Urk! I don't know much at all about Frame Relay as it's not really used in the UK. What they are saying is that you have three locations, each with a LAN of 100 users, and you want to implement a WAN to connect them together. If I'm right 'fractional T1' is what we'd call a kilostream over here, so it might be say 512k or something. That's the first thing you 'll need to decide, how much bandwidth you'll need. Since it's a question not a real-world design the best you can do there is make qualified assumptions about this mythical company and justify them (specifically what kind of business do they do - how much of the traffic will be local and how much will traverse the WAN, what kind of response times they'll require etc). Once you've got a figure for that the rest is a matter of googling for routers that will support your chosen WAN links and drawing up a purchase list for the kit. Plus a nice diagram or two on how it will all hang together. And for a few extra marks mention things like security; by putting a few Access Control Lists on your routers you can limit the traffic to just the desirable stuff and keep other things from crossing the WAN, and if your imaginary company's business warrants it you might consider firewalls as well. The bulk of your marks though look as if they will come from specifying the kit.
Hope that helps; feel free to kick your ideas around here for review
