diff --git a/apps/roadm/src/main/java/org/onosproject/roadm/RoadmService.java b/apps/roadm/src/main/java/org/onosproject/roadm/RoadmService.java
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+/*
+ * 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.roadm;
+
+import com.google.common.collect.Range;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.OchSignal;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.flow.FlowId;
+
+import java.util.Set;
+
+/**
+ * ROADM service interface. Provides an interface for ROADM power configuration.
+ *
+ * This application relies on the PowerConfig and LambdaQuery behaviours.
+ *
+ * The device's PowerConfig implementation should be parameterized as
+ * {@code PowerConfig<Object>} in order to support both Direction and OchSignal.
+ * For a reference implementation of PowerConfig, please see
+ * OplinkRoadmPowerConfig
+ *
+ * In this application, a "connection" refers to the selection of a channel
+ * to direct from an input to an output port. Connections are implemented
+ * using FlowRules with an input port selector, optical channel selector,
+ * and output port treatment (see RoadmManager#createConnection()).
+ *
+ * This application currently only supports fixed grid channels.
+ */
+public interface RoadmService {
+
+    /**
+     * Set target power for a port if the port has configurable target power.
+     *
+     * @param deviceId DeviceId of the device to configure
+     * @param portNumber PortNumber of the port to configure
+     * @param power value to set target power to
+     */
+    void setTargetPortPower(DeviceId deviceId, PortNumber portNumber, long power);
+
+    /**
+     * Returns the target power for a port if the port has configurable target power.
+     *
+     * @param deviceId DeviceId of the device to configure
+     * @param portNumber PortNumber of the port to configure
+     * @return the target power if the port has a target power, null otherwise
+     */
+    Long getTargetPortPower(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Sets the attenuation of a connection. This does not check that attenuation
+     * is within the acceptable range.
+     *
+     * @param deviceId DeviceId of the device to configure
+     * @param portNumber PortNumber of either the input or output port
+     * @param ochSignal channel to set attenuation for
+     * @param attenuation attenuation value to set to
+     */
+    void setAttenuation(DeviceId deviceId, PortNumber portNumber, OchSignal ochSignal,
+                        long attenuation);
+
+    /**
+     * Returns the attenuation of a connection.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of either the input or output port
+     * @param ochSignal channel to search for
+     * @return attenuation if found, null otherwise
+     */
+    Long getAttenuation(DeviceId deviceId, PortNumber portNumber, OchSignal ochSignal);
+
+    /**
+     * Returns the current port power.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of the port
+     * @return current power if found, null otherwise
+     */
+    Long getCurrentPortPower(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Returns the current channel power.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of either the input or output port of the connection
+     * @param ochSignal channel to search for
+     * @return channel power if found, null otherwise
+     */
+    Long getCurrentChannelPower(DeviceId deviceId, PortNumber portNumber,
+                                OchSignal ochSignal);
+
+    /**
+     * Returns the channels supported by a port.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of the port
+     * @return the set of supported channels
+     */
+    Set<OchSignal> queryLambdas(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Creates a new internal connection on a device without attenuation. This does
+     * not check that the connection is actually valid (e.g. an input port to an
+     * output port).
+     *
+     * Connections are represented as flows with an input port, output port, and
+     * channel. Implementation of attenuation is up to the vendor.
+     *
+     * @param deviceId DeviceId of the device to create this connection for
+     * @param priority priority of the flow
+     * @param isPermanent permanence of the flow
+     * @param timeout timeout in seconds
+     * @param inPort input port
+     * @param outPort output port
+     * @param ochSignal channel to use
+     * @return FlowId of the FlowRule representing the connection
+     */
+    FlowId createConnection(DeviceId deviceId, int priority, boolean isPermanent,
+                          int timeout, PortNumber inPort, PortNumber outPort,
+                          OchSignal ochSignal);
+
+    /**
+     * Creates a new internal connection on a device with attenuation. This does
+     * not check that the connection is actually valid (e.g. an input port to an
+     * output port, attenuation if within the acceptable range).
+     *
+     * Connections are represented as flows with an input port, output port, and
+     * channel. Implementation of attenuation is up to the vendor.
+     *
+     * @param deviceId DeviceId of the device to create this connection for
+     * @param priority priority of the flow
+     * @param isPermanent permanence of the flow
+     * @param timeout timeout in seconds
+     * @param inPort input port
+     * @param outPort output port
+     * @param ochSignal channel to use
+     * @param attenuation attenuation of the connection
+     * @return FlowId of the FlowRule representing the connection
+     */
+    FlowId createConnection(DeviceId deviceId, int priority, boolean isPermanent,
+                          int timeout, PortNumber inPort, PortNumber outPort,
+                          OchSignal ochSignal, long attenuation);
+
+    /**
+     * Removes an internal connection from a device by matching the FlowId and
+     * removing the flow representing the connection. This will remove any flow
+     * from any device so FlowId should correspond with a connection flow.
+     *
+     * @param deviceId DeviceId of the device to remove the connection from
+     * @param flowId FlowId of the flow representing the connection to remove
+     */
+    void removeConnection(DeviceId deviceId, FlowId flowId);
+
+    /**
+     * Returns true if the target power for this port can be configured.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of the port to check
+     * @return true if the target power for this port can be configured, false
+     * otherwise
+     */
+    boolean hasPortTargetPower(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Returns true if value is within the acceptable target power range of the port.
+     * Returns false if the port does not have a configurable target
+     * power.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param portNumber PortNumber of the port to check
+     * @param power value to check
+     * @return true if value is within the acceptable target power range, false
+     * otherwise
+     */
+    boolean portTargetPowerInRange(DeviceId deviceId, PortNumber portNumber, long power);
+
+    /**
+     * Returns true if value is within the acceptable attenuation range of a
+     * connection, and always returns false if the connection does not support
+     * attenuation. The attenuation range is determined by either the input
+     * or output port of the connection.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param portNumber PortNumber of either the input or output port of the connection
+     * @param att value to check
+     * @return true if value is within the acceptable attenuation range, false
+     * otherwise
+     */
+    boolean attenuationInRange(DeviceId deviceId, PortNumber portNumber, long att);
+
+    /**
+     * Returns true if the port is an input port.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param portNumber PortNumber of the port to check
+     * @return true if the port is an input port, false otherwise
+     */
+    boolean validInputPort(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Returns true if the port is an output port.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param portNumber PortNumber of the port to check
+     * @return true if the port is an output port, false otherwise
+     */
+    boolean validOutputPort(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Returns true if the channel is supported by the port. The port can be either
+     * an input or output port.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param portNumber PortNumber of the port to check
+     * @param ochSignal channel to check
+     * @return true if the channel is supported by the port, false otherwise
+     */
+    boolean validChannel(DeviceId deviceId, PortNumber portNumber, OchSignal ochSignal);
+
+    /**
+     * Returns true if the channel is not being used by a connection on the
+     * device.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param ochSignal channel to check
+     * @return true if the channel is not in use, false otherwise
+     */
+    boolean channelAvailable(DeviceId deviceId, OchSignal ochSignal);
+
+    /**
+     * Returns true if the connection from the input port to the output port is
+     * valid. This currently only checks if the given input and output ports are,
+     * respectively, valid input and output ports.
+     *
+     * @param deviceId DeviceId of the device to check
+     * @param inPort input port of the connection
+     * @param outPort output port of the connection
+     * @return true if the connection is valid, false otherwise
+     */
+    boolean validConnection(DeviceId deviceId, PortNumber inPort, PortNumber outPort);
+
+    /**
+     * Returns the acceptable target port power range for a port.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of the port
+     * @return range if found, null otherwise
+     */
+    Range<Long> targetPortPowerRange(DeviceId deviceId, PortNumber portNumber);
+
+    /**
+     * Returns the acceptable attenuation range for a connection.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of either the input or output port
+     * @param ochSignal channel to check
+     * @return range if found, null otherwise
+     */
+    Range<Long> attenuationRange(DeviceId deviceId, PortNumber portNumber,
+                                 OchSignal ochSignal);
+
+    /**
+     * Returns the expected input power range for an input port.
+     *
+     * @param deviceId DeviceId of the device
+     * @param portNumber PortNumber of an input port
+     * @return range if found, null otherwise
+     */
+    Range<Long> inputPortPowerRange(DeviceId deviceId, PortNumber portNumber);
+}