Changed emulator design and started to create the emuvim Mininet wrapper layer.
diff --git a/emuvim/__init__.py b/emuvim/api/__init__.py
similarity index 100%
rename from emuvim/__init__.py
rename to emuvim/api/__init__.py
diff --git a/emuvim/__init__.py b/emuvim/cli/__init__.py
similarity index 100%
copy from emuvim/__init__.py
copy to emuvim/cli/__init__.py
diff --git a/emuvim/__init__.py b/emuvim/cli/__main__.py
similarity index 100%
copy from emuvim/__init__.py
copy to emuvim/cli/__main__.py
diff --git a/emuvim/dcemulator/__init__.py b/emuvim/dcemulator/__init__.py
new file mode 100644
index 0000000..64f6616
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+++ b/emuvim/dcemulator/__init__.py
@@ -0,0 +1,4 @@
+"""
+Distributed Cloud Emulator (dcemulator)
+(c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
+"""
\ No newline at end of file
diff --git a/emuvim/__init__.py b/emuvim/dcemulator/link.py
similarity index 100%
copy from emuvim/__init__.py
copy to emuvim/dcemulator/link.py
diff --git a/emuvim/dcemulator/net.py b/emuvim/dcemulator/net.py
new file mode 100644
index 0000000..8ea41a7
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+++ b/emuvim/dcemulator/net.py
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+"""
+Distributed Cloud Emulator (dcemulator)
+(c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
+"""
+import logging
+
+from mininet.net import Mininet
+from mininet.node import Controller, OVSKernelSwitch, Switch
+from mininet.cli import CLI
+from mininet.log import setLogLevel, info
+from mininet.link import TCLink, Link
+
+from node import Datacenter
+
+
+class DCNetwork(object):
+
+    def __init__(self):
+        self.dcs = {}
+        self.switches = {}
+        self.links = []
+
+        # create a Mininet/Dockernet network
+        setLogLevel('info')  # set Mininet loglevel
+        self.mnet = Mininet(controller=Controller, switch=OVSKernelSwitch)
+        self.mnet.addController('c0')
+
+    def addDatacenter(self, name):
+        """
+        Create and add a logical cloud data center to the network.
+        """
+        if name in self.dcs:
+            raise Exception("Data center name already exists: %s" % name)
+        dc = Datacenter(name)
+        dc.net = self  # set reference to network
+        self.dcs[name] = dc
+        dc.create()  # finally create the data center in our Mininet instance
+        logging.info("added data center: %s" % name)
+        return dc
+
+    def addSwitch(self, name):
+        """
+        We can also add additional SDN switches between data centers.
+        """
+        s = self.mnet.addSwitch(name)
+        self.switches[name] = s
+        logging.info("added switch: %s" % name)
+        return s
+
+    def addLink(self, node1, node2):
+        assert node1 is not None
+        assert node2 is not None
+        # ensure type of node1
+        if isinstance( node1, basestring ):
+            if node1 in self.dcs:
+                node1 = self.dcs[node1].switch
+            elif node1 in self.switches:
+                node1 = self.switches[node1]
+        if isinstance( node1, Datacenter ):
+            node1 = node1.switch
+        # ensure type of node2
+        if isinstance( node2, basestring ):
+            if node2 in self.dcs:
+                node2 = self.dcs[node2].switch
+            elif node2 in self.switches:
+                node2 = self.switches[node2]
+        if isinstance( node2, Datacenter ):
+            node2 = node2.switch
+        # create link if everything is correct
+        if (node1 is not None and isinstance(node1, OVSKernelSwitch)
+                and node2 is not None and isinstance(node2, OVSKernelSwitch)):
+            self.mnet.addLink(node1, node2)  # TODO we need TCLinks with user defined performance her
+        else:
+            raise Exception(
+                "one of the given nodes is not a Mininet switch or None")
+
+    def start(self):
+        # start
+        for dc in self.dcs.itervalues():
+            dc.start()
+        self.mnet.start()
+
+    def stop(self):
+        self.mnet.stop()
+
+    def CLI(self):
+        CLI(self.mnet)
+
diff --git a/emuvim/dcemulator/node.py b/emuvim/dcemulator/node.py
new file mode 100644
index 0000000..b12751f
--- /dev/null
+++ b/emuvim/dcemulator/node.py
@@ -0,0 +1,46 @@
+"""
+Distributed Cloud Emulator (dcemulator)
+(c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
+"""
+import logging
+
+
+DCDPID_BASE = 1000  # start of switch dpid's used for data center switches
+
+
+class Datacenter(object):
+    """
+    Represents a logical data center to which compute resources
+    (Docker containers) can be added at runtime.
+    """
+
+    def __init__(self, name):
+        self.net = None  # DCNetwork to which we belong
+        self.name = name
+        self.switch = None  # first prototype assumes one "bigswitch" per DC
+
+    def _get_next_dc_dpid(self):
+        global DCDPID_BASE
+        DCDPID_BASE += 1
+        return DCDPID_BASE
+
+    def create(self):
+        """
+        Each data center is represented by a single switch to which
+        compute resources can be connected at run time.
+
+        TODO: This will be changes in the future to support multiple networks
+        per data center
+        """
+        self.switch = self.net.mnet.addSwitch(
+            "%s.s1" % self.name, dpid=hex(self._get_next_dc_dpid())[2:])
+        logging.debug("created data center switch: %s" % str(self.switch))
+
+    def start(self):
+        pass
+
+    def addCompute(self):
+        pass
+
+    def removeCompute(self):
+        pass
diff --git a/emuvim/example_topology.py b/emuvim/example_topology.py
new file mode 100644
index 0000000..f2be310
--- /dev/null
+++ b/emuvim/example_topology.py
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+"""
+This is an example topology for the distributed cloud emulator (dcemulator).
+(c) 2015 by Manuel Peuster <manuel.peuster@upb.de>
+
+The original Mininet API has to be completely hidden and not be used by this
+script.
+"""
+import logging
+from dcemulator.net import DCNetwork
+
+logging.basicConfig(level=logging.DEBUG)
+
+
+def create_topology1():
+    # initialize network
+    net = DCNetwork()
+
+    # add data centers
+    dc1 = net.addDatacenter("dc1")
+    dc2 = net.addDatacenter("dc2")
+    dc3 = net.addDatacenter("dc3")
+    dc4 = net.addDatacenter("dc4")
+    # add additional SDN switches to our topology
+    s1 = net.addSwitch("s1")
+    # add links between data centers
+    net.addLink(dc1, dc2)
+    net.addLink("dc1", s1)
+    net.addLink(s1, "dc3")
+    net.addLink(s1, dc4)
+    # start network
+    net.start()
+    net.CLI()  # TODO remove this when we integrate APIs?
+    net.stop()  # TODO remove this when we integrate APIs?
+    # start APIs (to access emulated cloud data centers)
+    pass  # TODO: how to reflect one API endpoint per DC?
+
+
+def main():
+    create_topology1()
+
+
+if __name__ == '__main__':
+    main()