diff --git a/bridge_master.py b/bridge_master.py
index 237fdae..e2f3576 100644
--- a/bridge_master.py
+++ b/bridge_master.py
@@ -38,6 +38,7 @@ from time import time,sleep,perf_counter
 import importlib.util
 import re
 import copy
+import json
 from setproctitle import setproctitle
 
 #from crccheck.crc import Crc32
@@ -409,6 +410,15 @@ def subMapWrite():
     except:
         logger.warning('(SUBSCRIBER) Cannot write SUB_MAP to file')
         
+def topoWrite():
+    try:
+        _fh = open(CONFIG['ALIASES']['PATH'] + CONFIG['ALIASES']['TOPO_FILE'],'w')
+        json.dump(TOPO,_fh)
+        _fh.close()
+        logger.info('(TOPO) Writing topography file to disk')
+    except:
+        logger.warning('(TOPO) Cannot write topography file to disk')
+        
 #Subscriber Map trimmer loop
 def SubMapTrimmer():
     logger.debug('(SUBSCRIBER) Subscriber Map trimmer loop started')
@@ -552,9 +562,8 @@ def topoTrimmer():
         if len(TOPO[_src]) == 0:
             _toprem.append(_src)
     for _remove in _toprem:
-        TOPO.pop(_remove)
-        
-    print(TOPO)
+        TOPO.pop(_remove)        
+    topoWrite()
             
                 
 
@@ -2933,6 +2942,9 @@ if __name__ == '__main__':
         reactor.stop()
         if CONFIG['ALIASES']['SUB_MAP_FILE']:
             subMapWrite()
+        if CONFIG['ALIASES']['TOPO_FILE']:
+            topoWrite()
+        
 
     # Set signal handers so that we can gracefully exit if need be
     for sig in [signal.SIGINT, signal.SIGTERM]:
@@ -3149,7 +3161,7 @@ if __name__ == '__main__':
     
     #topography trimmer
     topo_trimmer_task = task.LoopingCall(topoTrimmer)
-    topo_trimmer = topo_trimmer_task.start(610)
+    topo_trimmer = topo_trimmer_task.start(10)#610
     topo_trimmer.addErrback(loopingErrHandle)
     
     
diff --git a/config.py b/config.py
index 15caf6d..1cb289b 100755
--- a/config.py
+++ b/config.py
@@ -186,7 +186,9 @@ def build_config(_config_file):
                     'SUB_MAP_FILE': config.get(section, 'SUB_MAP_FILE'),
                     'LOCAL_SUBSCRIBER_FILE': config.get(section, 'LOCAL_SUBSCRIBER_FILE'),
                     'SERVER_ID_URL': config.get(section, 'SERVER_ID_URL'),
-                    'SERVER_ID_FILE': config.get(section, 'SERVER_ID_FILE')
+                    'SERVER_ID_FILE': config.get(section, 'SERVER_ID_FILE'),
+                    'TOPO_FILE': config.get(section, 'TOPO_FILE'),
+                    
                     
                 })
                 
diff --git a/hblink.py b/hblink.py
index 8611954..adac2a3 100755
--- a/hblink.py
+++ b/hblink.py
@@ -269,10 +269,12 @@ class OPENBRIDGE(DatagramProtocol):
             logger.trace('(%s) *BridgeControl* not sending BCVE, TARGET_IP currently not known',self._system) 
 
     def send_my_bcto(self):
+        _hops = 1
+        _hops = _hops.to_bytes(1,'big')
         for system in self._CONFIG['SYSTEMS']:
             if self._CONFIG['SYSTEMS'][system]['MODE'] == 'OPENBRIDGE' and self._CONFIG['SYSTEMS'][system]['VER'] > 5:
                 if self._config['ENHANCED_OBP'] and self._config['TARGET_IP']:
-                    _packet = b''.join([BCTO,self._CONFIG['GLOBAL']['SERVER_ID'],self._CONFIG['SYSTEMS'][system]['NETWORK_ID'],self._CONFIG['SYSTEMS'][system]['VER'].to_bytes(1,"big")])
+                    _packet = b''.join([BCTO,self._CONFIG['GLOBAL']['SERVER_ID'],self._CONFIG['SYSTEMS'][system]['NETWORK_ID'],self._CONFIG['SYSTEMS'][system]['VER'].to_bytes(1,"big"),_hops])
                     _h = blake2b(key=self._config['PASSPHRASE'], digest_size=16)
                     _h.update(_packet)
                     _hash = _h.digest()
@@ -283,17 +285,19 @@ class OPENBRIDGE(DatagramProtocol):
                     logger.trace('(%s) *BridgeControl* not sending BCTO, TARGET_IP currently not known. DST: %s, VER: %s ',self._system,int_id(self._CONFIG['SYSTEMS'][system]['NETWORK_ID']),self._CONFIG['SYSTEMS'][system]['VER'])
                 
                 
-    def retransmit_bcto(self,_string):
+    def retransmit_bcto(self,_string,_hops):
+        _hops += 1
+        _hops = _hops.to_bytes(1,'big')
         for system in self._CONFIG['SYSTEMS']:
             if self._CONFIG['SYSTEMS'][system]['MODE'] == 'OPENBRIDGE' and self._CONFIG['SYSTEMS'][system]['VER'] > 5:
                 if self._config['ENHANCED_OBP'] and self._config['TARGET_IP']:
-                    _packet = b''.join([BCTO,_string])
+                    _packet = b''.join([BCTO,_string,_hops])
                     _h = blake2b(key=self._config['PASSPHRASE'], digest_size=16)
                     _h.update(_packet)
                     _hash = _h.digest()
                     _packet = b''.join([_packet,_hash])
                     self.transport.write(_packet, (self._config['TARGET_IP'], self._config['TARGET_PORT']))
-                    logger.trace('(%s) *BridgeControl* retransmitted BCTO.')
+                    logger.trace('(%s) *BridgeControl* retransmitted BCTO.',self._system)
                 else:
                     logger.trace('(%s) *BridgeControl* not retransmitting BCTO, TARGET_IP currently not known.',self._system)
             
@@ -751,9 +755,14 @@ class OPENBRIDGE(DatagramProtocol):
                         _src[4:8]
                         _dst[8:12]
                         _ver[12:13]
+                        _hops[13:14]
                         if _hash == _hash2:
                             logger.trace('(%s) *ProtoControl* BCTO received: %s connected to %s with proto ver. %s'. self._system, int_id(_src), int_id(_dst), int.from_bytes_ver,'big')
-                            self.retransmit_bcto(_packet[:13])
+                            if (int(_hops.from_bytes('big')) < 10):
+                                retransmit_bcto(_packet[:14])
+                            else:
+                                if _hops > 10:
+                                    logger.trace('(%s) *BridgeControl* not retransmitting BCTO - hop count exceeded',self._system)
                             self.process_bcto(src,dst,ver)
                         else:
                             h,p = _sockaddr