Sipek project!
See http://sipekphone.googlepages.com/!
Q: How to use sipek TLS with openser?
A: First put certificate and private key created by openser to application folder and rename them to server.crt and pkey.key! Check option TLS in Sipek->Settings.
Q: What to do if something goes wrong?
A: Check configuration, network status, or see the sipek discussions for similar problems. Finaly analize pjsip.log file by yourself or send question to sipek discussion group.
Good luck! Sasa