JP3216612B2 - ATM communication device and cell disassembly method for ATM communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM communication apparatus, and more particularly, to an ATM communication apparatus and a cell disassembly method for an ATM communication apparatus, which reduce a delay associated with cell disassembly when receiving an ATM cell.

[0002]

2. Description of the Related Art Historically, communication networks were initially constructed as voice-based networks mainly for telephone communication, but thereafter, with the advancement of information and communication technology, data networks for data communication were developed. Networks have been established. In the past, voice-based networks and data-based networks were clearly separated according to their purpose, but the two are more economical because they can share transmission lines and equipment used. Therefore, the construction of a network integrating both types of networks has been considered. In this case, the data network is generally more advantageous from the viewpoint of the cost versus the amount of transmitted information, and thus the direction of integration by incorporating a voice network into the data network is becoming established. . As such an example, for example, an Internet telephone is already in practical use. Furthermore, the mainstream of data network is ATM (Asynchronous Tra
nsfer mode), voice communication is also required to be converted to ATM, and as a telephone communication system using the ATM system, VTOA (Voice Telephony) is used.
y Over ATM) system is being put to practical use.

FIG. 3 shows a conceptual configuration of a network in which a voice system and a data system are integrated. In this network, an ATM switch 1 in an ATM network 11
Transmission of data converted into ATM cells via 2, 13;
By performing the exchange, a data network based on the ATM system is formed. On the other hand, the voice communication device 1
4, 15 is a communication device corresponding to the audio system of the network, the voice line, each telephone 16 ₁
16 _n , 17 _{1 to} 17 _n .

[0004] Such voice communication devices 14 and 15 are called A
In order to connect to the TM network 11, the voice communication devices 14, 1
5 are provided with ATM terminals 18 and 19, respectively.
It is necessary to perform mutual conversion between the signal of the M line and the signal of the voice line.

FIG. 4 shows a conceptual configuration of an ATM terminal. In an ATM terminal, an LSI (Large Scale Integrated Circuit) that realizes a function of a physical layer in an ATM protocol that defines an ATM protocol is used.
t), the ATM layer and the SAR (Seg
SAR layer unit 22 which is an LSI for realizing the function of a layer. The physical layer unit 21 performs mutual conversion between a signal on the transmission line and an ATM cell composed of binary data in accordance with the function of a transmission line such as an optical fiber or a coaxial line constituting the ATM line. The SAR layer unit 22 performs multiplexing / demultiplexing and switching of ATM cells as a function of the ATM layer, and an AAL (ATM Adaptation Layer) that realizes an additional function corresponding to a service type as a function of the SAR layer.
er) Among the protocols, processing of ATM cell disassembly and assembly is executed based on the specification of the AAL2 interface corresponding to voice transmission. Therefore, at the time of reception (hereinafter, the function of each unit is mainly limited to the reception state), an ATM line signal received from the ATM network is multiplexed with an ATM cell in the physical layer unit 21. The cell is converted into a cell frame, and the SAR layer unit 22 decomposes the cell frame to separate ATM cells, and further, from the AAL2 cells for voice transmission, each CPS (Common Part) corresponding to a plurality of voice channels. Su
blayer) separates the packet, outputs it to an output port or a memory for temporarily storing data, and restores an audio signal from these through a decoding unit (not shown). Note that a UTOPIA interface (Universal Test and Operations PHY Interface) is used as an interface for data exchange between the physical layer unit 21 and the SAR layer unit 22.
rface for ATM) is specified.

[0006] Figure 5 shows the format of the AA L 2 cells. AAL2 cell 23 that performs voice transmission is
ATM header 24 indicating the destination of the cell, etc., and payload 2
It consists of five. Further, the payload 25 includes an STF 26 for transmitting control information and a plurality of CPS packets 27.
It consists of Each CPS packet 27 includes a header 28 having a fixed length and a payload 29 having a variable length. The header 28 includes data such as a channel ID indicating a channel number and a payload length. The payload 29 is composed of compression-coded variable-length audio data.

At the time of reception, the SAR layer 22
The audio data is extracted by decomposing the AL2 cell into each CPS packet. For this purpose, it is necessary to perform a process of separating each CPS packet based on the header information of each CPS packet. A for performing such processing
As a disassembly apparatus for the AL2 cell, for example, Japanese Unexamined Patent Publication No.
Japanese Patent Application Laid-Open Nos. 65576, 10-65577 and the like are known.

FIG. 6 shows an example of the configuration of a conventional cell disassembly apparatus (see Japanese Patent Application Laid-Open No. H10-65577). In this conventional cell disassembly apparatus, a header of an ATM cell input to an ATM input FIFO (First In First Out memory) 31 is converted into a standard cell header analysis unit 3.
Analyze in step 2. And when it was AAL2 cell,
Further, the packet header analysis unit 33 analyzes the header of each CPS packet and identifies the channel ID and the payload length of each CPS packet. And write control unit 3
4 writes the respective payload data from the ATM input FIFO 31 to the cell disassembly memory 35 by identifying the break of each CPS packet from the identified payload length, and then, based on the control of the read controller 36, By sequentially reading from the decomposition memory 35, the band-compressed audio data is transferred for each output destination corresponding to the channel ID.

FIG. 7 is a flowchart showing a cell disassembly operation in the conventional cell disassembly apparatus. In the cell disassembly device shown in FIG.
The input process for the L2 cell is performed (step P1), and then the payload is analyzed (step P2), and the CPS
The break of the packet is determined, the data is written into the cell decomposition memory 35, and then the read processing is performed based on the payload length (step P3). Now, n in one ATM cell
It is assumed that CPS packets are included. One ATM cell is composed of 53 bytes, but the UTOPIA interface performs 1-byte processing for each clock, and therefore requires 53 clocks in the cell input processing. Next, assuming that a clock is required for analyzing the header of one CPS packet, in the payload analysis processing,
na clock is required. Further, if it is assumed that b clocks are required to transfer one CPS packet, nb clocks are required to read from the cell decomposition memory 35.
Therefore, in the conventional cell disassembly apparatus, (53 + na + nb) clocks were required for the disassembly processing of one ATM cell.

[0010]

By the way, in the VTOA system, when voice is to be transmitted as cells,
Since it takes time for the cell processing on the transmission side, the transfer of ATM cells, and the decellulation processing on the reception side, a delay occurs in the transmitted voice, which is a serious problem in the quality of the reproduced voice. FIG. 8 shows a flowchart of the VTOA process. On the transmitting side, the input voice is coded by a predetermined coding method and converted into binary data (step S1), and then the binary data is subjected to a predetermined compression process (step S2). A CPS packet is generated based on a predetermined protocol, converted into an ATM cell (step S3), and then transferred via an ATM (step S4). On the receiving side, the transmitted ATM cells are subjected to decellularization processing for separating CPS packets based on a predetermined protocol (step S5), and then the data compressed by the reverse processing of the transmitting side is expanded. To restore binary data (step S
6) Further, the binary data generated by expansion is decoded by a predetermined decoding method (step S7), and the audio data is restored and output.

In voice transmission, the presence of delay is a major problem in maintaining voice quality, and it is necessary to minimize the occurrence of delay. In the flowchart shown in FIG. 8, when the transmitting side attempts to assemble 1 ATM cell by using the voice information of the same channel, the voice information has a smaller information amount than the data information.
The time for storing data for TM cells becomes longer,
The delay is significantly increased. Also, in order to enable efficient transmission of voice information, a method of compressing information on the transmission side and expanding information on the reception side is adopted, but this further increases delay in voice transmission. .

Therefore, in order to reduce the delay caused by such a cause, one channel of voice information is divided and transmitted over a plurality of ATM cells.
A method is adopted in which voice information of a plurality of channels is carried in a cell and transmitted, so that a delay at the time of voice transmission on the transmission side is reduced.

On the other hand, the receiving side is also required to reduce the processing delay, but conventionally, no appropriate measure has been taken to respond to such a request.

[0014] The present invention has been made in view of the above-described circumstances, and an ATM communication apparatus has a receiving side that uses an AT.
ATM communication device and ATM capable of reducing processing delay when separating respective voice information from M cells
An object of the present invention is to provide a cell disassembly method for a communication device.

[0015]

In order to solve the above-mentioned problems, an invention according to claim 1 is an ATM communication apparatus for receiving a cell assembled from a plurality of packets and separating voice information included in each of the packets. The interface
Assembled from multiple packets received via
Cell input without storing cells in FIFO memory
Reception control means, and the header of each packet contained in the cell.
Information extraction that analyzes the data and extracts the boundary information of each packet
Means and a FIFO memo for storing the payload of the cell
And the cell reception control means includes one of the cells in the cell.
In parallel with sending the part to the information extraction means,
Store the payload of the above cell in FIFO memory
A is, the destination address of the payload, according to the boundary information of each packet read out from the FIFO memory according to the boundary information of each packet extracted by analyzing the header of each packet included in the cell Characterized in that it is configured to be forwarded to

According to a second aspect of the present invention, a cell assembled from a plurality of CPS packets is received and each of the CPS packets is received.
A plurality of CPSs received via an interface, related to an ATM communication device for separating voice information included in a packet
Extraction of part of the cell assembled from packets
In parallel with the transmission to the stage, the above cell is stored in the FIFO memory.
Cell reception control means for storing a payload of
AAL by analyzing the header of each CPS packet included in
Information extracting means for extracting boundary information of each CPS packet in the cell when recognizing that the cell is two cells;
Table means for storing the extracted boundary information for each CPS packet, a FIFO memory for storing the cell payload from the cell reception control means, and each CP from the FIFO memory in accordance with the stored boundary information.
To read out the payload of the S packet, respond to the boundary information
Read means for transferring data to each of the transfer destination addresses .

According to a third aspect of the present invention, there is provided the ATM communication apparatus according to the second aspect, wherein the boundary information comprises a start address and an end address of each CPS packet, and the reading means comprises: , The start address of each payload is obtained from the start address of the CPS packet and the header length, and the payload of each CPS packet is read out according to the start address of the payload and the end address.

According to a fourth aspect of the present invention, there is provided the ATM communication apparatus according to the third aspect, wherein the information extracting means stores information on a header length of a CPS packet and a payload length of a first CPS packet in the AAL2 cell. using, above
Calculating a start address and end address of the first CPS packet in serial AAL2 cell, further using information and payload length of the last address and the header length and each CPS packet, sequentially starting address of the next CPS packet and It is characterized in that it is configured to calculate the final address.

According to a fifth aspect of the present invention, there is provided A
According to the TM communication apparatus, the boundary information includes a start address and an end address of a payload of each CPS packet, and the reading unit determines each CPS packet according to a start address and an end address of the payload of each CPS packet.
It is characterized in that it is configured to read the payload of the PS packet.

According to a sixth aspect of the present invention, there is provided the ATM communication apparatus according to the fifth aspect, wherein the information extracting means includes information on a header length of a CPS packet and a payload length of a first CPS packet in the AAL2 cell. Is used to calculate the start address and the end address of the payload from the start address of the first CPS packet in the AAL2 cell, and further calculate the end address and the header length.
And using the information of the payload length of each CPS packet, sequentially, it is characterized by being configured to calculate a start address and end address of the payload of the next CPS packet.

According to a seventh aspect of the present invention, there is provided a cell disassembly method for an ATM communication apparatus for receiving a cell assembled from a plurality of packets and separating voice information contained in each of the packets, via an interface. The cell payload assembled from a plurality of received packets is
In parallel with storing in the FO memory, the header of each packet included in the cell is analyzed to extract boundary information of each packet, and each packet is extracted from the FIFO memory according to the boundary information of each extracted packet. Is read and transferred to each transfer destination address according to the boundary information.

The invention according to claim 8 is characterized in that a plurality of CPs are provided.
The present invention relates to a cell disassembly method of an ATM communication device for receiving a cell assembled from S packets and separating voice information included in each of the CPS packets , via an interface.
In parallel with storing the payload of the cell assembled from the received plurality of CPS packets in the FIFO memory, the header of the plurality of CPS packets is analyzed and AAL2
When the cell is recognized as a cell,
Extracting boundary information of the PS packet, storing the extracted boundary information in a table for each CPS packet,
To read out the payload of each CPS packet from said FIFO memory in response to the stored boundary information, the boundary
It is characterized in that data is transferred to each transfer destination address according to the information .

According to a ninth aspect of the present invention, there is provided the cell disassembly method for an ATM communication apparatus according to the eighth aspect, wherein the boundary information includes a start address and an end address of each CPS packet. The present invention is characterized in that the start address of each payload is obtained from the start address and the header length, and the payload of each CPS packet is read according to the start address of the payload and the end address.

The invention described in claim 10 is the same as the claim 9.
The method according to any one of claims 1 to 3, wherein
Header length of CPS packet and initial C in L2 cell
Using the information on the payload length of the PS packet,
The start address and the last address of the first CPS packet in the AL2 cell are calculated, and the start address and the last address of the next CPS packet are sequentially calculated using the information of the last address, the header length and the payload length of each CPS packet. It is characterized in that an address is calculated.

The invention according to claim 11 is the same as the invention according to claim 8.
According to the cell disassembly method of the ATM communication device described above, the boundary information includes a start address and an end address of a payload of each CPS packet, and according to a start address and an end address of the payload of each CPS packet,
It is characterized by reading the payload of each CPS packet.

The invention according to claim 12 is the first invention.
1. According to the cell disassembly method for an ATM communication device described in
Using the information on the header length of the CPS packet in the AL2 cell and the payload length of the first CPS packet, the start address and the last address of the payload are calculated from the start address of the first CPS packet in the AAL2 cell. Using the information of the address, the header length, and the payload length of each CPS packet,
Sequentially, the start address of the payload of the next CPS packet
And a final address.

[0027]

[Action] In the configuration of the ATM communication apparatus of the present invention receives the cell assembled from a plurality of packets, an ATM communication apparatus for separating the audio information each packet has, FIFO memory payload of the cell in parallel with the storing, extracting boundary information for each packet by analyzing the header of each packet included in the cell, the boundary
Each packet read from the FIFO memory according to the information
The payload of each transfer destination according to the above boundary information.
Since the transfer is made to the address, the time required from the reception of the ATM cell to the separation of each voice information can be reduced.

Further, in the cell disassembly method for an ATM communication device according to the present invention, a cell assembled from a plurality of packets is
Receives and separates voice information contained in each of the above packets
In the cell disassembly method of the ATM communication device, the payload of the received cell is stored in a FIFO memory, and the header of the received cell is analyzed to recognize that it is an AAL2 cell. extract information, the boundary information the extracted CP
Since each S packet is stored in the table means and the payload of each CPS packet is read from the FIFO memory according to the stored boundary information, the time required from the reception of the ATM cell to the separation of each voice information can be reduced. it can.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. The description will be specifically made using an embodiment. FIG. 1 is a block diagram showing a configuration of a cell disassembly apparatus according to one embodiment of the present invention, and FIG.
It is a figure which shows the storage information of FO, and the content of a CPS packet storage information table. As shown in FIG. 1, the cell disassembly device of this example includes a cell reception control unit 1, an input FIFO 2, an information extraction unit 3, an ATM header analysis unit 4, a CPS packet header analysis unit 5, and a CPS packet storage unit. It is roughly composed of an information table 6 and a reading section 7.

The cell reception control unit 1 receives the ATM cell via the UTOPIA interface, stores the payload in the input FIFO 2, and sends out the designated portion in the ATM cell to the information extraction unit 3. The input FIFO2 is
It stores and outputs the payload of the ATM cell input via the cell reception control unit 1 in a first-in first-out manner. The input FIFO 2 is provided to absorb a difference in data transmission speed between the input side and the output side. That is, while the input via the UTOPIA interface is in units of 1 byte (8 bits), the data length of the audio output differs depending on the output destination.
This is because each byte (32 bits). The information extraction unit 3 extracts the VPI (Virt) of the ATM cell from the ATM header.
ual Path Identifier) and VCI (Virtual Channel Id)
entifier) is extracted and sent to the ATM header analysis unit 4, and the header of the CPS packet is sent to the CPS packet analysis unit 5. The ATM header analysis unit 4 includes a VPI and a VC
Based on I, it is determined whether or not the ATM cell is an AAL2 cell. The CPS packet header analysis unit 5
The transfer destination address is determined by the channel ID of the packet header, and the input FI is determined by the header length and the payload length.
The start address and the end address in FO2 are calculated and sent to the CPS packet storage information table 6. CPS
The packet storage information table 6 stores these pieces of information sent from the CPS packet analysis unit 5. The reading unit 7 reads data from the start address to the last address and transfers the data to the designated transfer destination based on the information stored in the CPS packet storage information table 6.

In the input FIFO 2, as shown in FIG. 2A, a CPS packet is stored using the start address and the end address of the CPS packet as boundary information. Further, in the CPS packet storage information table 6, as shown in FIG. 2B, header information of each CPS packet is stored as a set of a transfer destination address, a packet start address, and a packet end address. I have.

The operation of this embodiment will be described below with reference to FIGS. In the cell disassembly device shown in FIG. 1, upon receiving an input of an ATM cell via the UTOPIA interface, the cell reception control unit 1 inputs the payload of the ATM cell to the input FIFO 2 so as to input the ATM.
Each CPS packet included in the cell is stored sequentially. At this time, the position of each CPS packet is indicated by its start address and end address, as shown in FIG. The cell reception control unit 1 receives the input FI
The designated part in the ATM cell is sent to the information extracting unit 3 in parallel with the storing process to the FO2. When the input of the ATM cell is started, the information extraction unit 3 firstly outputs the V from the ATM header.
The PI and VCI are extracted and sent to the ATM header analyzer 4. When the ATM header analyzer 4 determines from the VPI and VCI that the cell is an AAL2 cell composed of a CPS packet, the analysis for decomposing the CPS packet is started.

First, the information extraction unit 3 extracts the header of the first CPS packet in the payload and sends it to the CPS packet header analysis unit 5. Upon receiving this, the CPS packet header analyzer 5 calculates the start address and the end address of the CPS packet from the header length and the payload length, and obtains the length of the first CPS packet, thereby obtaining the next CPS packet. Is predicted, and this is notified to the information extracting unit 3. Thereby, the information extraction unit 3
Then, the header information of the next CPS packet can be extracted. On the other hand, the CPS packet header analyzer 5
The transfer destination address is determined based on the channel ID in the header information of the packet.
It is stored in the packet storage information table 6.

Next, the information extracting unit 3 calculates the next C
From the start position of the PS packet, the header of the next CPS packet is extracted and sent to the CPS packet header analysis unit 5. As a result, the CPS packet header analyzer 5
The transfer destination address, the start address and the end address of the CPS packet are obtained and stored in the CPS packet storage information table 6, and the length of the next CPS packet is calculated and notified to the information extracting unit 3, by this,
The information extracting unit 3 further extracts the next CPS packet.

Thereafter, by repeating such processing, the transfer destination addresses of all CPS packets and the start and end addresses of the CPS packets included in the input ATM cell are stored in the CPS packet storage information table 6. , Each CP as shown in FIG.
A table of the S packet transfer destination and boundary information is generated.

The reading unit 7 sequentially retrieves a set of information of the transfer destination address, the start address, and the last address of each CPS packet from the CPS packet storage information table 6, and from the address obtained by adding the header length of the CPS packet to the start address. Data up to the last address, ie, C
The payload of the PS packet is read and transferred to an output port or a memory, which is an output destination specified by a transfer destination address, by a DMA (Direct Memory Access) process. The compression-encoded audio data, which is output data, is sent to a decoding unit (not shown) via an output port or a memory for temporarily holding the data, and is decoded and decompressed to restore the audio data. The data is output to a terminal such as a telephone.

As described above, according to the ATM communication apparatus of this embodiment, after the header information is analyzed by the packet header analysis unit 33 as in the case of the conventional example shown in FIG.
Instead of transferring cells from the input FIFO 31 to the cell disassembly memory 35, as shown in FIG.
In parallel with the storage in the CPS 2, the cell payload is analyzed, the boundary information of the CPS packet is stored in the CPS packet storage information table 6, and using this information, the CPS from the input FIFO 2 by the reading unit 7 is used. Since the payload is cut out, there is no delay required for the processing of disassembling and analyzing the CPS packet after receiving the ATM cell, and thus the delay in voice transmission can be reduced. In the case of this example, for example, na for payload analysis, which is necessary in the conventional example shown in FIG.
Clock time is reduced. Thus, for example, n = 1
When 0, a = 2, the processing time for 20 clocks is saved. If the operating clock is 33 MHz, the delay can be reduced by about 600 ns.

Since the cell disassembly memory 35 of the conventional example shown in FIG. 6 is not required, the number of memories required for the CPS cell disassembly process can be reduced, and the cell disassembly from the ATM input FIFO 31 can be performed. Since the process of transferring the CPS payload to the memory 35 becomes unnecessary, the delay required for this transfer process is eliminated. Further, in the case of the conventional example shown in FIG.
After writing to O31, the read control unit 36 outputs the audio data of the CPS payload by DMA transfer while the packet header analysis unit 33 detects the boundary of the CPS payload. Controlling the transfer was complicated,
In this example, as shown in FIG.
Since the DMA transfer of the payload can be performed only by reading the CPS payload from the input FIFO 2 based on the storage information of the CPS packet storage information table 6, the control of the DMA transfer in the read control unit 7 is simplified.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific structure is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. Even this is included in the present invention. For example, CPS
The packet header analysis unit 5 calculates the start address and the end address of the payload of each CPS packet,
The information may be stored in the CPS packet storage information table 6, and the reading unit 7 may read the payload of each CPS packet from the input FIFO 2 based on the storage information. Since the process of adding the header length to the data becomes unnecessary, the reading process can be speeded up, and the delay time for cell decomposition can be reduced. Further, the reading unit 7 may read out each CPS packet including the header from the input FIFO 2 and perform the decoding process. In this case, the CPS packet storage information table 6 stores the start address of each CPS packet and the The information of the last address is stored, and the read unit 7 uses this stored information to read each CP from the input FIFO 2.
What is necessary is just to read S packet. In addition, in the reading unit 7, by providing a plurality of DMA channels, CPS payloads or CPSs for a plurality of output destinations are provided.
It is also possible to perform parallel transfer of PS packets, thereby improving the speed of reading from the input FIFO 2.

[0040]

As described above, as described above, the AT of the present invention is used.
According to the M-communication device and the cell disassembly method for the ATM communication device, the A-cell is stored in the input FIFO in parallel with the A-cell.
The payload of the TM cell is analyzed, boundary information of the CPS packet is stored, and the input FIFO is used by using this information.
Since the CPS payload is read from O, the time required from the reception of the ATM cell to the output of the audio information of each CPS packet can be shortened. As a result, there is a problem in the voice transmission in the ATM system. The occurrence of delay can be reduced. In addition, the number of memories required for CPS cell disassembly can be reduced, and the DPS at the time of outputting the CPS payload from the input FIFO can be reduced.
Control of MA transfer is simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a cell disassembly apparatus according to one embodiment of the present invention.

FIG. 2 shows information stored in an input FIFO and a CP in the device.
It is a figure showing the contents of the S packet storage information table.

FIG. 3 is a diagram showing a conceptual configuration of a network in which a voice system and a data system are integrated.

FIG. 4 is a diagram showing a conceptual configuration of an ATM terminal.

FIG. 5 is a diagram showing a format of an AAL2 cell.

FIG. 6 is a diagram illustrating a configuration example of a conventional cell disassembly apparatus.

FIG. 7 is a flowchart showing a cell disassembly operation in the conventional cell disassembly apparatus.

FIG. 8 is a diagram showing a flowchart of a VTOA process.

[Explanation of symbols]

1 cell reception control unit 2 inputs FIF O (memory means) 3 information extraction section (data extraction means) 4 ATM header analyzer (information extraction unit) 5 CPS packet header analyzing unit (information extraction unit) 6 CPS packet storage information table ( Table means) 7 Readout unit (readout means)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-11-187044 (JP, A) JP-A-2000-41044 (JP, A) JP-A-2000-41051 (JP, A) JP-A-10-145392 ( JP, A) JP-A-10-17373 (JP, A) WO 96/34478 (WO, A1) IEICE technical report SSE97-52 IEICE technical report SSE97-6 (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/56 H04L 12/28

Claims (12)

(57) [Claims] 1. A cell assembled from a plurality of packets
To separate the audio information of each of the packets.
ATM communication device,From multiple packets received through the interface
Do not store assembled cells in FIFO memory.
Cell reception control means for inputting The header of each packet contained in the cell is analyzed and each packet is analyzed.
Information extracting means for extracting boundary information of a packet; A FIFO memory for storing the cell payload.
And The cell reception control means stores a part of the cell in the information.
In parallel with the transmission to the information extracting means, the FIFO memo
Storing the payload of the cell in the  By analyzing the header of each packet contained in the cellExtraction
Of each packetAccording to the boundary information, the FIFO
The payload of each packet read from the memory
Configured to forward to each forwarding address according to world information
An ATM communication device characterized in that the communication is performed. 2. An ATM communication device for receiving a cell assembled from a plurality of CPS packets and separating voice information included in each of the CPS packets, the ATM communication device comprising a plurality of CPS packets received via an interface.
Part of the cell assembled from the
In parallel with the delivery, the payout of the cell to the FIFO memory is performed.
Cell reception control means for storing a load; and information extraction means for extracting the boundary information of each CPS packet in the cell when analyzing the header of each CPS packet included in the cell and recognizing that the cell is an AAL2 cell. A table means for storing the extracted boundary information for each CPS packet, a FIFO memory for storing the cell payload from the cell reception control means, and a FIFO memory for storing the cell information from the FIFO memory according to the stored boundary information. to read out the payload of the CPS packet, the boundary
An ATM communication device comprising: a reading unit that transfers data to each transfer destination address according to information . 3. The boundary information comprises a start address and a final address of each CPS packet, and the reading means obtains a start address of each payload from a start address of each CPS packet and a header length. 3. The ATM communication device according to claim 2, wherein a payload of each CPS packet is read according to a start address of the payload and the last address. 4. The information extracting means uses the information on the header length of the CPS packet in the AAL2 cell and the payload length of the first CPS packet to determine the start address and the last address of the first CPS packet in the AAL2 cell. And calculating the start address and the last address of the next CPS packet sequentially from the last address by using information of the header length and the payload length of each CPS packet from the last address. The ATM communication device according to claim 3, wherein 5. The method according to claim 1, wherein the boundary information includes a start address and an end address of a payload of each CPS packet, and the reading unit determines the start address and the end address of the payload of each CPS packet. 3. The ATM communication device according to claim 2, wherein the ATM communication device is configured to read a payload. 6. The information extracting means uses the information on the header length of the CPS packet in the AAL2 cell and the payload length of the first CPS packet to calculate the payload of the payload from the start address of the first CPS packet in the AAL2 cell. Calculate the start address and the end address, and further calculate the end address, the header length, and each CP.
6. The ATM communication apparatus according to claim 5, wherein a start address and an end address of the payload of the next CPS packet are sequentially calculated using information on the payload length of the S packet. 7. A cell assembled from a plurality of packets
To separate the audio information of each of the packets.
In a cell disassembly method for an ATM communication device,Interf
Assembled from multiple packets received through the
CellPayloadIs stored in the FIFO memory.
In parallel, each packet included in the cell is Unpack header
To extract the boundary information of each packet, Of each extracted packet The FIFO according to the boundary information
O Read the payload of each packet from the memory,
Transfer to each transfer destination address according to the boundary information is special.
A cell disassembly method for an ATM communication device. 8. A cell disassembly method for an ATM communication apparatus for receiving a cell assembled from a plurality of CPS packets and separating voice information included in each of the CPS packets, the plurality of CPS packets received via an interface.
In parallel with storing the payload of the cell assembled from the cell in the FIFO memory, when the header of a plurality of CPS packets is analyzed to recognize that the cell is an AAL2 cell, boundary information of each CPS packet in the cell is identified. extracted, the extracted boundary information stored in the table means for each CPS packet, to read out the payload of each CPS packet from said FIFO memory in response to the stored boundary information, the boundary
A cell disassembly method for an ATM communication device, wherein the cell is transferred to each transfer destination address according to information . 9. The boundary information includes a start address and a final address of each CPS packet, and a start address of each payload is obtained from a start address of each CPS packet and a header length. 9. The AT according to claim 8, wherein a payload of each CPS packet is read according to the last address.
A cell disassembly method for an M communication device. 10. The first CAL packet in the AAL2 cell using information on the header length of the CPS packet in the AAL2 cell and the payload length of the first CPS packet.
The start address and the last address of the PS packet are calculated, and the last address, the header length and each CP are calculated.
10. The cell disassembly method for an ATM communication device according to claim 9, wherein the start address and the end address of the next CPS packet are sequentially calculated using information on the payload length of the S packet. 11. The method according to claim 11, wherein the boundary information includes a start address and an end address of a payload of each CPS packet, and the payload of each CPS packet is read according to a start address and an end address of the payload of each CPS packet. The ATM according to claim 8, wherein:
Cell disassembly method for communication device. 12. Using the information on the header length of the CPS packet in the AAL2 cell and the payload length of the first CPS packet, the first CAL packet in the AAL2 cell is used.
The start address and the last address of the payload are calculated from the start address of the PS packet, and the start address of the next CPS packet is sequentially calculated using the information of the last address, the header length, and the payload length of each CPS packet. The method according to claim 11, wherein the address and the last address are calculated.