Method of and an apparatus for releasing a cut-through connection

• US 6,731,637 B2
• Filed: 08/04/1999
• Issued: 05/04/2004
• Est. Priority Date: 08/07/1998
• Status: Expired due to Fees

• Current Assignee: Juniper Networks Incorporated
• Original Assignee: NEC Corporation
• Inventors: Ikeda, Hiroshi, Isoyama, Kazuhiko
• Primary Examiner(s): Duong, Frank
• Application Number:
  US09/368,180
• Publication Number:
  US 20030202515A1
• Time in Patent Office: 1,735 Days
• Field of Search: 370/229, 370/230, 370/235, 370/395.1, 370/396, 370/397, 370/398, 370/399, 370/395.2, 370/395.52, 370/400, 370/409
• US Class Current: 370/395.2
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5636 Monitoring or policing, e.g. compliance with allocated rate, corrective actions
• CPC Class Codes: H04L 2012/5667 IP over ATM
• CPC Class Codes: H04L 49/257 Cut-through or wormhole routing

Abstract

To provide an apparatus for releasing a cut-through connection in a network node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node without charging large load on software processings, the apparatus for releasing a cut-through connection comprises a timer (21) having time counters each assigned to a cut-through connection and outputting a time-out notification signal (20) when a count value of the time counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the time counter being incremented along with time passage and being reset when the cut-through connection is established and when a cell of the cut-through connection arrives to the network node.

Claims

1. An apparatus for releasing a cut-through connection in a network node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node;

the apparatus comprising;

a timer having an up/down counter assigned to the cut-through connection and outputting a time-out notification signal when a count value of the up/down counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the up/down counter being reset when the cut-through connection is established, being incremented according to clock pulses having a cell cycle predetermined for the cut-through connection and being decremented when a cell of the cut-through connection arrives to the network node;

a connection-release control unit for controlling a cell processing unit to release the cut-through connection according to the time-out notification signal; and

a connection-release message generator for transmitting a connection-release requesting message of the cut-through connection towards a next node according to the time-out notification signal.

2. An apparatus for releasing a cut-through connection in a net-work node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node;

the apparatus comprising;

a timer having a time counter assigned to the cut-through connection and outputting a time-out notification signal when a count value of the time counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the time counter being incremented along with time passage and being reset when the cut-through connection is established and when a cell of the cut-through connection arrives to the network node;

a connection-release control unit for controlling a cell processing unit to release the cut-through connection according to the time-out notification signal; and

a connection-release message generator for transmitting a connection-release requesting message of the cut-through connection towards a next node according to the time-out notification signal.

3. An apparatus as recited in claim 2, wherein the time-out threshold value is registered in a time-out threshold memory.

4. An apparatus for releasing a cut-through connection in a net-work node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node;

the apparatus comprising;

a timer having an up/down counter assigned to the cut-through connection and outputting a time-out notification signal when a count value of the up/down counter has attained to a time-out threshold value determined corresponding to the cut-through connection, the up/down counter being reset when the cut-through connection is established, being incremented according to clock pulses having a cell cycle predetermined for the cut-through connection and being decremented by one when a cell of the cut-through connection arrives to the network node.

5. An apparatus as recited in claim 4, wherein the clock pulses are generated by a cycle-clock generator referring to a value of the cell cycle which is registered in a cell-cycle memory corresponding to the cut-through connection.

6. An apparatus as recited in claim 4, wherein the time-out threshold value is registered in a time-out threshold memory.

7. A method of releasing a cut-through connection in a network node when traffic on the cut-through connection becomes smaller than a fixed value by monitoring traffic of each of cut-through connections established in the network node;

the method comprising steps of;

assigning and resetting an up/down counter for a cut-through connection and registering a time-out threshold value for the up/down counter when the cut-through connection is established;

incrementing the up/clown counter according to clock pulses having a cell cycle predetermined for the cut-through connection;

decrementing by one the up/down counter when a cell of the cut-through connection arrives to the network node; and

outputting a time-out notification signal when a count value of the time counter has attained to the time-out threshold value.