Hi everyone,
I'm having a hard time transferring calls when the users are on different FreeSWITCH servers behind kamailio.

The users are distributed as follows:
user1@sip.test.com -> Kamailio - ds_select_dst(1,1) -> FreeSWITCH1
user2@sip.test.com-> Kamailio - ds_select_dst(1,1) -> FreeSWITCH1
user3@sip.test.com -> Kamailio - ds_select_dst(1,1) -> FreeSWITCH2

When user1 calls user2 and user2 does an attended transfer to user3, the following happens:
285  67.220453  USER2_IP -> KAMAILIO_IP SIP 726 Request: REFER sip:mod_sofia@FreeSWITCH1_IP:5060, in-dialog |
286  67.220674 KAMAILIO_IP -> FreeSWITCH1_IP SIP 877 Request: REFER sip:mod_sofia@FreeSWITCH1_IP:5060, in-dialog |
287  67.223651 FreeSWITCH1_IP -> KAMAILIO_IP SIP 925 Status: 202 Accepted |
288  67.223753 KAMAILIO_IP -> USER2_IP  SIP 838 Status: 202 Accepted |
289  67.225502 FreeSWITCH1_IP -> KAMAILIO_IP SIP/SDP 1225 Request: INVITE sip:user3@sip.test.com |
290  67.387323 KAMAILIO_IP -> 69.172.200.109 SIP/SDP 1420 Request: INVITE sip:user3@sip.test.com |

Turns out 69.172.200.109 is the actual IP address of sip.test.com (I've probably should have gone with sip.example.com or something else).
What is the proper way to route that INVITE back to the other FreeSWITCH server so that the transfer would work?
Thanks!

Kind regards,
--
Iskren Hadzhinedev