KR0168927B1 - Atm vpi controlling apparatus - Google Patents

Abstract

The present invention relates to an apparatus and method for managing an ATM connection manager in an ATM switch subscriber matching device. The present invention provides an apparatus and method for managing an ATM connection identifier for controlling a connection identifier table for managing the connection manager using the connection identifier table. To do this, the virtual path table 32 that stores the virtual path information; A connection identifier table 33 that stores a connection identifier; And connection identifier processing means (31) for controlling the connection identifier table (33), wherein the method applied to the apparatus comprises: a first step (61 to 64) of examining an execution command if it is in an execution state; A second step (65, 66, 73) outputting a registration command and a normal execution result if registration is performed; A third step (67 to 73) outputting a comparison command and outputting a deletion command and a normal execution result if the deletion is performed; A fourth step (74 to 83) outputting a comparison command and outputting contents of the connection identifier table state 0 and the connection identifier table state 1 if the search is performed; And a fifth step (84, 85) that outputs a result indicating that the command is wrong if the command is other than registration, deletion, and retrieval, and it does not restrict the use of VPI / VCI to the subscriber or operator. There is an effect that can be controlled.

Description

ATM connection identifier management device and method

1 is a block diagram of an ATM subscriber matching unit to which the present invention is applied.

2 is a block diagram of an ATM layer processing unit to which the present invention is applied.

3 is a block diagram of a connection identifier management unit according to the present invention.

4 is a block diagram of a connection identifier processing unit according to the present invention.

5 is an internal register structure diagram of a connection identifier table management unit according to the present invention.

6 is a flow chart in accordance with the present invention.

* Explanation of symbols for main parts of the drawings

31: connection identifier processing unit 32: virtual route table

33: connection identifier table 41: VPI / VCI extraction unit

42: cell output unit 43: VP connection information processing unit

44: connection identifier table management unit

The present invention relates to an ATM connection manager management apparatus and method thereof in an Asynchronous Transfer Mode (ATM) exchange subscriber matching device.

The subscriber matching device of the ATM switch receives the cell inputted from the subscriber and uses the virtual path identifier (VPI) and virtual channel identifier (VCI) included in the header of the subscriber cell to connect to the corresponding connection. It performs the management for, performs various maintenance management (OAM) function, and adds routing information so that the cell can be routed to the destination, and delivers the cell to the switch.

In order to perform these functions, a certain amount of data must be stored for each connection, and a connection identifier (Connetion Identification) is required to find the data.

However, the VPI / VCI defined in the cell header consists of 24 bits in the case of a subscriber-network matching device (UNI: User Network Interface), and 28 bits in the network-network matching device (NNI: Network Network Interface).

Therefore, if you use both VPI / VCI as connection identifier, you need to have 224 (16,776,216) or 228 (268,435,456) words (size that can manage all the data related to the connection) to manage connection related information. This is not practical in reality. Therefore, it is efficient and economical to limit the number of virtual connections that can be accommodated and process as much memory as necessary.

The subscriber matching device limits the number of virtual connections, stores information about each connection in memory, and finds connection identifiers that contain information about each connection from the input cell's VPI / VCI. It is necessary to perform the function of header conversion by obtaining information about each connection using the address of the memory that stores the data. The method of obtaining each connection information uses RAM and CAM (Content Address). There are two ways to use memory.

First, the method of using RAM is to limit the number of bits of VPI / VCI that a user can use, thereby limiting the available VPI / VCI. For example, if you limit the number of VPIs available to users to 32 and the number of VCIs available on each virtual path to 256, you can have an ATM cell with 213 connection-related data memories instead of 224 connection memories. have.

However, in this case, it is difficult to use because the user must limit the range of VPIs and VCIs available to the user, and the amount of VCIs available in each virtual path is limited, and the exchange provides only the virtual path connection. In this case, since the VCI is not referenced, a waste of memory also occurs. In this case, however, the use of a typical SRAM or dual port RAM has the advantage of being simple to control and relatively fast in response.

In the method using CAM, when a VPI / VCI is input to the CAM and compared with data registered in the CAM, the matched VPI / VCI is stored. This method uses a memory address as a connection identifier.

Since a CAM for use in a conventional LAN gateway can compare data of up to 64 bits, VPI / VCI 24 bits used in UNI or 28 bits used in NNI can be used without any restriction.

Therefore, there is no need to limit the range of VPI and VCI usage as in the method of using RAM, but only the total number of connections that can be provided to the user in subscriber matching device according to the capacity of CAM. The number of VCIs that can be used in an arbitrary virtual path connection is not limited, and the network manager assigning VPI and VCIs to subscribers or subscribers can be greatly provided with ease of use.

However, the conventional CAM is developed for a gateway of a LAN and, in the case of hardware control, has a disadvantage in that it is very complicated to control and the response time is slow, thereby increasing the delay time in processing a cell. .

Meanwhile, in order to support a virtual route leased line service in an ATM exchange, it is essential to obtain unique connection information only with an input VPI regardless of the VCI of an input cell. To do this, the subscriber matching device of the ATM exchanger first obtains information on the virtual connection using only the VPI, and then distinguishes whether the input VPI is the VPI for the virtual path connection or the VPI for the virtual channel connection.

When RAM is used for header translation, even though the VPI for virtual path connection and the VPI for virtual channel connection are simultaneously supported, the VCI that can be used for each VPI is fixed so that the VCI that can be used with the VPI for virtual channel connection is fixed. However, when using CAM, the VCI that can be used with the VPI for virtual channel connection is not limited because the VCI that can be used in any VPI is not fixed.

Accordingly, an object of the present invention is to provide an apparatus and method for managing an ATM connection identifier for controlling the connection identifier table to manage the connection manager using the connection identifier table.

In order to achieve the above object, the present invention provides a virtual path table that stores virtual path information; A connection identifier table storing a connection identifier; And extracting a virtual path identifier (VPI) from a cell received from an external physical layer processing means, reading virtual path connection information from the virtual path table, and reading a connection identifier from the connection identifier table. A connection identifier processing means for outputting a cell and a connection identifier to an external reception header converting means or requesting registration or deletion of a new connection identifier from an external subscriber control means to control the connection identifier table; do.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

FIG. 1 is a block diagram of a subscriber matching unit to which the present invention is applied, where 11 is a physical layer processor, 12 is an ATM layer processor, 13 is a switch interface unit, 14 is a subscriber controller, and 15 is a clock receiver.

When the physical layer processor 11 receives data from the subscriber line, the physical layer processor 11 extracts an ATM cell from the frame data and transfers the ATM cell to the ATM layer processor 12 or loads the ATM cell received from the ATM layer processor 12 into a frame. Transfer to the track.

When the ATM layer processing unit 12 receives a cell from the physical layer processing unit 11, it performs various maintenance management (OAM) functions and performs routing processing to transfer to the switch interface unit 13 or the switch interface unit 13. In order to transfer the internal cell received from the physical layer processing unit 11 performs the function of converting to an ATM cell.

The switch interface unit 13 converts the internal cell received from the ATM layer processing unit 12 into serial data and performs line coding to transfer the internal data to the switch network or to convert serial data received from the switch network into parallel data and The cell is extracted and transferred to the ATM layer processing unit 12.

The subscriber controller 14 controls the physical layer processor 11 and the ATM layer processor 12, and the clock receiver 15 receives the system clock and provides a clock to each processor.

2 is a configuration diagram of an ATM layer processing unit to which the present invention is applied, where 21 is a connection identifier management unit, 22 is a reception header conversion unit, 23 is a switch link matching unit, 24 is a transmission header conversion unit, and 25 is a physical layer matching unit, respectively. Indicates.

The connection identifier manager 21 reads the cell from the physical layer processor 11 under the control of the subscriber controller 14, extracts the connection identifier, and transfers the connection identifier together with the cell to the reception header converter 22.

The reception header converting unit 22 receives the cell and the connection identifier from the connection identifier managing unit 21, performs the header conversion using the connection information of the corresponding connection, and performs various maintenance management (OAM) functions.

The switch link matching unit 23 receives the cell whose header has been converted from the reception header conversion unit 22 and transfers the cell to the switch interface unit or transfers the cell received from the switch interface unit to the transmission header conversion unit 24. .

The transmission header conversion unit 24 performs header conversion of the transmission cell using the routing information of the cell received by the switch link matching unit 23 and transmits the header to the physical layer matching unit 25.

The physical layer matching unit 25 receives a cell whose header is converted from the transmission header converting unit 24, extracts a connection identifier, performs various maintenance management (OAM) functions, and transfers the cell to the physical layer processing unit 11. To pass.

3 is a configuration diagram of a connection identifier management unit according to the present invention, where 31 is a connection identifier processing unit, 32 is a virtual path table, and 33 is a connection identifier table.

The connection identifier processing unit 31 extracts a virtual path identifier (VPI) from the cell received from the physical layer processing unit 11, reads virtual path connection information from the virtual path table 32, and sends it to the connection identifier table 33. Reads the connection identifier from the ATM cell and outputs the connection identifier to the reception header conversion unit 22, or receives the registration, deletion, etc. of the new connection identifier from the subscriber control unit 14 to control the connection identifier table 33 accordingly. .

The virtual path table 32 is configured with dual port RAM to store virtual path information, and the connection identifier table 33 stores connection identifier information.

4 is a configuration diagram of a connection identifier processing unit according to the present invention, where 41 is a VPI / VCI extraction unit, 42 is a cell output unit, 43 is a VP connection information processing unit, and 44 is a connection identifier table management unit, respectively.

When the ATM cell is input, the VPI / VCI extracting unit 41 extracts the VPI and delivers it to the virtual path information processing unit 43, extracts the VCI, and delivers it to the connection identifier table management unit 44, and transfers the received ATM cell to the cell. Transfer to the output unit 42.

The virtual path connection information processor 43 outputs the VPI received from the VPI / VCI extractor 41 to the virtual path table 32 to determine whether the corresponding virtual path connection is a virtual path connection (VPC) or a virtual channel connection (VCC). The connection type information and the virtual path connection identifier for confirming the recognition are received and transmitted to the connection identifier table manager 25.

When the cell is input, the connection identifier table manager 44 receives the connection type information and the virtual path connection identifier from the virtual path connection information processor 43 and receives the VCI from the VPI / VCI extracting unit 41 to receive the connection identifier table. And outputs the connection identifier to the cell output unit 42. At this time, if the virtual path connection type is a virtual path connection, the VCI values are all set to 0 to search the connection manager table to find a unique connection identifier regardless of the VCI assigned by the subscriber, and in the case of the virtual channel connection, extracted from the subscriber cell. The connection identifier table 33 is retrieved using the VCI.

In addition, when the subscriber control unit 14 wants to register a new connection identifier or delete the registered identifier, the virtual register of the new connection, VCI, etc. are written to the internal register of the connection identifier table manager 44 as shown in FIG. After inputting a desired command, the terminal receives the connection identifier search of the receiving cell, processes it, and writes the result of the processing into the result portion of the register to inform the subscriber controller 14 of the result.

For example, to register a new connection, the subscriber control unit records the virtual path connection information in the virtual path connection information field of the internal register, records the VCI in the VCI field, and then writes B0000001 in the command portion. When a command is written, the execution status bit indicating the instruction status is automatically set to 1, and the hardware periodically checks this execution status bit and if it is set to 1, the corresponding data and instructions are passed to the connection identifier table 33 to make a new connection. Register the identifier and write the result as 0 in the result field to clear the execution status bit to 0 to indicate that the command was successful, indicating that the registration was successful.

After writing the command, the subscriber controller 14 continuously checks the execution status bit to check whether the requested command has been performed.

When searching for a connection identifier that is already registered, record the virtual path connection information and VCI and write B0000011 in the command field as in the case of registration. Then, the connection identifier table manager 44 executes the command in the same manner. In the case of the connection identifier, the status register of the connection identifier table 33 is read and written in the connection identifier table state 0 and the connection identifier table state 1, and a result B00000 indicating that the instruction is normally executed is written in the result field.

When the result is 0, the subscriber controller 14 may read the connection identifier table state 0 to know the connection identifier of the retrieved connection. The connection identifier is data of bits 1 to 10 of the connection identifier table state 0. If a connection is not registered when a search is requested, B00001 is entered in the result. In this case, the subscriber control unit 14 does not need to read the connection identifier table state 0. If you want to delete a registered connection, enter B0000010 in the command field. The result is the same as when searching. If you want to delete an unregistered connection, the result is B00001.

The cell output unit 42 outputs the ATM cell delivered from the VPI / VCI extraction unit 41 to the reception header converting unit 22, receives the connection identifier retrieved from the connection identifier table management unit 44, and synchronizes with the cell. B1111111111 is outputted as a connection identifier when a cell of an unregistered connection is inputted.

6 is a flow chart according to the present invention.

First, it determines whether it is in the running state (61), if it is not in the running state, waits until the next cycle (73), then determines whether it is in the running state again, and if it is in the running state, outputs the virtual path connection information (62) and outputs the virtual channel identifier. (63) examine the execution instruction (64).

When the execution command is a registration request, in order to inform the subscriber controller 14 that the registration command is properly registered in the connection identifier table 33 (65), the instruction execution result 0 of FIG. 5 is written and the execution status bit is cleared. After (66) it waits until the next cycle (73).

If the execution command is a delete request, a comparison command is output to the connection identifier table 33 (68) and a check is made to see if a connection identifier is registered (69). In the case of a registered connection, the delete command is sent to the connection identifier table 33. After output (70), 0 is written to the instruction execution result and the execution status bit is cleared (71), and then waits until the next cycle (73). When the comparison request is made for the unregistered connection, the result indicating that the requested connection is not registered is written in the command execution result and the execution status bit is cleared (72) and waited until the next cycle (73).

If the execution command is a search, the comparison command is output to the connection identifier table 33 (74) to check whether the connection identifier is registered and registered (75). Output the register read signal (76) to read the status register, write its contents to the connection identifier table state 0 of FIG. 5 (77) and output the read signal (78) to read the status register and read the connection register table to state 1 The contents are written (79) and 0 is written to the instruction execution result to clear the execution status bit (80), and then waits until the next cycle (81). When an unregistered connection is searched, a result indicating that the search request connection is not registered is written in the command execution result, and after the execution status bit is cleared (82), it waits until the next cycle (83).

In the case of other instructions, a result indicating that the instruction is invalid is written in the instruction execution result, and the execution state bit is cleared (84) and waited until the next cycle (85).

As described above, the present invention uses a dual port RAM having a size of 4096 bytes as a virtual path table and simultaneously uses a connection identifier table having a size of 1024 words when using both UNI and NNI. A total of 1024 connections can be provided to subscribers. To increase connection capacity, capacity can be increased by connecting connection identifier tables in parallel, and connection is not restricted to using VPI / VCI for subscribers or operators. There is an effect that can be controlled very conveniently.

Claims (6)

A virtual route table 32 that stores virtual route information; A connection identifier table 33 that stores a connection identifier; And extracting a virtual path identifier (VPI) from a cell received from an external physical layer processing means (11) to read virtual path connection information from the virtual path table (32), and from the connection identifier table (33). Reads the connection identifier and outputs the ATM (Asynchronous Transfer Mode) cell and the connection identifier to the external receiving header converting means 22, or receives a request for registration, deletion, etc. of a new connection identifier from the external subscriber control means 21. And a connection identifier processing means (31) for controlling the identifier table (33). 2. The apparatus of claim 1, wherein the virtual route table (32) comprises a dual port RAM. The method of claim 1, wherein the connection identifier processing means 31 receives an ATM cell from the physical layer processing means 11, extracts and outputs a virtual path identifier (VPI), and extracts a virtual channel identifier (VCI). A VPI / VCI extraction means 41 for outputting the received ATM cell and delivering the received ATM cell; Virtual path connection information processing means for outputting a virtual path identifier (VPI) received from the VPI / VCI extracting means 41 to the virtual path table 32 to receive and output connection type information and a virtual path connection identifier ( 43); The connection type table 33 receives the connection type information and the virtual path connection identifier from the virtual path connection information processing means 43 and receives a virtual channel identifier (VCI) from the VPI / VCI extracting means 41. Connection identifier table management means (44) for receiving and outputting a connection identifier as a result, and for registering a new connection identifier or deleting a registered identifier according to the control of the subscriber control means (14); And outputting the ATM cell transmitted from the VPI / VCI extracting means 41 to the receiving header converting means 22, receiving the connection identifier from the connection identifier table managing means 44, and outputting the cell identifier in synchronization with cell synchronization. And a cell output means (42). 4. The method of claim 3, wherein the connection identifier managing means 44 searches the connection identifier table 33 by resetting all virtual channel identifier (VCI) values to 0 when the virtual path connection is performed. Regardless of the virtual channel identifier (VCI) assigned by the subscriber, a unique connection identifier is searched for, and in the case of a virtual channel connection, the connection identifier table 33 is searched by using the virtual channel identifier (VCI) extracted from the subscriber cell. ATM connection identifier management device. 4. The method of claim 3, wherein the connection identifier management means 44 registers a new connection identifier or deletes a registered identifier under the control of the subscriber control means 14, wherein the connection identifier table management means 25 In the internal register of), write the virtual path connection information, virtual channel identifier (VCI), etc. of the new connection and input the desired command. After the connection identifier search of the receiving cell is completed, the processing is completed and the result of the processing is written in the register part of the register. Inserting device and transmitting the result to the subscriber control means (14). An ATM connection identifier management method applied to an ATM connection identifier management device, comprising: a first step (61 through 64) of outputting virtual path connection information, and outputting a virtual channel identifier and then examining an execution command if an execution state; A second step (65, 66, 73) of waiting for the next cycle after outputting a registration command and a normal execution result when the execution command is a registration request as a result of the investigation of the first steps (61 to 64); As a result of the investigation of the first steps (61 to 64), if the execution command is a delete request, a comparison command is output and it is checked whether a connection identifier is registered. A third step (67 to 73) of waiting until the next cycle and, if it is not registered, outputting a result indicating that the requested connection has not been registered and waiting until the next cycle; As a result of the determination of the first step (61 to 64), if the execution command is a search, a comparison command is output, and if the connection identifier is registered, and if it is a registered connection, a status register read signal is output by outputting a connection identifier table. Outputs the contents of status 0, reads the status register again, outputs the contents of the connection identifier table status 1, waits until the next cycle after outputting normal results, and if it is not registered, the connection requesting the search was not registered. A fourth step 74 to 83 outputting a notification result and waiting for the next period; And fifth steps 84 and 85 for outputting a result of notifying that the command is incorrect and waiting for the next cycle when the search results of the first steps 61 to 64 are commands other than registration, deletion, and search. ATM connection identifier management method characterized in that.