diff --git a/app/Main/MapUpdate.php b/app/Main/MapUpdate.php
index 0a4e03c..302ce11 100644
--- a/app/Main/MapUpdate.php
+++ b/app/Main/MapUpdate.php
@@ -13,6 +13,13 @@ use Ratchet\ConnectionInterface;
 
 class MapUpdate implements MessageComponentInterface {
 
+    /**
+     * timestamp (ms) from last healthCheck ping
+     * -> timestamp received from remote TCP socket
+     * @var
+     */
+    protected $healthCheckToken;
+
     /**
      * expire time for map access tokens (seconds)
      * @var int
@@ -44,6 +51,13 @@ class MapUpdate implements MessageComponentInterface {
      */
     protected $subscriptions;
 
+    /**
+     * enable debug output
+     * -> check debug() for more information
+     * @var bool
+     */
+    protected $debug = false;
+
     /**
      * internal socket for response calls
      * @var null | \React\ZMQ\SocketWrapper
@@ -78,6 +92,9 @@ class MapUpdate implements MessageComponentInterface {
                 case 'subscribe':
                     $this->subscribe($conn, $load);
                     break;
+                case 'healthCheck':
+                    $this->validateHealthCheck($conn, $load);
+                    break;
                 default:
                     break;
             }
@@ -103,6 +120,26 @@ class MapUpdate implements MessageComponentInterface {
         $conn->close();
     }
 
+    /**
+     * Check token (timestamp from initial TCP healthCheck poke against token send from client
+     * @param ConnectionInterface $conn
+     * @param $token
+     */
+    private function validateHealthCheck($conn, $token){
+        $isValid = 0;
+
+        if(
+            $token && $this->healthCheckToken &&
+            $token === $this->healthCheckToken
+        ){
+            $isValid = 1;
+        }
+        $conn->send( json_encode($isValid) );
+
+        // reset token
+        $this->healthCheckToken = null;
+    }
+
     /**
      * subscribes a connection to valid accessible maps
      * @param ConnectionInterface $conn
@@ -388,7 +425,8 @@ class MapUpdate implements MessageComponentInterface {
                 $response = $this->deleteMapId($task, $load);
                 break;
             case 'healthCheck':
-                $response = 1;
+                $this->healthCheckToken = (float)$load;
+                $response = 'OK';
                 break;
         }
 
@@ -509,6 +547,34 @@ class MapUpdate implements MessageComponentInterface {
     protected function log($text){
         $text = date('Y-m-d H:i:s') . ' ' . $text;
         echo $text . "\n";
+
+        $this->debug();
+    }
+
+    protected function debug(){
+        if( $this->debug ){
+            $mapId = 1;
+            $characterId = 1946320202;
+
+            $subscriptions = $this->subscriptions[$mapId];
+            $connectionsForChar = count($this->characters[$characterId]);
+            $mapAccessData = $this->mapAccessData[$mapId][$characterId];
+            echo "\n" . "========== START ==========" . "\n";
+
+            echo "-> characterAccessData: " . "\n";
+            var_dump( $this->characterAccessData );
+
+            echo "\n" . "-> Subscriptions mapId: " . $mapId . " " . "\n";
+            var_dump($subscriptions);
+
+            echo "\n" . "-> connectionsForChar characterId: " . $characterId . " count: " .  $connectionsForChar . " " . "\n";
+
+            echo "-> mapAccessData: " . "\n";
+            var_dump($mapAccessData);
+
+            echo "\n" . "========== END ==========" . "\n";
+        }
+
     }
 
 }
\ No newline at end of file
diff --git a/app/WebSockets.php b/app/WebSockets.php
index 3972c15..c21afdb 100644
--- a/app/WebSockets.php
+++ b/app/WebSockets.php
@@ -34,7 +34,8 @@ class WebSockets {
         // Listen for the web server to make a ZeroMQ push after an ajax request
         $context = new React\ZMQ\Context($loop);
 
-        $pull = $context->getSocket(\ZMQ::SOCKET_REP);
+        //$pull = $context->getSocket(\ZMQ::SOCKET_REP);
+        $pull = $context->getSocket(\ZMQ::SOCKET_PULL);
         // Binding to 127.0.0.1 means, the only client that can connect is itself
         $pull->bind( $this->dns );