diff --git a/core/nat.go b/core/nat.go
index 6fe4d07..55c1480 100644
--- a/core/nat.go
+++ b/core/nat.go
@@ -113,7 +113,6 @@ func getNATType(host string, udp1 int, udp2 int) (publicIP string, NATType int,
 
 func publicIPTest(publicIP string, echoPort int) (hasPublicIP int, hasUPNPorNATPMP int) {
 	var echoConn *net.UDPConn
-	//This piece is in another goroutine in the old code! Please check the update diary.
 	gLog.Println(LvDEBUG, "echo server start")
 	var err error
 	echoConn, err = net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: echoPort})
@@ -125,7 +124,6 @@ func publicIPTest(publicIP string, echoPort int) (hasPublicIP int, hasUPNPorNATP
 	go func() {
 		// close outside for breaking the ReadFromUDP
 		// wait 5s(30s?) for echo testing
-		gLog.Println(LvDEBUG, "the own goroutine of echo server run")
 		buf := make([]byte, 1600)
 		echoConn.SetReadDeadline(time.Now().Add(time.Second * 30))
 		n, addr, err := echoConn.ReadFromUDP(buf)