diff --git a/connMgr.py b/connMgr.py
new file mode 100644
index 0000000..5735219
--- /dev/null
+++ b/connMgr.py
@@ -0,0 +1,143 @@
+
+
+
+# Connection Manager
+
+# This module is informed by the several state machines in case of good connection.
+#   It calculates an overall ConnectionLevel.
+#   This ConnectionLevel is provided to the state machines, so that each state machine
+#   has the possiblity to decide whether it needs to do something or just stays silent.
+#   
+#   The basic rule is, that a good connection on higher layer (e.g. TCP) implicitely
+#   confirms the good connection on lower layer (e.g. Modem presence). This means,
+#   the lower-layer state machine can stay silent as long as the upper layers are working
+#   fine.
+
+CONNLEVEL_100_APPL_RUNNING = 100
+CONNLEVEL_80_TCP_RUNNING = 80
+CONNLEVEL_50_SDP_DONE = 50
+CONNLEVEL_20_TWO_MODEMS_FOUND = 20
+CONNLEVEL_15_SLAC_ONGOING = 15
+CONNLEVEL_10_ONE_MODEM_FOUND = 10
+CONNLEVEL_5_ETH_LINK_PRESENT = 5
+
+CONNMGR_TIMER_MAX = (5*33) # 5 seconds until an OkReport is forgotten.
+CONNMGR_TIMER_MAX_10s = (10*33) # 10 seconds until an OkReport is forgotten.
+CONNMGR_TIMER_MAX_15s = (15*33) # 15 seconds until an OkReport is forgotten.
+
+
+class connMgr():
+    def getConnectionLevel(self):
+        return self.ConnectionLevel
+
+    def __init__(self, callbackAddToTrace, callbackShowStatus):
+        self.timerEthLink = 0
+        self.timerModemLocal = 0
+        self.timerModemRemote = 0
+        self.timerSlac = 0
+        self.timerSDP = 0
+        self.timerTCP = 0
+        self.timerAppl = 0
+        self.ConnectionLevel = 0
+        self.ConnectionLevelOld = 0
+        self.cycles = 0
+        self.addToTrace = callbackAddToTrace
+        
+    def mainfunction(self):
+        # count all the timers down
+        if (self.timerEthLink>0):
+            self.timerEthLink-=1
+        if (self.timerModemLocal>0):
+            self.timerModemLocal-=1
+        if (self.timerModemRemote>0):
+            self.timerModemRemote-=1
+        if (self.timerSlac>0):
+            self.timerSlac-=1
+        if (self.timerSDP>0):
+            self.timerSDP-=1
+        if (self.timerTCP>0):
+            self.timerTCP-=1
+        if (self.timerAppl>0):
+            self.timerAppl-=1
+        # Based on the timers, calculate the connectionLevel.
+        if (self.timerAppl>0):
+            self.ConnectionLevel=CONNLEVEL_100_APPL_RUNNING
+        else:
+            if (self.timerTCP>0):
+                self.ConnectionLevel=CONNLEVEL_80_TCP_RUNNING
+            else:
+                if (self.timerSDP>0):
+                    self.ConnectionLevel=CONNLEVEL_50_SDP_DONE
+                else:
+                    if (self.timerModemRemote>0):
+                        self.ConnectionLevel=CONNLEVEL_20_TWO_MODEMS_FOUND
+                    else:
+                        if (self.timerSlac>0):
+                            self.ConnectionLevel=CONNLEVEL_15_SLAC_ONGOING
+                        else:
+                            if (self.timerModemLocal>0):
+                                self.ConnectionLevel=CONNLEVEL_10_ONE_MODEM_FOUND
+                            else:
+                                if (self.timerEthLink>0):
+                                    self.ConnectionLevel=CONNLEVEL_5_ETH_LINK_PRESENT
+                                else:
+                                    self.ConnectionLevel=0
+        if (self.ConnectionLevelOld!=self.ConnectionLevel):
+            self.addToTrace("[CONNMGR] ConnectionLevel changed from " + str(self.ConnectionLevelOld) + " to " + str(self.ConnectionLevel))
+            self.ConnectionLevelOld = self.ConnectionLevel
+        self.cycles+=1
+
+    def ModemFinderOk(self, numberOfFoundModems):
+        if (numberOfFoundModems>=1):
+            self.timerModemLocal = CONNMGR_TIMER_MAX
+        if (numberOfFoundModems>=2):
+            self.timerModemRemote = CONNMGR_TIMER_MAX_10s # 10s for the slac sequence, to avoid too fast timeout
+
+    def SlacOk(self):
+        # The SetKey was sent to the local modem. This leads to restart of the
+        # local modem, and potenially also for the remote modem. If both modems are up,
+        # they need additional time to pair. We need to be patient during this process. */
+        self.timerSlac = CONNMGR_TIMER_MAX_15s
+
+    def SdpOk(self):
+        self.timerSDP = CONNMGR_TIMER_MAX
+
+    def TcpOk(self):
+        self.timerTCP = CONNMGR_TIMER_MAX
+
+    def ApplOk(self):
+        self.timerAppl = CONNMGR_TIMER_MAX
+
+
+def testCallbackAddToTrace(s):
+    print("callbackAddToTrace: " + s)
+
+def testCallbackShowStatus(s):
+    print("callbackShowStatus: " + s)
+
+if __name__ == "__main__":
+    print("Testing ConnectionManager...")
+    cm = connMgr(testCallbackAddToTrace, testCallbackShowStatus)
+    print("connection level " + str(cm.getConnectionLevel()))
+    cm.mainfunction()
+    print("connection level " + str(cm.getConnectionLevel()))
+    cm.SlacOk()
+    cm.mainfunction()
+    print("connection level " + str(cm.getConnectionLevel()))
+    for i in range(1000):
+        cm.mainfunction()
+    cm.ModemFinderOk(1)
+    for i in range(1000):
+        cm.mainfunction()
+    cm.ModemFinderOk(2)
+    for i in range(1000):
+        cm.mainfunction()
+    cm.SdpOk()
+    for i in range(1000):
+        cm.mainfunction()
+    cm.TcpOk()
+    for i in range(1000):
+        cm.mainfunction()
+    cm.ApplOk()
+    for i in range(1000):
+        cm.mainfunction()