diff --git a/impl/src/main/java/org/opencord/olt/impl/OsgiPropertyConstants.java b/impl/src/main/java/org/opencord/olt/impl/OsgiPropertyConstants.java
index 1db37e5..0e82f37 100644
--- a/impl/src/main/java/org/opencord/olt/impl/OsgiPropertyConstants.java
+++ b/impl/src/main/java/org/opencord/olt/impl/OsgiPropertyConstants.java
@@ -62,4 +62,9 @@
 
     public static final String REQUIRED_DRIVERS_PROPERTY_DELAY = "requiredDriversPropertyDelay";
     public static final int REQUIRED_DRIVERS_PROPERTY_DELAY_DEFAULT = 5;
+
+    public static final String UPSTREAM_ONU = "upstreamOnu";
+    public static final String UPSTREAM_OLT = "upstreamOlt";
+    public static final String DOWNSTREAM_ONU = "downstreamOnu";
+    public static final String DOWNSTREAM_OLT = "downstreamOlt";
 }