diff --git a/src/main/java/org/onosproject/cordvtn/api/ConnectionHandler.java b/src/main/java/org/onosproject/cordvtn/api/ConnectionHandler.java
new file mode 100644
index 0000000..5676221
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/ConnectionHandler.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2015-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+/**
+ * Entity capable of handling a subject connected and disconnected situation.
+ */
+public interface ConnectionHandler<T> {
+
+    /**
+     * Processes the connected subject.
+     *
+     * @param subject subject
+     */
+    void connected(T subject);
+
+    /**
+     * Processes the disconnected subject.
+     *
+     * @param subject subject.
+     */
+    void disconnected(T subject);
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/CordService.java b/src/main/java/org/onosproject/cordvtn/api/CordService.java
new file mode 100644
index 0000000..b6fa9b0
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/CordService.java
@@ -0,0 +1,177 @@
+/*
+ * Copyright 2015-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onosproject.net.Host;
+import org.onosproject.openstackinterface.OpenstackNetwork;
+import org.onosproject.openstackinterface.OpenstackSubnet;
+
+import java.util.Map;
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+public final class CordService {
+
+    public enum ServiceType {
+        PRIVATE,
+        PUBLIC,
+        MANAGEMENT
+    }
+
+    private final CordServiceId id;
+    private final long segmentationId;
+    private final ServiceType serviceType;
+    private final IpPrefix serviceIpRange;
+    private final IpAddress serviceIp;
+    private final Map<Host, IpAddress> hosts;
+    private final Set<CordServiceId> tenantServices;
+
+    /**
+     * Default constructor.
+     *
+     * @param vNet OpenStack network
+     * @param subnet OpenStack subnet
+     * @param hosts host and tunnel ip map
+     * @param tenantServices list of tenant service ids
+     */
+    public CordService(OpenstackNetwork vNet, OpenstackSubnet subnet,
+                       Map<Host, IpAddress> hosts, Set<CordServiceId> tenantServices) {
+        this.id = CordServiceId.of(vNet.id());
+        this.segmentationId = Long.parseLong(vNet.segmentId());
+        this.serviceType = getServiceType(vNet.name());
+        this.serviceIpRange = IpPrefix.valueOf(subnet.cidr());
+        this.serviceIp = IpAddress.valueOf(subnet.gatewayIp());
+        this.hosts = hosts;
+        this.tenantServices = tenantServices;
+    }
+
+    /**
+     * Returns service ID.
+     *
+     * @return service id
+     */
+    public CordServiceId id() {
+        return id;
+    }
+
+    /**
+     * Returns segmentation ID of this service.
+     *
+     * @return segmentation id
+     */
+    public long segmentationId() {
+        return segmentationId;
+    }
+
+    /**
+     * Returns service type.
+     *
+     * @return service type
+     */
+    public ServiceType serviceType() {
+        return serviceType;
+    }
+
+    /**
+     * Returns service IP range.
+     *
+     * @return CIDR
+     */
+    public IpPrefix serviceIpRange() {
+        return serviceIpRange;
+    }
+
+    /**
+     * Returns service IP address.
+     *
+     * @return ip address
+     */
+    public IpAddress serviceIp() {
+        return serviceIp;
+    }
+
+    /**
+     * Returns hosts associated with this service.
+     *
+     * @return list of hosts
+     */
+    public Map<Host, IpAddress> hosts() {
+        return hosts;
+    }
+
+    /**
+     * Returns tenant service IDs.
+     *
+     * @return list of tenant service id
+     */
+    public Set<CordServiceId> tenantServices() {
+        return tenantServices;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof CordService)) {
+            return false;
+        }
+        final CordService other = (CordService) obj;
+        return Objects.equals(this.id, other.id);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("id", id)
+                .add("segmentationId", segmentationId)
+                .add("serviceType", serviceType)
+                .add("serviceIpRange", serviceIpRange)
+                .add("serviceIp", serviceIp)
+                .add("tenantServices", tenantServices)
+                .toString();
+    }
+
+    /**
+     * Returns network type from network name.
+     * It assumes that network name contains network type.
+     *
+     * @param netName network name
+     * @return network type, or PRIVATE if it doesn't match any type
+     */
+    private ServiceType getServiceType(String netName) {
+        checkNotNull(netName);
+
+        String name = netName.toUpperCase();
+        if (name.contains(ServiceType.PUBLIC.toString())) {
+            return ServiceType.PUBLIC;
+        } else if (name.contains(ServiceType.MANAGEMENT.toString())) {
+            return ServiceType.MANAGEMENT;
+        } else {
+            return ServiceType.PRIVATE;
+        }
+    }
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/CordServiceId.java b/src/main/java/org/onosproject/cordvtn/api/CordServiceId.java
new file mode 100644
index 0000000..b8a22a2
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/CordServiceId.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2015-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import org.onlab.util.Identifier;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Representation of service identifier.
+ */
+public final class CordServiceId extends Identifier<String> {
+    /**
+     * Default constructor.
+     *
+     * @param id service identifier
+     */
+    private CordServiceId(String id) {
+        super(id);
+    }
+
+    /**
+     * Returns the CordServiceId with value.
+     *
+     * @param id service id
+     * @return CordServiceId
+     */
+    public static CordServiceId of(String id) {
+        checkNotNull(id);
+        return new CordServiceId(id);
+    }
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/CordVtnConfig.java b/src/main/java/org/onosproject/cordvtn/api/CordVtnConfig.java
new file mode 100644
index 0000000..008012e
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/CordVtnConfig.java
@@ -0,0 +1,171 @@
+/*
+ * Copyright 2015-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.TpPort;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.config.Config;
+import org.slf4j.Logger;
+
+import java.util.Map;
+import java.util.Set;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Configuration object for CordVtn service.
+ */
+public class CordVtnConfig extends Config<ApplicationId> {
+
+    protected final Logger log = getLogger(getClass());
+
+    public static final String PRIVATE_GATEWAY_MAC = "privateGatewayMac";
+    public static final String PUBLIC_GATEWAYS = "publicGateways";
+    public static final String GATEWAY_IP = "gatewayIp";
+    public static final String GATEWAY_MAC = "gatewayMac";
+    public static final String LOCAL_MANAGEMENT_IP = "localManagementIp";
+    public static final String OVSDB_PORT = "ovsdbPort";
+
+    public static final String SSH_PORT = "sshPort";
+    public static final String SSH_USER = "sshUser";
+    public static final String SSH_KEY_FILE = "sshKeyFile";
+
+    public static final String CORDVTN_NODES = "nodes";
+    public static final String HOSTNAME = "hostname";
+    public static final String HOST_MANAGEMENT_IP = "hostManagementIp";
+    public static final String DATA_PLANE_IP = "dataPlaneIp";
+    public static final String DATA_PLANE_INTF = "dataPlaneIntf";
+    public static final String BRIDGE_ID = "bridgeId";
+
+    /**
+     * Returns the set of nodes read from network config.
+     *
+     * @return set of CordVtnNodeConfig or empty set
+     */
+    public Set<CordVtnNode> cordVtnNodes() {
+
+        Set<CordVtnNode> nodes = Sets.newHashSet();
+        JsonNode jsonNodes = object.get(CORDVTN_NODES);
+        if (jsonNodes == null) {
+            log.debug("No CORD VTN nodes found");
+            return nodes;
+        }
+
+        for (JsonNode jsonNode : jsonNodes) {
+            try {
+                NetworkAddress hostMgmt = NetworkAddress.valueOf(getConfig(jsonNode, HOST_MANAGEMENT_IP));
+                NetworkAddress localMgmt = NetworkAddress.valueOf(getConfig(object, LOCAL_MANAGEMENT_IP));
+                if (hostMgmt.prefix().contains(localMgmt.prefix()) ||
+                        localMgmt.prefix().contains(hostMgmt.prefix())) {
+                    log.error("hostMamt and localMgmt cannot be overlapped, skip this node");
+                    continue;
+                }
+
+                Ip4Address hostMgmtIp = hostMgmt.ip().getIp4Address();
+                SshAccessInfo sshInfo = new SshAccessInfo(
+                        hostMgmtIp,
+                        TpPort.tpPort(Integer.parseInt(getConfig(object, SSH_PORT))),
+                        getConfig(object, SSH_USER), getConfig(object, SSH_KEY_FILE));
+
+                String hostname = getConfig(jsonNode, HOSTNAME);
+                CordVtnNode newNode = new CordVtnNode(
+                        hostname, hostMgmt, localMgmt,
+                        NetworkAddress.valueOf(getConfig(jsonNode, DATA_PLANE_IP)),
+                        TpPort.tpPort(Integer.parseInt(getConfig(object, OVSDB_PORT))),
+                        sshInfo,
+                        DeviceId.deviceId(getConfig(jsonNode, BRIDGE_ID)),
+                        getConfig(jsonNode, DATA_PLANE_INTF),
+                        CordVtnNodeState.noState());
+
+                nodes.add(newNode);
+            } catch (IllegalArgumentException | NullPointerException e) {
+                log.error("{}", e.toString());
+            }
+        }
+
+        return nodes;
+    }
+
+    /**
+     * Returns value of a given path. If the path is missing, show log and return
+     * null.
+     *
+     * @param path path
+     * @return value or null
+     */
+    private String getConfig(JsonNode jsonNode, String path) {
+        jsonNode = jsonNode.path(path);
+
+        if (jsonNode.isMissingNode()) {
+            log.error("{} is not configured", path);
+            return null;
+        } else {
+            return jsonNode.asText();
+        }
+    }
+
+    /**
+     * Returns private network gateway MAC address.
+     *
+     * @return mac address, or null
+     */
+    public MacAddress privateGatewayMac() {
+        JsonNode jsonNode = object.get(PRIVATE_GATEWAY_MAC);
+        if (jsonNode == null) {
+            return null;
+        }
+
+        try {
+            return MacAddress.valueOf(jsonNode.asText());
+        } catch (IllegalArgumentException e) {
+            log.error("Wrong MAC address format {}", jsonNode.asText());
+            return null;
+        }
+    }
+
+    /**
+     * Returns public network gateway IP and MAC address pairs.
+     *
+     * @return map of ip and mac address
+     */
+    public Map<IpAddress, MacAddress> publicGateways() {
+        JsonNode jsonNodes = object.get(PUBLIC_GATEWAYS);
+        if (jsonNodes == null) {
+            return Maps.newHashMap();
+        }
+
+        Map<IpAddress, MacAddress> publicGateways = Maps.newHashMap();
+        jsonNodes.forEach(jsonNode -> {
+            try {
+                publicGateways.put(
+                        IpAddress.valueOf(jsonNode.path(GATEWAY_IP).asText()),
+                        MacAddress.valueOf(jsonNode.path(GATEWAY_MAC).asText()));
+            } catch (IllegalArgumentException | NullPointerException e) {
+                log.error("Wrong address format {}", e.toString());
+            }
+        });
+
+        return publicGateways;
+    }
+}
+
diff --git a/src/main/java/org/onosproject/cordvtn/api/CordVtnNode.java b/src/main/java/org/onosproject/cordvtn/api/CordVtnNode.java
new file mode 100644
index 0000000..c63a9e4
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/CordVtnNode.java
@@ -0,0 +1,220 @@
+/*
+ * Copyright 2015-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.packet.TpPort;
+import org.onosproject.net.DeviceId;
+
+import java.util.Comparator;
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Representation of a compute infrastructure node for CORD VTN service.
+ */
+public final class CordVtnNode {
+
+    private final String hostname;
+    private final NetworkAddress hostMgmtIp;
+    private final NetworkAddress localMgmtIp;
+    private final NetworkAddress dpIp;
+    private final TpPort ovsdbPort;
+    private final SshAccessInfo sshInfo;
+    private final DeviceId bridgeId;
+    private final String dpIntf;
+    private final CordVtnNodeState state;
+
+    public static final Comparator<CordVtnNode> CORDVTN_NODE_COMPARATOR =
+            (node1, node2) -> node1.hostname().compareTo(node2.hostname());
+
+    /**
+     * Creates a new node.
+     *
+     * @param hostname hostname
+     * @param hostMgmtIp host management network address
+     * @param localMgmtIp local management network address
+     * @param dpIp data plane network address
+     * @param ovsdbPort port number for OVSDB connection
+     * @param sshInfo SSH access information
+     * @param bridgeId integration bridge identifier
+     * @param dpIntf data plane interface name
+     * @param state cordvtn node state
+     */
+    public CordVtnNode(String hostname, NetworkAddress hostMgmtIp, NetworkAddress localMgmtIp,
+                       NetworkAddress dpIp, TpPort ovsdbPort, SshAccessInfo sshInfo,
+                       DeviceId bridgeId, String dpIntf, CordVtnNodeState state) {
+        this.hostname = checkNotNull(hostname, "hostname cannot be null");
+        this.hostMgmtIp = checkNotNull(hostMgmtIp, "hostMgmtIp cannot be null");
+        this.localMgmtIp = checkNotNull(localMgmtIp, "localMgmtIp cannot be null");
+        this.dpIp = checkNotNull(dpIp, "dpIp cannot be null");
+        this.ovsdbPort = checkNotNull(ovsdbPort, "ovsdbPort cannot be null");
+        this.sshInfo = checkNotNull(sshInfo, "sshInfo cannot be null");
+        this.bridgeId = checkNotNull(bridgeId, "bridgeId cannot be null");
+        this.dpIntf = checkNotNull(dpIntf, "dpIntf cannot be null");
+        this.state = state;
+    }
+
+    /**
+     * Returns cordvtn node with new state.
+     *
+     * @param node cordvtn node
+     * @param state cordvtn node init state
+     * @return cordvtn node
+     */
+    public static CordVtnNode getUpdatedNode(CordVtnNode node, CordVtnNodeState state) {
+        return new CordVtnNode(node.hostname,
+                               node.hostMgmtIp, node.localMgmtIp, node.dpIp,
+                               node.ovsdbPort,
+                               node.sshInfo,
+                               node.bridgeId,
+                               node.dpIntf, state);
+    }
+
+    /**
+     * Returns the hostname.
+     *
+     * @return hostname
+     */
+    public String hostname() {
+        return this.hostname;
+    }
+
+    /**
+     * Returns the host management network address.
+     *
+     * @return network address
+     */
+    public NetworkAddress hostMgmtIp() {
+        return this.hostMgmtIp;
+    }
+
+    /**
+     * Returns the local management network address.
+     *
+     * @return network address
+     */
+    public NetworkAddress localMgmtIp() {
+        return this.localMgmtIp;
+    }
+
+    /**
+     * Returns the data plane network address.
+     *
+     * @return network address
+     */
+    public NetworkAddress dpIp() {
+        return this.dpIp;
+    }
+
+    /**
+     * Returns the port number used for OVSDB connection.
+     *
+     * @return port number
+     */
+    public TpPort ovsdbPort() {
+        return this.ovsdbPort;
+    }
+
+    /**
+     * Returns the SSH access information.
+     *
+     * @return ssh access information
+     */
+    public SshAccessInfo sshInfo() {
+        return this.sshInfo;
+    }
+
+    /**
+     * Returns the identifier of the integration bridge.
+     *
+     * @return device id
+     */
+    public DeviceId intBrId() {
+        return this.bridgeId;
+    }
+
+    /**
+     * Returns the identifier of the OVSDB device.
+     *
+     * @return device id
+     */
+    public DeviceId ovsdbId() {
+        return DeviceId.deviceId("ovsdb:" + this.hostMgmtIp.ip().toString());
+    }
+
+    /**
+     * Returns data plane interface name.
+     *
+     * @return data plane interface name
+     */
+    public String dpIntf() {
+        return this.dpIntf;
+    }
+
+    /**
+     * Returns the state of the node.
+     *
+     * @return state
+     */
+    public CordVtnNodeState state() {
+        return this.state;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof CordVtnNode) {
+            CordVtnNode that = (CordVtnNode) obj;
+            if (Objects.equals(hostname, that.hostname) &&
+                    Objects.equals(hostMgmtIp, that.hostMgmtIp) &&
+                    Objects.equals(localMgmtIp, that.localMgmtIp) &&
+                    Objects.equals(dpIp, that.dpIp) &&
+                    Objects.equals(ovsdbPort, that.ovsdbPort) &&
+                    Objects.equals(sshInfo, that.sshInfo) &&
+                    Objects.equals(bridgeId, that.bridgeId) &&
+                    Objects.equals(dpIntf, that.dpIntf)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(hostname, hostMgmtIp, localMgmtIp, dpIp,
+                            ovsdbPort, sshInfo, bridgeId, dpIntf);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("hostname", hostname)
+                .add("hostMgmtIp", hostMgmtIp)
+                .add("localMgmtIp", localMgmtIp)
+                .add("dpIp", dpIp)
+                .add("port", ovsdbPort)
+                .add("sshInfo", sshInfo)
+                .add("bridgeId", bridgeId)
+                .add("dpIntf", dpIntf)
+                .add("state", state)
+                .toString();
+    }
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/CordVtnNodeState.java b/src/main/java/org/onosproject/cordvtn/api/CordVtnNodeState.java
new file mode 100644
index 0000000..1121390
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/CordVtnNodeState.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+/**
+ * Entity that defines possible init state of the cordvtn node.
+ */
+public interface CordVtnNodeState {
+    /**
+     * Returns null for no state.
+     *
+     * @return null
+     */
+    static CordVtnNodeState noState() {
+        return null;
+    }
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/CordVtnService.java b/src/main/java/org/onosproject/cordvtn/api/CordVtnService.java
new file mode 100644
index 0000000..5950670
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/CordVtnService.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2015-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.MacAddress;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.HostId;
+
+import java.util.Map;
+
+/**
+ * Service for provisioning overlay virtual networks on compute nodes.
+ */
+public interface CordVtnService {
+
+    String CORDVTN_APP_ID = "org.onosproject.cordvtn";
+
+    /**
+     * Adds a new VM on a given node and connect point.
+     *
+     * @param node cordvtn node
+     * @param connectPoint connect point
+     */
+    void addServiceVm(CordVtnNode node, ConnectPoint connectPoint);
+
+    /**
+     * Removes a VM from a given node and connect point.
+     *
+     * @param connectPoint connect point
+     */
+    void removeServiceVm(ConnectPoint connectPoint);
+
+    /**
+     * Creates dependencies for a given tenant service.
+     *
+     * @param tServiceId id of the service which has a dependency
+     * @param pServiceId id of the service which provide dependency
+     * @param isBidirectional true to enable bidirectional connectivity between two services
+     */
+    void createServiceDependency(CordServiceId tServiceId,
+                                 CordServiceId pServiceId,
+                                 boolean isBidirectional);
+
+    /**
+     * Removes all dependencies from a given tenant service.
+     *
+     * @param tServiceId id of the service which has a dependency
+     * @param pServiceId id of the service which provide dependency
+     */
+    void removeServiceDependency(CordServiceId tServiceId, CordServiceId pServiceId);
+
+    /**
+     * Updates virtual service gateways.
+     *
+     * @param vSgHost host id of vSG host
+     * @param serviceVlan service vlan id
+     * @param vSgs map of ip and mac address of vSGs running in this vSG host
+     */
+    void updateVirtualSubscriberGateways(HostId vSgHost, String serviceVlan,
+                                         Map<IpAddress, MacAddress> vSgs);
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/NetworkAddress.java b/src/main/java/org/onosproject/cordvtn/api/NetworkAddress.java
new file mode 100644
index 0000000..23c7318
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/NetworkAddress.java
@@ -0,0 +1,114 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkArgument;
+
+/**
+ * Representation of a network address, which consists of IP address and prefix.
+ */
+public final class NetworkAddress {
+    private final IpAddress ip;
+    private final IpPrefix prefix;
+
+    /**
+     * Constructor for a given IP address and prefix.
+     *
+     * @param ip ip address
+     * @param prefix ip prefix
+     */
+    public NetworkAddress(IpAddress ip, IpPrefix prefix) {
+        this.ip = ip;
+        this.prefix = prefix;
+    }
+
+    /**
+     * Converts a CIDR notation string into a network address.
+     *
+     * @param cidr cidr
+     * @return network address
+     * @throws IllegalArgumentException if the cidr is not valid
+     */
+    public static NetworkAddress valueOf(String cidr) {
+        checkArgument(cidr.contains("/"));
+
+        IpAddress ipAddress = IpAddress.valueOf(cidr.split("/")[0]);
+        IpPrefix ipPrefix = IpPrefix.valueOf(cidr);
+
+        return new NetworkAddress(ipAddress, ipPrefix);
+    }
+
+    /**
+     * Returns the IP address value of the network address.
+     *
+     * @return ip address
+     */
+    public IpAddress ip() {
+        return this.ip;
+    }
+
+    /**
+     * Returns the IP prefix value of the network address.
+     *
+     * @return ip prefix
+     */
+    public IpPrefix prefix() {
+        return this.prefix;
+    }
+
+    /**
+     * Converts a network address to a CIDR notation.
+     *
+     * @return cidr notation string
+     */
+    public String cidr() {
+        return ip.toString() + "/" + prefix.prefixLength();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof NetworkAddress) {
+            NetworkAddress that = (NetworkAddress) obj;
+            if (Objects.equals(ip, that.ip) && Objects.equals(prefix, that.prefix)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(ip, prefix);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("IpAddress", ip)
+                .add("IpPrefix", prefix)
+                .toString();
+    }
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/SshAccessInfo.java b/src/main/java/org/onosproject/cordvtn/api/SshAccessInfo.java
new file mode 100644
index 0000000..7679348
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/SshAccessInfo.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.cordvtn.api;
+
+import com.google.common.base.MoreObjects;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.TpPort;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Representation of SSH access information.
+ */
+public final class SshAccessInfo {
+
+    private final Ip4Address remoteIp;
+    private final TpPort port;
+    private final String user;
+    private final String privateKey;
+
+    /**
+     * Creates a new SSH access information.
+     *
+     * @param remoteIp ssh remote ip address
+     * @param port ssh port number
+     * @param user user name
+     * @param privateKey path of ssh private key
+     */
+    public SshAccessInfo(Ip4Address remoteIp, TpPort port, String user, String privateKey) {
+        this.remoteIp = checkNotNull(remoteIp);
+        this.port = checkNotNull(port);
+        this.user = checkNotNull(user);
+        this.privateKey = checkNotNull(privateKey);
+    }
+
+    /**
+     * Returns the remote IP address.
+     *
+     * @return ip address
+     */
+    public Ip4Address remoteIp() {
+        return this.remoteIp;
+    }
+
+    /**
+     * Returns the port number.
+     *
+     * @return ssh port
+     */
+    public TpPort port() {
+        return this.port;
+    }
+
+    /**
+     * Returns the user name.
+     *
+     * @return user name
+     */
+    public String user() {
+        return this.user;
+    }
+
+    /**
+     * Returns the private key path.
+     *
+     * @return privateKey
+     */
+    public String privateKey() {
+        return privateKey;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (obj instanceof SshAccessInfo) {
+            SshAccessInfo that = (SshAccessInfo) obj;
+            if (Objects.equals(remoteIp, that.remoteIp) &&
+                    Objects.equals(port, that.port) &&
+                    Objects.equals(user, that.user) &&
+                    Objects.equals(privateKey, that.privateKey)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(remoteIp, port, user, privateKey);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("remoteIp", remoteIp)
+                .add("port", port)
+                .add("user", user)
+                .add("privateKey", privateKey)
+                .toString();
+    }
+}
diff --git a/src/main/java/org/onosproject/cordvtn/api/package-info.java b/src/main/java/org/onosproject/cordvtn/api/package-info.java
new file mode 100644
index 0000000..7d41963
--- /dev/null
+++ b/src/main/java/org/onosproject/cordvtn/api/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * API for CORD VTN application.
+ */
+package org.onosproject.cordvtn.api;
\ No newline at end of file