Where can I find some documentation on configuring / testing the internal
modem?

I called HPRC and was told to use modmutil and was even emailed instructions
for it, but it requires a support license password (why is a modem utility
so dangerous that it needs a password)?

Is there another way?

What I want to do is create a pager job that can use the modem to dial a
support pager if something goes wrong in our nightly production. I have
tried echoing a dial command to the ldev but it hangs at this point until I
do an abortio on the ldev.