User traffic control apparatus for asynchronous transfer mode networks

Claim 1

An apparatus for controlling asynchronous transfer mode (ATM) traffic streams that a plurality of traffic sources (TS1, TS2, . . . , and TSn) send into a UPC (Usage Parameter Control) unit of an ATM network the apparatus, comprising: a plurality of leaky bucket buffers (LB1, LB2, . . . , and LBn) each being filled with incoming ATM cells from a corresponding traffic source (TSi) (where, i=1, 2, . . . , or n) but, at the same time, draining an average number of cells per a given time slot, wherein said each leaky bucket (LBi) has a bucket level L i (t) (where, t represents an arbitrary time) proportional to the number of the ATM cells filled therein; a plurality of virtual bucket buffers (VB1, VB2, . . . , and VBn) corresponding to said leaky buckets (LB1, LB2, . . . , and LBn), respectively, wherein said each virtual bucket (VBi) has a bucket level R i (t) of a maximum value while a corresponding leaky bucket (LBi) is filled with at least one ATM cell and has the bucket level R i (t) of a value less than the maximum value thereof and inversely proportional to a time having been elapsed since said corresponding leaky bucket (LBi) has been empty; detection means for detecting whether the cells drained from said leaky buckets are the conforming cells and for providing information regarding traffic streams where there exist conforming cells; calculation means for calculating a value of priority function η i (t) corresponding to the traffic streams having the conforming cells by η i (t)=L i (t)-R i (t); priority determination means for determining a top priority traffic stream by comparing the priority function values η i (t); and ATM multiplexing means for sending the top priority traffic stream to said UPC unit in preference to the other streams.

Claim 2

An apparatus for controlling asynchronous transfer mode (ATM) traffic streams that a plurality of traffic sources (TS1, TS2, . . . , and TSn) send into a UPC (Usage Parameter Control) unit of an ATM network the apparatus, comprising: a plurality of leaky bucket buffers (LB1, LB2, . . . , and LBn) each being filled with incoming ATM cells from a corresponding traffic source (TSi) (where, i=1, 2, . . . , or n) but, at the same time, draining an average number of cells per a given time slot, wherein said each leaky bucket (LBi) has a bucket level L i (t) (where, t represents an arbitrary time) proportional to the number of the ATM cells filled therein; a plurality of virtual bucket buffers (VB1, VB2, . . . , and VBn) corresponding to said leaky buckets (LB1, LB2, . . . , and LBn), respectively, wherein said each virtual bucket (VBi) has a bucket level R i (t) of a maximum value while a corresponding leaky bucket (LBi) is filled with at least one ATM cell and has the bucket level R i (t) of a value less than the maximum value thereof and inversely proportional to a time having been elapsed since said corresponding leaky bucket (LBi) has been empty; detection means for detecting whether the cells drained from said leaky buckets are the conforming cells and for providing information regarding traffic streams where there exist conforming cells; calculation means for calculating a value of priority function η i (t) corresponding to the traffic streams having the conforming cells by η i (t)=L i (t)-R i (t); priority determination means for determining a top priority traffic stream by comparing the priority function values η i (t); and ATM multiplexing means for sending the top priority traffic stream to said UPC unit in preference to the other streams.

Claim 5

A method for controlling asynchronous transfer mode (ATM) traffic streams arriving at a usage parameter control (UPC) unit in an ATM network, the method comprising: buffering incoming ATM cells from each of a plurality of traffic sources producing ATM traffic streams into a corresponding leaky bucket buffer LB i ; draining an average number of cells from each bucket LB i during a given time slot, wherein each leaky bucket buffer LB i has a bucket level L i (t) proportional to a number of ATM cells present in the buffer LB i ; calculating a virtual bucket level R i (t) corresponding to each leaky bucket buffer LB i , where R i (t) is set to a predetermined maximum value when at least one cell is present in the corresponding leaky bucket LB i and where R i (t) is inversely proportional to an elapsed time since the corresponding leaky bucket buffer LB i has been empty when the bucket LB i is empty; detecting whether the ATM cells drained from each leaky bucket buffer LB i are conforming cells in order to identify traffic sources having conforming cells; calculating a value of priority function η i (t) corresponding to the identified traffic streams having conforming cells using the equation η i (t)=L i (t)-R i (t); determining a top priority traffic source by comparing the priority function values η i (t) of the identified traffic streams having conforming cells; and selecting the top priority traffic stream for routing to the UPC unit.

Claim 6

A method for controlling asynchronous transfer mode (ATM) traffic streams arriving at a usage parameter control (UPC) unit in an ATM network, the method comprising: buffering incoming ATM cells from each of a plurality of traffic sources producing ATM traffic streams into a corresponding leaky bucket buffer LB i ; draining an average number of cells from each bucket LB i during a given time slot, wherein each leaky bucket buffer LB i has a bucket level L i (t) proportional to a number of ATM cells present in the buffer LB i ; calculating a virtual bucket level R i (t) corresponding to each leaky bucket buffer LB i , where R i (t) is set to a predetermined maximum value when at least one cell is present in the corresponding leaky bucket LB i and where R i (t) is inversely proportional to an elapsed time since the corresponding leaky bucket buffer LB i has been empty when the bucket LB i is empty; detecting whether the ATM cells drained from each leaky bucket buffer LB i are conforming cells in order to identify traffic sources having conforming cells; calculating a value of priority function η i (t) corresponding to the identified traffic streams having conforming cells using the equation η i (t)=L i (t)-R i (t); determining a top priority traffic source by comparing the priority function values η i (t) of the identified traffic streams having conforming cells; and selecting the top priority traffic stream for routing to the UPC unit.