I thought one of the main reasons for using the OBiTALK Web Portal was to administer remote/unattended OBi's.
How do you dial ***9 remotely?
I never tried, but can't you forward the incoming call to aa2 (that is, administrative IVR)? Maybe for specific caller id. Obviously, while you are doing it the device
will reboot; so the need to reboot once more may become moot

Well rebooting as a way of fixing "I'm hung" issues,
Well, if the device is hung, it will probably not respond to commands from web portal. Heck, for me it was
really hung and didn't respond to commands from the router, either!