--- /dev/null
+
+/*
+ * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.opendaylight.controller.sal.inventory;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentMap;
+
+import org.opendaylight.controller.sal.core.Node;
+import org.opendaylight.controller.sal.core.NodeConnector;
+import org.opendaylight.controller.sal.core.Property;
+
+/**
+ * The interface class that describes methods invoked from SAL toward the protocol
+ * plugin to solicit existing inventory data.
+ */
+public interface IPluginInInventoryService {
+ /**
+ * The method retrieves all the existing nodes and properties attached
+ *
+ * @return map of {@link org.opendaylight.controller.sal.core.Node} and {@link org.opendaylight.controller.sal.core.Property}
+ */
+ public ConcurrentMap<Node, Map<String, Property>> getNodeProps();
+
+ /**
+ * The method retrieve all the existing nodeConnectors and their properties
+ *
+ * @param refresh true if it needs to solicit Openflow core; otherwise, retrieve from local cache.
+ * @return map of {@link org.opendaylight.controller.sal.core.NodeConnector} and {@link org.opendaylight.controller.sal.core.Property}
+ */
+ public ConcurrentMap<NodeConnector, Map<String, Property>> getNodeConnectorProps(
+ Boolean refresh);
+}