Fibre optic net connection 2 mbps speed.
Is this line dedicated solely to playing the clanwar, or will there be other people like family or friends using the network for stuff like Internet browsing? This is a pretty limited connection, and even if there aren't other people using it, my concern is that there might be software like an antivirus program or Windows downloading updates that would use bandwidth in the background.
For what it's worth, if
absolutely nothing else was running on the connection, 2mbps would be more than sufficient for a VC:MP game. Even in a worst-case scenario, I don't expect it to use more than 256kb/s in normal gameplay.