diff --git a/trunk/src/rtmp/srs_protocol_handshake.hpp b/trunk/src/rtmp/srs_protocol_handshake.hpp
index 8a5ab77b7..05b29482f 100644
--- a/trunk/src/rtmp/srs_protocol_handshake.hpp
+++ b/trunk/src/rtmp/srs_protocol_handshake.hpp
@@ -313,7 +313,9 @@ namespace srs
 #endif
 
 /**
-* try complex handshake, if failed, fallback to simple handshake.
+* simple handshake.
+* user can try complex handshake first, 
+* rollback to simple handshake if error ERROR_RTMP_TRY_SIMPLE_HS
 */
 class SrsSimpleHandshake
 {