Patent ID: 6920111

Claim:
A method of controlling traffic in a multi-level system, said method comprising: incrementing a first counter associated with a first node in a first level of said system, said first counter for controlling traffic flow from said first node to a node that is downstream of said first node, said first counter incremented by a fixed amount at time intervals established by an update scheme and decremented by a first variable amount that corresponds to the amount of traffic sent from said first node, said first node eligible to send traffic if said first counter exceeds said first variable amount; and incrementing a second counter associated with a second node in another level of said system, wherein said second counter controls traffic flow from said second node to a node that is downstream of said second node, said second counter incremented by a fixed amount at time intervals established by said update scheme and decremented by a second variable amount that corresponds to the amount of traffic sent from said second node, said second node eligible to send traffic if said second counter exceeds said second variable amount; wherein said first counter and said second counter are incremented at different frequencies.