My ATA has a public (dynamic) IP addres, so there should not be NAT issues, correct?
I have copied all the SIP and codec settings as in the
voxalot's faq/tutorial for SPA3102 (including setting SIP port to 5060 and G711u as Preferred Codec).
Also I tried to call my ATA via Sipbroker PSTN assess number and get the same result: my ATA does not ring and calls go to voicemail. So it has nothing to do with Callcentric. The problem is clearly between my ATA (SPA2102) and Voxalot.
RESOLVED