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1 .. include:: replace.txt | 1 .. include:: replace.txt |
2 | 2 |
3 BRITE Integration | 3 BRITE Integration |
4 ------------------ | 4 ------------------ |
5 | 5 |
6 This model implements an interface to BRITE, the Boston university· | 6 This model implements an interface to BRITE, the Boston university· |
7 Representative Internet Topology gEnerator [1]_. BRITE is a standard tool for· | 7 Representative Internet Topology gEnerator [1]_. BRITE is a standard tool for· |
8 generating realistic internet topologies. The ns-3 model, described herein,· | 8 generating realistic internet topologies. The ns-3 model, described herein,· |
9 provides a helper class to facilitate generating ns-3 specific topologies· | 9 provides a helper class to facilitate generating ns-3 specific topologies· |
10 using BRITE configuration files. BRITE builds the original graph which is· | 10 using BRITE configuration files. BRITE builds the original graph which is· |
11 stored as nodes and edges in the ns-3 BriteTopolgyHelper class. In the ns-3 | 11 stored as nodes and edges in the ns-3 BriteTopolgyHelper class. In the ns-3 |
12 integeration of BRITE, the generator generates a topology and then provides | 12 integration of BRITE, the generator generates a topology and then provides |
13 access to leaf nodes for each AS generated. ns-3 users can than attach· | 13 access to leaf nodes for each AS generated. ns-3 users can than attach· |
14 custom topologies to these leaf nodes either by creating them manually or | 14 custom topologies to these leaf nodes either by creating them manually or |
15 using topology generators provided in ns-3.·· | 15 using topology generators provided in ns-3.·· |
16 | 16 |
| 17 There are three major types of topologies available in BRITE: Router,· |
| 18 AS, and Hierarchical which is a combination of AS and Router. For the· |
| 19 purposes of ns-3 simulation, the most useful are likely to be Router and· |
| 20 Hierarchical. Router level topologies be generated using either the Waxman· |
| 21 model or the Barabasi-Albert model. Each model has different parameters that |
| 22 effect topology creation. For flat router topologies, all nodes are considered· |
| 23 to be in the same AS. |
| 24 |
| 25 BRITE Hierarchical topologies contain two levels. The first is the AS level.· |
| 26 This level can be also be created by using either the Waxman model or the· |
| 27 Barabasi-Albert model. Then for each node in the AS topology, a router level· |
| 28 topology is constructed. These router level topologies can again either use· |
| 29 the Waxman model or the Barbasi-Albert model. BRITE interconnects these separat
e· |
| 30 router topologies as specified by the AS level topology. Once the hierarchical· |
| 31 topology is constructed, it is flattened into a large router level topology. |
| 32 |
| 33 Further information can be found in the BRITE user manual::: |
| 34 |
| 35 http://www.cs.bu.edu/brite/publications/usermanual.pdf |
| 36 |
17 Model Description | 37 Model Description |
18 ***************** | 38 ***************** |
19 | 39 |
20 The model relies on building an external BRITE library,· | 40 The model relies on building an external BRITE library,· |
21 and then building some ns-3 helpers that call out to the library.·· | 41 and then building some ns-3 helpers that call out to the library.·· |
22 The source code for the ns-3 helpers lives in the directory· | 42 The source code for the ns-3 helpers lives in the directory· |
23 ``src/brite/helper``. | 43 ``src/brite/helper``. |
24 | 44 |
25 Design | 45 Design |
26 ====== | 46 ====== |
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37 References | 57 References |
38 ========== | 58 ========== |
39 | 59 |
40 .. [1] Alberto Medina, Anukool Lakhina, Ibrahim Matta, and John Byers. BRITE: An
Approach to Universal Topology Generation. In Proceedings of the International
Workshop on Modeling, Analysis and Simulation of Computer and Telecommunications
Systems- MASCOTS '01, Cincinnati, Ohio, August 2001. | 60 .. [1] Alberto Medina, Anukool Lakhina, Ibrahim Matta, and John Byers. BRITE: An
Approach to Universal Topology Generation. In Proceedings of the International
Workshop on Modeling, Analysis and Simulation of Computer and Telecommunications
Systems- MASCOTS '01, Cincinnati, Ohio, August 2001. |
41 | 61 |
42 Usage | 62 Usage |
43 ***** | 63 ***** |
44 | 64 |
45 The brite-generic-example can be referenced to see basic usage of the BRITE | 65 The brite-generic-example can be referenced to see basic usage of the BRITE |
46 interface. In summary, the BriteTopologyHelper is used as the interface point | 66 interface. In summary, the BriteTopologyHelper is used as the interface point |
47 by passing in a BRITE configuration file. Once the topology is created users· | 67 by passing in a BRITE configuration file. Along with the configuration file a |
48 can then install network stacks on the nodes in the topology using InstallStack | 68 BRITE formatted random seed file can also be passed in. If a seed file is not |
49 and can then assign IPs to the topology using AssignIpv4Addresses or AssignIpv6A
ddresses. | 69 passed in, the helper will create a seed file using ns-3's UniformRandomVariable
. |
50 The pointToPoint helper used to create the topology can be retrieved via a get m
ethod so | 70 Once the topology has been generated by BRITE, BuildBriteTopology() is called to |
51 that traces can be added to the internal BRITE topology. | 71 create the ns-3 representation. Next IP Address can be assigned to the topology |
| 72 using either AssignIpv4Addresses() or AssignIpv6Addresses(). It should be noted |
| 73 that each point-to-point link in the topology will be treated as a new network· |
| 74 therefore for IPV4 a /30 subnet should be used to avoid wasting a large amount o
f· |
| 75 the available address space.·· |
| 76 |
| 77 Example BRITE configuration files can be found in /src/brite/examples/conf_files
/. |
| 78 ASBarbasi and ASWaxman are examples of AS only topologies. The RTBarabasi and |
| 79 RTWaxman files are examples of router only topologies. Finally the· |
| 80 TD_ASBarabasi_RTWaxman configuration file is an example of a Hierarchical topolo
gy |
| 81 that uses the Barabasi-Albert model for the AS level and the Waxman model for ea
ch· |
| 82 of the router level topologies. Information on the BRITE parameters used in th
ese files· |
| 83 can be found in the BRITE user manual. |
52 | 84 |
53 | 85 |
54 Building BRITE Integration | 86 Building BRITE Integration |
55 ========================== | 87 ========================== |
56 | 88 |
57 The first step is to download and build the ns-3 specific BRITE repository::: | 89 The first step is to download and build the ns-3 specific BRITE repository::: |
58 | 90 |
59 $ hg clone http://code.nsnam.org/BRITE | 91 $ hg clone http://code.nsnam.org/BRITE |
60 $ cd BRITE | 92 $ cd BRITE |
61 $ make | 93 $ make |
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93 the conf_files directory for more examples. | 125 the conf_files directory for more examples. |
94 | 126 |
95 tracing: Enables ascii tracing. | 127 tracing: Enables ascii tracing. |
96 | 128 |
97 nix: Enables nix-vector routing. Global routing is used by default. | 129 nix: Enables nix-vector routing. Global routing is used by default. |
98 | 130 |
99 The generic BRITE example also support visualization using pyviz, assuming | 131 The generic BRITE example also support visualization using pyviz, assuming |
100 python bindings in ns-3 are enabled::: | 132 python bindings in ns-3 are enabled::: |
101 | 133 |
102 $ ./waf --run brite-generic-example --vis | 134 $ ./waf --run brite-generic-example --vis |
| 135 ·· |
| 136 Simulations involving BRITE can also be used with MPI. The total number of MPI
instances is· |
| 137 passed to the BRITE topology helper where a modulo divide is used to assign the
nodes for each· |
| 138 AS to a MPI instance. An example can be found in src/brite/examples::: |
| 139 |
| 140 $ mpirun -np 2 ./waf --run brite-MPI-example |
| 141 ········ |
| 142 Please see the ns-3 MPI documentation for information on setting up MPI with ns-
3. |
| 143 |
| 144 |
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