JP2000224186A - Oam processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an OAM processing system that, with an easy circuit, which reduces the throughput of a CLAD processing by OAM processing in an ATM transmitter can be avoided. SOLUTION: An OAM cell insertion/extraction processing section 30 is provided in the middle of a UTOPIA interface section, that is used for connection between an SAR processing section 20 and a PHY layer processing section 40. Furthermore, in addition to a system control processing processor section 10, an OAM control processing processor section 40 that exclusively conducts OAM control processing is provided. Thus, the load of the control processing relating to the OAM by the system control processing processor section 10 is relieved, so as to enhance the processing capability of the CLAD processing for reducing the reduction in the throughput.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an OAM processing method, particularly, an ATM layer and a physical (PHY) in an ATM transmission apparatus.
UTOPIA (Universal Test) used when connecting the internal configuration circuits constituting the layers
and Operations LayerInter
OAM (Operation, Adminis) configured using a face for ATM (Interface for ATM) interface
(Translation and Maintainance).

[0002]

2. Description of the Related Art LAN (Local Area Net)
VBR (Var) such as work data and packet data
ATM (i.e., Bit Rate) data
(Asynchronous Transfer Mo
de: Asynchronous transfer mode) There is a case where it is desired to make a cell and transmit it to a remote place. In this case, AAL5 (ATM Ad) is used as a cell assembly / disassembly protocol for performing ATM cell conversion.
CLAD (Cell Assembly and Di) using an application Layer Type 5)
(assembly) processing is performed to realize data transmission.

FIG. 8 is a block diagram showing a conventional example of an apparatus for performing this CLAD processing. This apparatus includes a system control processing processor unit 10 and a SAR (Segmentation).
and Reassembly Sublayer)
It has a processing unit 20 and a PHY layer processing unit 40. PH
The Y-layer processing unit 40 performs the cell synchronization processing of the ATM cell by continuously starting the physical interface with the transmission line 60.

The SAR processing section 20 performs processing for disassembling and assembling LAN data and packet data into ATM cells. A general-purpose processor bus 11 is connected between the system control processing processor unit 10 and the SAR processing unit 20. The PHY layer monitoring control bus 13 is connected between the system control processing processor unit 10 and the PHY layer processing unit 40. In addition, general interfaces connected between the PHY layer processing unit 40 and the SAR processing unit 20 are UTOPIA interfaces 21 and 22.

[0005] The system control processing processor unit 10 controls the entire apparatus. Here, the protocol termination of the LAN data and the packet data is performed, and the control for transferring the data for performing the remote communication via the transmission path 60 to the SAR processing unit 20 is also performed. The main control of the ATM cell assembly / disassembly by the SAR processing unit 20 is also performed by the system control processing processor unit 10. System control processor 1
0 and the SAR processing unit 20 perform data transfer and control command transfer via the general-purpose processor bus 11. In addition, the system control processing processor unit 10 monitors a failure of the transmission path 60 detected by the PHY layer processing unit 40 via the PHY layer monitoring control bus 13.

[0008] In the case of the conventional apparatus shown in FIG. 8, the processing of the OAM cells necessary for constructing the ATM network is all performed under the control of the system processing processor 10 in the SAR processing, similarly to the ordinary data transmission / reception processing. This is performed via the unit 20.

[0007]

However, in the above-mentioned prior art, there is a problem that the throughput of the CLAD processing is reduced. The reason is that the ATM layer OAM
This is because the processing is performed by the system control processing processor unit via the SAR processing unit. In addition, the fact that the system control processor directly monitors and controls the PHY layer processor is one of the factors that lower the throughput.

Accordingly, it is an object of the present invention to provide an OAM processing method that improves the throughput of CLAD processing.

Another object of the present invention is to provide a transmission apparatus for processing ATM cells, not only for CLAD processing,
An object of the present invention is to provide an OAM processing method that enables an OAM cell to be processed without causing a large change in an existing ATM cell data processing circuit in a configuration in which an M layer and a PHY layer are connected by a UTOPIA interface. .

[0010]

In order to solve the above-mentioned problems, the OAM processing system according to the present invention employs the following characteristic configuration.

(1) System control processing processor section, S
In an OAM processing method having an AR processing unit and a physical layer processing unit and performing a CLAD process in ATM transmission, it is determined whether or not a received cell is an OAM cell from header information of an ATM cell received from the physical layer processing unit, An OAM processing method for sending to the SAR processing unit only when the cell is not an OAM cell.

(2) When the received cell received from the physical layer processing unit is an OAM cell, the OAM cell is
The OAM processing method according to (1), wherein the OAM processing is performed by an OAM control processor separate from the AR processing.

(3) An OAM interface unit for interconnecting the SAR processing unit and the physical layer processing unit has an OAM
An OAM cell insertion / extraction processing unit for performing cell insertion and extraction is provided, and an OAM control processing processor for controlling the processing unit is provided separately from the system control processing processor.
OAM processing method for processing M cells.

(4) The OAM processing method according to (4), wherein the OAM cell insertion / extraction processing unit includes a reception operation control unit and a transmission operation control unit.

(5) The OAM processing method according to (4), wherein the OAM cell insertion / extraction processing unit has a FIFO memory for temporarily buffering cells from the reception operation control unit and the transmission operation control unit, respectively.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the OAM processing system according to the present invention will be described in detail with reference to FIGS.

FIG. 1 is a block diagram of a system for implementing the OAM processing method of the present invention. This system includes a system control processor 10, an SAR processor 20, an OAM cell insertion / extraction unit 30, a PHY layer processor 40, an OAM control processor 50, and a transmission line 6.
0. Note that the system of FIG. 1 uses many components similar to those of the conventional device of FIG. 6, and therefore, the same reference numerals are used for the same components for convenience.

The system control processing processor unit 10 is connected to the SAR processing unit 20 via a general-purpose processor bus 11 (for example, a PCI bus).
Is controlled. Further, the system control processing processor unit 10 also performs overall control of the CLAD device,
It also performs protocol termination of various VBR data such as LAN data from a terminal connected to the LAD device via a LAN and packet data from a packet terminal connected via a serial interface.

The SAR processing unit 20 extracts data such as packets to be transmitted under the control of the system control processing unit 10 from the internal memory of the system control processor unit 10, performs cell processing, divides the ATM cells, and divides the ATM cells into ATM cells.
Through the OPIA interface 21, the packet is sent to the OAM cell insertion / extraction processing unit 30. It also performs decellularization processing of the ATM cells received from the OAM cell insertion / extraction processing unit 30 via the receiving UTOPIA interface 22, assembles them into data such as packets, and transfers the data to the internal memory of the system control processing processor unit 10.

The PHY layer processing unit 40 has a physical interface of the transmission line 60, and performs a PHY (physical) layer termination process. Further, the OAM cell insertion / extraction processing unit 30 is transmitted via the transmission side UTOPIA interface 31.
An ATM cell header of the transmitted ATM cell is transmitted to the transmission path after performing HEC (Header Error Control) addition processing. Further, it detects the HEC from the signal input from the transmission line 60, performs cell synchronization processing of the ATM cell, and sends out the ATM cell to the OAM cell insertion / extraction processing unit 30 as the ATM cell received via the receiving UTOPIA interface 32.

The OAM cell insertion / extraction processing unit 30
SAR is controlled by the M control processor 50.
OAM between transmission cells transmitted by the processing unit 20
Perform processing to insert cells. Further, it is determined from the header information of the ATM cell received from the PHY layer processing unit 40 whether or not the received cell is an OAM cell.
The data is transferred to the M control processing processor unit 50, and is sent to the SAR processing unit 20 if it is not an OAM cell.

The OAM control processor unit 50
It controls the AM cell insertion / extraction processing unit 30. In addition, generation of transmission OAM cells, determination of contents of reception OAM cells, and OA
Various timer processes for transmitting and receiving M cells are also performed. And PHY
The failure of the transmission path 60 detected by the layer processing unit is also monitored. The OAM control processor unit 50 includes a processor therein, and is connected to the OAM insertion / extraction processor 30 and the PHY layer processor 40 via an I / O bus 51 of the processor.

Next, FIG. 2 shows the OA of the system shown in FIG.
FIG. 3 is a detailed block diagram illustrating an example of the internal configuration of an M insertion / extraction processing unit 30. The OAM insertion / extraction processing unit 30 extracts an OAM cell from the ATM cell received from the transmission side and the transmission side into which the OAM cell is inserted with respect to the flow of the ATM cell transmitted from the SAR processing unit 20 to the transmission path 60. Divided into receiving side.

The transmitting side includes a transmitting operation control unit 301 for controlling the transmitting side operation, a FIFO (first in first out) memory 304 in which the OAM control processor unit 50 sets data of the transmitting OAM cell, and a UTOPIA interface when the OAM cell is inserted. S that generates the SOC signal
It comprises an OC generation unit 305 and a selector 306 for selecting which of an ATM cell and an OAM cell from the SAR processing unit 20 is to be transmitted to the PHY layer processing unit 40.

The receiving side includes a receiving operation control section 302 for controlling the operation of the receiving side and an O when the receiving cell is an OAM cell.
And a FIFO memory 307 for temporarily buffering the data before delivering it to the AM control processor unit 50. Further, CP which is an interface between both the transmitting side and the receiving side and the OAM control processing processor unit 50
A U interface 303 is also provided.

Next, the operation of the embodiment of the present invention will be described.
This will be described with reference to FIGS. The configuration example of the embodiment of the present invention is configured by the block diagram as shown in FIG. 1 as described above. OAM cell insertion / extraction processing unit 3
0 and the OAM control processor section 50 are greatly different from those of the prior art, so that the operation will be described focusing on this section.

FIG. 2 is a detailed block diagram showing an example of the internal configuration of the OAM cell insertion / extraction processing unit 30 as described above. The OAM cell insertion / extraction processing unit 30 operates based on control from the OAM control processing processor unit 50 for both processing on the transmission side and processing on the reception side.

First, the operation on the transmitting side will be described in detail by taking an alarm transfer OAM process as an example. The OAM control processor unit 50 monitors the I / O register prepared in the PHY layer processing unit 40 via the processor I / O bus 51 to monitor the failure of the transmission path 60 of the physical layer. . As will be described later, OAM cell insertion and
When the OAM cell reception is notified from the receiving side of the extraction unit 30, the OAM cell data is extracted, the content thereof is determined, and
The presence or absence of an alarm in the TM layer is constantly monitored.

When the transmitting side detects that it is necessary to send an OAM cell for alarm transfer by the continuous monitoring, the O
OAM for transmission inside AM cell insertion / extraction section 30
OAM cell data to be transmitted is set to a FIFO memory 304 that temporarily buffers cell data. The data set at this time is set including the OAM cell header information. As a setting procedure, a procedure may be used in which I / O writing is performed 53 times sequentially from the first byte of the header information of the OAM cell to the 48th byte of the payload information.

The data of the OAM cell to be transmitted is stored in the FIFO
After the setting in the memory 304, an OAM cell transmission request is subsequently made to the transmission operation control unit 301 of the OAM cell insertion / extraction unit 30. The OAM cell transmission request may be prepared by preparing a transmission request I / O register in the transmission operation control unit 301 and performing I / O writing on the I / O register. After making an OAM cell transmission request, the transmission operation control unit 3
01 and detects the end of OAM cell transmission.

The transmission end is detected by the transmission operation control unit 30.
1 prepares an I / O register,
The process may be a process of continuously detecting the / O read, or a process of generating an interrupt from the transmission operation control unit 301 and notifying the OAM control processor unit 50 of it. Next, when the end of the OAM cell transmission is detected, the transmission timer is started. This transmission timer is a timer for determining an interval for transmitting the OAM cell. In the alarm transfer by the OAM cell, the OAM cell is generally transmitted at an interval of about one cell per second. After activating the transmission timer, it continues to monitor whether or not the transmission condition of the OAM cell continues.

If the transmission timer times out while the OAM cell transmission condition is continuously detected, the OAM
FIFO memory 30 inside cell insertion / extraction unit 30
4, the process returns to the process of setting the data of the OAM cell to be transmitted, and the OAM cell transmission process is repeated. If the OAM cell transmission condition disappears during the repetition of the process, the transmission timer is stopped and reset, and the process returns to the process of detecting the OAM cell transmission condition. The above is the basic operation of the OAM cell transmission process in the OAM control processor 50, and FIG. 3 is a flowchart showing the basic operation.

Similarly, the operation of the transmission operation control section 301 inside the OAM cell insertion / extraction processing section 30 will be described. The transmission operation control unit 301 operates in an idle state when there is no OAM cell transmission request from the OAM control processor unit 50. This idle state is defined as S
The AR processing unit 20 and the PHY layer processing unit 40
This is the same state as directly connected by the A interface.

The selector 306 inside the OAM cell insertion / extraction processing unit 30 is controlled by the transmission operation control unit 301 so as to output the A-side input, and the input SAR TxD 211 and the SAR TxSOC transmitted from the SAR processing unit 20 are output.
212 sends PHY T to the PHY layer processing unit 40 as it is.
It is output as xD311 and PHY TxSOC312. Similarly, the control signal SAR Tx_Clav 213 defined on the UTOPIA interface is P
HY Tx_Clav313 becomes PHY TxEN3
14 becomes SAR Tx_EN214. When an OAM cell transmission request is issued from the OAM control processor unit 50 to the transmission operation control unit 301, the transmission operation control unit 301 determines whether the SAR processing unit 20 is transmitting an ATM cell.

This determination is made in SAR Tx_Clav 21
3 and the state of PHY Tx_EN 314. SA
When the R processing unit 20 is transmitting an ATM cell,
It waits until the transmitting ATM cell is completed. When the transmission is completed, the SAR Tx_EN214 signal
It causes the AR processing unit 20 to temporarily stop the ATM cell transmission. The OA from the OAM control processor 50
When there is an M cell transmission request, the SAR
If no cell is being transmitted, immediately SARTx_
ATM signal to SAR processing unit 20 by EN214 signal
Pause cell transmission.

Subsequently, the data of the transmission OAM cell is OAM
FIF set by control processing processor unit 50
A read signal is sent to the O memory 304. At the same time, a request signal for starting the SOC signal generation is sent to the SOC generation unit 305, and at the same time, control is performed so that the selector 306 selects the B-side input. Of course PHY
PHYTx_Clav 313 which is a UTOPIA interface control signal between the layer processing unit 40 and PHY
The control of Tx_EN 314 is also considered.

The OAM to the PHY layer processing unit 40
It counts until 53 bytes of cell transmission are transmitted. O
When the transmission of the AM cell is completed, the transmission of the OAM cell is notified to the OAM control processor 50, and the reading of the FIFO memory 304 is stopped, and the selection of the A-side input to the selector 306 is also controlled. This completes the OAM cell transmission control for one cell, and the transmission operation control unit 301 returns to the idle state. This is OAM
Transmission operation control unit 30 inside cell insertion / extraction processing unit 30
FIG. 4 is a flowchart showing the basic operation of the OAM cell transmission process of FIG.

Next, the operation of the receiving side will be described in detail with an example of an alarm transfer OAM process. The OAM control processor 50 constantly monitors whether there is an OAM cell reception notification from the OAM cell insertion / extraction processor 30. This monitoring method can be performed by preparing an I / O register in the reception operation control unit 302 inside the OAM cell insertion / extraction processing unit 30 and periodically detecting the I / O read until the OAM reception is seen. Good, reception operation control unit 30
Alternatively, a processing method of generating an interrupt and notifying the OAM control processor unit 50 of the notification may be used.

If OAM cell reception is detected,
The received OAM inside the cell insertion / extraction processing unit 30
The data of the received OAM cell is read from the FIFO memory 307 in which the cell is temporarily buffered.
This reading may be a process of continuously reading the I / O register 53 times by I / O reading. Subsequently, the OAM cell insertion / extraction processor 30 is notified of the completion of the OAM cell data extraction.

The notification of the completion of the extraction is sent to the reception operation control unit 302 inside the OAM cell insertion / extraction processing unit 30 by the I / O.
An O register may be prepared, and an I / O write may be performed on the O register. Subsequently, the contents of the read OAM cell data are determined. Further, it is confirmed whether or not the reception timer is operating, and if not, the reception timer is started. This reception timer is a timer for monitoring the recovery of the transmission line alarm in the ATM layer by the OAM cell. Generally, when the OAM cell for the alarm transfer is not received for about 3 seconds, the failure is recovered.

Following the process of starting the timer, whether or not the OAM cell requiring the alarm transfer processing in the ATM layer is received based on the content of the data of the received OAM cell determined earlier,
Also, it is determined whether the alarm transfer in the ATM layer is unnecessary. If necessary, it notifies the sender alarm forwarding process. Subsequently, the upper system control processor 10 is notified that a failure in the ATM layer has been detected. This notification is performed using the interface bus 12 between the processors provided between the system control processor unit 10 and the OAM control processor unit 50.

After the above processing, the process returns to the OAM cell reception notification monitoring process. If there is no OAM cell reception notification, it is further determined whether the reception timer is operating,
If it is not in operation, the monitoring of the OAM cell reception notification is continued, and if the reception timer is in operation, the timeout of the reception timer is further monitored. When the timeout of the reception timer is detected, it is determined that the failure of the ATM layer has been recovered, and the upper system control processing processor 10
It notifies that the failure in the TM layer has been recovered. Up to this point, the basic operation of the OAM cell receiving process in the OAM control processor 50 has been described, and FIG. 5 is a flowchart showing this.

Similarly, the operation of the receiving operation control section 302 inside the OAM cell insertion / extraction processing section 30 will be described. When there is no ATM cell reception request from the PHY layer processing unit 40, the reception operation control unit 302 operates in the idle state. This idle state is a state in which no processing is performed. PHY layer processing unit 40
From the ATM cell reception request is a control signal PHY Rx_Clav defined on the UTOPIA interface.
323.

When an ATM cell reception request is detected from the PHY layer processing unit 40, PHY Rx_EN 324 is transmitted to extract one cell of data. It is determined whether the received ATM cell data for one cell is an OAM cell or not based on the header part of the extracted one cell. If the received OAM cell is an OAM cell, the data of the received OAM cell is written to the FIFO memory 307 that temporarily buffers the received OAM cell until the received OAM cell is delivered to the OAM control processor unit 50.

Next, the OAM control processor 50 is notified of the OAM cell reception. After the notification, the OAM control processor 50 extracts the data of the OAM cell, waits for the notification of the completion of the extraction, returns to the idle state, and returns the ATM from the PHY layer processor 40 again.
Monitor cell reception requests. If the received ATM cell is other than the OAM cell based on the header discrimination, a process of transferring the received ATM cell to the SAR processing unit 40 is performed. SAR for the SAR processing unit 40
Rx_Clav 223 is transmitted to notify the reception of the ATM cell.

Thereafter, the SAR from the SAR processing unit 40
The SAR processing unit 40 knows from the Rx_EN 224 whether the ATM cell can be extracted. When the extraction becomes possible, the SAR processing unit 40 outputs the received ATM cell data to the SAR processing unit 40, returns to the idle state, and returns to the PHY layer processing unit 40 again. Monitor the ATM cell reception request from The above is the basic operation of the OAM cell reception process of the reception operation control unit 302 inside the OAM cell insertion / extraction processing unit 30, and FIG. 6 is a flowchart showing this operation.

FIG. 7 shows an example of a network configuration in which a CLAD device configured using the OAM cell processing method utilizing the UTOPIA interface of the present invention is applied to an ATM network.

In the above-described embodiment, the FIFO inside the OAM cell insertion / extraction processing unit shown in FIG.
Instead of fixing the capacity of the memories 304 and 306 to 8 bits × 53, the capacity of the memory is increased to 8 bits × 53 × N (N is an integer of 1 or more), and a process of transmitting N OAM cells is performed by OA.
In a case where the transmission can be performed by a single transmission request from the M control processor unit 50, it is possible to deliver N OAM cells to the OAM control processor unit 50 by one OAM cell reception notification. Extended to

The embodiment of the OAM processing system of the present invention has been described in detail. However, the present invention should not be limited to only such examples, and those skilled in the art can easily understand that various modifications can be made without departing from the gist of the present invention.

[0050]

As described above, the OAM processing method of the present invention separates a specific processing called OAM cell processing from a processing block for performing ATM cell conversion and decell processing and a block for controlling the block. The processing which affects the ATM cellized decellularization processing is processed by another block, so that the load on the ATM cellized decellularization processing can be reduced. Therefore, it is possible to improve the throughput of the processing for converting the transmission data into ATM cells.

A general interface for connecting the ATM layer block and the PHY layer block is as follows.
Utopia interface
By adding a circuit mainly to the A interface part, it is possible to provide a method of processing an OAM cell without making a large circuit change to an existing ATM layer block or PHY layer block. OAM cell processing can be relatively easily added to the device.

[Brief description of the drawings]

FIG. 1 is a block diagram of a preferred embodiment of an OAM processing method according to the present invention.

FIG. 2 is a detailed block diagram of an OAM cell insertion / extraction processing unit in FIG. 1;

FIG. 3 is a flowchart of a transmission operation of the OAM processing method in FIG.

FIG. 4 is a flowchart of a transmission operation of the OAM processing method in FIG. 1;

FIG. 5 is a flowchart of a receiving operation of the OAM processing method in FIG. 1;

FIG. 6 is a flowchart of a receiving operation of the OAM processing method in FIG. 1;

FIG. 7 is a CLA using the OAM processing method according to the present invention;
This is an application example of the D device to an ATM network.

FIG. 8 is a block diagram of an apparatus that performs a conventional CLAD process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 System control processing processor unit 20 SAR processing unit 21, 22, 31, 32 UTOPIA interface 30 OAM cell insertion / extraction processing unit 40 Physical (PHY) layer processing unit 50 OAM control processing processor unit 301 Transmission operation control unit 302 Reception operation control Unit 304, 307 FIFO memory

Claims (5)

[Claims] 1. An OAM processing system having a system control processing processor unit, an SAR processing unit, and a physical layer processing unit, and performing a CLAD process in ATM transmission, receiving from an ATM cell header information received from the physical layer processing unit. An OAM processing method characterized in that it is determined whether or not a cell is an OAM cell, and the cell is transmitted to the SAR processing unit only when the cell is not an OAM cell. 2. The method according to claim 1, wherein when the received cell received from the physical layer processing unit is an OAM cell, the OAM cell is processed by an OAM control processing processor separate from the SAR processing unit. OAM processing method described in 1. 3. An OAM control section for providing an OAM cell insertion section and an OAM cell insertion / extraction section for performing extraction of an OAM cell in a UTOPIA interface section for interconnecting a SAR processing section and a physical layer processing section, and controlling the processing section. An OAM processing method wherein a processor section is provided separately from the system control processing processor section to process OAM cells. 4. The OAM processing method according to claim 4, wherein said OAM cell insertion / extraction processing unit includes a reception operation control unit and a transmission operation control unit. 5. The OAM according to claim 4, wherein the OAM cell insertion / extraction processing unit has a FIFO memory for temporarily buffering cells from the reception operation control unit and the transmission operation control unit, respectively. Processing method.