I have an Asterisk (11.5.0) connect to one of my own SIP server cluster. My cluster has a load balancer handling all incoming request, and few call handling units, the load balancer and call handling units all have their unique IP.
For calls from Asterisk to my cluster, I configured Asterisk to send INVITE to the load balancer IP, the call handling unit sends 18x and 200 OK back to Asterisk from call handling unit’s IP, and Asterisk send ACK to call handling unit’s IP, so everything looks fine.
However, when call handing unit sends in-dialogue INVITE (eg to put call on hold), Asterisk sends 200 OK to the load balancer’s IP, even though the INVITE is from call handling unit and the Contact has call handling unit’s IP.
I have added both load balancer and call handling units in sip.conf, and tried all combination of different settings for type, nat, canreinvite, etc. but nothing works.
I wonder if anyone else has run into this situation before? Any insight is appraciated!