ATM switching system for multicast data communication

• US 6,301,255 B1
• Filed: 12/22/1997
• Issued: 10/09/2001
• Est. Priority Date: 12/21/1996
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Seong-Yong
• Primary Examiner(s): YAO, KWANG BIN
• Application Number:
  US08/995,995
• Time in Patent Office: 1,387 Days
• Field of Search: 370/389, 370/390, 370/392, 370/395, 370/396, 370/397, 370/398, 370/399, 370/409, 370/412, 370/417, 370/418, 370/428, 370/429, 370/432, 370/474
• US Class Current: 370/399
• CPC Class Codes: H04L 2012/5642 Multicast/broadcast/point-multipoint, e.g. VOD
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

An asynchronous transfer mode (ATM) switching system includes a cell switching assembly having at least one switch port for transferring an ATM cell, and a subscriber board having a plurality of subscriber ports. A cell processing apparatus for use in the ATM switching system includes a look-up memory for storing control information for determining whether to copy an ATM cell from the switch port, and a cell copy controller for copying the ATM cell from the switch port and transferring ATM cells copied to the subscriber ports according to the control information stored in the look-up memory. If the ATM cell is a point-to-point communication cell, the ATM switching system translates the header included in the cell according to control information and transfers the ATM cell having the translated header to at least one of the subscriber ports. However, if the ATM cell is a point-to-point communication cell, the ATM switching system selects the subscriber ports based on the translated header and transfers the cell of which header is separated to the selected subscriber ports.

Claims

1. An asynchronous transfer mode switching system for point-to-point and point-to-multipoint communications, said systems, comprising:

a cell switching assembly having at least one switch port where a plurality of fixed-size cells are inputted, each of said cells including a header having a check bit identifying whether the cell is a point-to-point cell or else is a point-to-multipoint cell;

a subscriber board having a plurality of subscriber ports; and

a cell processing apparatus installed in said subscriber board, said cell processing apparatus comprising;

means for determining whether a communication cell corresponds to a one of the point-to-point cell and the point-to-multipoint cell;

means for copying a communication cell from said switch port;

means for transferring the communication cell copied to corresponding subscriber ports connected to said subscriber board when the communication cell from said switch port corresponds to a point-to-multipoint cell; and

means for demultiplexing the communication cell from said switch port and transferring the demultiplexed cell to a corresponding one of said subscriber ports when the communication cell from said switch port corresponds to a point-to-point cell;

said cell processing apparatus further comprising a cell copy controller comprising a look-up memory for storing control information for determining whether to copy the communication cell from said switch port and a cell copy controller for copying the communication cell from said switch port and transferring the communication cell copied to the subscriber ports according to said control information stored in the look-up memory, said cell controller further comprising;

a means for translating the header of the communication cell based on the control information stored in the look-up memory;

a means for transferring the communication cell having the translated header to at least one of the subscriber ports according to said control information;

a means for separating the translated header and a remaining payload; and

a means for transferring the separated header and payload to a corresponding one of said subscriber ports when transferring the communication cell having the translated header.

2. The asynchronous transfer mode switching system of claim 1, further comprising a plurality of subscriber output buffers corresponding to the respective subscriber ports.

3. The asynchronous transfer mode switching system of claim 2, wherein said cell copy controller further comprises:

a means for generating write signals for a corresponding one of said subscriber ports to temporarily store in corresponding subscriber output buffers those cells not transferred to a one of said subscriber ports; and

a means for thereafter transferring not-transferred cells to the subscriber ports when transferring the separated header and remaining cells to the subscriber ports.

4. A cell processing apparatus of an asynchronous transfer mode (ATM) switching system including a cell switching assembly having at least one switch port for transferring an ATM cell, and a subscriber board having a plurality of subscriber ports, comprising:

installed in said subscriber board, a look-up memory for storing control information for determining whether to cope an incoming communication cell from said switch port; and

installed in said subscriber board, a cell copy controller comprising;

a means for copying the communication cell from said switch port and transferring communication cells copied to the subscriber ports according to said control information stored in the look-up memory;

a means for translating a header of the communication cell based on the control information stored in the look-up memory, and a means for transferring the communication cell having the translated header to at least one of the subscriber ports according to said control information; and

a means for separating the translated header and a remaining payload and transferring the separated header and payload to a corresponding one of said subscriber ports when transferring the communication cell having the translated header.

5. The cell processing apparatus of claim 4, further comprising a plurality of subscriber output buffers corresponding to the respective subscriber ports.

6. The cell processing apparatus of claim 5, wherein said cell copy controller further comprises a means for generating write signals for a corresponding one of said subscriber ports to temporarily store in corresponding subscriber output buffers cells not transferred to the subscriber ports and means for thereafter transferring to the subscriber ports the cells not transferred to the subscriber ports.

7. A cell processing method, comprising the steps of:

(1) determining for an asynchronous transfer mode (ATM) switching system including a cell switching assembly having at least one switch port for transferring an ATM cell, the cell including a header having a check bit identifying whether the cell is a point-to-point cell or else is a point-to-multipoint cell, and a subscriber board having a plurality of subscriber ports, whether an incoming communication cell from said switch port corresponds to a one of a point-to-point cell and a point-to-multipoint cell;

(2) when the communication cell corresponds to a point-to-multipoint cell, translating a header included in the communication cell according to a control datum;

(3) selecting a subscriber port based on the header translation of the immediately preceding step;

(4) transferring the communication cell to the subscriber port selected in the immediately preceding step;

(5) demultiplexing the communication cell to transfer the demultiplexed cell to a predetermined one of said subscriber ports, when the communication cell corresponds to the point-to-point cell; and

(6) copying the communication cell to transfer communication cells copied to at least one of said subscriber ports, when the communication cell corresponds to the point-to-multipoint cell.