Patent ID: 8081644

Claim:
A method implemented by a network node for controlling a queue buffer, the queue buffer being connected to a link and being arranged to queue data units of a flow in a queue, comprising the steps of: determining a value of a length parameter related to the length of the queue; comparing the value with a length threshold value; performing a congestion notification procedure if the value is greater than the length threshold value, wherein the congestion notification procedure when performed drops or marks one or more data units; performing an automatic threshold adaptation procedure, wherein the automatic threshold adaptation procedure comprises a procedure for adjusting the length threshold value on the basis of one or more flow control parameters, wherein the automatic threshold adaptation procedure determines when the congestion notification procedure would be performed to drop or mark one or more of the data units; and determining, in a procedure, one or more of the one or more flow control parameters from a flow control parameter introduced by one of a sender and a receiver of the flow queued in the queue; introducing the flow control parameter by the receiver and inserting it into data units sent from the receiver to the sender; and wherein the buffer is provided in a network node of a communication network connecting the sender and the receiver, further comprising the step of extracting, in a procedure for determining the flow control parameter, the flow control parameter from the data units at the network node.