My plan is to reject new inbound requests if there is already a certain number of open connections on one Kamailio server. I could answer with a 503 and directly close the connection forcing the client to reconnect and the loadbalancer to send traffic to a different node on the next connect. It's just a last-resort measure to prevent Kamailio from running into the configured TCP connection limit (workarounding a poorly-implemented external load balancer).

Since I didn't find anything in the docs: Is there a pseudovariable containing the current number of open tcp/tls connections on this Kamailio? I can (and already do) query them via kamcmd or rpc, but can I access the variable from inside the routing script as well?