Method for adapting committed information rate over frame relay switched network

In a data communication network including a number of terminating equipments (TE) each connected to one of a plurality of frame handlers (FH) by a data link control identifier (DLCI), a method for controlling the bandwidth allocated to communications between the TEs comprising the steps:

• at each of said FHs setting an Explicit Congestion Notification (ECN) bit when the FH receives more data to transmit than it can transmit or if the FH has imposed a delay on network traffic received from a DLCI;
• at each of the TEs periodically determining if an ECN has been received and incrementing the CIR in a period in which ECN was not received only if it had not been decremented in the prior period and the amount by which the CIR is to be incremented is increased from the amount determined in the prior period;
• and decrementing the CIR in a period in which ECN was received by an amount derived in the prior period if it had not been reduced in the prior period and reduced by an amount derived in the prior period augmented by a predetermined value if it had been reduced in a prior period, wherein the amount for the decrementing or incrementing is derived dynamically.