def topology():
"Create a network."
net = Mininet(controller=Controller, link=TCLink, accessPoint=OVSKernelAP)
print "*** Creating nodes"
sta1 = net.addStation('sta1', ip="192.168.0.1/24")
sta2 = net.addStation('sta2', ip="192.168.0.2/24")
sta3 = net.addStation('sta3', ip="192.168.0.3/24")
sta4 = net.addStation('sta4', ip="192.168.0.4/24")
ap1 = net.addAccessPoint('ap1', ssid="ssid_1", mode="g", channel="1")
ap2 = net.addAccessPoint('ap2', ssid="ssid_1", mode="g", channel="1")
c0 = net.addController('c0',
controller=Controller,
ip='127.0.0.1',
port=6653)
net.runAlternativeModule('./mac80211_hwsim.ko')
print "*** Configuring wifi nodes"
net.configureWifiNodes()
print "*** Adding Link"
net.addLink(ap1, ap2, link='wds')
net.addLink(sta1, ap1)
net.addLink(sta2, ap1)
net.addLink(sta3, ap2)
net.addLink(sta4, ap2)
print "*** Starting network"
net.build()
c0.start()
ap1.start([c0])
ap2.start([c0])
print "*** Running CLI"
CLI(net)
print "*** Stopping network"
net.stop()
