diff --git a/apps/openstackswitching/api/pom.xml b/apps/openstackswitching/api/pom.xml
new file mode 100644
index 0000000..f5e6f94
--- /dev/null
+++ b/apps/openstackswitching/api/pom.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2015 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onosproject</groupId>
+        <artifactId>onos-openstackswitching</artifactId>
+        <version>1.4.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-openstackswitching-api</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>SONA Openstack Switching  application API</description>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.compendium</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.core</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackNetwork.java b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackNetwork.java
similarity index 96%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackNetwork.java
rename to apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackNetwork.java
index 7bfdf29..1b28d0c 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackNetwork.java
+++ b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackNetwork.java
@@ -77,6 +77,11 @@
         return this.networkType;
     }
 
+    @Override
+    protected Object clone() throws CloneNotSupportedException {
+       return super.clone();
+    }
+
     public static final class Builder {
         private String name;
         private String tenantId;
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackPort.java b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackPort.java
similarity index 95%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackPort.java
rename to apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackPort.java
index 4326b4f..50afdf3 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackPort.java
+++ b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackPort.java
@@ -19,6 +19,7 @@
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 
@@ -179,6 +180,16 @@
     //
     //}
 
+    @Override
+    public Object clone() {
+        OpenstackPort op = new OpenstackPort(this.status, this.name, this.adminStateUp,
+                this.networkId, this.tenantId, this.deviceOwner, this.macAddress,
+                (HashMap) this.fixedIps.clone(), this.id,
+                Collections.unmodifiableList(this.securityGroups), this.deviceId);
+
+        return op;
+    }
+
     /**
      * OpenstackPort Builder class.
      */
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSubnet.java b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackSubnet.java
similarity index 90%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSubnet.java
rename to apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackSubnet.java
index 39d783e..bc536e8 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSubnet.java
+++ b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackSubnet.java
@@ -15,6 +15,10 @@
  */
 package org.onosproject.openstackswitching;
 
+import org.onlab.packet.Ip4Address;
+
+import java.util.List;
+
 import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
@@ -26,13 +30,13 @@
     private boolean enableHhcp;
     private String networkId;
     private String tenantId;
-    private String dnsNameservers;
+    private List<Ip4Address> dnsNameservers;
     private String gatewayIp;
     private String cidr;
     private String id;
 
     private OpenstackSubnet(String name, boolean enableHhcp, String networkId,
-                            String tenantId, String dnsNameservers, String gatewayIp,
+                            String tenantId, List<Ip4Address> dnsNameservers, String gatewayIp,
                             String cidr, String id) {
         this.name = name;
         this.enableHhcp = enableHhcp;
@@ -69,7 +73,7 @@
         return tenantId;
     }
 
-    public String dnsNameservers() {
+    public List<Ip4Address> dnsNameservers() {
         return dnsNameservers;
     }
 
@@ -85,8 +89,6 @@
         return id;
     }
 
-    // TODO : Implement the following functions when necessary
-
     /**
      * OpenstackSubnet Builder class.
      *
@@ -96,7 +98,7 @@
         private boolean enableDhcp;
         private String networkId;
         private String tenantId;
-        private String dnsNameservers;
+        private List<Ip4Address> dnsNameservers;
         private String gatewayIp;
         private String cidr;
         private String id;
@@ -127,7 +129,7 @@
             return this;
         }
 
-        public Builder setDnsNameservers(String dnsNameservers) {
+        public Builder setDnsNameservers(List<Ip4Address> dnsNameservers) {
             this.dnsNameservers = dnsNameservers;
 
             return this;
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingService.java b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingService.java
similarity index 62%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingService.java
rename to apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingService.java
index 3d40d51..16898d7 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingService.java
+++ b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingService.java
@@ -15,8 +15,10 @@
  */
 package org.onosproject.openstackswitching;
 
+import java.util.Collection;
+
 /**
- * It handles port management REST API from Openstack for VMs.
+ * Handles port management REST API from Openstack for VMs.
  */
 public interface OpenstackSwitchingService {
 
@@ -40,16 +42,41 @@
     void updatePorts();
 
     /**
-     * Store the network information created by openstack.
+     * Stores the network information created by openstack.
      *
      * @param openstackNetwork network information
      */
     void createNetwork(OpenstackNetwork openstackNetwork);
 
     /**
-     * Store the subnet information created by openstack.
+     * Stores the subnet information created by openstack.
      *
      * @param openstackSubnet subnet information
      */
     void createSubnet(OpenstackSubnet openstackSubnet);
+
+    /**
+     * Returns port information list for the network ID given.
+     *
+     * @param networkId Network ID of the ports
+     * @return port information list
+     */
+    Collection<OpenstackPort> ports(String networkId);
+
+    /**
+     * Returns port information for the port ID given.
+     *
+     * @param portId Port ID
+     * @return port information
+     */
+    OpenstackPort port(String portId);
+
+    /**
+     * Returns network information list for the network ID given.
+     *
+     * @param networkId Network ID
+     * @return network information list
+     */
+    OpenstackNetwork network(String networkId);
+
 }
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/package-info.java b/apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/package-info.java
similarity index 100%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/package-info.java
rename to apps/openstackswitching/api/src/main/java/org/onosproject/openstackswitching/package-info.java
diff --git a/apps/openstackswitching/app/app.xml b/apps/openstackswitching/app/app.xml
new file mode 100644
index 0000000..e982b90
--- /dev/null
+++ b/apps/openstackswitching/app/app.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2015 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.
+  -->
+<app name="org.onosproject.openstackswitching" origin="ON.Lab" version="${project.version}"
+     featuresRepo="mvn:${project.groupId}/${project.artifactId}/${project.version}/xml/features"
+     features="${project.artifactId}">
+    <description>${project.description}</description>
+    <artifact>mvn:${project.groupId}/onos-app-openstackswitching/${project.version}</artifact>
+    <artifact>mvn:${project.groupId}/onos-app-dhcp-api/${project.version}</artifact>
+    <artifact>mvn:${project.groupId}/onos-app-dhcp/${project.version}</artifact>
+</app>
diff --git a/apps/openstackswitching/app/features.xml b/apps/openstackswitching/app/features.xml
new file mode 100644
index 0000000..58bdb4a
--- /dev/null
+++ b/apps/openstackswitching/app/features.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<!--
+  ~ Copyright 2015 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.
+  -->
+<features xmlns="http://karaf.apache.org/xmlns/features/v1.2.0" name="${project.artifactId}-${project.version}">
+    <repository>mvn:${project.groupId}/${project.artifactId}/${project.version}/xml/features</repository>
+    <feature name="onos-app-openstackswitching" version="${project.version}"
+             description="${project.description}">
+        <feature>onos-api</feature>
+        <bundle>mvn:${project.groupId}/onos-app-openstackswitching/${project.version}</bundle>
+        <bundle>mvn:${project.groupId}/onos-app-dhcp-api/${project.version}</bundle>
+        <bundle>mvn:${project.groupId}/onos-app-dhcp/${project.version}</bundle>
+    </feature>
+</features>
diff --git a/apps/openstackswitching/app/pom.xml b/apps/openstackswitching/app/pom.xml
new file mode 100644
index 0000000..27aa127
--- /dev/null
+++ b/apps/openstackswitching/app/pom.xml
@@ -0,0 +1,131 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2015 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>org.onosproject</groupId>
+        <artifactId>onos-openstackswitching</artifactId>
+        <version>1.4.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>onos-app-openstackswitching</artifactId>
+    <packaging>bundle</packaging>
+
+    <description>SONA Openstack Switching  applications</description>
+    <properties>
+        <onos.version>1.4.0-SNAPSHOT</onos.version>
+        <onos.app.name>org.onosproject.openstackswitching</onos.app.name>
+        <web.context>/onos/openstackswitching</web.context>
+        <api.version>1.0.0</api.version>
+        <api.title>ONOS OpenStack Switching REST API</api.title>
+        <api.description>
+            APIs for receiving Neutron information.
+        </api.description>
+        <api.package>org.onosproject.openstackswitching.web</api.package>
+        <onos.app.origin>SKT, Inc.</onos.app.origin>
+    </properties>
+
+
+    <dependencies>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-app-openstackswitching-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-rest</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onlab-rest</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>javax.ws.rs</groupId>
+            <artifactId>jsr311-api</artifactId>
+            <version>1.1.1</version>
+        </dependency>
+        <dependency>
+            <groupId>com.sun.jersey</groupId>
+            <artifactId>jersey-servlet</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-annotations</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.compendium</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.osgi</groupId>
+            <artifactId>org.osgi.core</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.onosproject</groupId>
+            <artifactId>onos-app-dhcp-api</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.felix</groupId>
+                <artifactId>maven-bundle-plugin</artifactId>
+                <extensions>true</extensions>
+                <configuration>
+                    <instructions>
+                        <_wab>src/main/webapp/</_wab>
+                        <Bundle-SymbolicName>
+                            ${project.groupId}.${project.artifactId}
+                        </Bundle-SymbolicName>
+                        <Import-Package>
+                            org.slf4j,
+                            org.osgi.framework,
+                            javax.ws.rs,
+                            javax.ws.rs.core,
+                            com.sun.jersey.api.core,
+                            com.sun.jersey.spi.container.servlet,
+                            com.sun.jersey.server.impl.container.servlet,
+                            com.fasterxml.jackson.databind,
+                            com.fasterxml.jackson.databind.node,
+                            com.fasterxml.jackson.core,
+                            org.apache.karaf.shell.commands,
+                            com.google.common.*,
+                            org.onlab.packet.*,
+                            org.onosproject.*
+                        </Import-Package>
+                        <Web-ContextPath>${web.context}</Web-ContextPath>
+                    </instructions>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackArpHandler.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackArpHandler.java
similarity index 98%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackArpHandler.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackArpHandler.java
index 0c139d8..f281e4a 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackArpHandler.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackArpHandler.java
@@ -31,7 +31,7 @@
 import java.util.Map;
 
 /**
- * It handles ARP packet from VMs.
+ * Handles ARP packet from VMs.
  */
 public class OpenstackArpHandler {
 
diff --git a/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingConfig.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingConfig.java
new file mode 100644
index 0000000..12a9c2c
--- /dev/null
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingConfig.java
@@ -0,0 +1,47 @@
+/*
+ * Copyright 2014 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.openstackswitching;
+
+import org.onosproject.core.ApplicationId;
+import org.onosproject.net.config.Config;
+import org.onosproject.net.config.basics.BasicElementConfig;
+
+/**
+ * Handles configuration for OpenstackSwitching app.
+ */
+public class OpenstackSwitchingConfig extends Config<ApplicationId> {
+    public static final String DONOTPUSH = "do_not_push_flows";
+
+    /**
+     * Returns the flag whether the app pushes flows or not.
+     *
+     * @return the flag or false if not set
+     */
+    public boolean doNotPushFlows() {
+        String flag = get(DONOTPUSH, "false");
+        return Boolean.valueOf(flag);
+    }
+
+    /**
+     * Sets the flag whether the app pushes flows or not.
+     *
+     * @param flag the flag whether the app pushes flows or not
+     * @return self
+     */
+    public BasicElementConfig doNotPushFlows(boolean flag) {
+        return (BasicElementConfig) setOrClear(DONOTPUSH, flag);
+    }
+}
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingManager.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingManager.java
similarity index 79%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingManager.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingManager.java
index 6cc431d..0e7ebac 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingManager.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingManager.java
@@ -15,6 +15,7 @@
  */
 package org.onosproject.openstackswitching;
 
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import org.apache.felix.scr.annotations.Activate;
@@ -33,6 +34,10 @@
 import org.onosproject.net.Device;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.Port;
+import org.onosproject.net.config.ConfigFactory;
+import org.onosproject.net.config.NetworkConfigEvent;
+import org.onosproject.net.config.NetworkConfigListener;
+import org.onosproject.net.config.NetworkConfigRegistry;
 import org.onosproject.net.device.DeviceEvent;
 import org.onosproject.net.device.DeviceListener;
 import org.onosproject.net.device.DeviceService;
@@ -43,17 +48,21 @@
 import org.onosproject.net.packet.PacketService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
 import java.util.List;
 import java.util.Map;
+import java.util.Collection;
+import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+import static org.onosproject.net.config.basics.SubjectFactories.APP_SUBJECT_FACTORY;
 
 @SuppressWarnings("ALL")
 @Service
 @Component(immediate = true)
 /**
- * It populates forwarding rules for VMs created by Openstack.
+ * Populates forwarding rules for VMs created by Openstack.
  */
 public class OpenstackSwitchingManager implements OpenstackSwitchingService {
 
@@ -73,11 +82,15 @@
     protected FlowObjectiveService flowObjectiveService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected NetworkConfigRegistry cfgService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected DhcpService dhcpService;
 
     public static final int DHCP_PORT = 67;
 
     private ApplicationId appId;
+    private boolean doNotPushFlows;
     private OpenstackArpHandler arpHandler;
 
     private OpenstackSwitchingRulePopulator rulePopulator;
@@ -85,7 +98,17 @@
 
     private InternalPacketProcessor internalPacketProcessor = new InternalPacketProcessor();
     private InternalDeviceListener internalDeviceListener = new InternalDeviceListener();
-
+    private InternalConfigListener internalConfigListener = new InternalConfigListener();
+    private final Set<ConfigFactory> factories = ImmutableSet.of(
+            new ConfigFactory<ApplicationId, OpenstackSwitchingConfig>(APP_SUBJECT_FACTORY,
+                    OpenstackSwitchingConfig.class,
+                    "openstackswitching") {
+                @Override
+                public OpenstackSwitchingConfig createConfig() {
+                    return new OpenstackSwitchingConfig();
+                }
+            }
+    );
     // Map <port_id, OpenstackPort>
     private Map<String, OpenstackPort> openstackPortMap;
     // Map <network_id, OpenstackNetwork>
@@ -101,17 +124,24 @@
     protected void activate() {
         appId = coreService
                 .registerApplication("org.onosproject.openstackswitching");
-        rulePopulator = new OpenstackSwitchingRulePopulator(appId, flowObjectiveService);
         packetService.addProcessor(internalPacketProcessor, PacketProcessor.director(1));
         deviceService.addListener(internalDeviceListener);
-
+        cfgService.addListener(internalConfigListener);
+        factories.forEach(cfgService::registerConfigFactory);
+        OpenstackSwitchingConfig cfg =
+                cfgService.getConfig(appId, OpenstackSwitchingConfig.class);
+        if (cfg != null) {
+            doNotPushFlows = cfg.doNotPushFlows();
+        }
         openstackPortMap = Maps.newHashMap();
         openstackNetworkMap = Maps.newHashMap();
         openstackSubnetMap = Maps.newHashMap();
 
         vniPortMap = Maps.newHashMap();
         tunnelPortMap = Maps.newHashMap();
+
         arpHandler = new OpenstackArpHandler(openstackPortMap, packetService);
+
         log.info("Started");
     }
 
@@ -119,6 +149,7 @@
     protected void deactivate() {
         packetService.removeProcessor(internalPacketProcessor);
         deviceService.removeListener(internalDeviceListener);
+        cfgService.removeListener(internalConfigListener);
 
         deviceEventExcutorService.shutdown();
 
@@ -127,43 +158,10 @@
 
     @Override
     public void createPorts(OpenstackPort openstackPort) {
-        //For DHCP purpose
-        //registerDhcpInfo(openstackPort);
+        registerDhcpInfo(openstackPort);
         openstackPortMap.put(openstackPort.id(), openstackPort);
     }
 
-    /*
-    private void registerDhcpInfo(OpenstackPort openstackPort) {
-        Ip4Address ip4Address;
-        Ip4Address subnetMask;
-        Ip4Address dhcpServer;
-        Ip4Address gatewayIPAddress;
-        Ip4Address domainServer;
-        OpenstackSubnet openstackSubnet;
-
-        ip4Address = (Ip4Address) openstackPort.fixedIps().values().toArray()[0];
-
-        openstackSubnet = openstackSubnetMap.values().stream()
-                .filter(n -> n.networkId().equals(openstackPort.networkId()))
-                .findFirst().get();
-
-        int prefix;
-        String[] parts = openstackSubnet.cidr().split("/");
-        prefix = Integer.parseInt(parts[1]);
-        int mask = 0xffffffff << (32 - prefix);
-        byte[] bytes = new byte[]{(byte) (mask >>> 24),
-                (byte) (mask >> 16 & 0xff), (byte) (mask >> 8 & 0xff), (byte) (mask & 0xff)};
-
-        subnetMask = Ip4Address.valueOf(bytes);
-        gatewayIPAddress = Ip4Address.valueOf(openstackSubnet.gatewayIp());
-        dhcpServer = gatewayIPAddress;
-        domainServer = Ip4Address.valueOf("8.8.8.8");
-
-        dhcpService.setStaticMappingOpenstack(openstackPort.macAddress(),
-                ip4Address, subnetMask, dhcpServer, gatewayIPAddress, domainServer);
-    }
-    */
-
     @Override
     public void deletePorts() {
 
@@ -179,13 +177,41 @@
         openstackNetworkMap.put(openstackNetwork.id(), openstackNetwork);
     }
 
-
     @Override
     public void createSubnet(OpenstackSubnet openstackSubnet) {
         openstackSubnetMap.put(openstackSubnet.id(), openstackSubnet);
         log.debug("Added Subnet Info {}", openstackNetworkMap.get(openstackSubnet.id()));
     }
 
+    @Override
+    public Collection<OpenstackPort> ports(String networkId) {
+
+        List<OpenstackPort> portList = openstackPortMap.values().stream()
+                .filter(p -> p.networkId().equals(networkId))
+                .collect(Collectors.toList());
+
+        return portList;
+    }
+
+    @Override
+    public OpenstackPort port(String portName) {
+        String uuid = portName.substring(3);
+        return (OpenstackPort) openstackPortMap.values().stream()
+                .filter(p -> p.id().startsWith(uuid))
+                .findFirst().get().clone();
+    }
+
+    @Override
+    public OpenstackNetwork network(String networkId) {
+        OpenstackNetwork on = null;
+        try {
+            on = (OpenstackNetwork) openstackNetworkMap.get(networkId).clone();
+        } catch (CloneNotSupportedException e) {
+            log.error("Cloning is not supported {}", e);
+        }
+        return on;
+    }
+
     private void processDeviceAdded(Device device) {
         log.debug("device {} is added", device.id());
         rulePopulator.populateDefaultRules(device.id());
@@ -211,6 +237,49 @@
         // TODO: need to update the vniPortMap
     }
 
+    private void registerDhcpInfo(OpenstackPort openstackPort) {
+        Ip4Address ip4Address;
+        Ip4Address subnetMask;
+        Ip4Address dhcpServer;
+        Ip4Address gatewayIPAddress;
+        Ip4Address domainServer;
+        OpenstackSubnet openstackSubnet;
+
+        ip4Address = (Ip4Address) openstackPort.fixedIps().values().toArray()[0];
+
+        openstackSubnet = openstackSubnetMap.values().stream()
+                .filter(n -> n.networkId().equals(openstackPort.networkId()))
+                .findFirst().get();
+
+        subnetMask = Ip4Address.valueOf(buildSubnetMask(openstackSubnet.cidr()));
+        gatewayIPAddress = Ip4Address.valueOf(openstackSubnet.gatewayIp());
+        dhcpServer = gatewayIPAddress;
+        // TODO: supports multiple DNS servers
+        if (openstackSubnet.dnsNameservers().isEmpty()) {
+            domainServer = Ip4Address.valueOf("8.8.8.8");
+        } else {
+            domainServer = openstackSubnet.dnsNameservers().get(0);
+        }
+        List<Ip4Address> options = Lists.newArrayList();
+        options.add(subnetMask);
+        options.add(dhcpServer);
+        options.add(gatewayIPAddress);
+        options.add(domainServer);
+
+        dhcpService.setStaticMapping(openstackPort.macAddress(), ip4Address, true, options);
+    }
+
+    private byte[] buildSubnetMask(String cidr) {
+        int prefix;
+        String[] parts = cidr.split("/");
+        prefix = Integer.parseInt(parts[1]);
+        int mask = 0xffffffff << (32 - prefix);
+        byte[] bytes = new byte[]{(byte) (mask >>> 24),
+                (byte) (mask >> 16 & 0xff), (byte) (mask >> 8 & 0xff), (byte) (mask & 0xff)};
+
+        return bytes;
+    }
+
     /**
      * Populates the flow rules for traffic to VMs in different Cnode using
      * Nicira extention.
@@ -407,8 +476,8 @@
     private class InternalDeviceListener implements DeviceListener {
 
         @Override
-        public void event(DeviceEvent event) {
-            deviceEventExcutorService.execute(new InternalEventHandler(event));
+        public void event(DeviceEvent deviceEvent) {
+            deviceEventExcutorService.execute(new InternalEventHandler(deviceEvent));
         }
     }
 
@@ -422,6 +491,11 @@
 
         @Override
         public void run() {
+
+            if (doNotPushFlows) {
+                return;
+            }
+
             switch (deviceEvent.type()) {
                 case DEVICE_ADDED:
                     processDeviceAdded((Device) deviceEvent.subject());
@@ -453,6 +527,23 @@
         }
     }
 
+    private class InternalConfigListener implements NetworkConfigListener {
+
+        @Override
+        public void event(NetworkConfigEvent event) {
+            if (((event.type() == NetworkConfigEvent.Type.CONFIG_ADDED ||
+            event.type() == NetworkConfigEvent.Type.CONFIG_UPDATED)) &&
+                    event.configClass().equals(OpenstackSwitchingConfig.class)) {
+                OpenstackSwitchingConfig cfg = cfgService.getConfig(appId,
+                        OpenstackSwitchingConfig.class);
+                if (cfg != null) {
+                    doNotPushFlows = cfg.doNotPushFlows();
+                    log.info("Switching mode reconfigured");
+                }
+            }
+        }
+   }
+
     private final class PortInfo {
         DeviceId deviceId;
         String portName;
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingRulePopulator.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingRulePopulator.java
similarity index 99%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingRulePopulator.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingRulePopulator.java
index f6e9806..fa0b7e6 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingRulePopulator.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/OpenstackSwitchingRulePopulator.java
@@ -37,8 +37,7 @@
 import org.slf4j.LoggerFactory;
 
 /**
- * It populates switching flow rules.
- *
+ * Populates switching flow rules.
  */
 public class OpenstackSwitchingRulePopulator {
 
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/package-info.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/package-info.java
similarity index 100%
copy from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/package-info.java
copy to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/package-info.java
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkCodec.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkCodec.java
similarity index 100%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkCodec.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkCodec.java
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkWebResource.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkWebResource.java
similarity index 100%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkWebResource.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackNetworkWebResource.java
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortCodec.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortCodec.java
similarity index 98%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortCodec.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortCodec.java
index 765b690..94a1edb 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortCodec.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortCodec.java
@@ -29,7 +29,7 @@
 import java.util.HashMap;
 
 /**
- * It encodes and decodes the OpenstackPort.
+ * Encodes and decodes the OpenstackPort.
  */
 public class OpenstackPortCodec extends JsonCodec<OpenstackPort> {
 
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortWebResource.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortWebResource.java
similarity index 97%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortWebResource.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortWebResource.java
index 67a9ceb..e531ba4 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortWebResource.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackPortWebResource.java
@@ -53,7 +53,7 @@
 
             OpenstackSwitchingService switchingService = get(OpenstackSwitchingService.class);
             switchingService.createPorts(openstackPort);
-            log.info("REST API ports is called with {}", portNode.toString());
+            log.debug("REST API ports is called with {}", portNode.toString());
             return Response.status(Response.Status.OK).build();
         } catch (Exception e) {
             log.error("Creates VirtualPort failed because of exception {}",
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
similarity index 82%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
index a643057..e504550 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
@@ -18,17 +18,21 @@
 import com.fasterxml.jackson.databind.JsonNode;
 
 
+import com.fasterxml.jackson.databind.node.ArrayNode;
 import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.collect.Lists;
+import org.onlab.packet.Ip4Address;
 import org.onosproject.codec.CodecContext;
 import org.onosproject.codec.JsonCodec;
 import org.onosproject.openstackswitching.OpenstackSubnet;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-/**
- * It encodes and decodes the OpenstackSubnet.
- */
+import java.util.List;
 
+/**
+ * Encodes and decodes the OpenstackSubnet.
+ */
 public class OpenstackSubnetCodec extends JsonCodec<OpenstackSubnet> {
     private static Logger log = LoggerFactory
             .getLogger(OpenstackSubnetCodec.class);
@@ -52,7 +56,11 @@
         boolean enableDhcp = subnetInfo.path(ENABLE_DHCP).asBoolean();
         String networkId = subnetInfo.path(NETWORK_ID).asText();
         String tenantId = subnetInfo.path(TENANT_ID).asText();
-        String dnsNameservsers = subnetInfo.path(DNS_NAMESERVERS).asText();
+        ArrayNode dnsNameservsers = (ArrayNode) subnetInfo.path(DNS_NAMESERVERS);
+        List<Ip4Address> dnsList = Lists.newArrayList();
+        if (dnsNameservsers != null && !dnsNameservsers.isMissingNode()) {
+            dnsNameservsers.forEach(dns -> dnsList.add(Ip4Address.valueOf(dns.asText())));
+        }
         String gatewayIp = subnetInfo.path(GATEWAY_IP).asText();
         String cidr = subnetInfo.path(CIDR).asText();
         String id = subnetInfo.path(ID).asText();
@@ -62,7 +70,7 @@
                 .setEnableDhcp(enableDhcp)
                 .setNetworkId(networkId)
                 .setTenantId(tenantId)
-                .setDnsNameservers(dnsNameservsers)
+                .setDnsNameservers(dnsList)
                 .setGatewayIp(gatewayIp)
                 .setCidr(cidr)
                 .setId(id)
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetWebResource.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetWebResource.java
similarity index 96%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetWebResource.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetWebResource.java
index af1ae9d..bc0bb8e 100644
--- a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetWebResource.java
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetWebResource.java
@@ -51,7 +51,7 @@
 
             OpenstackSwitchingService switchingService = get(OpenstackSwitchingService.class);
             switchingService.createSubnet(openstackSubnet);
-            log.info("REST API subnets is called with {}", subnetNode.toString());
+            log.debug("REST API subnets is called with {}", subnetNode.toString());
             return Response.status(Response.Status.OK).build();
         } catch (Exception e) {
             log.error("Creates VirtualSubnet failed because of exception {}",
diff --git a/apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/package-info.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/package-info.java
similarity index 100%
rename from apps/openstackswitching/src/main/java/org/onosproject/openstackswitching/web/package-info.java
rename to apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/package-info.java
diff --git a/apps/openstackswitching/src/main/webapp/WEB-INF/web.xml b/apps/openstackswitching/app/src/main/webapp/WEB-INF/web.xml
similarity index 100%
rename from apps/openstackswitching/src/main/webapp/WEB-INF/web.xml
rename to apps/openstackswitching/app/src/main/webapp/WEB-INF/web.xml
diff --git a/apps/openstackswitching/pom.xml b/apps/openstackswitching/pom.xml
index 52129b6..9dbdcf5 100644
--- a/apps/openstackswitching/pom.xml
+++ b/apps/openstackswitching/pom.xml
@@ -26,101 +26,18 @@
         <relativePath>../pom.xml</relativePath>
     </parent>
 
-    <artifactId>onos-app-openstackswitching</artifactId>
-    <packaging>bundle</packaging>
+    <artifactId>onos-openstackswitching</artifactId>
+    <packaging>pom</packaging>
 
-    <description>SONA Openstack Switching  applications</description>
-    <properties>
-        <onos.version>1.4.0-SNAPSHOT</onos.version>
-        <onos.app.name>org.onosproject.openstackswitching</onos.app.name>
-        <web.context>/onos/openstackswitching</web.context>
-        <api.version>1.0.0</api.version>
-        <api.title>ONOS OpenStack Switching REST API</api.title>
-        <api.description>
-            APIs for receiving Neutron information.
-        </api.description>
-        <api.package>org.onosproject.openstackswitching.web</api.package>
-        <onos.app.origin>SKT, Inc.</onos.app.origin>
-    </properties>
+    <description>SONA Openstack Switching application</description>
 
+    <modules>
+        <module>api</module>
+        <module>app</module>
+    </modules>
 
     <dependencies>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-rest</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onlab-rest</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>javax.ws.rs</groupId>
-            <artifactId>jsr311-api</artifactId>
-            <version>1.1.1</version>
-        </dependency>
-        <dependency>
-            <groupId>com.sun.jersey</groupId>
-            <artifactId>jersey-servlet</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-databind</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>com.fasterxml.jackson.core</groupId>
-            <artifactId>jackson-annotations</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.osgi</groupId>
-            <artifactId>org.osgi.compendium</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.osgi</groupId>
-            <artifactId>org.osgi.core</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.onosproject</groupId>
-            <artifactId>onos-app-dhcp-api</artifactId>
-            <version>${project.version}</version>
-        </dependency>
     </dependencies>
 
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.apache.felix</groupId>
-                <artifactId>maven-bundle-plugin</artifactId>
-                <extensions>true</extensions>
-                <configuration>
-                    <instructions>
-                        <_wab>src/main/webapp/</_wab>
-                        <Bundle-SymbolicName>
-                            ${project.groupId}.${project.artifactId}
-                        </Bundle-SymbolicName>
-                        <Import-Package>
-                            org.slf4j,
-                            org.osgi.framework,
-                            javax.ws.rs,
-                            javax.ws.rs.core,
-                            com.sun.jersey.api.core,
-                            com.sun.jersey.spi.container.servlet,
-                            com.sun.jersey.server.impl.container.servlet,
-                            com.fasterxml.jackson.databind,
-                            com.fasterxml.jackson.databind.node,
-                            com.fasterxml.jackson.core,
-                            org.apache.karaf.shell.commands,
-                            com.google.common.*,
-                            org.onlab.packet.*,
-                            org.onosproject.*
-                        </Import-Package>
-                        <Web-ContextPath>${web.context}</Web-ContextPath>
-                    </instructions>
-                </configuration>
-            </plugin>
-        </plugins>
-    </build>
-
 
 </project>