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#
# * This program is free software; you can redistribute it and/or modify
# * it under the terms of the GNU General Public License version 2 as
# * published by the Free Software Foundation;
# *
# * This program is distributed in the hope that it will be useful,
# * but WITHOUT ANY WARRANTY; without even the implied warranty of
# * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# * GNU General Public License for more details.
# *
# * You should have received a copy of the GNU General Public License
# * along with this program; if not, write to the Free Software
# * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
# Network topology
#
# n0 n1 n2 n3
# | | | |
# =================
# LAN
#
# - UDP flows from n0 to n1 and back
# - DropTail queues
# - Tracing of queues and packet receptions to file "udp-echo.tr"
import ns.applications
import ns.core
import ns.csma
import ns.internet
import ns.network
def main(argv):
#
# Allow the user to override any of the defaults and the above Bind() at
# run-time, via command-line arguments
#
cmd = ns.core.CommandLine()
cmd.Parse(argv)
#
# But since this is a realtime script, don't allow the user to mess with
# that.
#
ns.core.GlobalValue.Bind("SimulatorImplementationType", ns.core.StringValue("ns3::RealtimeSimulatorImpl"))
#
# Explicitly create the nodes required by the topology (shown above).
#
print "Create nodes."
n = ns.network.NodeContainer()
n.Create(4)
internet = ns.internet.InternetStackHelper()
internet.Install(n)
#
# Explicitly create the channels required by the topology (shown above).
#
print ("Create channels.")
csma = ns.csma.CsmaHelper()
csma.SetChannelAttribute("DataRate", ns.network.DataRateValue(ns.network.DataRate(5000000)))
csma.SetChannelAttribute("Delay", ns.core.TimeValue(ns.core.MilliSeconds(2)));
csma.SetDeviceAttribute("Mtu", ns.core.UintegerValue(1400))
d = csma.Install(n)
#
# We've got the "hardware" in place. Now we need to add IP addresses.
#
print ("Assign IP Addresses.")
ipv4 = ns.internet.Ipv4AddressHelper()
ipv4.SetBase(ns.network.Ipv4Address("10.1.1.0"), ns.network.Ipv4Mask("255.255.255.0"))
i = ipv4.Assign(d)
print ("Create Applications.")
#
# Create a UdpEchoServer application on node one.
#
port = 9 # well-known echo port number
server = ns.applications.UdpEchoServerHelper(port)
apps = server.Install(n.Get(1))
apps.Start(ns.core.Seconds(1.0))
apps.Stop(ns.core.Seconds(10.0))
#
# Create a UdpEchoClient application to send UDP datagrams from node zero to
# node one.
#
packetSize = 1024
maxPacketCount = 500
interPacketInterval = ns.core.Seconds(0.01)
client = ns.applications.UdpEchoClientHelper(i.GetAddress (1), port)
client.SetAttribute("MaxPackets", ns.core.UintegerValue(maxPacketCount))
client.SetAttribute("Interval", ns.core.TimeValue(interPacketInterval))
client.SetAttribute("PacketSize", ns.core.UintegerValue(packetSize))
apps = client.Install(n.Get(0))
apps.Start(ns.core.Seconds(2.0))
apps.Stop(ns.core.Seconds(10.0))
ascii = ns.network.AsciiTraceHelper()
csma.EnableAsciiAll(ascii.CreateFileStream("realtime-udp-echo.tr"))
csma.EnablePcapAll("realtime-udp-echo", False)
#
# Now, do the actual simulation.
#
print ("Run Simulation.")
ns.core.Simulator.Run()
ns.core.Simulator.Destroy()
print ("Done.")
if __name__ == '__main__':
import sys
main(sys.argv)
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