diff --git a/proxy/lib/webrtcconn.go b/proxy/lib/webrtcconn.go
index 42fb54b..1c8bf08 100644
--- a/proxy/lib/webrtcconn.go
+++ b/proxy/lib/webrtcconn.go
@@ -42,6 +42,9 @@ type webRTCConn struct {
 
 	bytesLogger bytesLogger
 
+	// protocol reflect the protocol field in the channel opening
+	// message of Data Channel Establishment Protocol.
+	// In snowflake it is used to transmit connection metadata.
 	protocol string
 }