Hi Cullet16,
never mind about the nominal speed for 50/50.
If only one side is using the connection at a certain time, surely it's not a problem if they use the full 100Mbit/s.
The problem arises when the connection is saturated, and neither user should have priority over the other.
This is called contention, and is a typical set-up on consumer connection (usually with around 50 users sharing a single connection on ADSL).
So you will need three router, one that connects to the leased line, and two that connect to the first router (which connects to the leased line).
On the first router, you will need to assign a subnet each for the 2nd and 3rd router.
You will then want to configure Quality of Service (QoS) so that both the 2nd and 3rd router have the same priority accessing bandwidth.
You will probably want to also configure certain priorities by Class of Service (CoS).
For example, say you are fully utilising the line at 100Mbit/s, but your neighbouring company is make a phone call using Voip.
Surely, they're phone traffic is more important than your downloads - else the call breaks up.
This is often pre-configured already.
In a nutshell, if you simply set up three routers in a triangle, fair sharing of the connection is pretty much already done for you.
Only special traffic (usually meaning voice or video conferencing) will need particular attention.
There is no need to assign 50% of the speed to each user.
