Traffic shaping device

• US 6,005,868 A
• Filed: 09/25/1997
• Issued: 12/21/1999
• Est. Priority Date: 09/27/1996
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ito, Atsuo
• Primary Examiner(s): Ton, Dang
• Assistant Examiner(s): Sam, Phirin
• Application Number:
  US08/937,707
• Time in Patent Office: 817 Days
• Field of Search: 370/413, 370/229, 370/230, 370/232, 370/233, 370/234, 370/235, 370/252, 370/253, 370/395, 370/397, 370/412, 370/415, 370/417, 370/444, 370/389, 370/391, 370/392, 370/394 , 370/396, 370/399, 370/400, 370/409, 370/411, 370/423
• US Class Current: 370/413
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04L 2012/5679 Arbitration or scheduling
• CPC Class Codes: H04L 2012/568 Load balancing, smoothing or shaping
• CPC Class Codes: H04L 2012/5681 Buffer or queue management
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

In a traffic shaping device which can control a cell sending rate with using a common circuit portion regardless of the number of cell buffers, cells 31 input to a cell input portion 32 are stored in corresponding ones of cell buffers 35₁ ˜35_N prepared for every one of traffics having different shaping rates. Cell buffer registers 41₁ ˜41_N are provided correspondingly to the cell buffers 35₁ ˜35_N and an output time from an output time notice counter 43 which is incremented every cell period is compared with values of cell output enabling time registers 48. One of the cell buffers which is enabled to output are permitted to output the cell stored therein if any through a cell output portion 37. Thereafter, the values of the cell output enabling time registers 48 are rewritten on the basis of contents of cell output interval registers 52. Regulation of priorities of the cell buffers is also performed by a priority registers 51.

Claims

1. A communication traffic shaping device comprising:

a plurality of cell buffers each provided for respective communication traffic signals having different shaping grades of cells arriving at said traffic shaping device according to an ATM transfer system;

a cell buffer selector means for identifying each of said cells arriving thereat and storing each of said cells in a corresponding one of the plurality of said cell buffers;

a cell output portion for outputting selected ones of each of said cells stored in the plurality of cell buffers;

an output time notice counter having a count value incremented every cell period as a minimum period required to send each of said cells from said cell output portion;

cell output enabling time registration means provided for the respective traffic signals having different shaping grades for sequentially registering output enabling times of said plurality of cell buffers corresponding to the respective traffic signals; and

cell sending permit means for comparing an output time noticed by said output time notice counter with the output enabling times registered in said cell output enabling time registration means provided for every virtual channel to enable one of said plurality of cell buffers to output the cell stored therein to said cell output portion and permitting enabled ones of said cell buffers to send the cell stored therein to said cell output portion.

2. A traffic shaping device as claimed in claim 1, wherein said cell output enabling time registration means comprises cell output interval registration means for registering a cell output interval for every one of said communication traffic signals having different shaping grades and cell output enabling time registration means for forming a sum by adding the cell output interval to a time at which said enabled ones of said cell buffers permitted by said cell permit means send at least one of each of said cells stored therein and registering the sum as a next output enabling time.

3. A communication traffic shaping device comprising:

a plurality of cell buffers each provided for respective communication traffic signals having different shaping grades of cells arriving at said plurality of cell buffers according to an ATM transfer system;

a cell buffer selector means for identifying each of said cells when each cell arrives and storing each of said cells in one of said plurality of cell buffers which corresponds to each of said cells;

a cell output portion for outputting selected ones of each of said cells stored in the plurality of cell buffers;

an output time notice counter having a count value incremented every cell period as a minimum period for sending each of said cells from said cell output portion;

cell output enabling time registration means provided for the respective communication traffic signals having different shaping grades for sequentially registering output enabling times of said plurality of cell buffers corresponding to the respective traffic signals;

priority registration means provided for each of the communication traffic signals having different shaping grades for registering priorities for cell outputs of each of the cells stored in corresponding ones of said plurality of cell buffers; and

cell sending permit means, said cell sending permit means, when there are a plurality of said plurality of cell buffers enabled to output their cells by comparing an output time noticed by said output time notice counter with the output enabling times registered in said cell output enabling time registration means provided for every virtual channel, permitting one of said plurality of enabled cell buffers which has a highest priority to output the cell stored therein to said cell output portion.

4. A communication traffic shaping device as claimed in claim 3, wherein said cell sending permit means comprises priority regulation means which, when there are a plurality of said plurality of cell buffers enabled, lowers the priority of said cell buffer permitted to output the cell stored therein which is registered as a registration content in said priority registration means and increases he priorities of said cell buffers not permitted to output the cells stored therein, which are registered by said priority registration means.

5. A communication traffic shaping device as claimed in claim 4, wherein said priority regulation means resets the registration content of said priority registration means when the priority is to be lowered and counts up the registration content of said priority registration means one by one when the priority is to be increased.