Cannot create socket

При тестировании производительности asterisk на hp dl380 g5 уже при 200 звонках в консоль стали сыпаться ошибки:

[2012-05-17 13:50:04] ERROR[28047] acl.c: Cannot create socket
[2012-05-17 13:50:04] WARNING[28047] res_rtp_asterisk.c: Unable to allocate RTP socket: Too many open files
[2012-05-17 13:50:04] WARNING[13662] app_dial.c: Unable to create channel of type 'SIP' (cause 20 - Unknown)
[2012-05-17 13:50:04] WARNING[28047] channel.c: Channel allocation failed: Can't create alert pipe! Try increasing max file descriptors with ulimit -n
[2012-05-17 13:50:04] WARNING[28047] chan_sip.c: Unable to allocate AST channel structure for SIP channel

При этом ulimit -a еще до запуска астериска:

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 16382
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) unlimited
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

asterisk -rx 'core show version'
Setting max files open to 65536
Asterisk 1.8.11.1-1digium1~squeeze built by pbuilder @ nighthawk on a x86_64 running Linux on 2012-04-25 17:23:34 UTC

uname -a Linux aster 2.6.32-5-amd64 #1 SMP Sun May 6 04:00:17 UTC 2012 x86_64 GNU/Linux

при нагрузке:

lsof | grep asterisk | wc -l
1196

load average не превышал 2.00