diff --git a/ws2012/P2P/uebungen/4/src/node/Node.java b/ws2012/P2P/uebungen/4/src/node/Node.java
index 312766aa..fe72c9de 100644
--- a/ws2012/P2P/uebungen/4/src/node/Node.java
+++ b/ws2012/P2P/uebungen/4/src/node/Node.java
@@ -217,15 +217,16 @@ public class Node {
 		private volatile boolean running = true;
 
 		public void run() {
+			SocketAddress receivedFrom = null;
+			int ack_id;
 
 			while (running) {
-				SocketAddress receivedFrom = null;
-				int ack_id;
-
 				try {
 					receivedFrom = channel.receive(buf);
 
-					if (buf.remaining() != 512) {
+					// channel.receive() is non blocking. So we need to check if
+					// something actually has been written to the buffer
+					if (buf.remaining() != BUF_SIZE) {
 						buf.flip();
 
 						byte messageType = buf.get();
@@ -248,17 +249,8 @@ public class Node {
 							LOGGER.info(name + " received ack from "
 									+ receivedFrom.toString());
 
-							if (acks.containsKey(ack_id)) {
-								Ack theAck = acks.get(ack_id);
-								if (theAck.check(receivedFrom)) {
-									acks.remove(theAck);
-
-								} else {
-									LOGGER.info("Received unexpected ack from "
-											+ receivedFrom.toString());
-								}
-							} else {
-								LOGGER.info("Received unexpected ack from "
+							if (!checkAck(receivedFrom, ack_id)) {
+								LOGGER.warning("Received unexpected ack from: "
 										+ receivedFrom.toString());
 							}
 
@@ -271,17 +263,18 @@ public class Node {
 							int idToRemove = getNeighborId(receivedFrom);
 							if (idToRemove != -1) {
 								neighbors.remove(idToRemove);
+								ack_id = buf.getInt();
+								sendAckTo(receivedFrom, ack_id);
 							}
-							ack_id = buf.getInt();
-
-							sendAckTo(receivedFrom, ack_id);
+							// If we don't know that neighbor, we don't have to
+							// ack
 							break;
 
 						case MessageType.NEW_NEIGHBOR:
 							ack_id = buf.getInt();
 							StringBuilder theAddr = new StringBuilder();
 
-							// Read 4 Bytes and 1 int
+							// Read 4 Bytes and 1 Integer = 1 IP address
 							for (int i = 0; i < 4; i++) {
 								theAddr.append(buf.get());
 								if (i < 3)
@@ -292,8 +285,9 @@ public class Node {
 							InetSocketAddress new_neighbor = new InetSocketAddress(
 									theAddr.toString(), port);
 
-							// check, if we have the neighbor already.
 							if (!hasNeighbor(new_neighbor)) {
+								// Add this neighbor to my neighbor list if it
+								// was not present before
 								neighbors.add(new_neighbor);
 
 								LOGGER.info(name + " from "
@@ -327,6 +321,17 @@ public class Node {
 			}
 		}
 
+		private boolean checkAck(SocketAddress receivedFrom, int ack_id) {
+			if (acks.containsKey(ack_id)) {
+				Ack theAck = acks.get(ack_id);
+				if (theAck.check(receivedFrom)) {
+					acks.remove(theAck);
+					return true;
+				}
+			}
+			return false;
+		}
+
 		public void terminate() {
 			running = false;
 		}