bandwith for user in e p

hi friends

1.we are going to implement sap to one of our client . i have doughts like what bandwith is needed for a single user to access the sap and is there any formula to caluculate

2. client is having 40 user s and they nee ecc and ep in a single box i mean sigle system landscape for this what is the hardware requirment wha is suggestable.

3. one java server proces can server how many users and upto how many server porcess i can increase in java engin (config tool )

thanks in advance dear friends

regards

raja