Traffic shaper with multiply queued virtual paths

Claim 2

The method of claim 1, wherein cell traffic enters said network (10) on a plurality of virtual paths, each virtual path separately having a first queue (22), second queue (24), first parameter, second parameter, and third parameter as described in claim 1.

Claim 3

The method of claim 1, comprising the additional step of attaching internal class information to said cells when said cells are received, said internal class information designating one queue among said first queue (22) and said second queue (24).

Claim 4

The method of claim 1, wherein said step of inserting forward resource-management cells comprises the further steps of: counting the cells taken from said second queue (24); and inserting a forward resource-management cell instead of taking a cell from said second queue (24), after a certain number of cells have been taken from said second queue (24), said certain number being specified by said third parameter.

Claim 5

The method of claim 1, wherein said backward resource-management cells have congestion indication information, and said step of altering comprises the further steps of: increasing said allowed cell rate when said backward resource-management cells do not indicate congestion; decreasing said allowed cell rate when said backward resource-management cells indicate congestion; and decreasing said allowed cell rate when no backward resource-management cell is received in reply to one of said forward management cells.

Claim 6

The method of claim 1, comprising the further steps of: storing a congestion indication for said virtual path in a register; extracting an explicit forward congestion indication from cells received from said network (10); updating said register according to said explicit forward congestion indication; extracting said forward resource-management cells from said cellstream; copying the congestion indication stored in said register to the forward resource-management cells thus extracted, thereby generating said backward resource-management cells; and returning said backward resource-management cells in reply to said forward resource-management cells; wherein said steps of storing, extracting, updating, extracting, copying, and returning are performed by a device that receives said cellstream from said network (10).

Claim 7

The method of claim 1, wherein said asynchronous-transfer-mode virtual-path-switching network (10) complies with traffic control recommendations for broadband integrated-services digital networks.

Claim 9

The method of claim 8, wherein cell traffic enters said network (10) on a plurality of virtual paths, each virtual path separately having a first queue (22), second queue (24), third queue (70), first parameter, second parameter, third parameter, and fourth parameter as described in claim 8.

Claim 10

The method of claim 8, comprising the additional step of attaching internal class information to said cells when said cells are received, said internal class information designating one queue among said first queue (22), said second queue (24), and said third queue (70).

Claim 11

The method of claim 8, wherein said step of inserting forward resource-management cells comprises the further steps of: counting the cells taken from said second queue (24); and inserting a forward resource-management cell instead of taking a cell from said second queue (24), after a certain number of cells have been taken from said second queue (24), said certain number being specified by said third parameter.

Claim 12

The method of claim 8, wherein said backward resource-management cells have congestion indication information, and said step of altering comprises the further steps of: increasing said allowed cell rate when said backward resource-management cells do not indicate congestion; decreasing said allowed cell rate when said backward resource-management cells indicate congestion; and decreasing said allowed cell rate when no backward resource-management cell is received in reply to one of said forward management cells.

Claim 13

The method of claim 8, comprising the further steps of: storing a congestion indication for said virtual path in a register; extracting an explicit forward congestion indication from cells received from said network (10); updating said register according to said explicit forward congestion indication; extracting said forward resource-management cells from said cellstream; copying the congestion indication stored in said register to the forward resource-management cells thus extracted, thereby generating said backward resource-management cells; and returning said backward resource-management cells in reply to said forward resource-management cells; wherein said steps of storing, extracting, updating, extracting, copying, and returning are performed by a device that receives said cellstream from said network (10).

Claim 14

The method of claim 8, wherein said asynchronous-transfer-mode virtual-path-switching network (10) complies with traffic control recommendations for broadband integrated-services digital networks.

Claim 15

A traffic shaper (6) for shaping cell traffic entering an asynchronous-transfer-mode virtual-path-switching network (10), comprising: a header converter (16) for receiving cells having header information, and converting said header information to information specifying an outgoing virtual path, an outgoing virtual channel, and an internal class, said internal class being one class among a first class and a second class; a plurality of first queues (22) for holding cells awaiting transmission on respective virtual paths; a corresponding plurality of second queues (24) for holding cells awaiting transmission on respective virtual paths; a corresponding plurality of inserters (26) coupled to respective second queues (24), generating forward resource-management cells for transmission on respective virtual paths; a cell distributor (18) coupled to said header converter (16), said first queues (22), and said second queues (24), for placing the cells received by said header converter (16) in said first queues (22) and said second queues (24) according to said outgoing virtual path and said internal class, cells for which said first class is specified being placed in said first queues (22) and cells for which said second class is specified being placed in said second queues (24); a read controller (28) coupled to said first queues (22), said second queues (24), and said inserters (26), for taking cells from said first queues (22) and said second queues (24), taking said forward resource-management cells from said inserters (26), and transmitting the cells thus taken in an outgoing cellstream; a traffic control table (32) for storing parameters designating peak cell rates of respective virtual paths, parameters designating allowed cell rates of respective virtual paths, and parameters designating resource-management cell rates of respective virtual paths, said allowed cell rates not exceeding respective peak cell rates and said resource-management cell rates being fractions of respective allowed cell rates; an extractor (34) for receiving cell traffic from said network (10) and extracting backward resource-management cells; an output scheduler (30) coupled to said read controller (28), said traffic control table (32), and said extractor (34), for monitoring said first queues (22) and said second queues (24), controlling said read controller (28), and adjusting said allowed cell rate responsive to said backward resource-management cells; wherein said output scheduler (30) commands said read controller (28) to take said cells for different virtual paths in turn, following a preference rule within each virtual path, giving the cells in said first queues (22) preference over said forward resource-management cells, giving said forward resource-management cells preference over the cells in said second queues (24), not permitting traffic of said forward resource-management cells to exceed respective resource-management cell rates, not permitting combined traffic of said forward resource-management cells and the cells taken from said second queues (24) to exceed respective allowed cell rates, and not permitting total cell traffic on respective virtual paths to exceed respective peak cell rates.

Claim 16

The traffic shaper of claim 15, wherein said output scheduler (30) keeps separate counts of the cells taken from each of said second queues (24), and commands said read controller (28) to take forward resource-management cells instead of taking cells from respective second queues (24), when respective counts reach values determined by respective resource-management cell rates.

Claim 17

The traffic shaper of claim 15, wherein said backward resource-management cells have congestion indication information, and said output scheduler (30) adjusts said allowed cell rates according to said congestion indication information.

Claim 18

The traffic shaper of claim 17, wherein said output scheduler (30) increases said allowed cell rates when said backward resource-management cells do not indicate congestion, decreases said allowed cell rate when said backward resource-management cells indicate congestion, and decreases said allowed cell rates when backward resource-management cells are not received in reply to said forward management cells.

Claim 19

The traffic shaper of claim 15, wherein said asynchronous-transfer-mode virtual-path-switching network (10) complies with traffic control recommendations for broadband integrated-services digital networks.

Claim 20

A traffic shaper (6) for shaping cell traffic entering an asynchronous-transfer-mode virtual-path-switching network (10), comprising: a header converter (16) for receiving cells having header information, and converting said header information to information specifying an outgoing virtual path, an outgoing virtual channel, and an internal class, said internal class being one class among a first class and a second class; a plurality of first queues (22) for holding cells awaiting transmission on respective virtual paths; a corresponding plurality of second queues (24) for holding cells awaiting transmission on respective virtual paths; a corresponding plurality of third queues (70) for holding cells awaiting transmission on respective virtual paths; a corresponding plurality of inserters (26) coupled to respective second queues (24), generating forward resource-management cells for transmission on respective virtual paths; a cell distributor (18) coupled to said header converter (16), said first queues (22), said second queues (24), and said third queues (70), for placing said cells in said first queues (22), said second queues (24), and said third queues (70) according to said outgoing virtual path and said internal class, cells for which said first class is specified being placed in said first queues (22), cells for which said second class is specified being placed in said second queues (24), and cells for which said third class is specified being placed in said third queues (70); a read controller (28) coupled to said first queues (22), said second queues (24), said third queues (70), and said inserters (26), for taking cells from said first queues (22), said second queues (24), and said third queues (70), taking said forward resource-management cells from said inserters (26), and transmitting the cells thus taken in an outgoing cellstream; a traffic control table (32) for storing parameters designating peak cell rates of respective virtual paths, parameters designating allowed cell rates of respective virtual paths, parameters designating priority cell rates of respective virtual paths, and parameters designating resource-management cell rates of respective virtual paths, said priority cell rates being less than respective peak cell rates, said allowed cell rates not exceeding respective peak cell rates, and said resource-management cell rates being fractions of respective allowed cell rates; an extractor (34) for receiving cells from said network (10) and extracting backward resource-management cells; an output scheduler (30) coupled to said read controller (28), said traffic control table (32), and said extractor (34), for monitoring said first queues (22), said second queues (24), and said third queues (70), controlling said read controller (28), and adjusting said allowed cell rate responsive to said backward resource-management cells; wherein said output scheduler (30) commands said read controller (28) to take said cells for different virtual paths in turn, following a preference rule within each virtual path, giving the cells in said third queues (70) preference over the cells in said first queues (22), giving the cells in said first queues (22) preference over said forward resource-management cells, giving said forward resource-management cells preference over the cells in said second queues (24), not permitting traffic of the cells taken from said third queues (70) to exceed respective priority cell rates, not permitting traffic of said forward resource-management cells to exceed respective resource-management cell rates, not permitting combined traffic of said forward resource-management cells and the cells taken from said second queues (24) to exceed respective allowed cell rates, and not permitting total cell traffic on respective virtual paths to exceed respective peak cell rates.

Claim 21

The traffic shaper of claim 20, wherein said output scheduler (30) keeps separate counts of the cells taken from each of said second queues (24), and commands said read controller (28) to take forward resource-management cells instead of taking cells from respective second queues (24), when respective counts reach values determined by said resource-management cell rates.

Claim 22

The traffic shaper of claim 20, wherein said backward resource-management cells have congestion indication information, and said output scheduler (30) adjusts said allowed cell rates according to said congestion indication information.

Claim 23

The traffic shaper of claim 22, wherein said output scheduler (30) increases said allowed cell rates when said backward resource-management cells do not indicate congestion, decreases said allowed cell rate when said backward resource-management cells indicate congestion, and decreases said allowed cell rates when backward resource-management cells are not received in reply to said forward management cells.

Claim 24

The traffic shaper of claim 20, wherein said asynchronous-transfer-mode virtual-path-switching network (10) complies with traffic control recommendations for broadband integrated-services digital networks.