link vBNG Service to ONOS vBNG Tenant
diff --git a/xos/configurations/cord/cord.yaml b/xos/configurations/cord/cord.yaml
index 47a33de..3e64ff5 100644
--- a/xos/configurations/cord/cord.yaml
+++ b/xos/configurations/cord/cord.yaml
@@ -54,6 +54,9 @@
           - onos_tenant:
               node: service_ONOS
               relationship: tosca.relationships.TenantOfService
+          - vbng_service:
+              node: service_vbng
+              relationship: tosca.relationships.UsedByService
       properties:
           dependencies: org.onosproject.proxyarp, org.onosproject.virtualbng, org.onosproject.openflow, org.onosproject.fwd
           config_addresses.json: >
diff --git a/xos/tosca/custom_types/xos.m4 b/xos/tosca/custom_types/xos.m4
index a673128..7a94d8b 100644
--- a/xos/tosca/custom_types/xos.m4
+++ b/xos/tosca/custom_types/xos.m4
@@ -569,6 +569,10 @@
         derived_from: tosca.relationships.Root
         valid_target_types: [ tosca.capabilities.xos.Service ]
 
+    tosca.relationships.UsedByService:
+        derived_from: tosca.relationships.Root
+        valid_target_types: [ tosca.capabilities.xos.Service ]
+
     tosca.relationships.ControllerDeployment:
         derived_from: tosca.relationships.Root
         valid_target_types: [ tosca.capabilities.xos.Deployment ]
diff --git a/xos/tosca/custom_types/xos.yaml b/xos/tosca/custom_types/xos.yaml
index 38f1453..9b307d6 100644
--- a/xos/tosca/custom_types/xos.yaml
+++ b/xos/tosca/custom_types/xos.yaml
@@ -745,6 +745,10 @@
         derived_from: tosca.relationships.Root
         valid_target_types: [ tosca.capabilities.xos.Service ]
 
+    tosca.relationships.UsedByService:
+        derived_from: tosca.relationships.Root
+        valid_target_types: [ tosca.capabilities.xos.Service ]
+
     tosca.relationships.ControllerDeployment:
         derived_from: tosca.relationships.Root
         valid_target_types: [ tosca.capabilities.xos.Deployment ]
diff --git a/xos/tosca/resources/onosapp.py b/xos/tosca/resources/onosapp.py
index 6cd5ac7..03c4eb5 100644
--- a/xos/tosca/resources/onosapp.py
+++ b/xos/tosca/resources/onosapp.py
@@ -6,7 +6,7 @@
 from translator.toscalib.tosca_template import ToscaTemplate
 import pdb
 
-from core.models import User, TenantAttribute
+from core.models import User, TenantAttribute, Service
 from services.onos.models import ONOSApp, ONOSService
 
 from xosresource import XOSResource
@@ -19,10 +19,16 @@
     def get_xos_args(self, throw_exception=True):
         args = super(XOSONOSApp, self).get_xos_args()
 
+        # provider_service is mandatory and must be the ONOS Service
         provider_name = self.get_requirement("tosca.relationships.TenantOfService", throw_exception=throw_exception)
         if provider_name:
             args["provider_service"] = self.get_xos_object(ONOSService, throw_exception=throw_exception, name=provider_name)
 
+        # subscriber_service is optional and can be any service
+        subscriber_name = self.get_requirement("tosca.relationships.UsedByService", throw_exception=False)
+        if subscriber_name:
+            args["subscriber_service"] = self.get_xos_object(Service, throw_exception=throw_exception, name=subscriber_name)
+
         return args
 
     def get_existing_objs(self):