Sip trunk through ipsec

General Help
1

This is my network:
pbx_a ----> ipcop_a <------ ipsec ------> ip_cop_b ----> pbx_b

pbx_a 192.168.101.3/24
ipcop_a 192.168.101.254/24

pbx_b 192.168.102.3/24
ipcop_b 192.168.102.254/24

Ipsec works, from network a i can reach network b and viceversa.
The same is for both pbx, so from a/b i can reach a/b (with a ping or using ssh for example)

With iperf i can send alot of SIP udp packets from pbx_a/pbx_b and the remote host can receive these packets.

Now, reading the logs / tcpdump from :
ipcop_a

-sip packets leave from ipcop_a -> to ipcop_b
-sip packets arrive from ipcop_b -> ipcop_a

ipcop_b

-sip packets leave from ipcop_b -> to ipcop_a
-sip packets NOT arrive from ipcop_a -> ipcop_b

Now, this is a strange thing, the ipcop_b not receive nothing.
The traffic in the tunel is encrypt so i think that is not a block/problem of my ISP
Then…why i can send alot of sip packets using iperf?

I already replace ipcop_a, but the problem persist.
This is the configuration of sip trunk:

PEER Details
host=192.168.102.3
username=GE01GE02
secret=GE01toGE02
type=friend
qualify=yes
context=from-trunk

2

Possibly on both machines under Settings -> SIP Settings -> NAT Settings -> Local Networks you need to have the local subnets defined so it doesn’t try to reformat the SIP header with the external IP.