[SR-Users] TLS performance testing

[Kristian Kielhofner]

On Tue, Dec 20, 2011 at 5:20 PM, Daniel-Constantin Mierla
<miconda at 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!

-- 
Kristian Kielhofner