Simple performance test of mininet experiment setting bandwidth

write in front

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Reference for this experiment

• This experiment was written about Opendaylight, but it doesn't seem to have anything to do with ODL, and the local controller POX is used.
• It is worth noting: After the experiment, be sure to use the mn -c command to clean up the process . Otherwise, problems such as ping failure between hosts and port occupation will be caused.
• Although it was a simple experiment, I had a deeper understanding of the virtual controller and a deeper understanding of the word software in SDN by asking the teacher during the process .

Experimental ideas

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• Python script to implement custom topology
• Set the bandwidth, delay and packet loss rate of the link
• iperf tests bandwidth performance between hosts

In short, one script solves all problems. The core of this experiment is to read the script.

Experimental topology

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Experimental procedure

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1. Build the environment

• Install mininet virtual machine

2. Create a script

• Enter the mininet/custom directory, create the script mymininet.py and add the content:

#!/usr/bin/python

from mininet.topo import Topo
from mininet.net import Mininet
from mininet.node import CPULimitedHost
from mininet.link import TCLink
from mininet.util import dumpNodeConnections
from mininet.log import setLogLevel

class SingleSwitchTopo(Topo):
    "Single switch connected to n hosts."
    def __init__(self, n=2, **opts):
        Topo.__init__(self, **opts)
        switch = self.addSwitch('s1')
        for h in range(n):
            #Each host gets 50%/n of system CPU
            host = self.addHost('h%s' % (h + 1), cpu=.5/n)
            #10 Mbps, 5ms delay, 0% Loss, 1000 packet queue
            self.addLink(host, switch, bw=10, delay='5ms', loss=0, max_queue_size=1000, use_htb=True)

def perfTest():
    "Create network and run simple performance test"
    topo = SingleSwitchTopo(n=4)
    net = Mininet(topo=topo,host=CPULimitedHost, link=TCLink)
    net.start()
    print "Dumping host connections"
    dumpNodeConnections(net.hosts)
    print "Testing network connectivity"
    net.pingAll()
    print "Testing bandwidth between h1 and h4"
    h1, h4 = net.get('h1', 'h4')
    net.iperf((h1, h4))
    net.stop()

if __name__=='__main__':
    setLogLevel('info')
    perfTest()

• This script has everything written, including the bandwidth settings of the link, the pingall command, and the iperf command. Just run the watch process.
• Understanding the script is the key!

run script

python mymininet.py
或者
chmod +x mymininet.py #添加文件执行属性
./mymininet.py

Effect screenshot

Experiment Summary and Precautions

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• Create a Mininet script through a python script, set the bandwidth, delay, packet loss rate, etc. (bw=10, delay='5ms', loss=0, max_queue_size=1000, use_htb=True) between device links, and have A limiting role, and testing performance between hosts through iperf.
• Note: mn -c cleans up the process .