ATM communication system

• US 5,274,641 A
• Filed: 08/20/1991
• Issued: 12/28/1993
• Est. Priority Date: 08/20/1990
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Iwamura, Kazuaki, Hanawa, Kazuhiko, Shobatake, Emiko, Shobatake, Yasuro, Kumaki, Yoshinari, Kamitake, Takashi
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): BLUM, RUSSELL
• Application Number:
  US07/747,850
• Time in Patent Office: 861 Days
• Field of Search: 370/60, 370/94.1, 370/79, 370/15, 370/16, 370/85.12, 370/85.14, 340/825.16
• US Class Current: 370/392
• CPC Class Codes: H04L 12/5602 Bandwidth control in ATM Networks, e.g. leaky bucket
• CPC Class Codes: H04L 2012/5625 Operations, administration and maintenance [OAM]
• CPC Class Codes: H04L 2012/5637 Leaky Buckets
• CPC Class Codes: H04L 2012/5647 Cell loss
• CPC Class Codes: H04L 2012/5649 Cell delay or jitter
• CPC Class Codes: H04L 2012/5651 Priority, marking, classes
• CPC Class Codes: H04L 2012/568 Load balancing, smoothing or shaping
• CPC Class Codes: H04L 49/103 using a shared central buffer; using a shared memory
• CPC Class Codes: H04L 49/20 Support for services
• CPC Class Codes: H04L 49/255 Control mechanisms for ATM switching fabrics
• CPC Class Codes: H04L 49/30 Peripheral units, e.g. input or output ports
• CPC Class Codes: H04L 49/3009 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/3081 ATM peripheral units, e.g. policing, insertion or extraction
• CPC Class Codes: H04L 49/309 Header conversion, routing tables or routing tags
• CPC Class Codes: H04L 49/503 Policing
• CPC Class Codes: H04L 49/552 by ensuring the integrity of packets received through redundant connections
• CPC Class Codes: H04L 49/555 Error detection
• CPC Class Codes: H04L 49/557 Error correction, e.g. fault recovery or fault tolerance

Abstract

A ATM communication system can satisfy various requests from a node system, a link system, and the like, by performing a self-format transform between a format to be transmitted and a format receiving an ATM switch, and using a cell processing function for performing polishing/shaping, counting of passed cells, counting of discarded cells, drop/insertion of OAM cell, and the like.

Claims

1. An ATM communication system including:

cell synchronization function means for detecting a header of a cell from an input bit string, and adding a mark to the header of the cell;

ATM switch means for performing cell switching processing of the cell;

routing tag adding function means for transforming a cell output form said cell synchronization function means and having a length suitable for transmission into a cell having a length to be able to be subjected to the cell switching processing by said ATM switch means;

routing tag deleting function means for transforming the cell having the length to be able to be subjected to the cell switching processing by said ATM switch means into a cell having the length suitable for transmission;

preliminary processing function means for performing, after the routing tag is deleted, predetermined processing necessary for a cell synchronization operation performed by said cell synchronization function means for the cell having the length suitable for transmission; and

function means, arranged between a first point between said cell synchronization function means and said routing tag adding function means, and a second point between said routing tag deleting function means and said preliminary processing function means, for inserting a cell of an arbitrary format into a cell flow passing through the first and second point.

2. An ATM communication system including:

cell synchronization function means for detecting a header of a cell from an input bit string, and adding a mark to the header of the cell;

ATM switch means for performing cell switching processing of the cell;

routing tag adding function means for transforming a cell output from said cell synchronization function means and having a length suitable for transmission into a cell having a length to be able to be subjected to the cell switching processing by said ATM switch means;

routing tag deleting function means for transforming the cell having the length to be able to be subjected to the cell switching processing by said ATM switch means into a cell having the length suitable for transmission;

preliminary processing function means for performing, after the routing tag is deleted, predetermined processing necessary for a cell synchronization operation performed by said cell synchronization function means for the cell having the length suitable for transmission; and

function means, arranged between a first point between said cell synchronization function means and said routing tag adding function means, and a second point between said routing tag deleting function means and said preliminary processing function means, for dropping a cell satisfying a predetermined condition from a cell flow passing through the first and second points.

3. An ATM communication system including:

cell synchronization function means for detecting a header of a cell from an input bit string, and adding a mark to the header of the cell;

ATM switch means for performing cell switching processing of the cell;

routing tag adding function means for transforming a cell output from said cell synchronization function means and having a length suitable for transmission into a cell having a length to be able to be subjected to the cell switching processing by said ATM switch means;

routing tag deleting function means for transforming the cell having the length to be able to be subjected to the cell switching processing by said ATM switch means into a cell having the length suitable for transmission;

preliminary processing function means for performing, after the routing tag is deleted, predetermined processing necessary for a cell synchronization operation performed by said cell synchronization function means for the cell having the length suitable for transmission; and

loop back function means arranged between a first point between said cell synchronization function means and said routing tag adding function means, and a second point between said routing tag deleting function means and said preliminary processing function means, and having a first function of dropping a cell satisfying a predetermined condition from a cell flow passing through the first point, and inserting the dropped cell into a cell flow passing through the second point, and a second function of dropping a cell satisfying a predetermined condition from a cell flow passing through the second point, and inserting the dropped cell into a cell flow passing through the first point.

4. An ATM communication system comprising:

a plurality of input buffers each having a cell discard class control function;

a plurality of output buffers each having a cell delay class control function; and

ATM switch means for receiving the flow of cells from said input buffers, and switching the cells, to output the flow of cells to said output buffers.

5. An ATM communication system including:

a functional element for providing information which shows a connection belonging to a cell discarded according to a predetermined condition, and

wherein said functional element comprises FIFO means which can temporarily hold a plurality of pieces of information which shows a connection belonging to a cell discarded according to a predetermined condition,

every time the information which shows a connection belonging to a cell discarded according to a predetermined condition is generated, the generated information is enqueued in said FIFO means, and

when said FIFO means is not empty, a request is issued to said control processor.

6. An ATM communication system including:

a functional element for providing information which is generated every cell period to a control processor for performing operation observation of functional elements constituting said ATM communication system, and

wherein said functional element comprises FIFO means which can temporarily hold a plurality of pieces of information which is generated for every cell period,

every time the information which is generated for every cell period is generated, the generated information is enqueued in said FIFO means,

when said FIFO means is not empty, a request is issued to said control processor, and

if said FIFO means is full when the information which may be generated for every cell period is generated, the information is discarded, and a message indicating that the information is discarded is informed to said control processor.

7. An ATM communication system including:

an ATM switch;

function means for transforming a VPI/VCI or a logical VCI of an input cell into a physical VCI as an identifier for looking up a routing tag table including a routing tag for designating a path in said ATM switch as at least a content of the table; and

means for discarding the input cell if converting from the VPI/VCI of the input cell to the physical VCI fails.

8. An ATM communication system including:

routing tag adding function means having a routing tag table having a plurality of entries to each of which is added error correction information; and

means for, when an error is found in a corresponding entry on the basis of the correction information of the entry of the routing tag table corresponding to an input cell, discarding the input cell.

9. An ATM communication system comprising:

cell processing function means including function means for generating an alarm cell according to a problem portion, and routing tag adding function means for generating the alarm cell when a problem is found between an input transmission path and said routing tag adding function means.

10. An ATM communication system comprising:

routing tag adding function means;

routing tag deleting function means for, when a fault is found in said routing tag adding function means in a cell processing function means, receiving a cell from said cell processing function means via an ATM switch and generating an alarm cell.

11. An ATM communication system comprising:

cell processing function means including function means for generating an alarm cell, wherein when a problem is found in link or node system connected to said cell processing function means by a transmission path, routing tag adding function means for generating an alarm cell is arranged in said cell processing function means to receive a cell from said link or node system.

12. A polishing apparatus for an ATM communication system, comprising:

a RAM for holding information for measuring a cell flow for each connection;

a register group for exchanging information with said RAM;

a first sequencer for controlling information transfer between said RAM and said register group;

an ALU for receiving information from said register group, and for performing arithmetic operations/bit operations; and

a second sequencer for controlling information transfer between said register group and said ALU.

13. An ATM communication system comprising:

a plurality of path handling systems; and

clockwise and counterclockwise ring-like transmission paths for coupling said path handling systems,

each of said path handling systems including;

a first drop/insert section connected to be inserted in said clockwise ring-like transmission path;

a second drop/insert section connected to be inserted in said counterclockwise ring-like transmission path;

a first loop back path extending from said first drop insert section to said second drop/insert section;

a second loop back path extending from said second drop/insert section to said first drop/inset section; and

a drop/insert path through which cells to be dropped from or to be inserted in the ring-like transmission paths flow,

wherein when connections of an active system are set among said path handling systems, connections of a stand-by system are simultaneously set,

the connection of the active system is set to go round one of two said ring-like transmission paths so that the connections start from a first path handling system as a starting point where an original connection is to be set, and are terminated at the first path handling system via a second path handling system as an end point where the original connection is to be set,

the connections of the stand-by system are set to go round a second ring-like transmission path in a direction opposite to a first ring-like transmission path for accommodating the connections of the active system, and

the connections of the active and stand-by systems are set to have the same identifiers at entrances and exits of the loop back path form the drop/insert section of the respective path handling systems inserted in the first ring-like transmission path to the drop/insert sections inserted in the second ring-like transmission path.

14. A system according to claim 13, wherein the path handling system as the original end point guides a user cell transferred along the connections of the active system to the drop/insert path, relays only an OAM cell, and sends the OAM cell onto the ring-like transmission path, so that the OAM cell flowing from the pass handling system at the starting point where the connection is to be set via the connections goes round the ring-like transmission path once, and is returned to the path handling system at the starting point where the connection is to be set, and a connection check operation is performed by confirming if the OAM cell normally goes round the ring-like transmission path once, and is returned to the path handling system at the starting point.

15. A system according to claim 13, wherein said insert/drop section has a copy function of outputting a cell input from the ring-like transmission path to the drop/insert path while relaying the cell to the ring-like transmission path in addition to three basic functions including drop, insert, and relay functions, and the path handling system executes the insert function in a start point of the connection of the ring-like transmission path, the relay function at a relay point of the connection, and the copy function at a point at which the copy cell drops while relaying the connection, when the cell is input to respective path handling systems, and thus allowing a 1-to-N drop connection of the pass handling systems connected by the ring-like transmission path as a whole.