Do I need a special switch for ISCSI SAN?

Hi,

I have a basic question about ISCSI SAN?

Do you need a special switch, with high buffer rate or something between ISCSI SAN like MD3200i and storage provided to servers?

what is the benefit of it over traditional layer 2 switches?

In case when you just have 1 ESX server and MDI3200 SAN, would it make more sense to make direct connection without 
use of switch or would it cause some issues, latency.

Thanks in advance