KR100232496B1 - User network interfacing apparatus of atm - Google Patents

Abstract

The present invention relates to a user network interface device in an asynchronous transmission mode for interfacing between an ATM terminal through a plurality of ports (25.6 Mbps ATM Network Interface Card (NIC)) and an ATM switch switching at 155 Mbps. The multiplexed ATM cells are multiplexed according to the transmission speed of the ATM switch. At this time, all of the signaling cells' VPI / VCI enter Φ 15 at signaling time. A multiplexer for multiplexing cells and applying them to an ATM switch after inserting an identifier of a port to be transmitted in an ATM cell to identify these ports when these cells are multiplexed is unknown to which port; A demultiplexer for demultiplexing ATM cells applied from an ATM switch and applying them to the plurality of ports, retransmitting the corresponding ATM cell to its original value to a port corresponding to an identifier inserted into the ATM cell; A switch interface is provided to interface between the multiplexer, the demultiplexer, and the ATM switch.

Description

User Network Interface Device in Asynchronous Transfer Mode

The present invention relates to an asynchronous transfer mode (ATM), and more particularly, to an apparatus capable of distinguishing ports of a user network interface for interfacing between a terminal and an ATM switch.

In ATM, there is a user network interface that interfaces between a terminal and an ATM switch. The user network interface interfaces between terminals with different transmission speeds and ATM switches. For example, if 25.6 Mbps terminals are connected to the ports of the user network interface, and one ATM switch has a speed of 155 Mbps, the user network interface multiplexes the ATM cells of these ports and delivers them to the ATM switch at 155 Mbps. do. Similarly, the user network interface de-multiplexes ATM cells delivered at 155Mbps from the ATM switch to 25Mbps, allowing ATM cells to be transmitted to terminals connected to each port.

On the other hand, in the structure of the user network interface, it is necessary to accurately transmit the ATM cells applied from the ATM switch to the corresponding terminal. The user network interface indicates the terminal location where the ATM cells are transmitted, that is, the corresponding port of the user network interface. It is necessary to send ATM cells to the corresponding port in response to this indication. In call set up, the control module controlling the ATM system determines using a signaling cell. Since the VPI / VCI of these signaling cells is fixed at Φ 15, an appointment is needed to distinguish them. Since they exist in a system, you can make an appointment in advance and proceed accordingly. The information that distinguishes these can be transmitted and received to the desired terminal using 3, 4, 5 bits of the VPI.

However, in the conventional user network interface, a method for indicating a port of a user network interface to which an ATM cell transmitted through the user network interface is to be transmitted has not been proposed.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and an object of the present invention is to indicate a transport port in an ATM cell multiplexed within a user network interface and to transmit ATM cells to a port corresponding to the indicated transport port in the ATM cell. It is to provide a user network interface device of ATM.

1 is a block diagram of a user network interface device in an asynchronous transmission mode according to the present invention.

2 is a diagram illustrating an embodiment of inserting a port identifier in a user network interface device of the asynchronous transmission mode according to the present invention;

3 illustrates a cell state in an asynchronous transmission mode.

4 is a schematic block diagram of an apparatus for decoding a port identifier in a user network interface device in an asynchronous transmission mode according to the present invention;

<Description of the symbols for the main parts of the drawings>

10: ATM switch 20, 30: user network interface device

20-1, 30-1: Multiplexer 20-2, 30-2: Demultiplexer

20-3, 30-3: switch interface

The present invention for achieving this object is a user network interface device of the asynchronous transmission mode having a plurality of ports, and interfaces between the ATM terminal and the ATM switch through a plurality of ports, the ATM cells applied from a plurality of ports A multiplexer multiplexed according to the transmission speed of the ATM switch and inserting an identifier of a port to be transmitted in the ATM cell; A demultiplexer for demultiplexing ATM cells applied from an ATM switch to the plurality of ports, and transmitting the corresponding ATM cell to a port corresponding to an identifier inserted into the ATM cell; A switch interface is provided to interface between the multiplexer, the demultiplexer, and the ATM switch.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a user network interface device of an ATM according to the present invention. As illustrated, user network interfaces 20 and 30 are connected to one ATM switch 10, respectively.

As illustrated, a plurality of ports P10-P13 and P00-P03 are connected to the user network interfaces 20 and 30, and ports P10-P13 and P00-P03 have a predetermined transmission rate. The terminals are connected. In the present embodiment, as described above, the ATM switch 10 has a speed of 155 Mbps and the ATM cells input and output to the ports P10-P13 and P01-P03 have a speed of 25.6 Mbps.

In this case, the user network interfaces 20 and 30 are each of the multiplexers 20-1 and 30-1, the demultiplexers 20-2 and 30-2, and the switch interfaces 20-3 and 30-3, respectively. Each of the ports P10-P13 and P00-P03 connected to the multiplexers 20-1 and 30-1 is assigned an identifier (ID).

In this configuration, the multiplexers 20-1 and 30-1 multiplex the 25.6 Mbps ATM cells applied from the ports P10-P14 and P00-P04 and then switch the switch interfaces 20-3 and 30-3. These ATM cells are applied to the ATM switch 10 by way of example. At this time, the multiplexers 20-1 and 30-1 insert and output the respective ports P10-P13 and P00-P03 IDs in the VPI of the cell header of the ATM as shown in FIG. That is, the ATM cell has a structure as shown in FIG. 3, and the VPI is used to indicate the routine path of the cell. Here, the ports P10 to P13 to transmit the ATM cell in this VPI, (P00). -P03) is inserted. In order to insert the port's ID into the VPI, this ID insertion operation must be synchronized with the ATM cells. It is well known to those skilled in the art that such synchronization is possible by inserting a port ID into a VPI at a desired position by synchronizing with a Start Of Cell (SOC) signal, for example, in the cell mode of the UTOPIA interface. Sleeping will be easy to see.

ATM cells inserted with the IDs of the ports P10-P13 and P00-P03 by the above-described process are connected to the demultiplexers 20-3 and 30-3 of the user network interfaces 20 and 30 through the switch 10. Is approved.

The demultiplexers 20-3 and 30-3 transmit 155Mbps ATM cells to each port P10-P13 and P01-P03 by demultiplexing the ATM cells from the switch 10 at 25.6Mbps. At this time, the port ID is inserted into the VPI in the header of the ATM cell, and the demultiplexers 20-3 and 30-3 decode the port ID to decode the ATM cells to the corresponding ports P10-P13 and P00-P03. That is, it is possible to transmit to the ports (P10-P13), (P00-P03) corresponding to the port ID.

Here, the entire information in the VPI is required to retrieve the port ID present in the VPI in the ATM cell. However, as shown in FIG. 3, the VPI is located at different byte positions in the cell. 4, the latch 40 may be configured in the demultiplexers 20-3 and 30-3.

That is, since the VPI of the first byte in the ATM cell is latched by the latch 40 and then decoded as the decoder 50 together with the VPI of the next byte, the VPI in the ATM cell can be decoded simultaneously.

As described above, in the present invention, an ATM cell can be transmitted by designating a port to be transmitted among a plurality of ports of the user network interface in ATM cell transmission through the user network interface.

Claims (3)

A user network interface device having an asynchronous transmission mode having a plurality of ports and interfacing between an ATM terminal and an ATM switch through a plurality of ports, A multiplexer for multiplexing ATM cells applied from the plurality of ports corresponding to the transmission speed of the ATM switch, and inserting an identifier of a port to be transmitted in the ATM cell; A demultiplexer for demultiplexing ATM cells applied from the ATM switch and applying them to the plurality of ports, and transmitting the corresponding ATM cell to a port corresponding to an identifier inserted into the ATM cell; User network interface device of the asynchronous transmission mode having a switch interface for interfacing between the multiplexer, demultiplexer and the ATM switch The method of claim 1, And the port identifier is inserted into a VPI in an ATM cell header. The method of claim 2, The demultiplexer, A latch for latching a VPI of the first byte in the ATM cell; And a decoder (50) for decoding the VPI of the next byte and the byte latched in the latch.

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