Elastix behind NAT?

Question

Mikrotik

Help me figure out Elastix forwarding behind NAT...
Elastix has:
external ip = 1.2.3.4
local network = 192.168.50.0/255.255.255.0
nat=yes
On MT:
/ip firewall filter add action=accept chain=forward dst -address=192.168.50.130 dst-port=5060,10000-20000 protocol=udp in-interface=l2tp
/ip firewall nat add action=dst-nat chain=dstnat dst-port=5060,10000-20000 in-interface=l2tp protocol=udp to-addresses=192.168.50.130
Registration passes... But on the feast the status is Unreacheble... The call is cut off accordingly...
I cling to the Softphone from my mobile phone