Patent ID: 7349334

Claim:
A packet flow control method for a switching node of a data transfer network, said method comprising: actively managing space allocations in a central queue for a plurality of ports of a switching node of a data transfer network, wherein the actively managing is based on an amount of currently unused space in the central queue; wherein the actively managing includes determining, based on an amount of currently-vacant storage space in a storage device of a port of the plurality of ports, whether the port accepts an offered space for use by the port to buffer received data packets, the offered space comprising a quantity of the amount of currently unused space in the central queue; and wherein said determining further comprises: (i) computing a total current credit for the port, wherein the total current credit is defined as a difference between a space allocation in the central queue for the port and an amount of the space allocation currently used to buffer the received data packets; (ii) comparing the total current credit to the amount of currently-vacant storage space in the storage device of the port; (iii) accepting the offered space if the amount of currently-vacant storage space in the storage device of the port is greater than the total current credit; and (iv) refusing the offered space if the amount of currently-vacant storage space in the storage device of the port is less than the total current credit.