diff --git a/protocols/tl1/ctl/src/main/java/org/onosproject/tl1/impl/DefaultTl1Controller.java b/protocols/tl1/ctl/src/main/java/org/onosproject/tl1/impl/DefaultTl1Controller.java
new file mode 100644
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+++ b/protocols/tl1/ctl/src/main/java/org/onosproject/tl1/impl/DefaultTl1Controller.java
@@ -0,0 +1,263 @@
+/*
+ * 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.tl1.impl;
+
+import io.netty.bootstrap.Bootstrap;
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.handler.codec.DelimiterBasedFrameDecoder;
+import io.netty.handler.codec.string.StringDecoder;
+import io.netty.util.CharsetUtil;
+import org.apache.commons.lang.StringUtils;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.onlab.util.Tools;
+import org.onosproject.mastership.MastershipService;
+import org.onosproject.net.DeviceId;
+import org.onosproject.tl1.Tl1Command;
+import org.onosproject.tl1.Tl1Controller;
+import org.onosproject.tl1.Tl1Device;
+import org.onosproject.tl1.Tl1Listener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.charset.Charset;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.CopyOnWriteArraySet;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+/**
+ * Implementation of TL1 controller.
+ *
+ * Handles the connection and input/output for all registered TL1 devices.
+ * Turn on debug logging if you want to see all message I/O.
+ *
+ * Per device, we track commands using a simple ctag-keyed map. This assumes the client is sending out unique ctag's.
+ */
+@Component(immediate = true)
+@Service
+public class DefaultTl1Controller implements Tl1Controller {
+    private final Logger log = LoggerFactory.getLogger(DefaultTl1Controller.class);
+
+    // TL1 message delimiter (semi colon)
+    private static final ByteBuf DELIMITER = Unpooled.copiedBuffer(new char[]{';'}, Charset.defaultCharset());
+    private static final String COMPLD = "COMPLD";
+    private static final String DENY = "DENY";
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected MastershipService mastershipService;
+
+    private ConcurrentMap<DeviceId, Tl1Device> deviceMap = new ConcurrentHashMap<>();
+    // Key: channel, value: map with key ctag, value: future TL1 msg (ctags are assumed unique per device)
+    private ConcurrentMap<Channel, ConcurrentMap<Integer, CompletableFuture<String>>> msgMap =
+            new ConcurrentHashMap<>();
+    private EventLoopGroup workerGroup = new NioEventLoopGroup();
+    private Set<Tl1Listener> tl1Listeners = new CopyOnWriteArraySet<>();
+    private ExecutorService executor;
+
+    @Activate
+    public void activate() {
+        executor = Executors.newFixedThreadPool(
+                Runtime.getRuntime().availableProcessors(),
+                Tools.groupedThreads("onos/tl1controller", "%d", log));
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        executor.shutdown();
+        deviceMap.clear();
+        msgMap.clear();
+        log.info("Stopped");
+    }
+
+    @Override
+    /**
+     * This implementation returns an empty string on failure.
+     */
+    public CompletableFuture<String> sendMsg(DeviceId deviceId, Tl1Command msg) {
+        log.debug("Sending TL1 message to device {}: {}", deviceId, msg);
+
+        Tl1Device device = deviceMap.get(deviceId);
+        if (device == null || !device.isConnected() || !mastershipService.isLocalMaster(deviceId)) {
+            return CompletableFuture.completedFuture(StringUtils.EMPTY);
+        }
+
+        // Create and store completable future, complete it in the channel handler when we receive a response
+        CompletableFuture<String> future = new CompletableFuture<>();
+        Channel channel = device.channel();
+        if (!msgMap.containsKey(channel)) {
+            return CompletableFuture.completedFuture(StringUtils.EMPTY);
+        }
+        msgMap.get(channel).put(msg.ctag(), future);
+
+        // Write message to channel
+        channel.writeAndFlush(Unpooled.copiedBuffer(msg.toString(), CharsetUtil.UTF_8));
+
+        return future;
+    }
+
+    @Override
+    public Optional<Tl1Device> getDevice(DeviceId deviceId) {
+        return Optional.ofNullable(deviceMap.get(deviceId));
+    }
+
+    @Override
+    public boolean addDevice(DeviceId deviceId, Tl1Device device) {
+        log.debug("Adding TL1 device {} {}", deviceId);
+
+        // Ignore if device already known
+        if (deviceMap.containsKey(deviceId)) {
+            log.error("Ignoring duplicate device {}", deviceId);
+            return false;
+        }
+
+        deviceMap.put(deviceId, device);
+        return true;
+    }
+
+    @Override
+    public void connectDevice(DeviceId deviceId) {
+        Tl1Device device = deviceMap.get(deviceId);
+        if (device == null || device.isConnected()) {
+            return;
+        }
+
+        Bootstrap b = new Bootstrap();
+        b.group(workerGroup)
+                .channel(NioSocketChannel.class)
+                .option(ChannelOption.SO_KEEPALIVE, true)
+                .handler(new ChannelInitializer<SocketChannel>() {
+                    @Override
+                    protected void initChannel(SocketChannel socketChannel) throws Exception {
+                        socketChannel.pipeline().addLast(new DelimiterBasedFrameDecoder(8192, DELIMITER));
+                        socketChannel.pipeline().addLast("stringDecoder", new StringDecoder(CharsetUtil.UTF_8));
+                        // TODO
+                        //socketChannel.pipeline().addLast(new Tl1Decoder());
+                        socketChannel.pipeline().addLast(new Tl1InboundHandler());
+                    }
+                })
+                .remoteAddress(device.ip().toInetAddress(), device.port())
+                .connect()
+                .addListener((ChannelFuture channelFuture) -> {
+                    if (channelFuture.isSuccess()) {
+                        msgMap.put(channelFuture.channel(), new ConcurrentHashMap<>());
+                        device.connect(channelFuture.channel());
+                        tl1Listeners.forEach(l -> executor.execute(() -> l.deviceConnected(deviceId)));
+                    }
+                });
+    }
+
+    @Override
+    public void removeDevice(DeviceId deviceId) {
+        disconnectDevice(deviceId);
+        deviceMap.remove(deviceId);
+    }
+
+    @Override
+    public void addListener(Tl1Listener listener) {
+        tl1Listeners.add(listener);
+    }
+
+    @Override
+    public void removeListener(Tl1Listener listener) {
+        tl1Listeners.remove(listener);
+    }
+
+    @Override
+    public void disconnectDevice(DeviceId deviceId) {
+        // Ignore if unknown device
+        Tl1Device device = deviceMap.get(deviceId);
+        if (device == null) {
+            return;
+        }
+
+        Channel channel = device.channel();
+        if (channel != null) {
+            channel.close();
+        }
+
+        msgMap.remove(channel);
+        device.disconnect();
+        tl1Listeners.forEach(l -> l.deviceDisconnected(deviceId));
+    }
+
+    @Override
+    public Set<DeviceId> getDeviceIds() {
+        return deviceMap.keySet();
+    }
+
+    @Override
+    public Collection<Tl1Device> getDevices() {
+        return deviceMap.values();
+    }
+
+    /**
+     * Crude filtering handler that will only complete our stored future upon receiving a TL1 response messages.
+     */
+    private class Tl1InboundHandler extends SimpleChannelInboundHandler<String> {
+        @Override
+        protected void channelRead0(ChannelHandlerContext ctx, String s) throws Exception {
+            log.debug("Received TL1 message {}", s);
+
+            // Search for "COMPLD" or "DENY" to identify a TL1 response,
+            // then return the remainder of the string.
+            String[] words = s.split("\\s");
+            for (int i = 0; i < words.length; i++) {
+                String w = words[i];
+                if (w.startsWith(COMPLD) || w.startsWith(DENY)) {
+                    // ctag is just in front of it
+                    int ctag = Integer.parseInt(words[i - 1]);
+                    // We return everything that follows to the caller (this will lose line breaks and such)
+                    String result = Arrays.stream(words).skip(i + 1).collect(Collectors.joining());
+                    // Set future when command is executed, good or bad
+                    Map<Integer, CompletableFuture<String>> msg = msgMap.get(ctx.channel());
+                    if (msg != null) {
+                        CompletableFuture<String> f = msg.remove(ctag);
+                        if (f != null) {
+                            f.complete(result);
+                        }
+                    }
+
+                    return;
+                }
+            }
+        }
+    }
+}