diff --git a/adaptercore/device_handler.go b/adaptercore/device_handler.go
index 20eb783..5fddcf7 100644
--- a/adaptercore/device_handler.go
+++ b/adaptercore/device_handler.go
@@ -51,8 +51,6 @@
 	coreProxy     *com.CoreProxy
 	AdapterProxy  *com.AdapterProxy
 	openOLT       *OpenOLT
-	nniPort       *voltha.Port
-	ponPort       *voltha.Port
 	exitChannel   chan int
 	lockDevice    sync.RWMutex
 	Client        oop.OpenoltClient
@@ -62,6 +60,7 @@
 	resourceMgr   *rsrcMgr.OpenOltResourceMgr
 	discOnus      map[string]bool
 	onus          map[string]*OnuDevice
+	nniIntfId     int
 }
 
 type OnuDevice struct {
@@ -100,6 +99,10 @@
 	dh.discOnus = make(map[string]bool)
 	dh.lockDevice = sync.RWMutex{}
 	dh.onus = make(map[string]*OnuDevice)
+	// The nniIntfId is initialized to -1 (invalid) and set to right value
+	// when the first IntfOperInd with status as "up" is received for
+	// any one of the available NNI port on the OLT device.
+	dh.nniIntfId = -1
 
 	//TODO initialize the support classes.
 	return &dh
@@ -173,7 +176,13 @@
 	log.Debugw("Sending port update to core", log.Fields{"port": port})
 	// Synchronous call to update device - this method is run in its own go routine
 	if err := dh.coreProxy.PortCreated(nil, dh.device.Id, port); err != nil {
-		log.Errorw("error-creating-nni-port", log.Fields{"deviceId": dh.device.Id, "error": err})
+		log.Errorw("error-creating-port", log.Fields{"deviceId": dh.device.Id, "portType": portType, "error": err})
+		return
+	}
+	// Once we have successfully added the NNI port to the core, if the
+	// locally cached nniIntfId is set to invalid (-1), set it to the right value.
+	if portType == voltha.Port_ETHERNET_NNI && dh.nniIntfId == -1 {
+		dh.nniIntfId = int(intfId)
 	}
 }
 
diff --git a/adaptercore/openolt_flowmgr.go b/adaptercore/openolt_flowmgr.go
index 570fff6..19abc26 100644
--- a/adaptercore/openolt_flowmgr.go
+++ b/adaptercore/openolt_flowmgr.go
@@ -380,11 +380,7 @@
 		return
 	}
 	log.Debugw("Created action proto", log.Fields{"action": *actionProto})
-	networkIntfId, err := f.getNniIntfID()
-	if err != nil {
-		log.Error("Error in getting NNI interface ID, Failed to add HSIA flow")
-		return
-	}
+	networkIntfId := f.deviceHandler.nniIntfId
 	flow := openolt_pb2.Flow{AccessIntfId: int32(intfId),
 		OnuId:         int32(onuId),
 		UniId:         int32(uniId),
@@ -447,11 +443,7 @@
 		log.Error("Error in making action protobuf for ul flow")
 		return
 	}
-	networkIntfId, err := f.getNniIntfID()
-	if err != nil {
-		log.Error("Error in getting NNI interface ID, Failed to add DHCP Trap Flow")
-		return
-	}
+	networkIntfId := f.deviceHandler.nniIntfId
 
 	dhcpFlow = openolt_pb2.Flow{AccessIntfId: int32(intfId),
 		OnuId:         int32(onuId),
@@ -520,11 +512,7 @@
 		return
 	}
 	log.Debugw("Created action proto", log.Fields{"action": *actionProto})
-	networkIntfId, err := f.getNniIntfID()
-	if err != nil {
-		log.Error("Error in getting NNI interface ID, Failed to add EAPOL Flow")
-		return
-	}
+	networkIntfId := f.deviceHandler.nniIntfId
 	upstreamFlow = openolt_pb2.Flow{AccessIntfId: int32(intfId),
 		OnuId:         int32(onuId),
 		UniId:         int32(uniId),
@@ -1224,11 +1212,7 @@
 	uniId := -1
 	gemPortId := -1
 	allocId := -1
-	networkInterfaceId, err := f.getNniIntfID()
-	if err != nil {
-		log.Error("Error in getting NNI interface ID, Failed to add DHCP Trap flow on NNI")
-		return
-	}
+	networkInterfaceId := f.deviceHandler.nniIntfId
 	flowStoreCookie := getFlowStoreCookie(classifier, uint32(0))
 	if present := f.resourceMgr.IsFlowCookieOnKVStore(uint32(networkInterfaceId), uint32(onuId), uint32(uniId), flowStoreCookie); present {
 		log.Debug("Flow-exists--not-re-adding")
@@ -1276,22 +1260,3 @@
 	}
 	return
 }
-
-func (f *OpenOltFlowMgr) getNniIntfID() (int32, error) {
-	device, err := f.deviceHandler.coreProxy.GetDevice(nil, f.deviceHandler.deviceId, f.deviceHandler.deviceId)
-	if err != nil {
-		log.Errorw("Failed to get device", log.Fields{"device-id": f.deviceHandler.deviceId})
-		return -1, err
-	}
-	var portNum uint32
-	for _, port := range device.Ports {
-		if port.Type == voltha.Port_ETHERNET_NNI {
-			portNum = port.PortNo
-			break
-		}
-	}
-
-	nniIntfId := IntfIdFromNniPortNum(portNum)
-	log.Debugw("NNI interface Id", log.Fields{"intf-id": nniIntfId})
-	return int32(nniIntfId), nil
-}