diff --git a/networking_sfc_library/Classes/Instance.yaml b/networking_sfc_library/Classes/Instance.yaml
index 56947ef..da21633 100644
--- a/networking_sfc_library/Classes/Instance.yaml
+++ b/networking_sfc_library/Classes/Instance.yaml
@@ -25,6 +25,7 @@ Properties:
   ports:
     Contract: [$.class(NeutronPort).notNull()]
     Default: []
+    Usage: InOut
 
 Methods:
   prepareStackTemplate: