diff --git a/src/main/java/envoy/server/ConnectionManager.java b/src/main/java/envoy/server/ConnectionManager.java
new file mode 100644
index 0000000..ac4b0c0
--- /dev/null
+++ b/src/main/java/envoy/server/ConnectionManager.java
@@ -0,0 +1,79 @@
+package envoy.server;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import com.jenkov.nioserver.ISocketIdListener;
+
+/**
+ * Project: <strong>envoy-server-standalone</strong><br>
+ * File: <strong>ConnectionManager.java</strong><br>
+ * Created: <strong>03.01.2020</strong><br>
+ * 
+ * @author Kai S. K. Engelbart
+ * @since Envoy Server Standalone v0.1-alpha
+ */
+public class ConnectionManager implements ISocketIdListener {
+
+	/**
+	 * Contains all socket IDs that have not yet performed a handshake / acquired
+	 * their corresponding user ID.
+	 * 
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	private Set<Long> pendingSockets = new HashSet<>();
+
+	/**
+	 * Contains all socket IDs that have acquired a user ID as keys to these IDs.
+	 * 
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	private Map<Long, Long> sockets = new HashMap<>();
+
+	private static ConnectionManager connectionManager = new ConnectionManager();
+
+	private ConnectionManager() {}
+
+	/**
+	 * @return a singleton instance of this object
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	public static ConnectionManager getInstance() { return connectionManager; }
+
+	@Override
+	public void socketCancelled(long socketId) {
+		if (!pendingSockets.remove(socketId))
+			sockets.entrySet().stream().filter(e -> e.getValue() == socketId).forEach(e -> sockets.remove(e.getValue()));
+	}
+
+	@Override
+	public void socketRegistered(long socketId) { pendingSockets.add(socketId); }
+
+	/**
+	 * Associates a socket ID with a user ID.
+	 * 
+	 * @param socketId the socket ID
+	 * @param userId   the user ID
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	public void registerUser(long socketId, long userId) {
+		sockets.put(socketId, userId);
+		pendingSockets.remove(socketId);
+	}
+
+	/**
+	 * @param userId the ID of the user registered at the a socket
+	 * @return the ID of the socket
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	public long getSocketId(long userId) { return sockets.get(userId); }
+
+	/**
+	 * @param userId the ID of the user to check for
+	 * @return {@code true} if the user is online
+	 * @since Envoy Server Standalone v0.1-alpha
+	 */
+	public boolean isOnline(long userId) { return sockets.containsKey(userId); }
+}
diff --git a/src/main/java/envoy/server/LoginCredentialProcessor.java b/src/main/java/envoy/server/LoginCredentialProcessor.java
index f208a3e..0a84edf 100644
--- a/src/main/java/envoy/server/LoginCredentialProcessor.java
+++ b/src/main/java/envoy/server/LoginCredentialProcessor.java
@@ -22,8 +22,10 @@ public class LoginCredentialProcessor implements ObjectProcessor<LoginCredential
 	public Class<LoginCredentials> getInputClass() { return LoginCredentials.class; }
 
 	@Override
-	public User process(LoginCredentials input) {
-		System.out.println("Received login credentials " + input);
-		return new User(currentUserId++, input.getName());
+	public User process(LoginCredentials input, long socketId) {
+		System.out.println(String.format("Received login credentials %s from socket ID %d", input, socketId));
+		User user = new User(currentUserId++, input.getName());
+		ConnectionManager.getInstance().registerUser(socketId, user.getId());
+		return user;
 	}
 }
diff --git a/src/main/java/envoy/server/MessageProcessor.java b/src/main/java/envoy/server/MessageProcessor.java
index ea52c55..8d80e53 100644
--- a/src/main/java/envoy/server/MessageProcessor.java
+++ b/src/main/java/envoy/server/MessageProcessor.java
@@ -18,5 +18,15 @@ public class MessageProcessor implements ObjectProcessor<Message, Void> {
 	public Class<Message> getInputClass() { return Message.class; }
 
 	@Override
-	public Void process(Message input) { return null; }
+	public Void process(Message message, long socketId) {
+
+		// TODO: Send message to recipient if online
+		ConnectionManager connectionManager = ConnectionManager.getInstance();
+		if (connectionManager.isOnline(message.getRecipientId())) {
+
+		}
+
+		// TODO: Add message to database
+		return null;
+	}
 }
diff --git a/src/main/java/envoy/server/ObjectProcessor.java b/src/main/java/envoy/server/ObjectProcessor.java
index 44c07e1..07c0480 100644
--- a/src/main/java/envoy/server/ObjectProcessor.java
+++ b/src/main/java/envoy/server/ObjectProcessor.java
@@ -22,9 +22,10 @@ public interface ObjectProcessor<T, U> {
 	Class<T> getInputClass();
 
 	/**
-	 * @param input the request object
+	 * @param input    the request object
+	 * @param socketId the ID of the socket from which the object was received
 	 * @return the response object
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	U process(T input);
+	U process(T input, long socketId);
 }
\ No newline at end of file
diff --git a/src/main/java/envoy/server/Startup.java b/src/main/java/envoy/server/Startup.java
index dd295a4..b616946 100644
--- a/src/main/java/envoy/server/Startup.java
+++ b/src/main/java/envoy/server/Startup.java
@@ -32,7 +32,9 @@ public class Startup {
 		Set<ObjectProcessor<?, ?>> processors = new HashSet<>();
 		processors.add(new LoginCredentialProcessor());
 		processors.add(new MessageProcessor());
+
 		Server server = new Server(8080, () -> new ObjectMessageReader(), new ObjectMessageProcessor(processors));
 		server.start();
+		server.getSocketProcessor().registerSocketIdListener(ConnectionManager.getInstance());
 	}
 }
\ No newline at end of file
diff --git a/src/main/java/envoy/server/net/ObjectMessageProcessor.java b/src/main/java/envoy/server/net/ObjectMessageProcessor.java
index 6f652d9..1bf707f 100644
--- a/src/main/java/envoy/server/net/ObjectMessageProcessor.java
+++ b/src/main/java/envoy/server/net/ObjectMessageProcessor.java
@@ -25,7 +25,7 @@ import envoy.server.ObjectProcessor;
  */
 public class ObjectMessageProcessor implements IMessageProcessor {
 
-	private final Set<ObjectProcessor<?, ?>> processors;
+	private final Set<ObjectProcessor<?, ?>>	processors;
 
 	/**
 	 * The constructor to set the {@link ObjectProcessor}s.
@@ -33,7 +33,9 @@ public class ObjectMessageProcessor implements IMessageProcessor {
 	 * @param processors the {@link ObjectProcessor} to set
 	 * @since Envoy Server Standalone v0.1-alpha
 	 */
-	public ObjectMessageProcessor(Set<ObjectProcessor<?, ?>> processors) { this.processors = processors; }
+	public ObjectMessageProcessor(Set<ObjectProcessor<?, ?>> processors) {
+		this.processors			= processors;
+	}
 
 	@SuppressWarnings("unchecked")
 	@Override
@@ -44,7 +46,7 @@ public class ObjectMessageProcessor implements IMessageProcessor {
 
 			// Process object
 			processors.stream().filter(p -> p.getInputClass().isInstance(obj)).forEach((@SuppressWarnings("rawtypes") ObjectProcessor p) -> {
-				Object responseObj = p.process(p.getInputClass().cast(obj));
+				Object responseObj = p.process(p.getInputClass().cast(obj), message.socketId);
 				if (responseObj != null) {
 					// Create message targeted at the client
 					Message response = writeProxy.getMessage();