[SR-Users] call limit by trunk/user

Hi all I need a solution to limit the amount of concurrent calls by trunk or user/subscriber. We have the following situation: Kamailio loadbalancer ==> 3 kamailio gateway with routing/business logic Kamailio is version 3.3 for all 4 systems. Loadbalancer has only the absolute minimum config to act as loadbalancert, the whole business logic is on gateway side (db connections, carrierroute, ...) Do you have a suggestion how to limit calls/connections? Has this to be done on the loadbalancer? Or is there a solution to do this on the gateways - so every gateway knows the currently opened connections? Thanks for helping Oli