diff --git a/src/client.py b/src/client.py
--- a/src/client.py
+++ b/src/client.py
@@ -8,11 +8,12 @@ import config as conf
 import stats
 from util import Progress
 from hashtree import HashTree,hashBlock
-from networkers import NetworkReader,NetworkWriter
+from netnode import BaseConnection,NetNode
 
 
-class Connection:
+class Connection(BaseConnection):
 	def __init__(self):
+		super().__init__()
 		sock=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 
 		sslContext=ssl.create_default_context(cafile=conf.peers)
@@ -21,34 +22,14 @@ class Connection:
 
 		self._socket=sslContext.wrap_socket(sock)
 		self._socket.connect((conf.hosts[0], conf.port))
-		fr=self._socket.makefile(mode="rb")
-		fw=self._socket.makefile(mode="wb")
 
-		self.incoming=NetworkReader(fr)
-		self.outcoming=NetworkWriter(fw)
-
-	def __enter__(self):
-		return self.incoming,self.outcoming
-
-	def __exit__(self, exc_type, exc_val, exc_tb):
-		self._socket.shutdown(socket.SHUT_RDWR)
-		self._socket.close()
+		self.createNetworkers()
 
 
-class Client:
+class Client(NetNode):
 	def __init__(self,filename,treeFile=""):
-		self._incoming=None
-		self._outcoming=None
-		self._filename=filename
-		self._treeFile=treeFile
-
 		print(datetime.now(), "initializing...")
-		if treeFile:
-			self._tree=HashTree.load(treeFile)
-		else:
-			self._tree=HashTree.fromFile(filename)
-
-		self._newLeaves=dict()
+		super().__init__(filename,treeFile)
 
 	## Asks server for node hashes to determine which are to be transferred.
 	#
@@ -157,10 +138,7 @@ class Client:
 		dataFile.close()
 
 		if self._treeFile:
-			log.info("updating hash tree...")
-			for (k,v) in self._newLeaves.items():
-				self._tree.updateLeaf(k, v)
-			self._tree.save(self._treeFile)
+			self._updateTree()
 
 	def setConnection(self,connection):
 		(self._incoming,self._outcoming)=connection
diff --git a/src/netnode.py b/src/netnode.py
new file mode 100644
--- /dev/null
+++ b/src/netnode.py
@@ -0,0 +1,48 @@
+import socket
+import logging as log
+
+from networkers import NetworkReader,NetworkWriter
+from hashtree import HashTree
+
+
+class BaseConnection: # abstract
+	def __init__(self):
+		self._socket=None
+		self.incoming=None
+		self.outcoming=None
+
+	def createNetworkers(self):
+		fr=self._socket.makefile(mode="rb")
+		fw=self._socket.makefile(mode="wb")
+
+		self.incoming=NetworkReader(fr)
+		self.outcoming=NetworkWriter(fw)
+
+	def __enter__(self):
+		return self.incoming,self.outcoming
+
+	def __exit__(self, exc_type, exc_val, exc_tb):
+		self._socket.shutdown(socket.SHUT_RDWR)
+		self._socket.close()
+
+
+class NetNode:
+	def __init__(self,filename,treeFile=""):
+		self._incoming=None
+		self._outcoming=None
+
+		self._filename=filename
+		self._treeFile=treeFile
+
+		if treeFile:
+			self._tree=HashTree.load(treeFile)
+		else:
+			self._tree=HashTree.fromFile(filename)
+
+		self._newLeaves=dict()
+
+	def _updateTree(self):
+		log.info("updating hash tree...")
+		for (k,v) in self._newLeaves.items():
+			self._tree.updateLeaf(k, v)
+		self._tree.save(self._treeFile)
diff --git a/src/server.py b/src/server.py
--- a/src/server.py
+++ b/src/server.py
@@ -3,29 +3,20 @@ import ssl
 import multiprocessing
 import logging as log
 
-from hashtree import HashTree,hashBlock
-from networkers import NetworkReader,NetworkWriter
+from hashtree import hashBlock
+from netnode import BaseConnection,NetNode
 import config as conf
 
 
-class Connection:
+class Connection(BaseConnection):
 	def __init__(self,serverSocket,sslContext):
+		super().__init__()
+
 		sock, address = serverSocket.accept()
 		self._socket=sslContext.wrap_socket(sock,server_side=True)
 
 		log.info('Connected by {0}'.format(address))
-		fr=self._socket.makefile(mode="rb")
-		fw=self._socket.makefile(mode="wb")
-
-		self.incoming=NetworkReader(fr)
-		self.outcoming=NetworkWriter(fw)
-
-	def __enter__(self):
-		return self.incoming,self.outcoming
-
-	def __exit__(self, exc_type, exc_val, exc_tb):
-		self._socket.shutdown(socket.SHUT_RDWR)
-		self._socket.close()
+		self.createNetworkers()
 
 
 class Miniserver:
@@ -49,18 +40,11 @@ class Miniserver:
 				p.join()
 
 
-class Server:
+class Server(NetNode):
 	def __init__(self,connection,filename,treeFile=""):
+		super().__init__(filename,treeFile)
 		(self._incoming,self._outcoming)=connection
-		self._filename=filename
-		self._treeFile=treeFile
 
-		if treeFile:
-			self._tree=HashTree.load(treeFile)
-		else:
-			self._tree=HashTree.fromFile(filename)
-
-		self._newLeaves=dict()
 		self.BLOCK_SIZE=self._tree.BLOCK_SIZE
 
 		self._lastIndex=-1
@@ -148,8 +132,5 @@ class Server:
 		self._dataFile.close()
 		self._dataFileHandle=None
 		if self._treeFile:
-			log.info("updating hash tree...")
-			for (k,v) in self._newLeaves.items():
-				self._tree.updateLeaf(k, v)
-			self._tree.save(self._treeFile)
+			self._updateTree()
 		log.info("done")