add a new type of RemoteLink in cluster edition that uses GRE tunnels

examples/clusterperf.py

@@ -0,0 +1,22 @@
+#!/usr/bin/python
+
+"clusterperf.py compare the maximum throughput between SSH and GRE tunnels"
+
+from mininet.examples.cluster import RemoteSSHLink, RemoteGRELink, RemoteHost
+from mininet.net import Mininet
+from mininet.log import setLogLevel
+
+def perf(Link):
+    net = Mininet( host=RemoteHost, link=Link )
+    h1 = net.addHost( 'h1')
+    h2 = net.addHost( 'h2', server='ubuntu2' )
+    net.addLink( h1, h2 )
+    net.start()
+    net.pingAll()
+    net.iperf()
+    net.stop()
+
+if __name__ == '__main__':
+    setLogLevel('info')
+    perf(RemoteSSHLink)
+    perf(RemoteGRELink)