[SR-Users] Kamailio as a sip/rtp proxy

Hi there, I am trying to implement a sip/rtp proxy. I have one public ip address with a domain name. example (whatever.com) On the lan side i have multiple asterisk instances all listening on 5060 for sip requests. These instances will be assigned to different customers I am hoping to run kamailio in front of these instances and route sip and rtp traffic to the correct asterisk instance. So in this use case asterisk instances will be used as application servers and kamailio will be used as a sip/rtpproxy with nathelper So my question is what would be the best way and using which modules can i route the requests for customerone.whatever.com to the first asterisk instance and customertwo.whatever.com to the second. is this achieved with the dispatcher module? and if so, where can it be defined that requests for cusomertone.whatever.com is routed to the first asterisk instance. Kind regards, Cormac O'Loughlin