111 lines
3.0 KiB
Python
111 lines
3.0 KiB
Python
#
|
|
# * SPDX-License-Identifier: GPL-2.0-only
|
|
|
|
# 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"
|
|
|
|
try:
|
|
from ns import ns
|
|
except ModuleNotFoundError:
|
|
raise SystemExit(
|
|
"Error: ns3 Python module not found;"
|
|
" Python bindings may not be enabled"
|
|
" or your PYTHONPATH might not be properly configured"
|
|
)
|
|
|
|
|
|
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.CommandLine()
|
|
cmd.Parse(argv)
|
|
|
|
#
|
|
# But since this is a realtime script, don't allow the user to mess with
|
|
# that.
|
|
#
|
|
ns.GlobalValue.Bind("SimulatorImplementationType", ns.StringValue("ns3::RealtimeSimulatorImpl"))
|
|
|
|
#
|
|
# Explicitly create the nodes required by the topology (shown above).
|
|
#
|
|
print("Create nodes.")
|
|
n = ns.NodeContainer()
|
|
n.Create(4)
|
|
|
|
internet = ns.InternetStackHelper()
|
|
internet.Install(n)
|
|
|
|
#
|
|
# Explicitly create the channels required by the topology (shown above).
|
|
#
|
|
print("Create channels.")
|
|
csma = ns.CsmaHelper()
|
|
csma.SetChannelAttribute("DataRate", ns.DataRateValue(ns.DataRate(5000000)))
|
|
csma.SetChannelAttribute("Delay", ns.TimeValue(ns.MilliSeconds(2)))
|
|
csma.SetDeviceAttribute("Mtu", ns.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.Ipv4AddressHelper()
|
|
ipv4.SetBase(ns.Ipv4Address("10.1.1.0"), ns.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.UdpEchoServerHelper(port)
|
|
apps = server.Install(n.Get(1))
|
|
apps.Start(ns.Seconds(1))
|
|
apps.Stop(ns.Seconds(10))
|
|
|
|
#
|
|
# Create a UdpEchoClient application to send UDP datagrams from node zero to
|
|
# node one.
|
|
#
|
|
packetSize = 1024
|
|
maxPacketCount = 500
|
|
interPacketInterval = ns.Seconds(0.01)
|
|
client = ns.UdpEchoClientHelper(i.GetAddress(1).ConvertTo(), port)
|
|
client.SetAttribute("MaxPackets", ns.UintegerValue(maxPacketCount))
|
|
client.SetAttribute("Interval", ns.TimeValue(interPacketInterval))
|
|
client.SetAttribute("PacketSize", ns.UintegerValue(packetSize))
|
|
apps = client.Install(n.Get(0))
|
|
apps.Start(ns.Seconds(2))
|
|
apps.Stop(ns.Seconds(10))
|
|
|
|
ascii = ns.AsciiTraceHelper()
|
|
csma.EnableAsciiAll(ascii.CreateFileStream("realtime-udp-echo.tr"))
|
|
csma.EnablePcapAll("realtime-udp-echo", False)
|
|
|
|
#
|
|
# Now, do the actual simulation.
|
|
#
|
|
print("Run Simulation.")
|
|
ns.Simulator.Stop(ns.Seconds(10))
|
|
ns.Simulator.Run()
|
|
ns.Simulator.Destroy()
|
|
print("Done.")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
import sys
|
|
|
|
main(sys.argv)
|