diff --git a/udmis/src/main/java/com/google/bos/udmi/service/messaging/impl/SimpleMqttPipe.java b/udmis/src/main/java/com/google/bos/udmi/service/messaging/impl/SimpleMqttPipe.java
index 5b1dd7f105..6e604ccf5b 100644
--- a/udmis/src/main/java/com/google/bos/udmi/service/messaging/impl/SimpleMqttPipe.java
+++ b/udmis/src/main/java/com/google/bos/udmi/service/messaging/impl/SimpleMqttPipe.java
@@ -153,8 +153,34 @@ private String makeMqttTopic(Bundle bundle) {
   }
 
   private String makeTopic(Envelope envelope) {
-    return format("/r/%s/d/%s/t/%s/f/%s",
-        envelope.deviceRegistryId, envelope.deviceId, envelope.subType, envelope.subFolder);
+    return format("/r/%s/d/%s/t/%s/f/%s/g/%s", envelope.deviceRegistryId, envelope.deviceId,
+        envelope.subType, envelope.subFolder, envelope.gatewayId);
+  }
+
+  private Map<String, String> parseEnvelopeTopic(String topic) {
+    // 0/1/2       /3/4     /5/6   [/7/8     [/9/10     ]]
+    //  /r/REGISTRY/d/DEVICE/t/TYPE[/f/FOLDER[/g/GATEWAY]]
+    String[] parts = topic.split("/", 12);
+    if (parts.length < 7 || parts.length > 11) {
+      throw new RuntimeException("Unexpected topic length: " + topic);
+    }
+    Envelope envelope = new Envelope();
+    checkState(Strings.isNullOrEmpty(parts[0]), "non-empty prefix");
+    checkState("r".equals(parts[1]), "expected registries");
+    envelope.deviceRegistryId = parts[2];
+    checkState("d".equals(parts[3]), "expected devices");
+    envelope.deviceId = parts[4];
+    checkState("t".equals(parts[5]), "expected type");
+    envelope.subType = SubType.fromValue(parts[6]);
+    if (parts.length >= 8) {
+      checkState("f".equals(parts[7]), "expected type");
+      envelope.subFolder = SubFolder.fromValue(parts[8]);
+    }
+    if (parts.length >= 10) {
+      checkState("g".equals(parts[9]), "expected gateway");
+      envelope.gatewayId = parts[10];
+    }
+    return toStringMap(envelope);
   }
 
   private void subscribeToMessages() {
@@ -220,28 +246,6 @@ public void messageArrived(String topic, MqttMessage message) {
     }
   }
 
-  private Map<String, String> parseEnvelopeTopic(String topic) {
-    // 0/1/2       /3/4     /5/6   [/7/8]
-    //  /r/REGISTRY/d/DEVICE/t/TYPE[/f/FOLDER]
-    String[] parts = topic.split("/", 10);
-    if (parts.length < 7 || parts.length > 9) {
-      throw new RuntimeException("Unexpected topic length: " + topic);
-    }
-    Envelope envelope = new Envelope();
-    checkState(Strings.isNullOrEmpty(parts[0]), "non-empty prefix");
-    checkState("r".equals(parts[1]), "expected registries");
-    envelope.deviceRegistryId = parts[2];
-    checkState("d".equals(parts[3]), "expected devices");
-    envelope.deviceId = parts[4];
-    checkState("t".equals(parts[5]), "expected type");
-    envelope.subType = SubType.fromValue(parts[6]);
-    if (parts.length >= 8) {
-      checkState("f".equals(parts[7]), "expected type");
-      envelope.subFolder = SubFolder.fromValue(parts[8]);
-    }
-    return toStringMap(envelope);
-  }
-
   @Override
   void resetForTest() {
     super.resetForTest();