I don't believe it is commercial asterisk, but I don't know and wasn't consulted on that. There is a PCI card added that directly interfaces with PRI phone lines. That card wasn't provided by the people that insisted on RHEL 4.5/CentOS 4.7, and cost around $5000 US dollars, which is well more than the brand new servers themselves cost.  I haven't touched asterisk in years (2003 or 2004 was the last time I used it), but at that time everything I knew about was done over TCP/IP, and this card isn't TCP/IP, it is some direct interface.

This BackupPC isn't going to be backing up an office or anything of the sort, there's just 2 linux servers, one doing the telephony and the other being the database of data to make the calls from. As what is really important is the database, it made more sense to put BackupPC on the telephony server. A 3rd (BackupPC only) server was ruled out on space and cost, so the point of failure kicked in. If the telephony box dies the database still exists, and the telephony is under contract to be rebuilt (though /var thereby /var/lib/backuppc as well lives on its own SAS disks), whereas keeping the database backup is my responsibility, and I'm familiar with BackupPC, though again, obviously not installing it on an out-of-date OS that's new to me!

Beyond all that, the telephony will be silent well above 99.9% of the time. It isn't making phone calls unless something on the order of natural disaster or a terrorist attack occur, and the continental US (save one day of infamy in 2001) is relatively safe. Our geographic location is light on natural disasters, but should one occur, this entire install is put in place to forewarn folks. Should the true purpose of this box kick on, I can easily script a something along the lines of {if telephony = ON, then /etc/init.d./backuppc stop}.

Thanks again for everyone's help, I'm a longtime lurker on these boards, and I was quite pleased to have support when my usualy install conditions were thrown out!