[SR-Users] load testing ims_charging

i am trying to load test the ims_charging module and notice some issues whenever i send test calls one by one, it's perfect. but when i use sipp and generate a bunch of calls, i would get this intermittently CRITICAL: ims_charging [ro_timer.c:122]: insert_ro_timer(): Trying to insert a bogus ro tl=0x7f207e91c2d0 tl->next=0x7f207e8b57b8 tl->prev=0x7f207e97c398 if i continue to hammer the server, it would end up failing all calls. When this issue happens, Ro_CCR will not return any value and will also not trigger the async route, looks like it just sits there frozen. during this time, sip client will receive a 408. also notice cdp complaining of latency usually around 1 second, using packet capture i am sure diameter server is responding properly. i think there is a choke point somewhere. i tried playing around with async_workers, no improvement. any pointers? Kelvin Chua