diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceDescriptions.java b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceDescriptions.java
new file mode 100644
index 0000000..f7fd7bc
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/device/impl/DeviceDescriptions.java
@@ -0,0 +1,91 @@
+package org.onlab.onos.store.device.impl;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.onos.net.DefaultAnnotations.union;
+
+import java.util.Collections;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.SparseAnnotations;
+import org.onlab.onos.net.device.DefaultDeviceDescription;
+import org.onlab.onos.net.device.DefaultPortDescription;
+import org.onlab.onos.net.device.DeviceDescription;
+import org.onlab.onos.net.device.PortDescription;
+import org.onlab.onos.store.Timestamp;
+import org.onlab.onos.store.common.impl.Timestamped;
+
+/*
+ * Collection of Description of a Device and Ports, given from a Provider.
+ */
+class DeviceDescriptions {
+
+    private volatile Timestamped<DeviceDescription> deviceDesc;
+
+    private final ConcurrentMap<PortNumber, Timestamped<PortDescription>> portDescs;
+
+    public DeviceDescriptions(Timestamped<DeviceDescription> desc) {
+        this.deviceDesc = checkNotNull(desc);
+        this.portDescs = new ConcurrentHashMap<>();
+    }
+
+    public Timestamp getLatestTimestamp() {
+        Timestamp latest = deviceDesc.timestamp();
+        for (Timestamped<PortDescription> desc : portDescs.values()) {
+            if (desc.timestamp().compareTo(latest) > 0) {
+                latest = desc.timestamp();
+            }
+        }
+        return latest;
+    }
+
+    public Timestamped<DeviceDescription> getDeviceDesc() {
+        return deviceDesc;
+    }
+
+    public Timestamped<PortDescription> getPortDesc(PortNumber number) {
+        return portDescs.get(number);
+    }
+
+    public Map<PortNumber, Timestamped<PortDescription>> getPortDescs() {
+        return Collections.unmodifiableMap(portDescs);
+    }
+
+    /**
+     * Puts DeviceDescription, merging annotations as necessary.
+     *
+     * @param newDesc new DeviceDescription
+     */
+    public synchronized void putDeviceDesc(Timestamped<DeviceDescription> newDesc) {
+        Timestamped<DeviceDescription> oldOne = deviceDesc;
+        Timestamped<DeviceDescription> newOne = newDesc;
+        if (oldOne != null) {
+            SparseAnnotations merged = union(oldOne.value().annotations(),
+                                             newDesc.value().annotations());
+            newOne = new Timestamped<DeviceDescription>(
+                    new DefaultDeviceDescription(newDesc.value(), merged),
+                    newDesc.timestamp());
+        }
+        deviceDesc = newOne;
+    }
+
+    /**
+     * Puts PortDescription, merging annotations as necessary.
+     *
+     * @param newDesc new PortDescription
+     */
+    public synchronized void putPortDesc(Timestamped<PortDescription> newDesc) {
+        Timestamped<PortDescription> oldOne = portDescs.get(newDesc.value().portNumber());
+        Timestamped<PortDescription> newOne = newDesc;
+        if (oldOne != null) {
+            SparseAnnotations merged = union(oldOne.value().annotations(),
+                                             newDesc.value().annotations());
+            newOne = new Timestamped<PortDescription>(
+                    new DefaultPortDescription(newDesc.value(), merged),
+                    newDesc.timestamp());
+        }
+        portDescs.put(newOne.value().portNumber(), newOne);
+    }
+}