User traffic control apparatus for asynchronous transfer mode networks

• US 6,167,050 A
• Filed: 04/08/1998
• Issued: 12/26/2000
• Est. Priority Date: 04/09/1997
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Chung, Jun-gun
• Primary Examiner(s): Patel, Ajit
• Assistant Examiner(s): Phunkulh, Bob A.
• Application Number:
  US09/057,620
• Time in Patent Office: 993 Days
• Field of Search: 370/389, 370/395, 370/412, 370/413, 370/414, 370/428, 370/429, 370/230, 370/232, 370/233, 370/235
• US Class Current: 370/235.1
• CPC Class Codes: H04L 2012/5637 Leaky Buckets
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

An ATM user traffic control apparatus adopts an MBEA (most behind expected arrival) multiplexing mechanism for UNI (User-to-Network Interface) and adaptively controls ATM traffic streams that a plurality of traffic sources send into a UPC (Usage Parameter Control) unit of an ATM network in consideration of traffic priorities of the traffic streams. The traffic control apparatus is provided with a plurality of small leaky bucket buffers and a plurality of virtual bucket buffers corresponding to the leaky buckets, respectively. A pair of leaky and virtual buckets are provided for each traffic source. The apparatus also includes a detection unit that detects whether the cells drained from the leaky buckets are conforming cells and provides information regarding the traffic streams where there exist conforming cells. A calculation unit for calculating the values of priority functions of the traffic streams with the conforming cells, and a priority determination unit for determining a top priority traffic stream by comparing the priority function values are provided for the apparatus. An ATM service multiplexer sends the top priority traffic stream to the UPC unit in preference to the other streams.

Claims

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.

2. The apparatus according to claim 1, wherein the maximum and the minimum values of the each virtual bucket level R_i (t) are zero and a predetermined minus value, respectively;

and said priority determination means takes a traffic stream with the smallest priority function value to be the top priority stream.

3. The apparatus according to claim 2, wherein said priority determination means determines the top priority stream by comparing the virtual bucket levels R_i (t) when there are at least two traffic streams having the same priority function value.

4. 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.

5. The method of claim 4, wherein:

the step of calculating a virtual bucket level R_i (t) corresponding to each leaky bucket buffer LB_i further comprises;

setting the maximum value of the each virtual bucket level R_i (t) to zero, and

setting a minimum value of the each virtual bucket level R_i (t) to a predetermined minus value; and

the step of determining a top priority traffic source further comprises selecting the traffic stream having the smallest priority function value to be the top priority stream.