diff --git a/ws2012/P2P/uebungen/4/src/node/Node.java b/ws2012/P2P/uebungen/4/src/node/Node.java
index aca269ec..c77880b4 100644
--- a/ws2012/P2P/uebungen/4/src/node/Node.java
+++ b/ws2012/P2P/uebungen/4/src/node/Node.java
@@ -69,7 +69,7 @@ public class Node {
 		// LOGGER.info("Name: " + getName() + ", Spawning new node.");
 		Node newNode = new Node();
 
-		int ack_id = generateAck(MessageType.INVITE, newNode.getAddress());
+		int ack_id = generateAck(newNode.getAddress());
 		buf.clear();
 		buf.put(MessageType.INVITE);
 		buf.putInt(ack_id);
@@ -86,7 +86,14 @@ public class Node {
 		return newNode;
 	}
 
-	public int generateAck(byte type, SocketAddress addr) {
+	/**
+	 * Adds a new ack, which this node is expecting to receive.
+	 * 
+	 * @param addr
+	 *            the SocketAddress the ack should be received from
+	 * @return the identifier for this ack
+	 */
+	public int generateAck(SocketAddress addr) {
 		int ack_id = generator.nextInt();
 		acks.put(ack_id, new Ack(addr));
 		return ack_id;
@@ -97,11 +104,11 @@ public class Node {
 	}
 
 	private void sendAddrTo(SocketAddress receiver, SocketAddress addr) {
-		buf.clear();
 		InetSocketAddress a = (InetSocketAddress) addr;
+		int ack_id = generateAck(addr);
 
+		buf.clear();
 		buf.put(MessageType.NEW_NEIGHBOR);
-		int ack_id = generateAck(MessageType.NEW_NEIGHBOR, addr);
 		buf.putInt(ack_id);
 
 		for (String part : a.getHostString().split("\\.")) {
@@ -119,6 +126,27 @@ public class Node {
 		}
 	}
 
+	/**
+	 * Sends an acknowledgment message to receiver (who hopefully is expecting
+	 * it)
+	 * 
+	 * @param receiver
+	 *            the node expecting an ack
+	 * @param ack_id
+	 *            the id to identify the ack
+	 */
+	private void sendAckTo(SocketAddress receiver, int ack_id) {
+		buf.clear();
+		buf.put(MessageType.ACK);
+		buf.putInt(ack_id);
+		buf.flip();
+		try {
+			channel.send(buf, receiver);
+		} catch (IOException e) {
+			// TODO
+		}
+	}
+
 	/**
 	 * This node circularly links all neighbors (no mesh!) and removes itself
 	 * from the network.
@@ -131,16 +159,14 @@ public class Node {
 			if (neighbors.size() > 2) {
 				int pred = ((i - 1) + neighbors.size()) % neighbors.size();
 				int succ = (i + 1) % neighbors.size();
-
 				sendAddrTo(neighbors.get(i), neighbors.get(succ));
-
 				sendAddrTo(neighbors.get(i), neighbors.get(pred));
 			} else if (neighbors.size() == 2) {
 				sendAddrTo(neighbors.get(i), neighbors.get(Math.abs(i - 1)));
 			}
 
 			buf.clear();
-			int ack_id = generateAck(MessageType.LEAVE, neighbors.get(i));
+			int ack_id = generateAck(neighbors.get(i));
 			buf.put(MessageType.LEAVE);
 			buf.putInt(ack_id);
 			buf.flip();
@@ -206,11 +232,7 @@ public class Node {
 
 							ack_id = buf.getInt();
 
-							buf.clear();
-							buf.put(MessageType.ACK);
-							buf.putInt(ack_id);
-							buf.flip();
-							channel.send(buf, receivedFrom);
+							sendAckTo(receivedFrom, ack_id);
 
 							neighbors.add(receivedFrom);
 							break;
@@ -251,11 +273,7 @@ public class Node {
 							}
 							ack_id = buf.getInt();
 
-							buf.clear();
-							buf.put(MessageType.ACK);
-							buf.putInt(ack_id);
-							buf.flip();
-							channel.send(buf, receivedFrom);
+							sendAckTo(receivedFrom, ack_id);
 							break;
 
 						case MessageType.NEW_NEIGHBOR:
@@ -283,11 +301,7 @@ public class Node {
 										+ new_neighbor.toString());
 							}
 
-							buf.clear();
-							buf.put(MessageType.ACK);
-							buf.putInt(ack_id);
-							buf.flip();
-							channel.send(buf, receivedFrom);
+							sendAckTo(receivedFrom, ack_id);
 
 							break;