Asterisk + vpn why does the call only go one way?

Question

Asterisk

there is an asterisk server at 192.168.10.5 with a gateway on which vpn pptp is raised with mpe encryption to another gateway 192.168.20.1 and a panasonic kx-tgp 600 192.168.20.5 base is connected to it with a cable. do not pass, show sip peers writes that the lane is UNREACHEBLE , however, pings from asterisk to the base pass. I will provide additional information.
Corrected mtu ping size 65500 to the 20.0 network
, turned off unnecessary nat on the 20.1 gateway, but there is no progress.
the problem is solved by setting extension host dynamic. I'm creating a new question in search of an answer why udp port is 1032 and not 5062.

Answer 1

freepbx or bare asterisk?
Does Traceroute work fine on both subsites?
qualify=yes is written in the peer

Answer 2

freepbx
traceroute networks ok