virtualbox modems

[pcmaster12]

I would like to practice with windows server fax server role. however to do something like that and get past basics I need modems. is there anyway with extensions, mods, etc. to make fake modems? And if so can I then add a modem say to a virtual XP system and have it dial one of the server modems? I know this is kind of an odd thing to want to do, but I know of places that actually use this role, so I think could be good to know. I don't know be much use other than training type scenarios, but I would think could be good for schools, etc. to use this too. nothing else just show how PPP connections work.
If not possible anybody like to make extension, etc. for this. I would like to have the option of like 1 modem then option for modem bank then by just incrementing these can get custom modem count. could just do like 4 modems though too that be enough to practice most things fax related, and about anything else I would think.

Thanks