NAT Problem

I try to NAT port 5060 over my Router, but when I connect to an extension then make a call, it’s just dial about 6 second. And in the log file I see this error

[2017-11-17 03:37:46] WARNING[29382] chan_sip.c: Retransmission timeout reached on transmission 88254MTMxOTc1ZjAwZTFkYTVlZmU5ZTgxNjMwODNjMmVkZGY for seqno 2 (Critical Response) -- See https://wiki.asterisk.org/wiki/display/AST/SIP+Retransmissions
Packet timed out after 6399ms with no response
[2017-11-17 03:37:46] WARNING[29382] chan_sip.c: Hanging up call 88254MTMxOTc1ZjAwZTFkYTVlZmU5ZTgxNjMwODNjMmVkZGY - no reply to our critical packet (see https://wiki.asterisk.org/wiki/display/AST/SIP+Retransmissions).

Please help me! Thanks you all!

On the Extension advanced settings, NAT > Yes.

(Some routers can kill active sip sessions, search online how to disable that)