Programming Assignment 2: Using Mininet and Mininet Python API

CustomTopo.py

#!/usr/bin/env python
'''
Coursera:
- Software Defined Networking (SDN) course
-- Programming Assignment 2

Professor: Nick Feamster
Teaching Assistant: Arpit Gupta, Muhammad Shahbaz
'''

from mininet.topo import Topo
from mininet.net import Mininet
from mininet.link import TCLink
from mininet.util import irange,dumpNodeConnections
from mininet.log import setLogLevel
from CustomTopo import *

class CustomTopo(Topo):
    "Simple Data Center Topology"
    "linkopts - (1:core, 2:aggregation, 3: edge) parameters"
    "fanout - number of child switch per parent switch"
    setLogLevel("info")
    def __init__(self, linkopts1, linkopts2, linkopts3, fanout=2, **opts):
        #logger.info("Initialize topology and default options")
        Topo.__init__(self, **opts)
        self.fanout = fanout
     
        core_sw = self.addSwitch('c1')
        #logger.debug("create core switch: " + core_sw)
        for i in irange(1, fanout):
            #logger.debug("create aggregation switch: " + str(i))
            aggregation_sw = self.addSwitch('a%s' %i)
            self.addLink(core_sw, aggregation_sw, **linkopts1)
            for j in irange(1, fanout):
                #logger.debug("create edge switch: " + str(j))
                edge_sw_number = fanout * (i-1) + j
                edge_sw = self.addSwitch('e%s' %edge_sw_number)
                self.addLink(aggregation_sw, edge_sw, **linkopts2) 
                for k in irange(1, fanout):
                    #logger.debug("create host: " + str(k))
                    host_number = fanout * (edge_sw_number - 1 )+ k
                    host = self.addHost('h%s' %host_number)
                    self.addLink(edge_sw, host, **linkopts3)
                    
topos = { 'custom': ( lambda: CustomTopo() ) }
'''
def SimpleTest():
    "Set up link parameters"
    print "a. Setting link parameters"
    "--- core to aggregation switches"
    linkopts1 = {'bw':50, 'delay':'5ms'}
    "--- aggregation to edge switches"
    linkopts2 = {'bw':30, 'delay':'10ms'}
    "--- edge switches to hosts"
    linkopts3 = {'bw':10, 'delay':'15ms'}

    "Creating network and run simple performance test"
    print "b. Creating Custom Topology"
    topo = CustomTopo(linkopts1, linkopts2, linkopts3, fanout=3)

    print "c. Firing up Mininet"
    net = Mininet(topo=topo, link=TCLink)
    net.start()
    dumpNodeConnections(net.hosts)
    h1 = net.get('h1')
    h27 = net.get('h27')

    print "d. Starting Test"
    # Start pings
    outputString = h1.cmd('ping', '-c6', h27.IP())

    print "e. Stopping Mininet"
    net.stop()


if __name__ == '__main__':
    #logging.basicConfig(level=logging.DEBUG)
    #logger = logging.getLogger("sdn2")
    SimpleTest()
'''