I have 2 SIP switches #1 residential #2 business. (yes odd i just have not migrated)
switch1) pbx registers to node1. call comes in on node3 it will transfer to node1 and then PBX. *no issues pbx is registered and knows the IP
switch2) i have 3 nodes, with a central database. pbx registers to node1 but call comes in on node3. node3 seeing the registration IP (from the database) sends the call to the PBX directly.
so scenario #2, there is no option that to have all 3 node IP in the explicit list right? because there is no DNS control to recognize tls.io has the 3 IP's as possibilities.