Yes, status of Voipstunt in Voxalot is Registered. I have also Cheapnet and it is also registered.
Work only SIP to PSTN call. Sip to Voipstunt user with software not work.
Now every max 3 minute of voip call or traditional call with my siemens c450IP, the line falls, and in phone display appear the line is engaged.
If I configure my siemens with Voipstunt instead of Voxalot then no problem.