On Tue, Dec 20, 2011 at 5:20 PM, Daniel-Constantin Mierla miconda@gmail.com wrote:
Hello,
with tls the limit is usually the cpu or memory, due to encryption/decryption, but you say they look ok.
What log level are you using in config?
Is the test tool keeping the tls connections open or they are closed and have to be open for each call? Can you spot if the delay is on incoming side or on outgoing? Wireshark can decrypt the traffic if you provide the certificate and start the sniffing before starting tls connections. Alternative, set:
modparam("tls", "cipher_list", "NULL")
and the traffic should be no longer encrypted, but this will not show if the bottleneck is the encryption process.
Also, benchmark module can help to see if execution of config file takes longer than usual.
Jan Janak did tls tests some time ago, the summary is part of:
http://sip-router.org/wiki/performance/v3.0-capacity
I have some results from a test with 6000 SIP messages/sec over tls, where CPU usage got about 60%. I guess something is becoming a bottleneck in your case, very likely a blocking operation since cpu is ok, just has to be discovered.
Cheers, Daniel
-- Daniel-Constantin Mierla -- http://www.asipto.com http://linkedin.com/in/miconda -- http://twitter.com/miconda
Daniel,
Thank you for getting back to me so quickly.
The log level is the default (debug=2). I tried setting cipher_list to NULL on client and server and now Kamailio has crashed (producing core file) during the last seven tests. It seems I can get to about 1000 registered users before this happens. How should I provide a backtrace?
Once I get past this issue I will try your other suggestions.
Thanks again!