diff --git a/common/src/main/java/io/netty/util/internal/MathUtil.java b/common/src/main/java/io/netty/util/internal/MathUtil.java
index 632b0d3515..e6a042c408 100644
--- a/common/src/main/java/io/netty/util/internal/MathUtil.java
+++ b/common/src/main/java/io/netty/util/internal/MathUtil.java
@@ -64,6 +64,20 @@ public final class MathUtil {
         return (index | length | (index + length) | (capacity - (index + length))) < 0;
     }
 
+    /**
+     * Compares two {@code int} values.
+     *
+     * @param  x the first {@code int} to compare
+     * @param  y the second {@code int} to compare
+     * @return the value {@code 0} if {@code x == y};
+     *         {@code -1} if {@code x < y}; and
+     *         {@code 1} if {@code x > y}
+     */
+    public static int compare(final int x, final int y) {
+        // do not subtract for comparison, it could overflow
+        return x < y ? -1 : (x > y ? 1 : 0);
+    }
+
     /**
      * Compare two {@code long} values.
      * @param x the first {@code long} to compare.
diff --git a/transport/src/main/java/io/netty/channel/DefaultChannelId.java b/transport/src/main/java/io/netty/channel/DefaultChannelId.java
index 1409bcbadd..cca96b91a9 100644
--- a/transport/src/main/java/io/netty/channel/DefaultChannelId.java
+++ b/transport/src/main/java/io/netty/channel/DefaultChannelId.java
@@ -178,10 +178,10 @@ public final class DefaultChannelId implements ChannelId {
 
         // random
         int random = ThreadLocalRandom.current().nextInt();
-        hashCode = random;
         i = writeInt(i, random);
-
         assert i == data.length;
+
+        hashCode = Arrays.hashCode(data);
     }
 
     private int writeInt(int i, int value) {
@@ -247,21 +247,35 @@ public final class DefaultChannelId implements ChannelId {
     }
 
     @Override
-    public int compareTo(ChannelId o) {
-        return 0;
+    public int compareTo(final ChannelId o) {
+        if (o instanceof DefaultChannelId) {
+            final byte[] otherData = ((DefaultChannelId)o).data;
+            if (this == o) {
+                // short circuit
+                return 0;
+            }
+            // lexicographic comparison
+            int len1 = data.length;
+            int len2 = otherData.length;
+            int len = Math.min(len1, len2);
+
+            for (int k = 0; k < len; k++) {
+                byte x = data[k];
+                byte y = otherData[k];
+                if (x != y) {
+                    // treat these as unsigned bytes for comparison
+                    return (x & 0xff) - (y & 0xff);
+                }
+            }
+            return len1 - len2;
+        }
+
+        return asLongText().compareTo(o.asLongText());
     }
 
     @Override
     public boolean equals(Object obj) {
-        if (obj == this) {
-            return true;
-        }
-
-        if (!(obj instanceof DefaultChannelId)) {
-            return false;
-        }
-
-        return Arrays.equals(data, ((DefaultChannelId) obj).data);
+        return this == obj || (obj instanceof DefaultChannelId && Arrays.equals(data, ((DefaultChannelId) obj).data));
     }
 
     @Override
diff --git a/transport/src/main/java/io/netty/channel/embedded/EmbeddedChannelId.java b/transport/src/main/java/io/netty/channel/embedded/EmbeddedChannelId.java
index 0bf0b25d45..7bd13ec4ed 100644
--- a/transport/src/main/java/io/netty/channel/embedded/EmbeddedChannelId.java
+++ b/transport/src/main/java/io/netty/channel/embedded/EmbeddedChannelId.java
@@ -40,7 +40,7 @@ final class EmbeddedChannelId implements ChannelId {
     }
 
     @Override
-    public int compareTo(ChannelId o) {
+    public int compareTo(final ChannelId o) {
         if (o instanceof EmbeddedChannelId) {
             return 0;
         }
diff --git a/transport/src/test/java/io/netty/channel/embedded/CustomChannelId.java b/transport/src/test/java/io/netty/channel/embedded/CustomChannelId.java
index 397df1a76e..8d42f29ea0 100644
--- a/transport/src/test/java/io/netty/channel/embedded/CustomChannelId.java
+++ b/transport/src/test/java/io/netty/channel/embedded/CustomChannelId.java
@@ -16,22 +16,25 @@
 package io.netty.channel.embedded;
 
 import io.netty.channel.ChannelId;
+import io.netty.util.internal.MathUtil;
 
 public class CustomChannelId implements ChannelId {
+
     private static final long serialVersionUID = 1L;
 
     private int id;
 
-    public CustomChannelId(int id) {
+    CustomChannelId(int id) {
         this.id = id;
     }
 
     @Override
-    public int compareTo(ChannelId o) {
+    public int compareTo(final ChannelId o) {
         if (o instanceof CustomChannelId) {
-            return id - ((CustomChannelId) o).id;
+            return MathUtil.compare(id, ((CustomChannelId)o).id);
         }
-        return -1;
+
+        return asLongText().compareTo(o.asLongText());
     }
 
     @Override
@@ -41,10 +44,7 @@ public class CustomChannelId implements ChannelId {
 
     @Override
     public boolean equals(Object obj) {
-        if (obj instanceof CustomChannelId) {
-            return id == ((CustomChannelId) obj).id;
-        }
-        return false;
+        return obj instanceof CustomChannelId && id == ((CustomChannelId) obj).id;
     }
 
     @Override