Hi Everybody,
found this out while still working on localization of tones for my country:
during configuration changes it happened that after a reboot, PSTN line was not available (green led OFF). After some search, I tracked it down to errors in the tone syntax. So if parsing of the tone fails, the PSTN line won't come up at boot.
Just to share this with the community, I found nothing googling around or searching here. Hope not already posted.