[SR-Users] Kamailio - Missing INVITEs

Hello, I connected Kamailio to a postgresql database (through sqlops module) and fetching result from a table containing around 300K records , where time processing of the single query is taking around 12 ms. I noticed that on huge load (around 200 - 300 calls per second) Kamailio is not processing all INVITE packets. For instance , I initialized a counter in Kamailio that increments on every INVITE , and on the other hand I counted the number of INVITEs found in Wireshark. I got a big difference (from 30K INVITES in Kamailio , I got 15K in Kamailio), though no errors were raised in kamailio log. How can I proceed in order to detect the problem? :( Any help would be appreciated. Regards, Ali