diff --git a/src/ParticipantUDP.cs b/src/ParticipantUDP.cs
index 01071b5..7d8b27b 100644
--- a/src/ParticipantUDP.cs
+++ b/src/ParticipantUDP.cs
@@ -15,6 +15,9 @@ namespace RoboidControl {
 
         public string name = "Participant";
 
+        public bool isIsolated = false;
+        public Participant remoteSite;
+
         public IPEndPoint endPoint = null;
         public UdpClient udpClient = null;
         public string broadcastIpAddress = "255.255.255.255";
@@ -23,19 +26,13 @@ namespace RoboidControl {
 
         #region Init
 
-        /// <summary>
-        /// Create a porticiapnt
-        /// </summary>
-        public ParticipantUDP() {
-            //senders.Add(this);
-        }
-
         /// <summary>
         /// Create a participant with the give UDP port
         /// </summary>
         /// <param name="port">The port number on which to communicate</param>
-        public ParticipantUDP(int port) : this() {
-            this.port = port;
+        public ParticipantUDP(int port = 0) : base("127.0.0.1", port) {
+            if (this.port == 0)
+                this.isIsolated = true;
         }
 
         /// <summary>
@@ -43,17 +40,16 @@ namespace RoboidControl {
         /// </summary>
         /// <param name="ipAddress">The ip address of the site server</param>
         /// <param name="port">The port number of the site server</param>
-        public ParticipantUDP(string ipAddress = "0.0.0.0", int port = 7681) : this() {
-            this.ipAddress = ipAddress;
-            this.port = port;
+        public ParticipantUDP(string ipAddress, int port = 7681, int localPort = 7681) : base("127.0.0.1", localPort) {
+            if (this.port == 0)
+                this.isIsolated = true;
+            else
+                this.remoteSite = new Participant(ipAddress, port);
 
-            this.udpClient = new UdpClient();
-            this.udpClient.Client.Bind(new IPEndPoint(IPAddress.Any, port)); // local port
-            // this.endPoint = new IPEndPoint(IPAddress.Parse(ipAddress), port); // for sending
-
-            // this.udpClient = new UdpClient(port); // for receiving
-            // this.udpClient.Client.Bind(new IPEndPoint(IPAddress.Any, port));
+            this.endPoint = new IPEndPoint(IPAddress.Any, localPort);
+            this.udpClient = new UdpClient(localPort);            
             this.udpClient.BeginReceive(new AsyncCallback(result => ReceiveUDP(result)), null);
+
         }
 
         /// <summary>
@@ -92,41 +88,27 @@ namespace RoboidControl {
             return participant;
         }
 
-        protected readonly Dictionary<byte, Func<Participant, byte, byte, Thing>> thingMsgProcessors = new();
-
-        // public delegate Thing ThingConstructor(Participant sender, byte networkId, byte thingId);
-        // public void Register(byte thingType, ThingConstructor constr) {
-        //     thingMsgProcessors[thingType] = new Func<Participant, byte, byte, Thing>(constr);
-        // }
-
-        // public void Register<ThingClass>(Thing.Type thingType) where ThingClass : Thing {
-        //     Register<ThingClass>((byte)thingType);
-        // }
-
-        // public void Register<ThingClass>(byte thingType) where ThingClass : Thing {
-        //     thingMsgProcessors[thingType] = (participant, networkId, thingId) =>
-        //         Activator.CreateInstance(typeof(ThingClass), participant, networkId, thingId) as ThingClass;
-        //     Console.WriteLine($"Registering {typeof(ThingClass)} for thing type {thingType}");
-        // }
+        // protected readonly Dictionary<byte, Func<Participant, byte, byte, Thing>> thingMsgProcessors = new();
 
         #endregion Init
 
         #region Update
 
         protected void ReceiveUDP(IAsyncResult result) {
-            if (this.udpClient == null || this.endPoint == null)
+        UnityEngine.Debug.Log("received");
+            if (this.udpClient == null) // || this.endPoint == null)
                 return;
 
-            byte[] data = this.udpClient.EndReceive(result, ref this.endPoint);
+            byte[] data = this.udpClient.EndReceive(result, ref endPoint);
             // This does not yet take multi-packet messages into account!
-            if (this.endPoint == null)
+            if (endPoint == null)
                 return;
 
             // We can receive our own publish (broadcast) packages. How do we recognize them????
             // It is hard to determine our source port
-            string ipAddress = this.endPoint.Address.ToString();
-            Participant remoteParticipant = GetParticipant(ipAddress, this.endPoint.Port);
-            remoteParticipant ??= AddParticipant(ipAddress, this.endPoint.Port);
+            string ipAddress = endPoint.Address.ToString();
+            Participant remoteParticipant = GetParticipant(ipAddress, endPoint.Port);
+            remoteParticipant ??= AddParticipant(ipAddress, endPoint.Port);
 
             ReceiveData(data, remoteParticipant);
 
diff --git a/src/SiteServer.cs b/src/SiteServer.cs
index 1032c7f..e6a9141 100644
--- a/src/SiteServer.cs
+++ b/src/SiteServer.cs
@@ -9,27 +9,18 @@ namespace RoboidControl {
     /// </summary>
     public class SiteServer : ParticipantUDP {
 
-        public SiteServer(int port = 7681) : this("0.0.0.0", port) { }
-
         /// <summary>
         /// Create a new site server
         /// </summary>
         /// <param name="port"></param>
-        public SiteServer(string ipAddress = "0.0.0.0", int port = 7681) : base() {
+        public SiteServer(int port = 7681) : base(port) {
             this.name = "Site Server";
 
-            this.ipAddress = ipAddress;
-            this.port = port;
-
-            this.endPoint = new IPEndPoint(IPAddress.Parse(ipAddress), port); // for sending
-
             Console.Write($"Prepare receive on port {port}");
-            this.udpClient = new UdpClient(port); // for receiving
-            this.udpClient.BeginReceive(
-                new AsyncCallback(result => ReceiveUDP(result)),
-                new Tuple<UdpClient, IPEndPoint>(this.udpClient, new(IPAddress.Any, port)));
+            this.endPoint = new IPEndPoint(IPAddress.Any, port);
+            this.udpClient = new UdpClient(port);
+            this.udpClient.BeginReceive(new AsyncCallback(result => ReceiveUDP(result)), null);
 
-            // Register<TouchSensor>(Thing.Type.TouchSensor);
         }
 
         /// <summary>
@@ -45,8 +36,8 @@ namespace RoboidControl {
         protected override void Process(Participant sender, ParticipantMsg msg) {
             base.Process(sender, msg);
             //if (msg.networkId == 0) {
-                //Console.WriteLine($"{this.name} received New Participant -> {sender.networkId}");
-                this.Send(sender, new NetworkIdMsg(sender.networkId));
+            //Console.WriteLine($"{this.name} received New Participant -> {sender.networkId}");
+            this.Send(sender, new NetworkIdMsg(sender.networkId));
             //}
         }
 
@@ -63,8 +54,8 @@ namespace RoboidControl {
                 //         newThing = msgProcessor(sender, msg.networkId, msg.thingId);
                 // }
                 // if (newThing == null) {
-                    newThing = new Thing(sender, msg.networkId, msg.thingId, msg.thingType);
-                    // Console.WriteLine("Created generic new core thing");
+                newThing = new Thing(sender, msg.networkId, msg.thingId, msg.thingType);
+                // Console.WriteLine("Created generic new core thing");
                 // }
                 if (msg.parentId != 0) {
                     Thing parentThing = Get(msg.networkId, msg.parentId);