explicit forward congestion indication (ATM) (EFCI)

Explicit Forward Congestion Indication (EFCI) is identified by a bit in the Payload Type Identifier(PTI) of the ATM header. This bit is then set in an ATM cell when data traffic is congested. By setting the EFCI bit, the end system recognizes the congestion and can react accordingly in terms of protocol, for example by reducing the cell rate.