FIX: Data centers now have a user defined label (to be identified) but use a short internal name 'dc%d' to avoid too long host/switch names causing Mininet to crash.
diff --git a/emuvim/dcemulator/net.py b/emuvim/dcemulator/net.py
index eace03a..2c7e106 100644
--- a/emuvim/dcemulator/net.py
+++ b/emuvim/dcemulator/net.py
@@ -29,17 +29,17 @@
             self, controller=Controller, switch=OVSKernelSwitch, **kwargs)
         self.addController('c0')
 
-    def addDatacenter(self, name):
+    def addDatacenter(self, label):
         """
         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)
+        if label in self.dcs:
+            raise Exception("Data center label already exists: %s" % label)
+        dc = Datacenter(label)
         dc.net = self  # set reference to network
-        self.dcs[name] = dc
+        self.dcs[label] = dc
         dc.create()  # finally create the data center in our Mininet instance
-        logging.info("added data center: %s" % name)
+        logging.info("added data center: %s" % label)
         return dc
 
     def addLink(self, node1, node2, **params):
@@ -76,11 +76,11 @@
 
         return Dockernet.addLink(self, node1, node2, **params)  # TODO we need TCLinks with user defined performance here
 
-    def addDocker( self, name, **params ):
+    def addDocker( self, label, **params ):
         """
         Wrapper for addDocker method to use custom container class.
         """
-        return Dockernet.addDocker(self, name, cls=EmulatorCompute, **params)
+        return Dockernet.addDocker(self, label, cls=EmulatorCompute, **params)
 
     def getAllContainers(self):
         """
diff --git a/emuvim/dcemulator/node.py b/emuvim/dcemulator/node.py
index 0e6eae8..6d615b5 100644
--- a/emuvim/dcemulator/node.py
+++ b/emuvim/dcemulator/node.py
@@ -52,7 +52,7 @@
         status["state"] = self.dcli.inspect_container(self.dc)["State"]
         status["id"] = self.dcli.inspect_container(self.dc)["Id"]
         status["datacenter"] = (None if self.datacenter is None
-                                else self.datacenter.name)
+                                else self.datacenter.label)
         return status
 
 
@@ -64,9 +64,15 @@
     Will also implement resource bookkeeping in later versions.
     """
 
-    def __init__(self, name):
+    DC_COUNTER = 1
+
+    def __init__(self, label):
         self.net = None  # DCNetwork to which we belong
-        self.name = name
+        # each node (DC) has a short internal name used by Mininet
+        # this is caused by Mininets naming limitations for swtiches etc.
+        self.name = "dc%d" % Datacenter.DC_COUNTER
+        Datacenter.DC_COUNTER += 1
+        self.label = label  # use this for user defined names
         self.switch = None  # first prototype assumes one "bigswitch" per DC
         self.containers = {}  # keep track of running containers