diff --git a/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmService.java b/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmService.java
index 5e235b872..a8f419170 100644
--- a/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmService.java
+++ b/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmService.java
@@ -53,7 +53,6 @@ public interface VirtualFireAlarmService {
     @Feature(code = "buzz", name = "Buzzer On / Off", description = "Switch on/off Virtual Fire Alarm Buzzer. (On / Off)")
     Response switchBuzzer(@PathParam("deviceId") String deviceId, @QueryParam("protocol") String protocol,
                              @FormParam("state") String state);
-    
 
     /**
      * Retrieve Sensor data for the device type
diff --git a/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmServiceImpl.java b/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmServiceImpl.java
index 16304986c..15e35a68d 100644
--- a/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmServiceImpl.java
+++ b/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/java/org/wso2/carbon/device/mgt/iot/virtualfirealarm/service/impl/VirtualFireAlarmServiceImpl.java
@@ -54,15 +54,7 @@ import org.wso2.carbon.identity.jwt.client.extension.dto.AccessTokenInfo;
 import org.wso2.carbon.identity.jwt.client.extension.exception.JWTClientException;
 import org.wso2.carbon.user.api.UserStoreException;
 
-import javax.ws.rs.Consumes;
-import javax.ws.rs.FormParam;
-import javax.ws.rs.GET;
-import javax.ws.rs.POST;
-import javax.ws.rs.PUT;
-import javax.ws.rs.Path;
-import javax.ws.rs.PathParam;
-import javax.ws.rs.Produces;
-import javax.ws.rs.QueryParam;
+import javax.ws.rs.*;
 import javax.ws.rs.core.Response;
 import java.io.IOException;
 import java.nio.ByteBuffer;
@@ -73,6 +65,7 @@ import java.util.*;
 public class VirtualFireAlarmServiceImpl implements VirtualFireAlarmService {
 
     private static final String XMPP_PROTOCOL = "XMPP";
+    private static final String MQTT_PROTOCOL = "MQTT";
     private static final String KEY_TYPE = "PRODUCTION";
     private static ApiApplicationKey apiApplicationKey;
     private static Log log = LogFactory.getLog(VirtualFireAlarmServiceImpl.class);
@@ -81,13 +74,24 @@ public class VirtualFireAlarmServiceImpl implements VirtualFireAlarmService {
     @Path("device/{deviceId}/buzz")
     public Response switchBuzzer(@PathParam("deviceId") String deviceId, @QueryParam("protocol") String protocol,
                                  @FormParam("state") String state) {
+        if (state == null || state.isEmpty()) {
+            log.error("State is not defined for the buzzer operation");
+            return Response.status(Response.Status.BAD_REQUEST).build();
+        }
         String switchToState = state.toUpperCase();
         if (!switchToState.equals(VirtualFireAlarmConstants.STATE_ON) && !switchToState.equals(
                 VirtualFireAlarmConstants.STATE_OFF)) {
             log.error("The requested state change shoud be either - 'ON' or 'OFF'");
             return Response.status(Response.Status.BAD_REQUEST).build();
         }
-        String protocolString = protocol.toUpperCase();
+        String protocolString;
+
+        if (protocol == null || protocol.isEmpty()) {
+            protocolString = MQTT_PROTOCOL;
+        } else {
+            protocolString = protocol.toUpperCase();
+        }
+
         if (log.isDebugEnabled()) {
             log.debug("Sending request to switch-bulb of device [" + deviceId + "] via " +
                               protocolString);
diff --git a/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/webapp/META-INF/permissions.xml b/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/webapp/META-INF/permissions.xml
index 8c18f748e..fbad43f95 100644
--- a/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/webapp/META-INF/permissions.xml
+++ b/components/iot-plugins/virtual-fire-alarm-plugin/org.wso2.carbon.device.mgt.iot.virtualfirealarm.api/src/main/webapp/META-INF/permissions.xml
@@ -37,7 +37,7 @@
 	</Permission>
     <Permission>
         <name>Control Buzz</name>
-        <path>/device-mgt/user/operations</path>
+        <path>/device-mgt/user/operation</path>
         <url>/device/*/buzz</url>
         <method>POST</method>
         <scope>virtual_firealarm_user</scope>
@@ -47,6 +47,6 @@
         <path>/device-mgt/user/stats</path>
         <url>/device/stats/*</url>
         <method>GET</method>
-        <scope>virtual_firealarm_device</scope>
+        <scope>virtual_firealarm_user</scope>
     </Permission>
 </PermissionConfiguration>
\ No newline at end of file