Hi Guys I am having a strange issue, when I have more than about 450 concurrent calls, rad_auth seems to fail to authorise calls. I see the Radius request received and replied with RAD-ACCEPT from the Radius server but I get the following error 2017-08-07 18:29:53.202133 [ERR] mod_rad_auth.c:504 RADIUS Authentication failure (RC=1) 2017-08-07 18:29:53.202133 [ERR] mod_rad_auth.c:702 An error occured during radius authorization. I have had a look as ulimit and seems to be fine. core file size (blocks, -c) 0 data seg size (kbytes, -d) unlimited scheduling priority (-e) 0 file size (blocks, -f) unlimited pending signals (-i) 128716 max locked memory (kbytes, -l) 64 max memory size (kbytes, -m) unlimited open files (-n) 65536 pipe size (512 bytes, -p) 8 POSIX message queues (bytes, -q) 819200 real-time priority (-r) 0 stack size (kbytes, -s) 8192 cpu time (seconds, -t) unlimited max user processes (-u) 128716 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited Anyone have any ideas? Regards