While it’s clear that outbound dialing with siptrunk fails, it does work with a different provider, telnyx, suggesting that there’s no networking problem preventing outbound calling:
I don’t know the significance, but I do see, on line 348:
<--- SIP read from UDP:63.247.69.226:5060 --->
SIP/2.0 404 Not Found
what does that indicate? Is that the root problem, or just a symptom?
In British English, at least, “number unobtainable” is the name that people, including the general public, give to the tone (continuous pure tone in the UK) when you dial an invalid or out of service number. So I was trying to translate the 404 to lay terms.