diff --git a/net/src/main/java/com/zfoo/net/router/attachment/SignalAttachment.java b/net/src/main/java/com/zfoo/net/router/attachment/SignalAttachment.java
index 7de58db3..d4c9e457 100644
--- a/net/src/main/java/com/zfoo/net/router/attachment/SignalAttachment.java
+++ b/net/src/main/java/com/zfoo/net/router/attachment/SignalAttachment.java
@@ -26,6 +26,10 @@ public class SignalAttachment implements IAttachment {
 
     public static final short PROTOCOL_ID = 0;
 
+    /**
+     * EN:Negative signalId are allowed
+     * CN:允许负数的signalId
+     */
     public static final AtomicInteger ATOMIC_ID = new AtomicInteger(0);
 
     /**
diff --git a/net/src/main/java/com/zfoo/net/session/Session.java b/net/src/main/java/com/zfoo/net/session/Session.java
index bcbdd2fb..0e4226b5 100644
--- a/net/src/main/java/com/zfoo/net/session/Session.java
+++ b/net/src/main/java/com/zfoo/net/session/Session.java
@@ -28,9 +28,9 @@ public class Session implements Closeable {
     private static final AtomicLong ATOMIC_LONG = new AtomicLong(0);
 
     /**
-     * The globally unique ID of the session
+     * The globally unique ID of the session and the negative sid are allowed
      */
-    private long sid;
+    private long sid = ATOMIC_LONG.incrementAndGet();
 
     private Channel channel;
 
@@ -52,10 +52,6 @@ public class Session implements Closeable {
         if (channel == null) {
             throw new IllegalArgumentException("channel cannot be empty");
         }
-	    this.sid = ATOMIC_LONG.incrementAndGet();
-	    if (this.sid <= 0) {
-		    throw new IllegalArgumentException("sid cannot be 0");
-	    }
         this.channel = channel;
     }
 
@@ -91,10 +87,6 @@ public class Session implements Closeable {
         return sid;
     }
 
-    public void setSid(long sid) {
-        this.sid = sid;
-    }
-
     public Channel getChannel() {
         return channel;
     }