Protection switching apparatus and method using node group in ring ATM system

• US 20040146005A1
• Filed: 12/11/2003
• Published: 07/29/2004
• Est. Priority Date: 01/29/2003
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Rim, Houn-Joung
• Application Number:
  US10/732,353
• Publication Number:
  US 20040146005A1
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04L 12/5601 Transfer mode dependent, e.g. ATM
• CPC Class Codes: H04L 2012/5612 Ring
• CPC Class Codes: H04L 2012/5627 Fault tolerance and recovery

Abstract

A protection switching apparatus and method uses a node group in a ring ATM system, wherein all connections existing in a node is regarded as one group and a ring node ID is given to each node, thereby including all node IDs of nodes with a subscriber in a GFC (Generic Flow Control) field of an ATM (Asynchronous Transfer Mode) cell that passes through every traffic of the ring, and switching every traffic in a node, the moment protection switching for an arbitrary node group is required.

Claims

1. A protection switching apparatus using a node group in a ring asynchronous transfer mode system, the apparatus comprising:

a physical layer processor extracting an asynchronous transfer mode cell from a receive frame from a physical layer and loading a cell that is received from an asynchronous transfer mode layer to the frame;

a pair of traffic filters for generating an alarm cell when fault is sensed in the opposite port, for transmitting the alarm cell, each of the traffic filters comprising a cell drop register for storing ring node identification, with when a cell with a designated ring node identification from a unidirectional network interface is received in a first field that is stored in a cell drop register, the traffic filter drops the cell, and when a cell with a designated ring node identification is inputted in a first field that is not stored in the cell drop register, the traffic filter passes the cell, for detecting an alarm cell that is received from another ring node, for setting an allocated bit value in a second field to a second value, and for transmitting the cell;

a controller for storing a ring node identification of its own in the cell drop register of the traffic filter that transmitted the alarm cell recognition signal when receiving an alarm cell recognition signal from the traffic filter, for deleting the ring node identification, and for transmitting a control signal to set its allocated bit in the alarm cell to the traffic filter; and

a cell routing unit for routing the cell to a local bus when receiving a cell with its designated ring node identification to the first field of the receive cell, and for routing the cell to a through bus when receiving a cell without its designated ring node identification to the first field of the receive cell.

2. The apparatus according to claim 1, wherein the alarm cell comprises:

a generic flow control field to which 1xF is allocated as a third value;

a virtual channel identifier field to which 0xFF is allocated as a fourth value; and

a virtual path identifier field including a bit that is set to 1 having allocated 1 as the second value.

3. The apparatus according to claim 1, wherein the traffic filter comprises:

a cell drop register for storing ring node identification, informing a cell to drop;

a traffic filter port for providing a port to exchange information about reception status of the alarm cell and port status between the traffic filters in a pair;

an alarm cell generator for generating and transmitting an alarm cell when a port fault indication signal is received, for receiving a cell from another ring node and transmitting the cell, for detecting an alarm cell in the cell from another ring node, and for allocating its allocated bit in the second field as the second value;

a port status detector for detecting status of a port, and when port fault is sensed, for outputting the port fault indication signal to the traffic filter paired with the controller; and

a generic flow control sorter for dropping the cell when the first field value of the receive cell from the alarm cell generator exists in the cell drop register, and for passing the cell when the first field value of the input cell from the alarm cell generator does exist in the cell drop register.

4. The apparatus according to claim 1, wherein the cell routing unit comprises:

a first cell router for routing the cell to the through bus that passes a subscriber traffic in another ring node within the ring;

a second cell router for routing the cell to the local bus that adds or drops the subscriber traffic in a corresponding node;

a bus selector for routing the cell to the first cell router when a fourth value is designated to a fourth field of the receive cell, and for routing the cell to the second cell router when the fourth value is not designated to the fourth field; and

an asynchronous transfer mode processor for setting the fourth value to the fourth field when receiving the cell with its designated ring node identification to the first field from the traffic field, and for transmitting the cell to the bus selector.

5. A protection switching method using a node group in a ring asynchronous transfer mode system, the method comprising:

recognizing, by a network asynchronous transfer mode ring unit of a ring node, port fault and notifying to an opposite network asynchronous transfer mode ring unit about the port fault;

designating, by a controller, a ring node identification of the controller to a cell drop register of the network asynchronous transfer mode ring unit with the port fault, and deleting the ring node identification out of a cell drop register of the opposite network asynchronous transfer mode ring unit;

generating an alarm cell and transmitting the alarm cell by the network asynchronous transfer mode ring unit that is notified of the port fault;

upon receiving an alarm cell from another ring node, designating a ring node identification of the controller to the cell drop register of an alarm cell-receiving network asynchronous transfer mode ring unit by the controller and deleting the ring node identification out of the cell drop register of the opposite network asynchronous transfer mode ring unit by the controller; and

writing node information of the unit to the input alarm cell and transmitting the alarm cell including the node information of the unit by the alarm cell-receiving network asynchronous transfer mode ring unit.

6. The method according to claim 5, wherein the alarm cell at the step of generating an alarm cell and transmitting the alarm cell, comprises 1xF as a field value for a generic flow control field, 0xFF as a field value for a virtual path identifier field, and an allocated bit to the alarm cell in a virtual channel identifier field is 1.

7. The method according to claim 5, wherein the step of designating the ring node identification and deleting the ring node identification comprises the sub-steps of:

extracting, at a traffic filter of the network asynchronous transfer mode ring unit, a generic flow control field value and a virtual path identifier field value of the receive cell, and when the generic flow control field value is 1xF and the virtual path identifier field value is 0xFF, recognizing the receive cell as an alarm cell, and notifying fault occurrence to the controller;

storing, at the controller, the ring node identification of the controller in the cell drop register of the traffic filter of the alarm cell-receiving network asynchronous transfer mode ring unit; and

deleting, at the controller, the ring node identification of the controller out of the cell drop register of the opposite network asynchronous transfer mode ring unit to the alarm cell-receiving network asynchronous transfer mode ring unit.

8. A protection switching method using a node group in a ring asynchronous transfer mode system, the method comprising the steps of:

when a network-connection node receives an alarm cell, detecting, at a network asynchronous transfer mode ring unit, that the alarm cell has been received, and extracting node information from the alarm cell;

notifying, at the network asynchronous transfer mode ring unit that detected receive of the alarm cell, to a controller about the receive of the alarm cell, and transmitting the node information extracted from the alarm cell to the controller;

deleting, at the controller, ring node identifications of nodes based on the node information included in the alarm cell of a cell drop register of the network asynchronous transfer mode ring unit in which the alarm cell is received; and

storing, at the controller, ring node identifications of nodes based on the node information included in the alarm cell of an cell drop register of an opposite network asynchronous transfer mode ring unit of the network asynchronous transfer mode ring unit to which the alarm cell is inputted.

9. A computer-readable medium having computer-executable instructions for performing a method, comprising:

recognizing, by a network asynchronous transfer mode ring unit of a ring node, port fault and notifying to an opposite network asynchronous transfer mode ring unit about the port fault;

designating, by a controller, a ring node identification of the controller to a cell drop register of the network asynchronous transfer mode ring unit with the port fault, and deleting the ring node identification out of a cell drop register of the opposite network asynchronous transfer mode ring unit;

generating an alarm cell and transmitting the alarm cell by the network asynchronous transfer mode ring unit that is notified of the port fault;

upon receiving an alarm cell from another ring node, designating a ring node identification of the controller to the cell drop register of an alarm cell-receiving network asynchronous transfer mode ring unit by the controller and deleting the ring node identification out of the cell drop register of the opposite network asynchronous transfer mode ring unit by the controller; and

writing node information of the unit to the input alarm cell and transmitting the alarm cell including the node information of the unit by the alarm cell-receiving network asynchronous transfer mode ring unit.

10. The computer-readable medium having computer-executable instructions for performing the method of claim 9, wherein the alarm cell at the step of generating an alarm cell and transmitting the alarm cell, comprises a first value as a field value for a generic flow control field, second value as a field value for a virtual path identifier field, and an allocated bit to the alarm cell in a virtual channel identifier field is 1, the first value being a value different than the allocated ring node identifications, the second value being value different than the allocated ring node identifications and different than the first value.

11. The computer-readable medium having computer-executable instructions for performing the method of claim 10, with the designating of the ring node identification and deleting the ring node identification comprises:

extracting, at a traffic filter of the network asynchronous transfer mode ring unit, a generic flow control field value and a virtual path identifier field value of the receive cell, and when the generic flow control field value is the first value and the virtual path identifier field value is the second value, recognizing the receive cell as an alarm cell, and notifying fault occurrence to the controller;

storing, at the controller, the ring node identification of the controller in the cell drop register of the traffic filter of the alarm cell-receiving network asynchronous transfer mode ring unit; and

deleting, at the controller, the ring node identification of the controller out of the cell drop register of the opposite network asynchronous transfer mode ring unit to the alarm cell-receiving network asynchronous transfer mode ring unit.

12. A computer-readable medium having stored thereon a data structure comprising:

a first field containing data representing, when a network-connection node receives an alarm cell, detecting, at a network asynchronous transfer mode ring unit, that the alarm cell has been received, and extracting node information from the alarm cell;

a second field containing data representing notifying, at the network asynchronous transfer mode ring unit that detected receive of the alarm cell, to a controller about the receive of the alarm cell, and transmitting the node information extracted from the alarm cell to the controller;

a third field containing data representing deleting, at the controller, ring node identifications of nodes based on the node information included in the alarm cell of a cell drop register of the network asynchronous transfer mode ring unit in which the alarm cell is received; and

fourth field containing data representing storing, at the controller, ring node identifications of nodes based on the node information included in the alarm cell of an cell drop register of an opposite network asynchronous transfer mode ring unit of the network asynchronous transfer mode ring unit to which the alarm cell is inputted.