I have four IAXModem 1.1.1 instances running on a Trixbox 2.6.1 machine that has been upgraded to asterisk 1.4.23. A ring group handles calls into this "fax pool", and until today was setup to ring the first available extension. Hylafax 4.4.4 is the back-end. It has been running now for two months and handled several thousand faxes swimmingly.
I have now had three occasions, however, where hylafax reports the first modem in the pool as "wedged", and if I call into the fax pool I get dead silence. I suspect the first modem is still answering the call, but is in such a state that it does not provide the fax tone. And hylafax cannot seem to talk to it at all.
Restarting with "service iaxmodem restart" solves the problem, which I now have as a cron job in the middle of the night, just in case.
Today it happened in the middle of the day and I had to do it manually.
Is this some kind of known issue?
No, not a known issue, although you're welcome to upgrade iaxmodem... but I don't think that it will help.
Do those incoming calls which reach silence generate a HylaFAX session log?
What does the Asterisk CLI say about those calls?
Did iaxmodem crash entirely... or is it just unresponsive?