diff --git a/core/store/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java b/core/store/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
new file mode 100644
index 0000000..5574d27
--- /dev/null
+++ b/core/store/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopology.java
@@ -0,0 +1,444 @@
+package org.onlab.onos.store.topology.impl;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSetMultimap;
+import org.onlab.graph.DijkstraGraphSearch;
+import org.onlab.graph.GraphPathSearch;
+import org.onlab.graph.TarjanGraphSearch;
+import org.onlab.onos.net.AbstractModel;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultPath;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.DefaultTopologyCluster;
+import org.onlab.onos.net.topology.DefaultTopologyVertex;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.collect.ImmutableSetMultimap.Builder;
+import static org.onlab.graph.GraphPathSearch.Result;
+import static org.onlab.graph.TarjanGraphSearch.SCCResult;
+import static org.onlab.onos.net.Link.Type.INDIRECT;
+
+/**
+ * Default implementation of the topology descriptor. This carries the
+ * backing topology data.
+ */
+public class DefaultTopology extends AbstractModel implements Topology {
+
+    private static final DijkstraGraphSearch<TopologyVertex, TopologyEdge> DIJKSTRA =
+            new DijkstraGraphSearch<>();
+    private static final TarjanGraphSearch<TopologyVertex, TopologyEdge> TARJAN =
+            new TarjanGraphSearch<>();
+
+    private static final ProviderId PID = new ProviderId("core", "org.onlab.onos.net");
+
+    private final long time;
+    private final TopologyGraph graph;
+
+    private final SCCResult<TopologyVertex, TopologyEdge> clusterResults;
+    private final ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> results;
+    private final ImmutableSetMultimap<PathKey, Path> paths;
+
+    private final ImmutableMap<ClusterId, TopologyCluster> clusters;
+    private final ImmutableSet<ConnectPoint> infrastructurePoints;
+    private final ImmutableSetMultimap<ClusterId, ConnectPoint> broadcastSets;
+
+    private ImmutableMap<DeviceId, TopologyCluster> clustersByDevice;
+    private ImmutableSetMultimap<TopologyCluster, DeviceId> devicesByCluster;
+    private ImmutableSetMultimap<TopologyCluster, Link> linksByCluster;
+
+
+    /**
+     * Creates a topology descriptor attributed to the specified provider.
+     *
+     * @param providerId  identity of the provider
+     * @param description data describing the new topology
+     */
+    DefaultTopology(ProviderId providerId, GraphDescription description) {
+        super(providerId);
+        this.time = description.timestamp();
+
+        // Build the graph
+        this.graph = new DefaultTopologyGraph(description.vertexes(),
+                                              description.edges());
+
+        this.results = searchForShortestPaths();
+        this.paths = buildPaths();
+
+        this.clusterResults = searchForClusters();
+        this.clusters = buildTopologyClusters();
+
+        buildIndexes();
+
+        this.broadcastSets = buildBroadcastSets();
+        this.infrastructurePoints = findInfrastructurePoints();
+    }
+
+    @Override
+    public long time() {
+        return time;
+    }
+
+    @Override
+    public int clusterCount() {
+        return clusters.size();
+    }
+
+    @Override
+    public int deviceCount() {
+        return graph.getVertexes().size();
+    }
+
+    @Override
+    public int linkCount() {
+        return graph.getEdges().size();
+    }
+
+    @Override
+    public int pathCount() {
+        return paths.size();
+    }
+
+    /**
+     * Returns the backing topology graph.
+     *
+     * @return topology graph
+     */
+    TopologyGraph getGraph() {
+        return graph;
+    }
+
+    /**
+     * Returns the set of topology clusters.
+     *
+     * @return set of clusters
+     */
+    Set<TopologyCluster> getClusters() {
+        return ImmutableSet.copyOf(clusters.values());
+    }
+
+    /**
+     * Returns the specified topology cluster.
+     *
+     * @param clusterId cluster identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(ClusterId clusterId) {
+        return clusters.get(clusterId);
+    }
+
+    /**
+     * Returns the topology cluster that contains the given device.
+     *
+     * @param deviceId device identifier
+     * @return topology cluster
+     */
+    TopologyCluster getCluster(DeviceId deviceId) {
+        return clustersByDevice.get(deviceId);
+    }
+
+    /**
+     * Returns the set of cluster devices.
+     *
+     * @param cluster topology cluster
+     * @return cluster devices
+     */
+    Set<DeviceId> getClusterDevices(TopologyCluster cluster) {
+        return devicesByCluster.get(cluster);
+    }
+
+    /**
+     * Returns the set of cluster links.
+     *
+     * @param cluster topology cluster
+     * @return cluster links
+     */
+    Set<Link> getClusterLinks(TopologyCluster cluster) {
+        return linksByCluster.get(cluster);
+    }
+
+    /**
+     * Indicates whether the given point is an infrastructure link end-point.
+     *
+     * @param connectPoint connection point
+     * @return true if infrastructure
+     */
+    boolean isInfrastructure(ConnectPoint connectPoint) {
+        return infrastructurePoints.contains(connectPoint);
+    }
+
+    /**
+     * Indicates whether the given point is part of a broadcast set.
+     *
+     * @param connectPoint connection point
+     * @return true if in broadcast set
+     */
+    boolean isBroadcastPoint(ConnectPoint connectPoint) {
+        // Any non-infrastructure, i.e. edge points are assumed to be OK.
+        if (!isInfrastructure(connectPoint)) {
+            return true;
+        }
+
+        // Find the cluster to which the device belongs.
+        TopologyCluster cluster = clustersByDevice.get(connectPoint.deviceId());
+        if (cluster == null) {
+            throw new IllegalArgumentException("No cluster found for device " + connectPoint.deviceId());
+        }
+
+        // If the broadcast set is null or empty, or if the point explicitly
+        // belongs to it, return true;
+        Set<ConnectPoint> points = broadcastSets.get(cluster.id());
+        return points == null || points.isEmpty() || points.contains(connectPoint);
+    }
+
+    /**
+     * Returns the size of the cluster broadcast set.
+     *
+     * @param clusterId cluster identifier
+     * @return size of the cluster broadcast set
+     */
+    int broadcastSetSize(ClusterId clusterId) {
+        return broadcastSets.get(clusterId).size();
+    }
+
+    /**
+     * Returns the set of pre-computed shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst) {
+        return paths.get(new PathKey(src, dst));
+    }
+
+    /**
+     * Computes on-demand the set of shortest paths between source and
+     * destination devices.
+     *
+     * @param src source device
+     * @param dst destination device
+     * @return set of shortest paths
+     */
+    Set<Path> getPaths(DeviceId src, DeviceId dst, LinkWeight weight) {
+        GraphPathSearch.Result<TopologyVertex, TopologyEdge> result =
+                DIJKSTRA.search(graph, new DefaultTopologyVertex(src),
+                                new DefaultTopologyVertex(dst), weight);
+        ImmutableSet.Builder<Path> builder = ImmutableSet.builder();
+        for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+            builder.add(networkPath(path));
+        }
+        return builder.build();
+    }
+
+
+    // Searches the graph for all shortest paths and returns the search results.
+    private ImmutableMap<DeviceId, Result<TopologyVertex, TopologyEdge>> searchForShortestPaths() {
+        ImmutableMap.Builder<DeviceId, Result<TopologyVertex, TopologyEdge>> builder = ImmutableMap.builder();
+
+        // Search graph paths for each source to all destinations.
+        LinkWeight weight = new HopCountLinkWeight(graph.getVertexes().size());
+        for (TopologyVertex src : graph.getVertexes()) {
+            builder.put(src.deviceId(), DIJKSTRA.search(graph, src, null, weight));
+        }
+        return builder.build();
+    }
+
+    // Builds network paths from the graph path search results
+    private ImmutableSetMultimap<PathKey, Path> buildPaths() {
+        Builder<PathKey, Path> builder = ImmutableSetMultimap.builder();
+        for (DeviceId deviceId : results.keySet()) {
+            Result<TopologyVertex, TopologyEdge> result = results.get(deviceId);
+            for (org.onlab.graph.Path<TopologyVertex, TopologyEdge> path : result.paths()) {
+                builder.put(new PathKey(path.src().deviceId(), path.dst().deviceId()),
+                            networkPath(path));
+            }
+        }
+        return builder.build();
+    }
+
+    // Converts graph path to a network path with the same cost.
+    private Path networkPath(org.onlab.graph.Path<TopologyVertex, TopologyEdge> path) {
+        List<Link> links = new ArrayList<>();
+        for (TopologyEdge edge : path.edges()) {
+            links.add(edge.link());
+        }
+        return new DefaultPath(PID, links, path.cost());
+    }
+
+
+    // Searches for SCC clusters in the network topology graph using Tarjan
+    // algorithm.
+    private SCCResult<TopologyVertex, TopologyEdge> searchForClusters() {
+        return TARJAN.search(graph, new NoIndirectLinksWeight());
+    }
+
+    // Builds the topology clusters and returns the id-cluster bindings.
+    private ImmutableMap<ClusterId, TopologyCluster> buildTopologyClusters() {
+        ImmutableMap.Builder<ClusterId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        SCCResult<TopologyVertex, TopologyEdge> result =
+                TARJAN.search(graph, new NoIndirectLinksWeight());
+
+        // Extract both vertexes and edges from the results; the lists form
+        // pairs along the same index.
+        List<Set<TopologyVertex>> clusterVertexes = result.clusterVertexes();
+        List<Set<TopologyEdge>> clusterEdges = result.clusterEdges();
+
+        // Scan over the lists and create a cluster from the results.
+        for (int i = 0, n = result.clusterCount(); i < n; i++) {
+            Set<TopologyVertex> vertexSet = clusterVertexes.get(i);
+            Set<TopologyEdge> edgeSet = clusterEdges.get(i);
+
+            ClusterId cid = ClusterId.clusterId(i);
+            DefaultTopologyCluster cluster =
+                    new DefaultTopologyCluster(cid, vertexSet.size(), edgeSet.size(),
+                                               findRoot(vertexSet).deviceId());
+            clusterBuilder.put(cid, cluster);
+        }
+        return clusterBuilder.build();
+    }
+
+    // Finds the vertex whose device id is the lexicographical minimum in the
+    // specified set.
+    private TopologyVertex findRoot(Set<TopologyVertex> vertexSet) {
+        TopologyVertex minVertex = null;
+        for (TopologyVertex vertex : vertexSet) {
+            if (minVertex == null ||
+                    minVertex.deviceId().toString()
+                            .compareTo(minVertex.deviceId().toString()) < 0) {
+                minVertex = vertex;
+            }
+        }
+        return minVertex;
+    }
+
+    // Processes a map of broadcast sets for each cluster.
+    private ImmutableSetMultimap<ClusterId, ConnectPoint> buildBroadcastSets() {
+        Builder<ClusterId, ConnectPoint> builder = ImmutableSetMultimap.builder();
+        for (TopologyCluster cluster : clusters.values()) {
+            addClusterBroadcastSet(cluster, builder);
+        }
+        return builder.build();
+    }
+
+    // Finds all broadcast points for the cluster. These are those connection
+    // points which lie along the shortest paths between the cluster root and
+    // all other devices within the cluster.
+    private void addClusterBroadcastSet(TopologyCluster cluster,
+                                        Builder<ClusterId, ConnectPoint> builder) {
+        // Use the graph root search results to build the broadcast set.
+        Result<TopologyVertex, TopologyEdge> result = results.get(cluster.root());
+        for (Map.Entry<TopologyVertex, Set<TopologyEdge>> entry : result.parents().entrySet()) {
+            TopologyVertex vertex = entry.getKey();
+
+            // Ignore any parents that lead outside the cluster.
+            if (clustersByDevice.get(vertex.deviceId()) != cluster) {
+                continue;
+            }
+
+            // Ignore any back-link sets that are empty.
+            Set<TopologyEdge> parents = entry.getValue();
+            if (parents.isEmpty()) {
+                continue;
+            }
+
+            // Use the first back-link source and destinations to add to the
+            // broadcast set.
+            Link link = parents.iterator().next().link();
+            builder.put(cluster.id(), link.src());
+            builder.put(cluster.id(), link.dst());
+        }
+    }
+
+    // Collects and returns an set of all infrastructure link end-points.
+    private ImmutableSet<ConnectPoint> findInfrastructurePoints() {
+        ImmutableSet.Builder<ConnectPoint> builder = ImmutableSet.builder();
+        for (TopologyEdge edge : graph.getEdges()) {
+            builder.add(edge.link().src());
+            builder.add(edge.link().dst());
+        }
+        return builder.build();
+    }
+
+    // Builds cluster-devices, cluster-links and device-cluster indexes.
+    private void buildIndexes() {
+        // Prepare the index builders
+        ImmutableMap.Builder<DeviceId, TopologyCluster> clusterBuilder = ImmutableMap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, DeviceId> devicesBuilder = ImmutableSetMultimap.builder();
+        ImmutableSetMultimap.Builder<TopologyCluster, Link> linksBuilder = ImmutableSetMultimap.builder();
+
+        // Now scan through all the clusters
+        for (TopologyCluster cluster : clusters.values()) {
+            int i = cluster.id().index();
+
+            // Scan through all the cluster vertexes.
+            for (TopologyVertex vertex : clusterResults.clusterVertexes().get(i)) {
+                devicesBuilder.put(cluster, vertex.deviceId());
+                clusterBuilder.put(vertex.deviceId(), cluster);
+            }
+
+            // Scan through all the cluster edges.
+            for (TopologyEdge edge : clusterResults.clusterEdges().get(i)) {
+                linksBuilder.put(cluster, edge.link());
+            }
+        }
+
+        // Finalize all indexes.
+        clustersByDevice = clusterBuilder.build();
+        devicesByCluster = devicesBuilder.build();
+        linksByCluster = linksBuilder.build();
+    }
+
+    // Link weight for measuring link cost as hop count with indirect links
+    // being as expensive as traversing the entire graph to assume the worst.
+    private static class HopCountLinkWeight implements LinkWeight {
+        private final int indirectLinkCost;
+
+        HopCountLinkWeight(int indirectLinkCost) {
+            this.indirectLinkCost = indirectLinkCost;
+        }
+
+        @Override
+        public double weight(TopologyEdge edge) {
+            // To force preference to use direct paths first, make indirect
+            // links as expensive as the linear vertex traversal.
+            return edge.link().type() == INDIRECT ? indirectLinkCost : 1;
+        }
+    }
+
+    // Link weight for preventing traversal over indirect links.
+    private static class NoIndirectLinksWeight implements LinkWeight {
+        @Override
+        public double weight(TopologyEdge edge) {
+            return edge.link().type() == INDIRECT ? -1 : 1;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("time", time)
+                .add("clusters", clusterCount())
+                .add("devices", deviceCount())
+                .add("links", linkCount())
+                .add("pathCount", pathCount())
+                .toString();
+    }
+}
diff --git a/core/store/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopologyGraph.java b/core/store/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopologyGraph.java
new file mode 100644
index 0000000..945ba05
--- /dev/null
+++ b/core/store/src/main/java/org/onlab/onos/store/topology/impl/DefaultTopologyGraph.java
@@ -0,0 +1,28 @@
+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.graph.AdjacencyListsGraph;
+import org.onlab.onos.net.topology.TopologyEdge;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyVertex;
+
+import java.util.Set;
+
+/**
+ * Default implementation of an immutable topology graph based on a generic
+ * implementation of adjacency lists graph.
+ */
+public class DefaultTopologyGraph
+        extends AdjacencyListsGraph<TopologyVertex, TopologyEdge>
+        implements TopologyGraph {
+
+    /**
+     * Creates a topology graph comprising of the specified vertexes and edges.
+     *
+     * @param vertexes set of graph vertexes
+     * @param edges    set of graph edges
+     */
+    public DefaultTopologyGraph(Set<TopologyVertex> vertexes, Set<TopologyEdge> edges) {
+        super(vertexes, edges);
+    }
+
+}
diff --git a/core/store/src/main/java/org/onlab/onos/store/topology/impl/DistributedTopologyStore.java b/core/store/src/main/java/org/onlab/onos/store/topology/impl/DistributedTopologyStore.java
new file mode 100644
index 0000000..567861e
--- /dev/null
+++ b/core/store/src/main/java/org/onlab/onos/store/topology/impl/DistributedTopologyStore.java
@@ -0,0 +1,141 @@
+package org.onlab.onos.store.topology.impl;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+import java.util.List;
+import java.util.Set;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.onos.event.Event;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Link;
+import org.onlab.onos.net.Path;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.net.topology.ClusterId;
+import org.onlab.onos.net.topology.GraphDescription;
+import org.onlab.onos.net.topology.LinkWeight;
+import org.onlab.onos.net.topology.Topology;
+import org.onlab.onos.net.topology.TopologyCluster;
+import org.onlab.onos.net.topology.TopologyEvent;
+import org.onlab.onos.net.topology.TopologyGraph;
+import org.onlab.onos.net.topology.TopologyStore;
+import org.onlab.onos.net.topology.TopologyStoreDelegate;
+import org.onlab.onos.store.AbstractStore;
+import org.slf4j.Logger;
+
+/**
+ * Manages inventory of topology snapshots using trivial in-memory
+ * structures implementation.
+ */
+//FIXME: I LIE I AM NOT DISTRIBUTED
+@Component(immediate = true)
+@Service
+public class DistributedTopologyStore
+extends AbstractStore<TopologyEvent, TopologyStoreDelegate>
+implements TopologyStore {
+
+    private final Logger log = getLogger(getClass());
+
+    private volatile DefaultTopology current;
+
+    @Activate
+    public void activate() {
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        log.info("Stopped");
+    }
+    @Override
+    public Topology currentTopology() {
+        return current;
+    }
+
+    @Override
+    public boolean isLatest(Topology topology) {
+        // Topology is current only if it is the same as our current topology
+        return topology == current;
+    }
+
+    @Override
+    public TopologyGraph getGraph(Topology topology) {
+        return defaultTopology(topology).getGraph();
+    }
+
+    @Override
+    public Set<TopologyCluster> getClusters(Topology topology) {
+        return defaultTopology(topology).getClusters();
+    }
+
+    @Override
+    public TopologyCluster getCluster(Topology topology, ClusterId clusterId) {
+        return defaultTopology(topology).getCluster(clusterId);
+    }
+
+    @Override
+    public Set<DeviceId> getClusterDevices(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterDevices(cluster);
+    }
+
+    @Override
+    public Set<Link> getClusterLinks(Topology topology, TopologyCluster cluster) {
+        return defaultTopology(topology).getClusterLinks(cluster);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst) {
+        return defaultTopology(topology).getPaths(src, dst);
+    }
+
+    @Override
+    public Set<Path> getPaths(Topology topology, DeviceId src, DeviceId dst,
+            LinkWeight weight) {
+        return defaultTopology(topology).getPaths(src, dst, weight);
+    }
+
+    @Override
+    public boolean isInfrastructure(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isInfrastructure(connectPoint);
+    }
+
+    @Override
+    public boolean isBroadcastPoint(Topology topology, ConnectPoint connectPoint) {
+        return defaultTopology(topology).isBroadcastPoint(connectPoint);
+    }
+
+    @Override
+    public TopologyEvent updateTopology(ProviderId providerId,
+            GraphDescription graphDescription,
+            List<Event> reasons) {
+        // First off, make sure that what we're given is indeed newer than
+        // what we already have.
+        if (current != null && graphDescription.timestamp() < current.time()) {
+            return null;
+        }
+
+        // Have the default topology construct self from the description data.
+        DefaultTopology newTopology =
+                new DefaultTopology(providerId, graphDescription);
+
+        // Promote the new topology to current and return a ready-to-send event.
+        synchronized (this) {
+            current = newTopology;
+            return new TopologyEvent(TopologyEvent.Type.TOPOLOGY_CHANGED, current);
+        }
+    }
+
+    // Validates the specified topology and returns it as a default
+    private DefaultTopology defaultTopology(Topology topology) {
+        if (topology instanceof DefaultTopology) {
+            return (DefaultTopology) topology;
+        }
+        throw new IllegalArgumentException("Topology class " + topology.getClass() +
+                " not supported");
+    }
+
+}
diff --git a/core/store/src/main/java/org/onlab/onos/store/topology/impl/PathKey.java b/core/store/src/main/java/org/onlab/onos/store/topology/impl/PathKey.java
new file mode 100644
index 0000000..60736b9
--- /dev/null
+++ b/core/store/src/main/java/org/onlab/onos/store/topology/impl/PathKey.java
@@ -0,0 +1,40 @@
+package org.onlab.onos.store.topology.impl;
+
+import org.onlab.onos.net.DeviceId;
+
+import java.util.Objects;
+
+/**
+ * Key for filing pre-computed paths between source and destination devices.
+ */
+class PathKey {
+    private final DeviceId src;
+    private final DeviceId dst;
+
+    /**
+     * Creates a path key from the given source/dest pair.
+     * @param src source device
+     * @param dst destination device
+     */
+    PathKey(DeviceId src, DeviceId dst) {
+        this.src = src;
+        this.dst = dst;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(src, dst);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof PathKey) {
+            final PathKey other = (PathKey) obj;
+            return Objects.equals(this.src, other.src) && Objects.equals(this.dst, other.dst);
+        }
+        return false;
+    }
+}