The Correction Layer mechanism is a Maestro component that ensures that packets from the same connection are handled by the same Security Group Module (SGM) in a multi-appliance system.This is especially important when NAT or VPNs are involved, as packets sent from the client to the server can be distributed to a different SGM than packets from the same session sent from the server to the client. The Correction Layer must then forward the packet to the correct SGM.