as the last message - the requirements of the company are that

building 1 floor 1 - 50 admin users
floor 2 - 50 computational vizualization users
building 2 - 50 manufacturing users
building 3 - 50 research lab users

the company runs 5 applications which are;

Application A - Demand access to computational vizulization data
(host: buildings 1 fl 2)
Application B - Continuous backup to storage server in computational
visualization lab (buildings 1 fl 2)
Application C - Manufacturing access to information in computational
visualization lab (building 2 fl 1)
Application D - Cost databases in administrative offices (building 1
fl 1)
Application E - Real time video conferencing so users don't have to
walk through buildings

Each user has one and only one workstation, which can only support
Ethernet or ATM network interface cards, but the servers can support
any type of interface. each host may have multiple NICs used to
aggregate bandwidth.

Notes: No more than 4 Ethernet switches may be cascaded together in 1