Patent ID: 7593329

Claim:
A service aware flow control apparatus for multiple classes of data packets, said apparatus comprising: a flow control sender comprising a buffer of an ingress port per Class Group or Class of Service (COS), a counter per COS, wherein each counter is configured to track an amount of buffer utilization per ingress port per COS, and each counter comprises an XOFF threshold level of congestion and an XON threshold, refresh timers per ingress port, the refresh timers being operatively connected to a controller and configured to time a refresh period in which the congestion at the only one buffer for the particular COS experiencing congestion is to be resolved, and the controller configured to detect, during transmission of the data packets, a counter associated with the buffer for the particular COS has risen to be greater than or equal to the XOFF threshold level of congestion, and to generate, upon expiration of one of the refresh timers, an XOFF message corresponding to only the one buffer for the particular COS for which the counter has risen to be greater than or equal to the XOFF threshold level of congestion, the XOFF message specifying the particular COS and a timeout value.