@jamal ( and @ Karuiki ), before we proceed, we first have to calculate the total expected load at peak and offpeak times. The resource, in this case is the internet. We also need to calculate total number of expected users ( irrespective of number of clients, as clients have number of users who now become number of internet port users). So, how many users in total are you expecting and given that they are a mix of corporate and domestic. If corporate, you know monday mornings email traffic would be extremely heavy etc.

 

So in a nutshell, firstly calculate total number of users. Next, each user will use certain ports eg http, pop, smtp. Lets do the traffic calculation first and follow thru with a step by step.