methods of these
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helpers are inherited by device helpers. Take a look at
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@code{src/helper/trace-helper.h} if you want to follow the discussion while
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looking at real code.
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The class @code{PcapHelperForDevice} provides the high level functionality
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for using pcap tracing in an @code{ns-3} device. Every device must implement a
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single virtual method inherited from this class.
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@verbatim
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virtual void EnablePcapInternal (std::string prefix, Ptr<NetDevice> nd, bool promiscuous) = 0;
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@end verbatim
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The signature of this method reflects the device-centric view of the situation
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at this level. All of the public methods inherited from class
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2@code{PcapUserHelperForDevice} reduce to calling this single device-dependent
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implementation method. For example, the lowest level pcap method,
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@verbatim
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void EnablePcap (std::string prefix, Ptr<NetDevice> nd, bool promiscuous = false);
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@verbatim
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will call the device implementation of @code{EnablePcapInternal} directly. All
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other public pcap tracing methods build on this implementation to provide
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additional user-level functionality. What this means to the user is that all
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device helpers in the system will have all of the pcap trace methods available;
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and these methods will all work in the same way across devices if the device
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implements @code{EnablePcapInternal} correctly.
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@subsubsection Pcap Tracing Device Helper Methods
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@verbatim
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void EnablePcap (std::string prefix, Ptr<NetDevice> nd, bool promiscuous = false);
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void EnablePcap (std::string prefix, std::string ndName, bool promiscuous = false);
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void EnablePcap (std::string prefix, NetDeviceContainer d, bool promiscuous = false);
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void EnablePcap (std::string prefix, NodeContainer n, bool promiscuous = false);
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void EnablePcap (std::string prefix, uint32_t nodeid, uint32_t deviceid, bool promiscuous = false);
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void EnablePcapAll (std::string prefix, bool promiscuous = false);
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@end verbatim
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You are encouraged to peruse the Doxygen for class @code{PcapHelperForDevice}
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to find the details of these methods; but to summarize ...
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You can enable pcap tracing on a particular node/net-device pair by providing a
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@code{Ptr<NetDevice>} to an @code{EnablePcap} method. The @code{Ptr<Node>} is
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implicit since the net device must belong to exactly one @code{Node}.
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For example,
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@verbatim
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Ptr<NetDevice> nd;
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...
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helper.EnablePcap ("prefix", nd);
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@end verbatim
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You can enable pcap tracing on a particular node/net-device pair by providing a
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@code{std::string} representing an object name service string to an
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@code{EnablePcap} method. The @code{Ptr<NetDevice>} is looked up from the name
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string. Again, the @code<Node> is implicit since the named net device must
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belong to exactly one @code{Node}. For example,
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@verbatim
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Names::Add ("server" ...);
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Names::Add ("server/eth0" ...);
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...
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helper.EnablePcap ("prefix", "server/ath0");
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@end verbatim
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You can enable pcap tracing on a collection of node/net-device pairs by
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providing a @code{NetDeviceContainer}. For each @code{NetDevice} in the container
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the type is checked. For each device of the proper type (the same type as is
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managed by the device helper), tracing is enabled. Again, the @code<Node> is
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implicit since the found net device must belong to exactly one @code{Node}.
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For example,
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@verbatim
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NetDeviceContainer d = ...;
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...
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helper.EnablePcap ("prefix", d);
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@end verbatim
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You can enable pcap tracing on a collection of node/net-device pairs by
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providing a @code{NodeContainer}. For each @code{Node} in the @code{NodeContainer}
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its attached @code{NetDevices} are iterated. For each @code{NetDevice} attached
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to each node in the container, the type of that device is checked. For each
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device of the proper type (the same type as is managed by the device helper),
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tracing is enabled.
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@verbatim
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NodeContainer n;
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...
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helper.EnablePcap ("prefix", n);
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@end verbatim
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You can enable pcap tracing on the basis of node ID and device ID as well as
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with explicit @code{Ptr}. Each @code{Node} in the system has an integer node ID
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and each device connected to a node has an integer device ID.
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@verbatim
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helper.EnablePcap ("prefix", 21, 1);
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@end verbatim
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Finally, you can enable pcap tracing for all devices in the system, with the
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same type as that managed by the device helper.
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@verbatim
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helper.EnablePcapAll ("prefix");
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@end verbatim
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In each of these cases, there is an additional parameter that defaults to false.
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This parameter indicates that the trace should not be gathered in promiscuous
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mode. If you do want your traces to include all traffic seen by the device
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(and the device supports promiscuous mode) simply add a true parameter to any
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of the calls above. For example,
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@verbatim
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Ptr<NetDevice> nd;
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...
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helper.EnablePcap ("prefix", nd, true);
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@end verbatim
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will enable promiscuous mode captures on the @code{NetDevice} specified by @code{nd}.
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@subsubsection Pcap Tracing Device Helper Filename Selection
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Implicit in all of the method descriptions above is the construction of the
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complete filenames by the implementation method. By convention, pcap traces
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in the @code{ns-3} system are of the form ``<prefix>-<node id>-<device id>.pcap''
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As previously mentioned, every node in the system will have a system-assigned
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node id; and every device will have an interface index (also called a device id)
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relative to its node. By default, then, a pcap trace file created as a result
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of enabling tracing on the first device of node 21 using the prefix ``prefix''
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would be ``prefix-21-1.pcap''.
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You can always use the @code{ns-3} object name service to make this more clear.
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For example, if you use the object name service to assign the name ``server''
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to node 21, the resulting pcap trace file name will automatically become,
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``prefix-server-1.pcap'' and if you also assign the name ``eth0'' to the
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device, your pcap file name will automatically pick this up and be called
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``prefix-server-eth0.pcap''.
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@subsection Ascii Tracing Device Helpers
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The behavior of the ascii trace helpers is substantially similar to the pcap
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case. Take a look at @code{src/helper/trace-helper.h} if you want to
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follow the discussion while looking at real code.
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The class @code{TraceHelperForDevice} adds the high level functionality for
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using ascii tracing to class @code{PcapHelperForDevice}. If a device helper
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inherits from class @code{TraceHelperForDevice} it gets both pcap and ascii
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tracing powers. Along with the internal pcap function, every device must
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also implement a single virtual method inherited from the ascii trace additions
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to this class.
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@verbatim
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virtual void EnableAsciiInternal (Ptr<OutputStreamObject> stream, std::string prefix, Ptr<NetDevice> nd) = 0;
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@end verbatim
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The signature of this method reflects the device-centric view of the situation
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at this level; and also the fact that the helper may be writing to a shared
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output stream. All of the public ascii-trace-related methods inherited from
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class @code{TraceHelperForDevice} reduce to calling this single device-
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dependent implementation method. For example, the lowest level ascii trace
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methods,
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@verbatim
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void EnableAscii (std::string prefix, Ptr<NetDevice> nd);
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void EnableAscii (Ptr<OutputStreamObject> stream, Ptr<NetDevice> nd);
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@verbatim
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will call the device implementation of @code{EnableAsciiInternal} directly,
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providing either a valid prefix or stream. All other public ascii tracing
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methods will build on these low-level functions to provide additional user-level
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functionality. What this means to the user is that all device helpers in the
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system will have all of the ascii trace methods available; and these methods
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will all work in the same way across devices if the devices implement
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@code{EnablAsciiInternal} correctly.
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@subsubsection Ascii Tracing Device Helper Methods
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@verbatim
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void EnableAscii (std::string prefix, Ptr<NetDevice> nd);
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void EnableAscii (Ptr<OutputStreamObject> stream, Ptr<NetDevice> nd);
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void EnableAscii (std::string prefix, std::string ndName);
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void EnableAscii (Ptr<OutputStreamObject> stream, std::string ndName);
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void EnableAscii (std::string prefix, NetDeviceContainer d);
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void EnableAscii (Ptr<OutputStreamObject> stream, NetDeviceContainer d);
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void EnableAscii (std::string prefix, NodeContainer n);
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void EnableAscii (Ptr<OutputStreamObject> stream, NodeContainer n);
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void EnableAscii (std::string prefix, uint32_t nodeid, uint32_t deviceid);
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void EnableAscii (Ptr<OutputStreamObject> stream, uint32_t nodeid, uint32_t deviceid);
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void EnableAsciiAll (std::string prefix);
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void EnableAsciiAll (Ptr<OutputStreamObject> stream);
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@end verbatim
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You are encouraged to peruse the Doxygen for class @code{TraceHelperForDevice}
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to find the details of these methods; but to summarize ...
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There are twice as many methods available for ascii tracing as there were for
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pcap tracing. This is because, in addition to the pcap-style model where traces
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from each unique node/device pair are written to a unique file, we support a model
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in which trace information for many node/device pairs is written to a common file.
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This means that the <prefix>-<node>-<device> file name generation mechanism is
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replaced by a mechanism to refer to a common file; and the number of API methods
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is doubled to allow all combinations.
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Just as in pcap tracing, you can enable ascii tracing on a particular
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node/net-device pair by providing a @code{Ptr<NetDevice>} to an @code{EnableAscii}
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method. The @code{Ptr<Node>} is implicit since the net device must belong to
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exactly one @code{Node}. For example,
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@verbatim
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Ptr<NetDevice> nd;
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...
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helper.EnableAscii ("prefix", nd);
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@end verbatim
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In this case, no trace contexts are written to the ascii trace file since they
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would be redundant. The system will pick the file name to be created using
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the same rules as described in the pcap section, except that the file will
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have the suffix ``.tr'' instead of ``.pcap''.
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If you want to enable ascii tracing on more than one net device and have all
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traces sent to a single file, you can do that as well by using an object to
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refer to a single file. We have already seen this in the ``cwnd'' example
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above:
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@verbatim
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Ptr<NetDevice> nd1;
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Ptr<NetDevice> nd2;
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...
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Ptr<OutputStreamObject> stream = asciiTraceHelper.CreateFileStream ("trace-file-name.tr");
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...
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helper.EnableAscii (stream, nd1);
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helper.EnableAscii (stream, nd2);
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@verbatim
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In this case, trace contexts are written to the ascii trace file since they
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are required to disambiguate traces from the two devices. Note that since the
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user is completely specifying the file name, the string should include the ``,tr''
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for consistency.
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You can enable ascii tracing on a particular node/net-device pair by providing a
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@code{std::string} representing an object name service string to an
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@code{EnablePcap} method. The @code{Ptr<NetDevice>} is looked up from the name
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string. Again, the @code<Node> is implicit since the named net device must
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belong to exactly one @code{Node}. For example,
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@verbatim
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Names::Add ("client" ...);
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Names::Add ("client/eth0" ...);
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Names::Add ("server" ...);
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Names::Add ("server/eth0" ...);
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...
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helper.EnableAscii ("prefix", "client/eth0");
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helper.EnableAscii ("prefix", "server/eth0");
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@end verbatim
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This would result in two files named ``prefix-client-eth0.tr'' and
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``prefix-server-eth0.tr'' with traces for each device in the respective trace
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file. Since all of the EnableAscii functions are overloaded to take a stream object,
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you can use that form as well:
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@verbatim
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Names::Add ("client" ...);
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Names::Add ("client/eth0" ...);
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Names::Add ("server" ...);
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Names::Add ("server/eth0" ...);
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...
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Ptr<OutputStreamObject> stream = asciiTraceHelper.CreateFileStream ("trace-file-name.tr");
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...
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helper.EnableAscii (stream, "client/eth0");
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helper.EnableAscii (stream, "server/eth0");
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@end verbatim
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This would result in a single trace file called ``trace-file-name.tr'' that
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contains all of the trace events for both devices. The events would be
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disambiguated by trace context strings.
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|
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You can enable ascii tracing on a collection of node/net-device pairs by
|
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providing a @code{NetDeviceContainer}. For each @code{NetDevice} in the container
|
||||
the type is checked. For each device of the proper type (the same type as is
|
||||
managed by the device helper), tracing is enabled. Again, the @code<Node> is
|
||||
implicit since the found net device must belong to exactly one @code{Node}.
|
||||
For example,
|
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|
||||
@verbatim
|
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NetDeviceContainer d = ...;
|
||||
...
|
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helper.EnableAscii ("prefix", d);
|
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@end verbatim
|
||||
|
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This would result in a number of ascii trace files being created, each of which
|
||||
follows the <prefix>-<node id>-<device id>.tr convention. Combining all of the
|
||||
traces into a single file is accomplished similarly to the examples above:
|
||||
|
||||
@verbatim
|
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NetDeviceContainer d = ...;
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...
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Ptr<OutputStreamObject> stream = asciiTraceHelper.CreateFileStream ("trace-file-name.tr");
|
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...
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helper.EnableAscii (stream, d);
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@end verbatim
|
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|
||||
You can enable ascii tracing on a collection of node/net-device pairs by
|
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providing a @code{NodeContainer}. For each @code{Node} in the @code{NodeContainer}
|
||||
its attached @code{NetDevices} are iterated. For each @code{NetDevice} attached
|
||||
to each node in the container, the type of that device is checked. For each
|
||||
device of the proper type (the same type as is managed by the device helper),
|
||||
tracing is enabled.
|
||||
|
||||
@verbatim
|
||||
NodeContainer n;
|
||||
...
|
||||
helper.EnableAscii ("prefix", n);
|
||||
@end verbatim
|
||||
|
||||
This would result in a number of ascii trace files being created, each of which
|
||||
follows the <prefix>-<node id>-<device id>.tr convention. Combining all of the
|
||||
traces into a single file is accomplished similarly to the examples above:
|
||||
|
||||
You can enable pcap tracing on the basis of node ID and device ID as well as
|
||||
with explicit @code{Ptr}. Each @code{Node} in the system has an integer node ID
|
||||
and each device connected to a node has an integer device ID.
|
||||
|
||||
@verbatim
|
||||
helper.EnableAscii ("prefix", 21, 1);
|
||||
@end verbatim
|
||||
|
||||
Of course, the traces can be combined into a single file as shown above.
|
||||
|
||||
Finally, you can enable pcap tracing for all devices in the system, with the
|
||||
same type as that managed by the device helper.
|
||||
|
||||
@verbatim
|
||||
helper.EnableAsciiAll ("prefix");
|
||||
@end verbatim
|
||||
|
||||
This would result in a number of ascii trace files being created, one for
|
||||
every device in the system of the type managed by the helper. All of these
|
||||
files will follow the <prefix>-<node id>-<device id>.tr convention. Combining
|
||||
all of the traces into a single file is accomplished similarly to the examples
|
||||
above.
|
||||
|
||||
@subsubsection Ascii Tracing Device Helper Filename Selection
|
||||
|
||||
Implicit in the prefix-style method descriptions above is the construction of the
|
||||
complete filenames by the implementation method. By convention, ascii traces
|
||||
in the @code{ns-3} system are of the form ``<prefix>-<node id>-<device id>.tr''
|
||||
|
||||
As previously mentioned, every node in the system will have a system-assigned
|
||||
node id; and every device will have an interface index (also called a device id)
|
||||
relative to its node. By default, then, an ascii trace file created as a result
|
||||
of enabling tracing on the first device of node 21, using the prefix ``prefix'',
|
||||
would be ``prefix-21-1.tr''.
|
||||
|
||||
You can always use the @code{ns-3} object name service to make this more clear.
|
||||
For example, if you use the object name service to assign the name ``server''
|
||||
to node 21, the resulting ascii trace file name will automatically become,
|
||||
``prefix-server-1.tr'' and if you also assign the name ``eth0'' to the
|
||||
device, your ascii trace file name will automatically pick this up and be called
|
||||
``prefix-server-eth0.tr''.
|
||||
|
||||
@subsection Pcap Tracing Protocol Helpers
|
||||
|
||||
The goal of these helpers is to make it easy to add a consistent pcap trace
|
||||
facility to protocols. We want all of the various flavors of pcap tracing to
|
||||
work the same across all protocols, so the methods of these helpers are
|
||||
inherited by stack helpers. Take a look at @code{src/helper/trace-helper.h}
|
||||
if you want to follow the discussion while looking at real code.
|
||||
|
||||
In this section we will be illustrating the methods as applied to the protocol
|
||||
@code{Ipv4}. To specify traces in similar protocols, just substitute the
|
||||
appropriate type. For example, use a @code{Ptr<Ipv6>} instead of a
|
||||
@code{Ptr<Ipv4>} and call @code{EnablePcapIpv6} instead of @code{EnablePcapIpv4}.
|
||||
|
||||
The class @code{PcapHelperForIpv4} provides the high level functionality for
|
||||
using pcap tracing in the @code{Ipv4} protocol. Every protocol enabling these
|
||||
methods must implement a single virtual method inherited from this class. There
|
||||
will be a separate implementation for @code{Ipv6}, for example, but the only
|
||||
difference will be in the method names and signatures. Different method names
|
||||
are required to disambiguate class @code{Ipv4} from @coe{Ipv6} which are both
|
||||
derived from class @code{Object}, and methods that share the same signature.
|
||||
|
||||
@verbatim
|
||||
virtual void EnablePcapIpv4Internal (std::string prefix, Ptr<Ipv4> ipv4, uint32_t interface) = 0;
|
||||
@end verbatim
|
||||
|
||||
The signature of this method reflects the protocol and interface-centric view
|
||||
of the situation at this level. All of the public methods inherited from class
|
||||
@code{PcapHelperForIpv4} reduce to calling this single device-dependent
|
||||
implementation method. For example, the lowest level pcap method,
|
||||
|
||||
@verbatim
|
||||
void EnablePcapIpv4 (std::string prefix, Ptr<Ipv4> ipv4, uint32_t interface);
|
||||
@verbatim
|
||||
|
||||
will call the device implementation of @code{EnablePcapIpv4Internal} directly.
|
||||
All other public pcap tracing methods build on this implementation to provide
|
||||
additional user-level functionality. What this means to the user is that all
|
||||
protocol helpers in the system will have all of the pcap trace methods
|
||||
available; and these methods will all work in the same way across
|
||||
protocols if the helper implements @code{EnablePcapIpv4Internal} correctly.
|
||||
|
||||
@subsubsection Pcap Tracing Protocol Helper Methods
|
||||
|
||||
These methods are designed to be in one-to-one correspondence with the @code{Node}-
|
||||
and @code{NetDevice}- centric versions of the device versions. Instead of
|
||||
@code{Node} and @code{NetDevice} pair constraints, we use protocol and interface
|
||||
constraints.
|
||||
|
||||
Note that just like in the device version, there are six methods:
|
||||
|
||||
@verbatim
|
||||
void EnablePcapIpv4 (std::string prefix, Ptr<Ipv4> ipv4, uint32_t interface);
|
||||
void EnablePcapIpv4 (std::string prefix, std::string ipv4Name, uint32_t interface);
|
||||
void EnablePcapIpv4 (std::string prefix, Ipv4InterfaceContainer c);
|
||||
void EnablePcapIpv4 (std::string prefix, NodeContainer n);
|
||||
void EnablePcapIpv4 (std::string prefix, uint32_t nodeid, uint32_t interface);
|
||||
void EnablePcapIpv4All (std::string prefix);
|
||||
@end verbatim
|
||||
|
||||
You are encouraged to peruse the Doxygen for class @code{PcapHelperForIpv4}
|
||||
to find the details of these methods; but to summarize ...
|
||||
|
||||
You can enable pcap tracing on a particular protocol/interface pair by providing a
|
||||
@code{Ptr<Ipv4>} and @code{interface} to an @code{EnablePcap} method. For example,
|
||||
|
||||
@verbatim
|
||||
Ptr<Ipv4> ipv4 = node->GetObject<Ipv4> ();
|
||||
...
|
||||
helper.EnablePcapIpv4 ("prefix", ipv4, 0);
|
||||
@end verbatim
|
||||
|
||||
You can enable pcap tracing on a particular node/net-device pair by providing a
|
||||
@code{std::string} representing an object name service string to an
|
||||
@code{EnablePcap} method. The @code{Ptr<Ipv4>} is looked up from the name
|
||||
string. For example,
|
||||
|
||||
@verbatim
|
||||
Names::Add ("serverIPv4" ...);
|
||||
...
|
||||
helper.EnablePcapIpv4 ("prefix", "serverIpv4", 1);
|
||||
@end verbatim
|
||||
|
||||
You can enable pcap tracing on a collection of protocol/interface pairs by
|
||||
providing an @code{Ipv4InterfaceContainer}. For each @code{Ipv4} / interface
|
||||
pair in the container the protocol type is checked. For each protocol of the
|
||||
proper type (the same type as is managed by the device helper), tracing is
|
||||
enabled for the corresponding interface. For example,
|
||||
|
||||
@verbatim
|
||||
NodeContainer nodes;
|
||||
...
|
||||
NetDeviceContainer devices = deviceHelper.Install (nodes);
|
||||
...
|
||||
Ipv4AddressHelper ipv4;
|
||||
ipv4.SetBase ("10.1.1.0", "255.255.255.0");
|
||||
Ipv4InterfaceContainer interfaces = ipv4.Assign (devices);
|
||||
...
|
||||
helper.EnablePcapIpv4 ("prefix", interfaces);
|
||||
@end verbatim
|
||||
|
||||
You can enable pcap tracing on a collection of protocol/interface pairs by
|
||||
providing a @code{NodeContainer}. For each @code{Node} in the @code{NodeContainer}
|
||||
the appropriate protocol is found. For each protocol, its interfaces are
|
||||
enumerated and tracing is enabled on the resulting pairs. For example,
|
||||
|
||||
@verbatim
|
||||
NodeContainer n;
|
||||
...
|
||||
helper.EnablePcapIpv4 ("prefix", n);
|
||||
@end verbatim
|
||||
|
||||
You can enable pcap tracing on the basis of node ID and interface as well. In
|
||||
this case, the node-id is translated to a @code{Ptr{Node} and the appropriate
|
||||
protocol is looked up in the node. The resulting protocol and interface are
|
||||
used to specify the resulting trace source.
|
||||
|
||||
@verbatim
|
||||
helper.EnablePcapIpv4 ("prefix", 21, 1);
|
||||
@end verbatim
|
||||
|
||||
Finally, you can enable pcap tracing for all interfaces in the system, with
|
||||
associated protocol being the same type as that managed by the device helper.
|
||||
|
||||
@verbatim
|
||||
helper.EnablePcapIpv4All ("prefix");
|
||||
@end verbatim
|
||||
|
||||
@subsubsection Pcap Tracing Protocol Helper Filename Selection
|
||||
|
||||
Implicit in all of the method descriptions above is the construction of the
|
||||
complete filenames by the implementation method. By convention, pcap traces
|
||||
taken for devices in the @code{ns-3} system are of the form
|
||||
``<prefix>-<node id>-<device id>.pcap''. In the case of protocol traces,
|
||||
there is a one-to-one correspondence between protocols and @code{Nodes}.
|
||||
This is because protocol @code{Objects} are aggregated to @code{Node Objects}.
|
||||
Since there is no global protocol id in the system, we use the corresponding
|
||||
node id in file naming. Threfore there is a possibility for file name
|
||||
collisions in automatically chosen trace file names. For this reason, the
|
||||
file name convention is changed for protocol traces.
|
||||
|
||||
As previously mentioned, every node in the system will have a system-assigned
|
||||
node id. Since there is a one-to-one correspondence between protocol instances
|
||||
and node instances we use the node id. Each interface has an interface id
|
||||
relative to its protocol. We use the convention
|
||||
"<prefix>-n<node id>-i<interface id>.pcap" for trace file naming in protocol
|
||||
helpers.
|
||||
|
||||
Therefore, by default, a pcap trace file created as a result of enabling tracing
|
||||
on interface 1 of the Ipv4 protocol of node 21 using the prefix ``prefix''
|
||||
would be ``prefix-n21-i1.pcap''.
|
||||
|
||||
You can always use the @code{ns-3} object name service to make this more clear.
|
||||
For example, if you use the object name service to assign the name ``serverIpv4''
|
||||
to the Ptr<Ipv4> on node 21, the resulting pcap trace file name will
|
||||
automatically become, ``prefix-nserverIpv4-i1.pcap''.
|
||||
|
||||
@subsection Ascii Tracing Protocol Helpers
|
||||
|
||||
The behavior of the ascii trace helpers is substantially similar to the pcap
|
||||
case. Take a look at @code{src/helper/trace-helper.h} if you want to
|
||||
follow the discussion while looking at real code.
|
||||
|
||||
In this section we will be illustrating the methods as applied to the protocol
|
||||
@code{Ipv4}. To specify traces in similar protocols, just substitute the
|
||||
appropriate type. For example, use a @code{Ptr<Ipv6>} instead of a
|
||||
@code{Ptr<Ipv4>} and call @code{EnableAsciiIpv6} instead of @code{EnableAsciiIpv4}.
|
||||
|
||||
The class @code{PcapAndAsciiHelperForIpv4} adds the high level functionality
|
||||
for using ascii tracing to the PcapHelperForIpv4. Every protocol must
|
||||
additionally implement a single virtual method inherited from this class.
|
||||
|
||||
@verbatim
|
||||
virtual void EnableAsciiIpv4Internal (Ptr<OutputStreamObject> stream, std::string prefix,
|
||||
Ptr<Ipv4> ipv4, uint32_t interface) = 0;
|
||||
@end verbatim
|
||||
|
||||
The signature of this method reflects the protocol- and interface-centric view
|
||||
of the situation at this level; and also the fact that the helper may be writing
|
||||
to a shared output stream. All of the public methods inherited from class
|
||||
@code{PcapAndAsciiTraceHelperForIpv4} reduce to calling this single device-
|
||||
dependent implementation method. For example, the lowest level ascii trace
|
||||
methods,
|
||||
|
||||
@verbatim
|
||||
void EnableAsciiIpv4 (std::string prefix, Ptr<Ipv4> ipv4, uint32_t interface);
|
||||
void EnableAsciiIpv4 (Ptr<OutputStreamObject> stream, Ptr<Ipv4> ipv4, uint32_t interface);
|
||||
@verbatim
|
||||
|
||||
will call the device implementation of @code{EnableAsciiIpv4Internal} directly,
|
||||
providing either the prefix or the stream. All other public ascii tracing
|
||||
methods will build on these low-level functions to provide additional user-level
|
||||
functionality. What this means to the user is that all device helpers in the
|
||||
system will have all of the ascii trace methods available; and these methods
|
||||
will all work in the same way across protocols if the protocols implement
|
||||
@code{EnablAsciiIpv4Internal} correctly.
|
||||
|
||||
@subsubsection Ascii Tracing Device Helper Methods
|
||||
|
||||
@verbatim
|
||||
void EnableAsciiIpv4 (std::string prefix, Ptr<Ipv4> ipv4, uint32_t interface);
|
||||
void EnableAsciiIpv4 (Ptr<OutputStreamObject> stream, Ptr<Ipv4> ipv4, uint32_t interface);
|
||||
|
||||
void EnableAsciiIpv4 (std::string prefix, std::string ipv4Name, uint32_t interface);
|
||||
void EnableAsciiIpv4 (Ptr<OutputStreamObject> stream, std::string ipv4Name, uint32_t interface);
|
||||
|
||||
void EnableAsciiIpv4 (std::string prefix, Ipv4InterfaceContainer c);
|
||||
void EnableAsciiIpv4 (Ptr<OutputStreamObject> stream, Ipv4InterfaceContainer c);
|
||||
|
||||
void EnableAsciiIpv4 (std::string prefix, NodeContainer n);
|
||||
void EnableAsciiIpv4 (Ptr<OutputStreamObject> stream, NodeContainer n);
|
||||
|
||||
void EnableAsciiIpv4 (std::string prefix, uint32_t nodeid, uint32_t deviceid);
|
||||
void EnableAsciiIpv4 (Ptr<OutputStreamObject> stream, uint32_t nodeid, uint32_t interface);
|
||||
|
||||
void EnableAsciiIpv4All (std::string prefix);
|
||||
void EnableAsciiIpv4All (Ptr<OutputStreamObject> stream);
|
||||
@end verbatim
|
||||
|
||||
You are encouraged to peruse the Doxygen for class @code{PcapAndAsciiHelperForIpv4}
|
||||
to find the details of these methods; but to summarize ...
|
||||
|
||||
There are twice as many methods available for ascii tracing as there were for
|
||||
pcap tracing. This is because, in addition to the pcap-style model where traces
|
||||
from each unique protocol/interface pair are written to a unique file, we
|
||||
support a model in which trace information for many protocol/interface pairs is
|
||||
written to a common file. This means that the <prefix>-n<node id>-<interface>
|
||||
file name generation mechanism is replaced by a mechanism to refer to a common
|
||||
file; and the number of API methods is doubled to allow all combinations.
|
||||
|
||||
Just as in pcap tracing, you can enable ascii tracing on a particular
|
||||
protocol/interface pair by providing a @code{Ptr<Ipv4>} and an @code{interface}
|
||||
to an @code{EnableAscii} method.
|
||||
For example,
|
||||
|
||||
@verbatim
|
||||
Ptr<Ipv4> ipv4;
|
||||
...
|
||||
helper.EnableAsciiIpv4 ("prefix", ipv4, 1);
|
||||
@end verbatim
|
||||
|
||||
In this case, no trace contexts are written to the ascii trace file since they
|
||||
would be redundant. The system will pick the file name to be created using
|
||||
the same rules as described in the pcap section, except that the file will
|
||||
have the suffix ``.tr'' instead of ``.pcap''.
|
||||
|
||||
If you want to enable ascii tracing on more than one interface and have all
|
||||
traces sent to a single file, you can do that as well by using an object to
|
||||
refer to a single file. We have already something similar to this in the
|
||||
``cwnd'' example above:
|
||||
|
||||
@verbatim
|
||||
Ptr<Ipv4> protocol1 = node1->GetObject<Ipv4> ();
|
||||
Ptr<Ipv4> protocol2 = node2->GetObject<Ipv4> ();
|
||||
...
|
||||
Ptr<OutputStreamObject> stream = asciiTraceHelper.CreateFileStream ("trace-file-name.tr");
|
||||
...
|
||||
helper.EnableAsciiIpv4 (stream, protocol1, 1);
|
||||
helper.EnableAsciiIpv4 (stream, protocol2, 1);
|
||||
@verbatim
|
||||
|
||||
In this case, trace contexts are written to the ascii trace file since they
|
||||
are required to disambiguate traces from the two interfaces. Note that since
|
||||
the user is completely specifying the file name, the string should include the
|
||||
``,tr'' for consistency.
|
||||
|
||||
You can enable ascii tracing on a particular protocol by providing a
|
||||
@code{std::string} representing an object name service string to an
|
||||
@code{EnablePcap} method. The @code{Ptr<Ipv4>} is looked up from the name
|
||||
string. The @code<Node> in the resulting filenames is implicit since there
|
||||
is a one-to-one correspondence between protocol instances and nodes,
|
||||
For example,
|
||||
|
||||
@verbatim
|
||||
Names::Add ("node1Ipv4" ...);
|
||||
Names::Add ("node2Ipv4" ...);
|
||||
...
|
||||
helper.EnableAsciiIpv4 ("prefix", "node1Ipv4", 1);
|
||||
helper.EnableAsciiIpv4 ("prefix", "node2Ipv4", 1);
|
||||
@end verbatim
|
||||
|
||||
This would result in two files named ``prefix-nnode1Ipv4-i1.tr'' and
|
||||
``prefix-nnode2Ipv4-i1.tr'' with traces for each interface in the respective
|
||||
trace file. Since all of the EnableAscii functions are overloaded to take a
|
||||
stream object, you can use that form as well:
|
||||
|
||||
@verbatim
|
||||
Names::Add ("node1Ipv4" ...);
|
||||
Names::Add ("node2Ipv4" ...);
|
||||
...
|
||||
Ptr<OutputStreamObject> stream = asciiTraceHelper.CreateFileStream ("trace-file-name.tr");
|
||||
...
|
||||
helper.EnableAsciiIpv4 (stream, "node1Ipv4", 1);
|
||||
helper.EnableAsciiIpv4 (stream, "node2Ipv4", 1);
|
||||
@end verbatim
|
||||
|
||||
This would result in a single trace file called ``trace-file-name.tr'' that
|
||||
contains all of the trace events for both interfaces. The events would be
|
||||
disambiguated by trace context strings.
|
||||
|
||||
You can enable ascii tracing on a collection of protocol/interface pairs by
|
||||
providing an @code{Ipv4InterfaceContainer}. For each protocol of the proper
|
||||
type (the same type as is managed by the device helper), tracing is enabled
|
||||
for the corresponding interface. Again, the @code<Node> is implicit since
|
||||
there is a one-to-one correspondence between each protocol and its node.
|
||||
For example,
|
||||
|
||||
@verbatim
|
||||
NodeContainer nodes;
|
||||
...
|
||||
NetDeviceContainer devices = deviceHelper.Install (nodes);
|
||||
...
|
||||
Ipv4AddressHelper ipv4;
|
||||
ipv4.SetBase ("10.1.1.0", "255.255.255.0");
|
||||
Ipv4InterfaceContainer interfaces = ipv4.Assign (devices);
|
||||
...
|
||||
...
|
||||
helper.EnableAsciiIpv4 ("prefix", interfaces);
|
||||
@end verbatim
|
||||
|
||||
This would result in a number of ascii trace files being created, each of which
|
||||
follows the <prefix>-n<node id>-i<interface>.tr convention. Combining all of the
|
||||
traces into a single file is accomplished similarly to the examples above:
|
||||
|
||||
@verbatim
|
||||
NodeContainer nodes;
|
||||
...
|
||||
NetDeviceContainer devices = deviceHelper.Install (nodes);
|
||||
...
|
||||
Ipv4AddressHelper ipv4;
|
||||
ipv4.SetBase ("10.1.1.0", "255.255.255.0");
|
||||
Ipv4InterfaceContainer interfaces = ipv4.Assign (devices);
|
||||
...
|
||||
Ptr<OutputStreamObject> stream = asciiTraceHelper.CreateFileStream ("trace-file-name.tr");
|
||||
...
|
||||
helper.EnableAsciiIpv4 (stream, interfaces);
|
||||
@end verbatim
|
||||
|
||||
You can enable ascii tracing on a collection of protocol/interface pairs by
|
||||
providing a @code{NodeContainer}. For each @code{Node} in the @code{NodeContainer}
|
||||
the appropriate protocol is found. For each protocol, its interfaces are
|
||||
enumerated and tracing is enabled on the resulting pairs. For example,
|
||||
|
||||
@verbatim
|
||||
NodeContainer n;
|
||||
...
|
||||
helper.EnableAsciiIpv4 ("prefix", n);
|
||||
@end verbatim
|
||||
|
||||
This would result in a number of ascii trace files being created, each of which
|
||||
follows the <prefix>-<node id>-<device id>.tr convention. Combining all of the
|
||||
traces into a single file is accomplished similarly to the examples above:
|
||||
|
||||
You can enable pcap tracing on the basis of node ID and device ID as well. In
|
||||
this case, the node-id is translated to a @code{Ptr{Node} and the appropriate
|
||||
protocol is looked up in the node. The resulting protocol and interface are
|
||||
used to specify the resulting trace source.
|
||||
|
||||
@verbatim
|
||||
helper.EnableAsciiIpv4 ("prefix", 21, 1);
|
||||
@end verbatim
|
||||
|
||||
Of course, the traces can be combined into a single file as shown above.
|
||||
|
||||
Finally, you can enable ascii tracing for all interfaces in the system, with
|
||||
associated protocol being the same type as that managed by the device helper.
|
||||
|
||||
@verbatim
|
||||
helper.EnableAsciiIpv4All ("prefix");
|
||||
@end verbatim
|
||||
|
||||
This would result in a number of ascii trace files being created, one for
|
||||
every interface in the system related to a protocol of the type managed by the
|
||||
helper. All of these files will follow the <prefix>-n<node id>-i<interface.tr
|
||||
convention. Combining all of the traces into a single file is accomplished
|
||||
similarly to the examples above.
|
||||
|
||||
@subsubsection Ascii Tracing Device Helper Filename Selection
|
||||
|
||||
Implicit in the prefix-style method descriptions above is the construction of the
|
||||
complete filenames by the implementation method. By convention, ascii traces
|
||||
in the @code{ns-3} system are of the form ``<prefix>-<node id>-<device id>.tr''
|
||||
|
||||
As previously mentioned, every node in the system will have a system-assigned
|
||||
node id. Since there is a one-to-one correspondence between protocols and nodes
|
||||
we use to node-id to identify the protocol identity. Every interface on a
|
||||
given rotocol will have an interface index (also called simply an interface)
|
||||
relative to its protocol. By default, then, an ascii trace file created as a result
|
||||
of enabling tracing on the first device of node 21, using the prefix ``prefix'',
|
||||
would be ``prefix-n21-i1.tr''. Use the prefix to disambiguate multiple protocols
|
||||
per node.
|
||||
|
||||
You can always use the @code{ns-3} object name service to make this more clear.
|
||||
For example, if you use the object name service to assign the name ``serverIpv4''
|
||||
to the protocol on node 21, and also specify interface one, the resulting ascii
|
||||
trace file name will automatically become, ``prefix-nserverIpv4-1.tr''.
|
||||
|
||||
@node Tracing implementation details
|
||||
@section Implementation details
|
||||
|
||||
Reference in New Issue
Block a user