Simple Networking question

I am not sure if this question belongs to this forum. But I didn't see anything else which could deal with networking topic for the sys-admins.

I have a general question: (I am just looking for a general idea, nothing very specific or hi-fi, just a general idea)

I'd really apperciate a response.

1.
A company has 5 identical 100BaseT Ethernet LANs. Each LAN has 20 workstations, 2 12-port switches and a server. These 5 networks are currently stand-alone (not connected together) but all the switches and servers are located in the same wiring closet.

---How to develop the simple backbone and describe it and what new-hardware would be required ?

2.
A company has 2 buildings that are half a mile apart. Each building has a 20 station 100 BaseT LAN, with a 24-port switch (and some unused ports).

---How to connect these two LAN together ? Which technology would be most cost-effective ?
-ATM technology ? What new hardware would be required.

Thanks a ton !

This sounds an awful lot like homework....


But anyway-

1) Do you want the 5 networks on the same subnet or in different subnets? If you want them all on the same subnet then just plug all the switches into a 'backbone' switch and wala...they're all connected. If you want them on different subnets then you'll need to either incorporate a few routers or a router with a few interfaces.

2) You could use quite a few different things. Some sort of WAN technology through the telco (frame, atm, etc), point of site laser, or if you own all the land between the buildings then bury some fiber in between the buildings.