Transfers between two FreePBX servers

[hassler (Barry Hassler - HCST)]

Here’s my scenario:
I manage two interconnected FreePBX installations (v13). The interconnection is a SIP trunk between the systems. Both systems have PRI incoming trunks as well, but not specifically relevant

x1204 (on PBX “A”) calls x3900 (on PBX “B”)
x3900 tries to transfer call to x1207 (back on PBX “A”)
This fails with “All Circuits are busy”

Watching logs, and SIP captures, the SIP invite from x3900 to x1207 gets an authentication failure from PBX “A”, I think because the call is coming from x1204, but with PBX “B” IP address, but I’m not positive about that.

The SIP Trunk on the two systems are almost identical, as:
type=peer
trustrpid=yes
sendrpid=pai
qualify=yes
nat=no
insecure=port,invite
host=
dtmfmode=rfc2833
disallow=all
directmedia=no
context=admin-hs-xfer
allow=ulaw

The only significant portion of the above admin-hs-xfer context is:
; Direct Extensions
exten => _[23456]XXX,1,NoOp(Incoming Transfer to ${EXTEN} from Admin PBX)
exten => _[23456]XXX,2,Goto(from-did-direct,${EXTEN},1)

Can anyone shed any light on this issue, and what needs to be changed to make it work?

[cynjut (Dave Burgess)]

Logs would come in handy. Show us a failed call.

[hassler (Barry Hassler - HCST)]

The asterisk log file from the PBX “B” side of the call is at https://pastebin.com/X4xiJUrj
Line 505 is where the call from 3900 back to 1207 goes out and sip replies as unauthorized.

Note, when they recreated this call for me, the original call came from 1207, not 1204, but same result.