diff --git a/src/core/DTNHost.java b/src/core/DTNHost.java
index 258be0450..502c5b48b 100644
--- a/src/core/DTNHost.java
+++ b/src/core/DTNHost.java
@@ -6,6 +6,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 import movement.MovementModel;
@@ -34,6 +35,7 @@ public class DTNHost implements Comparable<DTNHost> {
 	private List<MessageListener> msgListeners;
 	private List<MovementListener> movListeners;
 	private List<NetworkInterface> net;
+	private List<Connection> allConnections;
 	private ModuleCommunicationBus comBus;
 
 	static {
@@ -60,6 +62,7 @@ public DTNHost(List<MessageListener> msgLs,
 		this.address = getNextAddress();
 		this.name = groupId+address;
 		this.net = new ArrayList<NetworkInterface>();
+		this.allConnections = new ArrayList<Connection>();
 
 		for (NetworkInterface i : interf) {
 			NetworkInterface ni = i.replicate();
@@ -165,25 +168,21 @@ public ModuleCommunicationBus getComBus() {
 	 * @param con  The connection object whose state changed
 	 */
 	public void connectionUp(Connection con) {
+		this.allConnections.add(con);
 		this.router.changedConnection(con);
 	}
 
 	public void connectionDown(Connection con) {
+		this.allConnections.remove(con);
 		this.router.changedConnection(con);
 	}
 
 	/**
-	 * Returns a copy of the list of connections this host has with other hosts
-	 * @return a copy of the list of connections this host has with other hosts
+	 * Returns an immutable list of connections this host has with other hosts
+	 * @return an immutable list of connections this host has with other hosts
 	 */
 	public List<Connection> getConnections() {
-		List<Connection> lc = new ArrayList<Connection>();
-
-		for (NetworkInterface i : net) {
-			lc.addAll(i.getConnections());
-		}
-
-		return lc;
+		return Collections.unmodifiableList(allConnections);
 	}
 
 	/**
diff --git a/src/routing/MessageRouter.java b/src/routing/MessageRouter.java
index 4d21233a1..239848c1e 100644
--- a/src/routing/MessageRouter.java
+++ b/src/routing/MessageRouter.java
@@ -95,6 +95,8 @@ public abstract class MessageRouter {
 	private DTNHost host;
 	/** size of the buffer */
 	private long bufferSize;
+	/** current occupancy of the buffer */
+	private long bufferOccupancy;
 	/** TTL for all messages */
 	protected int msgTtl;
 	/** Queue mode for sending messages */
@@ -157,6 +159,7 @@ public void init(DTNHost host, List<MessageListener> mListeners) {
 		this.blacklistedMessages = new HashMap<String, Object>();
 		this.mListeners = mListeners;
 		this.host = host;
+		this.bufferOccupancy = 0;
 	}
 
 	/**
@@ -274,17 +277,11 @@ public long getBufferSize() {
 	 * size isn't defined)
 	 */
 	public long getFreeBufferSize() {
-		long occupancy = 0;
-
 		if (this.getBufferSize() == Integer.MAX_VALUE) {
 			return Integer.MAX_VALUE;
 		}
 
-		for (Message m : getMessageCollection()) {
-			occupancy += m.getSize();
-		}
-
-		return this.getBufferSize() - occupancy;
+		return this.getBufferSize() - this.bufferOccupancy;
 	}
 
 	/**
@@ -438,6 +435,7 @@ protected boolean isIncomingMessage(String id) {
 	 */
 	protected void addToMessages(Message m, boolean newMessage) {
 		this.messages.put(m.getId(), m);
+		this.bufferOccupancy += m.getSize();
 
 		if (newMessage) {
 			for (MessageListener ml : this.mListeners) {
@@ -453,6 +451,7 @@ protected void addToMessages(Message m, boolean newMessage) {
 	 */
 	protected Message removeFromMessages(String id) {
 		Message m = this.messages.remove(id);
+		this.bufferOccupancy -= m.getSize();
 		return m;
 	}