56 lines
2.8 KiB
Plaintext
56 lines
2.8 KiB
Plaintext
@node Organization
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@chapter Organization
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This manual is organized into several parts with several chapters per part.
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This chapter describes the overall software organization and the
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corresponding organization of this manual.
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ns-3 is a discrete-event network simulator in which the simulation core
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and models are implemented in C++. ns-3 is built as a library which
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may be statically or dynamically linked to a C++ main program that
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defines the simulation topology and starts the simulator. ns-3 also
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exports nearly all of its API to Python, allowing Python programs to
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import an "ns3" module in much the same way as in C++.
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@float Figure,fig:organization
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@caption{Software organization of ns-3}
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@center @image{figures/software-organization, 5in}
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@end float
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The source code for ns-3 is mostly organized in the @code{src/}
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directory and can be described by the diagram in @ref{fig:organization}.
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We will work our way from the bottom up; in general, modules
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only have dependencies on modules beneath them in the figure.
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We first describe Part 1 of the manual.
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The simulation core is implemented in @code{src/core}, and the core is
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used to build the simulation engine @code{src/simulator}. Packets are
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fundamental objects in a network simulator and are implemented in
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@code{src/packet}. These three simulation modules by themselves
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are intended to comprise a generic simulation core that can be used
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by different kinds of networks, not just Internet-based networks.
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The above modules of ns-3 are independent of specific network and
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device models, which are covered in later parts of this manual.
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In addition to the above ns-3 core, we describe also in Part 1 two
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other modules that supplement the core C++-based API. ns-3 programs
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may access all of the API directly or may make use of a so-called
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``helper API'' that provides convenient wrappers or encapsulation of
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low-level API calls. The fact that ns-3 programs can be written to
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two APIs (or a combination thereof) is a fundamental aspect of the
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simulator and is also covered in Part 1. We also describe how
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Python is supported in ns-3 as the last chapter of Part 1.
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The remainder of the manual is focused on documenting the models
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and supporting capabilities. Part 2 focuses on two fundamental
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objects in ns-3: the @code{Node} and @code{NetDevice}. Two
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special NetDevice types are designed to support network emulation
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use cases, and emulation is described in Part 3.
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Part 4 is devoted to Internet-related models, including the sockets
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API used by Internet applications. Part 5 covers applications, and
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Part 6 describes additional support for simulation, such as animators.
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The project maintains a separate manual devoted to testing and
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validation of ns-3 code (see the
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@uref{http://www.nsnam.org/tutorials.html,, ns-3 Testing and Validation manual}).
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