Hi All,
Please clarify the nat=yes setting for a SIP peer.
What I observed - SIP responses were sent back correctly to my NAT router.
Then my IP phone sent SDP packet and it contained internal network IP.
Asterisk started to send UDP packets to the internal IP - consequently they got lost.
The question: in my opinion nat=yes should override SDP IP address as well. So the UDP packets get sent to my NAT router. Or it was duty of my IP phone to figure out it from SIP headers?
I did setup STUN on the IP phone and it sends now external IP in SDP and stuff works. Anyway, I’m curious 
Thanks folks!
jb