OK, I got the FXO working in no time, but the problem is with the FXS. I am assuming I add it as a PSTN line in 3CX, so I configured that with the proper settings for the Sipura, but the line does not register. In the log I am seeing registration retries, but they are resolved to SIP:user@my_external_ip, even though the Sipura is on my internal network. Something seems wrong here... Anyone help me out? I'll post full working config as soon as I have this figured out.