diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/ExtensionResolver.java b/core/api/src/main/java/org/onosproject/net/behaviour/ExtensionResolver.java
new file mode 100644
index 0000000..54cbc7a
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/ExtensionResolver.java
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+package org.onosproject.net.behaviour;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.net.driver.HandlerBehaviour;
+import org.onosproject.net.flow.instructions.ExtensionInstruction;
+import org.onosproject.net.flow.instructions.ExtensionType;
+
+/**
+ * Provides access to the extension implemented by this driver.
+ */
+@Beta
+public interface ExtensionResolver extends HandlerBehaviour {
+
+    /**
+     * Gets an extension instruction instance of the specified type, if supported
+     * by the driver.
+     *
+     * @param type type of extension to get
+     * @return extension instruction
+     * @throws UnsupportedOperationException if the extension type is not
+     * supported by this driver
+     */
+    ExtensionInstruction getExtensionInstruction(ExtensionType type);
+}
diff --git a/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficTreatment.java b/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficTreatment.java
index ac37d1f..6beeecc 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficTreatment.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/DefaultTrafficTreatment.java
@@ -27,8 +27,10 @@
 import org.onlab.packet.TpPort;
 import org.onlab.packet.VlanId;
 import org.onosproject.core.GroupId;
+import org.onosproject.net.DeviceId;
 import org.onosproject.net.IndexedLambda;
 import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.instructions.ExtensionInstruction;
 import org.onosproject.net.flow.instructions.Instruction;
 import org.onosproject.net.flow.instructions.Instructions;
 import org.onosproject.net.meter.MeterId;
@@ -244,6 +246,7 @@
                 case L2MODIFICATION:
                 case L3MODIFICATION:
                 case L4MODIFICATION:
+                case EXTENSION:
                     current.add(instruction);
                     break;
                 case TABLE:
@@ -481,6 +484,12 @@
         }
 
         @Override
+        public TrafficTreatment.Builder extension(ExtensionInstruction extension,
+                                                  DeviceId deviceId) {
+            return add(Instructions.extension(extension, deviceId));
+        }
+
+        @Override
         public TrafficTreatment build() {
             if (deferred.size() == 0 && immediate.size() == 0
                     && table == null && !clear) {
diff --git a/core/api/src/main/java/org/onosproject/net/flow/TrafficTreatment.java b/core/api/src/main/java/org/onosproject/net/flow/TrafficTreatment.java
index 91c19b7..b14ab99 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/TrafficTreatment.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/TrafficTreatment.java
@@ -24,7 +24,9 @@
 import org.onlab.packet.TpPort;
 import org.onlab.packet.VlanId;
 import org.onosproject.core.GroupId;
+import org.onosproject.net.DeviceId;
 import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.instructions.ExtensionInstruction;
 import org.onosproject.net.flow.instructions.Instruction;
 import org.onosproject.net.flow.instructions.Instructions;
 import org.onosproject.net.meter.MeterId;
@@ -413,6 +415,15 @@
         Builder setUdpDst(TpPort port);
 
         /**
+         * Uses an extension treatment.
+         *
+         * @param extension extension treatment
+         * @param deviceId device ID
+         * @return a treatment builder
+         */
+        Builder extension(ExtensionInstruction extension, DeviceId deviceId);
+
+        /**
          * Builds an immutable traffic treatment descriptor.
          * <p>
          * If the treatment is empty when build() is called, it will add a default
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/AbstractExtensionInstruction.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/AbstractExtensionInstruction.java
new file mode 100644
index 0000000..9f22f88
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/AbstractExtensionInstruction.java
@@ -0,0 +1,71 @@
+/*
+ * 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.
+ */
+
+package org.onosproject.net.flow.instructions;
+
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Abstract implementation of the set/get property methods of ExtensionInstruction.
+ */
+public abstract class AbstractExtensionInstruction implements ExtensionInstruction {
+
+    private static final String INVALID_KEY = "Invalid property key: ";
+    private static final String INVALID_TYPE = "Given type does not match field type: ";
+
+    @Override
+    public <T> void setPropertyValue(String key, T value) throws ExtensionPropertyException {
+        Class<?> clazz = this.getClass();
+        try {
+            Field field = clazz.getDeclaredField(key);
+            field.setAccessible(true);
+            field.set(this, value);
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            throw new ExtensionPropertyException(INVALID_KEY + key);
+        }
+    }
+
+    @Override
+    public <T> T getPropertyValue(String key) throws ExtensionPropertyException {
+        Class<?> clazz = this.getClass();
+        try {
+            Field field = clazz.getDeclaredField(key);
+            field.setAccessible(true);
+            @SuppressWarnings("unchecked")
+            T result = (T) field.get(this);
+            return result;
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            throw new ExtensionPropertyException(INVALID_KEY + key);
+        } catch (ClassCastException e) {
+            throw new ExtensionPropertyException(INVALID_TYPE + key);
+        }
+    }
+
+    @Override
+    public List<String> getProperties() {
+        Class<?> clazz = this.getClass();
+
+        List<String> fields = new ArrayList<>();
+
+        for (Field field : clazz.getDeclaredFields()) {
+            fields.add(field.getName());
+        }
+
+        return fields;
+    }
+}
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionInstruction.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionInstruction.java
new file mode 100644
index 0000000..89e0cc5
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionInstruction.java
@@ -0,0 +1,78 @@
+/*
+ * 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.
+ */
+
+package org.onosproject.net.flow.instructions;
+
+import java.util.List;
+
+/**
+ * An extensible instruction type.
+ */
+public interface ExtensionInstruction {
+
+    /**
+     * Gets the type of the extension instruction.
+     *
+     * @return type
+     */
+    ExtensionType type();
+
+    /**
+     * Sets a property on the extension instruction.
+     *
+     * @param key property key
+     * @param value value to set for the given key
+     * @param <T> class of the value
+     * @throws ExtensionPropertyException if the given key is not a valid
+     * property on this extension instruction
+     */
+    <T> void setPropertyValue(String key, T value) throws ExtensionPropertyException;
+
+    /**
+     * Gets a property value of an extension instruction.
+     *
+     * @param key property key
+     * @param <T> class of the value
+     * @return value of the property
+     * @throws ExtensionPropertyException if the given key is not a valid
+     * property on this extension instruction
+     */
+    <T> T getPropertyValue(String key) throws ExtensionPropertyException;
+
+    /**
+     * Gets a list of all properties on the extension instruction.
+     *
+     * @return list of properties
+     */
+    List<String> getProperties();
+
+    /**
+     * Serialize the extension instruction to a byte array.
+     *
+     * @return byte array
+     */
+    byte[] serialize();
+
+    /**
+     * Deserialize the extension instruction from a byte array. The properties
+     * of this object will be overwritten with the data in the byte array.
+     *
+     * @param data input byte array
+     */
+    void deserialize(byte[] data);
+
+
+}
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionPropertyException.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionPropertyException.java
new file mode 100644
index 0000000..5750d09
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionPropertyException.java
@@ -0,0 +1,32 @@
+/*
+ * 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.
+ */
+
+package org.onosproject.net.flow.instructions;
+
+/**
+ * Exception indicating there was an error while setting/getting an extension
+ * instruction property.
+ */
+public class ExtensionPropertyException extends Exception {
+
+    public ExtensionPropertyException(String message) {
+        super(message);
+    }
+
+    public ExtensionPropertyException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionType.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionType.java
new file mode 100644
index 0000000..747a85b
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/ExtensionType.java
@@ -0,0 +1,92 @@
+/*
+ * 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.
+ */
+
+package org.onosproject.net.flow.instructions;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.MoreObjects;
+
+import java.util.Objects;
+
+/**
+ * Type of extension instructions.
+ */
+@Beta
+public final class ExtensionType {
+
+    /**
+     * A list of well-known named extension instruction type codes.
+     */
+    public enum ExtensionTypes {
+        // TODO fix type numbers to include experimenter id
+        NICIRA_SET_TUNNEL_DST(31);
+
+        private ExtensionType type;
+
+        /**
+         * Creates a new named extension instruction type.
+         *
+         * @param type type code
+         */
+        ExtensionTypes(int type) {
+            this.type = new ExtensionType(type);
+        }
+
+        /**
+         * Gets the extension type object for this named type code.
+         *
+         * @return extension type object
+         */
+        public ExtensionType type() {
+            return type;
+        }
+    }
+
+    private final int type;
+
+    /**
+     * Creates an extension type with the given int type code.
+     *
+     * @param type type code
+     */
+    public ExtensionType(int type) {
+        this.type = type;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(type);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof ExtensionType) {
+            final ExtensionType that = (ExtensionType) obj;
+            return this.type == that.type;
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(ExtensionType.class)
+                .add("type", type)
+                .toString();
+    }
+}
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/Instruction.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/Instruction.java
index 2f6a1cc..31ad80c 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/instructions/Instruction.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/Instruction.java
@@ -92,7 +92,12 @@
         /**
          * Signifies that the traffic should be modified in L4 way.
          */
-        L4MODIFICATION
+        L4MODIFICATION,
+
+        /**
+         * Signifies that an extension instruction will be used.
+         */
+        EXTENSION
     }
 
     /**
diff --git a/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java b/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java
index 8868bf7..aad407c 100644
--- a/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java
+++ b/core/api/src/main/java/org/onosproject/net/flow/instructions/Instructions.java
@@ -22,6 +22,7 @@
 import org.onlab.packet.TpPort;
 import org.onlab.packet.VlanId;
 import org.onosproject.core.GroupId;
+import org.onosproject.net.DeviceId;
 import org.onosproject.net.IndexedLambda;
 import org.onosproject.net.Lambda;
 import org.onosproject.net.OchSignal;
@@ -480,6 +481,20 @@
     }
 
     /**
+     * Creates an extension instruction.
+     *
+     * @param extension extension instruction
+     * @param deviceId device ID
+     * @return extension instruction
+     */
+    public static ExtensionInstructionWrapper extension(ExtensionInstruction extension,
+                                                        DeviceId deviceId) {
+        checkNotNull(extension, "Extension instruction cannot be null");
+        checkNotNull(deviceId, "Device ID cannot be null");
+        return new ExtensionInstructionWrapper(extension, deviceId);
+    }
+
+    /**
      *  Drop instruction.
      */
     @Deprecated
@@ -820,6 +835,59 @@
         }
     }
 
+    /**
+     *  Extension instruction.
+     */
+    public static class ExtensionInstructionWrapper implements Instruction {
+        private final ExtensionInstruction extensionInstruction;
+        private final DeviceId deviceId;
+
+        ExtensionInstructionWrapper(ExtensionInstruction extension, DeviceId deviceId) {
+            extensionInstruction = extension;
+            this.deviceId = deviceId;
+        }
+
+        public ExtensionInstruction extensionInstruction() {
+            return extensionInstruction;
+        }
+
+        public DeviceId deviceId() {
+            return deviceId;
+        }
+
+        @Override
+        public Type type() {
+            return Type.EXTENSION;
+        }
+
+        @Override
+        public String toString() {
+            return toStringHelper(type().toString())
+                    .add("extension", extensionInstruction)
+                    .add("deviceId", deviceId)
+                    .toString();
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(type().ordinal(), extensionInstruction, deviceId);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (obj instanceof ExtensionInstructionWrapper) {
+                ExtensionInstructionWrapper that = (ExtensionInstructionWrapper) obj;
+                return Objects.equals(extensionInstruction, that.extensionInstruction)
+                        && Objects.equals(deviceId, that.deviceId);
+
+            }
+            return false;
+        }
+    }
+
 }