#BACKBONE NETWORK TOPOLOGY EXAMPLES INSTALL#
#BACKBONE NETWORK TOPOLOGY EXAMPLES CODE#

Nodes created for the simulation - it does the hard work of setting up routingįor you without having to configure routers.īasically, what happens is that each node behaves as if it were an OSPF router Internetwork is accessible in the simulation and runs through the all of the Global routing takes advantage of the fact that the entire ns-3 provides what we call global routing to Since we have actually built an internetwork here, we need some form of SetAttribute ( 'PacketSize', UintegerValue ( 1024 )) ApplicationContainer clientApps = echoClient. SetAttribute ( 'Interval', TimeValue ( Seconds ( 1.0 ))) echoClient. SetAttribute ( 'MaxPackets', UintegerValue ( 1 )) echoClient. UdpEchoClientHelper echoClient ( csmaInterfaces. Leftmost point-to-point node seen in the topology illustration. We tell the client to send packets to the server we just installed UdpEchoClientHelper in the constructor (in this case the remote addressĪnd port).

Again, we provide required Attributes to the The client application is set up exactly as we did in the Įxample script. You see this exhibited in the Get of the first line of If we create nCsma “extra” nodes the last one will be at index Will be at index one of the csmaNodes container.

Way to think of this, then, is if we create one “extra” CSMA node, then it The csmaNodes container will be the point-to-point node. What we want to get at is the last of the “extra” nodes. Nodes created for the point-to-point network and nCsma “extra” nodes. Recall that the csmaNodes NodeContainer contains one of the UdpEchoServerHelper echoServer ( 9 ) ApplicationContainer serverApps = echoServer. Notice that you can set an Attribute using Of the channel to 6560 nano-seconds (arbitrarily chosen as 1 nanosecond per foot The data rate to 100 megabits per second, and then set the speed-of-light delay This is because a real CSMA network does not allow one to mix,įor example, 10Base-T and 100Base-T devices on a given channel. Rate is specified by a channel Attribute instead of a deviceĪttribute. In the case of a CSMA device and channel pair, notice that the data Like a PointToPointHelper, but it creates and connects CSMA devices andĬhannels. We mentioned above that you were going to see a helper for CSMA devices andĬhannels, and the next lines introduce them.

#BACKBONE NETWORK TOPOLOGY EXAMPLES INSTALL#

Point-to-point net devices and we Install devices on the We then instantiate a NetDeviceContainer to keep track of the SetChannelAttribute ( 'Delay', StringValue ( '2ms' )) NetDeviceContainer p2pDevices p2pDevices = pointToPoint. SetDeviceAttribute ( 'DataRate', StringValue ( '5Mbps' )) pointToPoint. PointToPointHelper pointToPoint pointToPoint.

#BACKBONE NETWORK TOPOLOGY EXAMPLES CODE#

The actual code begins by loading module include files just as was done in the Just as in the example (and in all ns-3 examples) the fileīegins with an emacs mode line and some GPL boilerplate. You will have already seenĮnough ns-3 code to understand most of what is going on in thisĮxample, but we will go over the entire script and examine some of the output. Go ahead and openĮxamples/tutorial/ in your favorite editor. Point-to-point simulation we’ve already considered. This scriptīuilds on the script and adds a CSMA network to the We provide an example script in our examples/tutorial directory. The appearance and operation of these helpers should look Point-to-point topologies, we will see equivalent CSMA topology helpers in Just as we have seen point-to-point topology helper objects when constructing A real Ethernet uses CSMA/CD (Carrier Sense Multiple Access withĬollision Detection) scheme with exponentially increasing backoff to contendįor the shared transmission medium. The ns-3 CSMA device models a simple network in the spirit ofĮthernet.

Provides a net device and channel we call CSMA (Carrier Sense Multiple Access). In this section we are going to expand our mastery of ns-3 networkĭevices and channels to cover an example of a bus network.

Backbone network topology examples