diff --git a/src/main/java/servlet/CalibrationServlet.java b/src/main/java/servlet/CalibrationServlet.java
index aa64918..33d16a6 100644
--- a/src/main/java/servlet/CalibrationServlet.java
+++ b/src/main/java/servlet/CalibrationServlet.java
@@ -65,11 +65,11 @@ public class CalibrationServlet extends HttpServlet{
 
             byte[] buf = new byte[256];
 
-            String dString = "CALIB=" + clientMacAddress + ";SERV=" + Inet4Address.getLocalHost().getHostAddress()+";LOC_ID="+locationId+";";
+            String dString = "{\"CALIB\": \"" + clientMacAddress + "\", \"SERV\": \"" + Inet4Address.getLocalHost().getHostAddress()+"\", \"LOC_ID\": \""+locationId+"\"}";
             buf = dString.getBytes();
 
             // send it
-            InetAddress group = InetAddress.getByName("230.0.0.1");
+            InetAddress group = InetAddress.getByName("10.255.255.255");
             DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 4446);
             socket.send(packet);
         } catch (IOException e) {
diff --git a/src/main/java/servlet/MapScaleServlet.java b/src/main/java/servlet/MapScaleServlet.java
index 2582f25..0c46f10 100644
--- a/src/main/java/servlet/MapScaleServlet.java
+++ b/src/main/java/servlet/MapScaleServlet.java
@@ -21,8 +21,8 @@ public class MapScaleServlet extends HttpServlet {
             int mapId = Integer.parseInt(servletRequest.getParameter("MAP_ID"));
             Map map = mapService.getMap(mapId);
             
-            servletResponse.setContentType("text/plain");
-            servletResponse.getWriter().print(String.format("{x1:%f;y1:%f;x2:%f;y2:%f}", map.getX_topLeft()
+            servletResponse.setContentType("application/json");
+            servletResponse.getWriter().print(String.format("{\"x1\":\"%f\",\"y1\":\"%f\",\"x2\":\"%f\",\"y2\":\"%f\"}", map.getX_topLeft()
                     , map.getY_topLeft(), map.getX_bottomRight(), map.getY_bottomRight()));
         }
         
diff --git a/src/main/java/servlet/PositioningServlet.java b/src/main/java/servlet/PositioningServlet.java
index d5a8051..ab51087 100644
--- a/src/main/java/servlet/PositioningServlet.java
+++ b/src/main/java/servlet/PositioningServlet.java
@@ -41,8 +41,8 @@ public class PositioningServlet extends HttpServlet{
             loc = posServ.getLocation(clientMacAddr);
         }while(loc==null);
         
-        servletResponse.setContentType("text/plain");
-        servletResponse.getWriter().print(String.format("{x:%f;y:%f;map:%d}", loc.getX(), loc.getY(), loc.getMap().getId()));
+        servletResponse.setContentType("application/json");
+        servletResponse.getWriter().print(String.format("{\"x\": \"%f\", \"y\": \"%f\", \"map\": \"%d\"}", loc.getX(), loc.getY(), loc.getMap().getId()));
     }
     
     @Override
@@ -62,11 +62,11 @@ public class PositioningServlet extends HttpServlet{
             
             byte[] buf = new byte[256];
         
-            String dString = "LOCATE=" + clientMacAddress + ";SERV=" + Inet4Address.getLocalHost().getHostAddress()+";";
+            String dString = "{\"LOCATE\": \"" + clientMacAddress + "\", \"SERV\": \"" + Inet4Address.getLocalHost().getHostAddress()+"\"}";
             buf = dString.getBytes();
         
             // send it
-            InetAddress group = InetAddress.getByName("230.0.0.1");
+            InetAddress group = InetAddress.getByName("10.255.255.255");
             DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 4446);
             socket.send(packet);
         } catch (IOException e) {
--
libgit2 0.21.4