JP2002009786A - Communication device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a communication device capable of reducing communication costs and effectively using network resources. SOLUTION: By performing multiplexing processing in a WAN node 200 on the transmission side, virtual channels V that are originally separate
The data transmitted via C1 to VC6 is transmitted via one virtual channel VC1. Also, the WA on the receiving side
In the N node 210, this one virtual channel VC
1 is demultiplexed and handled as if it were data transmitted via separate virtual channels VC1 to VC6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM (Asynchro
Nous Transfer Mode (WAN) using Wide Area N
etwork) environment, LAN (Local Area Network)
The present invention relates to a communication device that performs mutual conversion of data between an ATM connection and an ATM connection.

[0002]

2. Description of the Related Art Conventionally, a plurality of LAs have been transmitted through an ATM network.
A method of connecting N to form a WAN is used.
For example, each WAN node connected to the ATM network has 1
Alternatively, a plurality of LANs are connected. The WAN node decomposes data input from the connected LAN into fixed-length cells and transmits the cells to the ATM network. Also, the WAN node receives the ATM cell transmitted via the ATM network, assembles the data of the upper layer, and connects the connected LA.
Send to N side.

[0003] Normally, in an ATM network, a VP (virtual path; Virtua) is used between a telecommunications carrier providing the ATM network and a user.
l Path) or VC (Virtual Ch)
A contract to use the line is made for each annel). When a contract is made for each VP, the user can set the used bandwidth in units of, for example, 1 Mbps at the time of contract. In addition, the user,
A plurality of VCs can be multiplexed and transmitted and received within the contracted VP. Usually, the VP service is provided as a QoS (service quality) guarantee type service. On the other hand, V
When contracting for each C, the user is required to
The required number of contracts will be made. The VC service is provided as a QoS guaranteed service or a best effort service as required.

[0004]

In general, when the amount of data to be communicated is large, a contract is made for each VP,
When the number is small, a contract is made for each VC, but when different VCs are used depending on the application, there is a problem that the communication cost is higher in the VP service than in the VC service. For example, when considering a corporate network, there is a request to transmit and receive ATM and IP (Internet Protocol) routing information and signaling information, or voice and image data having different characteristics by specifying different VCs. In such a case, it is necessary to secure many VCs even if the amount of data transmitted and received by each VC is small.

[0005] Such communication using a plurality of VCs can be realized by contracting one VP having a predetermined band and allocating a plurality of VCs within the band. Since the contracted VP itself corresponds to the QoS guaranteed service, when a plurality of VCs corresponding to the best effort service are used efficiently in this VP, the processing of the WAN node as a relay device is performed. However, it is not a method that can be easily realized by anyone because of the complexity of the device and the increase in the device cost.

[0006] In addition, a VC contracted in the VC service
When the number of network resources increases, the number of network resources that must be secured in advance increases, so that there is a problem that effective use of network resources becomes difficult. The present invention has been created in view of the above points,
It is an object of the present invention to provide a communication device that can reduce communication costs and can effectively use network resources.

[0007]

In order to solve the above-mentioned problems, a communication apparatus according to the present invention transmits data addressed to a plurality of first connections generated by a first data generating means to the plurality of first connections. Multiplexing processing assigned to the time slot corresponding to each of the one connection is performed by the multiplexing means, and the multiplexed data is transmitted to the second connection by the data transmitting means. Originally, each data separately transmitted through each of the plurality of first connections is transmitted through one second connection by performing a multiplexing process on the data. Therefore, the communication cost can be reduced. Further, since the number of connections for actually transmitting and receiving data can be reduced, network resources can be effectively used.

The multiplexing means includes a first table indicating a correspondence between each of a plurality of first connections and a time slot, and performs a multiplexing process based on the contents of the first table. Is desirable. Setting and changing the contents of the first table facilitates setting and changing the contents of the multiplexing process.

Further, the multiplexing means described above comprises a plurality of first
It is desirable to variably control the number of time slots corresponding to the first connection when the connection of the first connection includes a service corresponding to the service category of the best effort type. This makes it easy to set the communication band of the first connection of the best effort type to an appropriate value in consideration of the traffic and the like using other first connections.

[0010] The multiplexing means performs processing for variably controlling the number of time slots without changing the contents of the first table, and performs multiplexing processing contrary to the contents of the first table. In this case, it is desirable to perform multiplexing processing including connection identification information indicating which of the plurality of first connections corresponds to the data.
Even when multiplexing processing that does not follow the contents of the first table is performed, the first connection having the correct correspondence can be specified by checking the connection identification information in the data receiving apparatus. .

The communication apparatus of the present invention monitors traffic of data corresponding to each of the plurality of first connections by means of traffic monitoring means.
It is desirable that the first table changing means dynamically changes the contents of the first table based on the monitoring result. Since each communication band of the first connection is dynamically changed in accordance with the actual data traffic, data can be efficiently transmitted and network resources can be effectively used.

In particular, the above-mentioned traffic monitoring means is provided with data storage means, and stores the data outputted by the first data generation means in correspondence with each of the plurality of first connections. By checking the amount of data before reading stored in the storage unit, the communication amount of data corresponding to each of the first connections can be monitored. Since the data traffic can be monitored simply by checking the amount of data stored in the data storage means, the processing load required for this monitoring can be reduced.

[0013] The first table changing means described above is for the case where a plurality of first connections include two or more corresponding to the best-effort service category. It is desirable to change the contents of the first table when there is a data communication amount that is lower than a predetermined lower limit value and a data communication amount that exceeds a predetermined upper limit value. When there are a plurality of best-effort type first connections instead of the fixed bandwidth type, the communication bandwidth of the first connection with a small data traffic is reduced, and conversely, the first bandwidth with a large data traffic is reduced. By increasing the communication band of the connection, data can be transmitted efficiently without changing the communication band of the plurality of first connections as a whole.

Further, the communication apparatus of the present invention includes the first connection setting / release means so as to perform predetermined connection setting processing and connection release processing to perform additional setting or partial release of the first connection. Preferably, the contents of the first table are dynamically changed by the second table changing means. As in the case of SVC in ATM, the contents of the first table are changed when data communication becomes necessary, so that the time slot can be made to correspond only to the actually set first connection. It is possible to set a communication band without any error.

Preferably, the first table contains information indicating whether each of the plurality of first connections is to be subjected to multiplexing processing by the multiplexing means. The multiplexing means, for a part of the plurality of first connections, based on the contents of the first table,
The multiplexing process for the corresponding data can be performed, and the multiplexing process for the corresponding data can not be performed for the rest, so that it is possible to use a conventional device that cannot perform the multiplexing process as a communication partner. Compatibility with the device can be ensured.

Further, the communication apparatus of the present invention receives the multiplexed data transmitted via the third connection by the data receiving means, and transmits the received multiplexed data to a plurality of fourth multiplexed data every time slot. The data is separated by the separating means in correspondence with one of the connections, and data for each of a plurality of fourth connections is generated. Originally, each data separately received via each of the plurality of third connections is received via one fourth connection by performing a multiplexing process on these data. Communication cost can be reduced. Further, since the number of connections for actually transmitting and receiving data can be reduced, network resources can be effectively used.

The demultiplexing means includes a second table indicating the relationship between each of the plurality of fourth connections and the time slot, and preferably performs the demultiplexing process based on the contents of the second table. . Setting or changing the contents of the second table facilitates setting or changing the contents of the separation processing.

The demultiplexing means detects the identification information by the detecting means when the identification information for specifying the fourth connection is added to the data obtained by separating the multiplexed data. It is desirable. The second data generation means can generate data by giving priority to the fourth connection specified based on the identification information. Even when a separation process that does not follow the contents of the second table is performed, the fourth connection with the correct correspondence can be specified.

Further, predetermined connection setting processing and connection release processing are performed by the second connection setting / release means, additional setting or partial release of the fourth connection is performed, and the second table setting means releases the second connection. It is desirable to dynamically change the contents of the table. As in the case of SVC in ATM, the contents of the second table are changed when data communication becomes necessary, so that the time slot can be made to correspond only to the actually set fourth connection. It is possible to set a communication band without any error.

It is desirable that the above-mentioned second table include information indicating whether or not each of the plurality of fourth connections is an object of separation processing by the separation processing means. The demultiplexing unit can perform the demultiplexing process on the corresponding data for a part of the plurality of fourth connections based on the contents of the second table, and can not separate the corresponding data on the rest.
A conventional device that cannot transmit multiplexed data can also be used as a communication partner, and compatibility with the conventional device can be ensured.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A communication apparatus according to an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a network including a WAN node as a communication device according to an embodiment. As shown in FIG. 1, the network of the present embodiment is an ATM network,
WAN nodes 200 and 210, terminal devices 300 and 310
It is comprised including. One WAN node 200
Accommodates one or a plurality of physical LAN lines 400, and the terminal device 3
LANs including “00” are connected. Similarly, the other W
The AN node 210 has one or more physical LANs.
A line 410 is accommodated, and a LAN including the terminal device 310 is connected via the LAN line 410.
Also, the two WAN nodes 200 and 210 are connected via an ATM network, and the two WAN nodes 200 and 210
During the period 210, a specific VC (for example, V
C1). A WAN is formed by these two WAN nodes 200 and 210 and the ATM network.

In general, in an ATM network, it is possible to set a plurality of VCs in a VP set corresponding to a physical transmission line such as an optical fiber. One VC is used to transmit various data from the node 200 to the other WAN node 210. That is, the WAN node 200 according to the present embodiment
The various types of data input from 0 are transmitted to a specific V that is set in advance with a communication provider providing an ATM network.
Send via C.

FIG. 2 is a diagram showing the state of data transmitted and received between WAN nodes 200 and 210. As shown in FIG. 2, in the present embodiment, the WAN node 200 on the transmitting side
By performing multiplexing processing at
1 to VC6 are transferred to one VC1.
To send over. Also, the receiving WAN node 210
, The multiplexed data received via this single VC1 is separated and treated as if it were data transmitted via separate VC1 to VC6. Hereinafter, the details of the data multiplexing / demultiplexing operation performed in accordance with such data transmission / reception operation will be described.

FIG. 3 is a diagram showing a detailed configuration of the WAN node 200. FIG. 4 is a diagram showing details of the disassembly / assembly of cells performed in the WAN node 200, and shows the relationship between layers. Note that the other WA
N node 210 also has the same configuration as WAN node 200, and a detailed description thereof will be omitted.

The WAN node 200 includes physical interface (I / F) units 10 and 12, a switch unit 20, a routing table 22, an AAL (ATM adaptation layer) function unit 30, a QoS determination unit 40, and a TDM (Time D
ivision Multiplex) function unit 50, ATM layer unit 60
It is comprised including.

The plurality of physical interface units 10 are for accommodating a physical LAN line 400. For example, 100BASE-
When T is used, each physical interface unit 10 is formed by a 100BASE-T Ethernet (registered trademark) card.

The switch unit 20 performs routing processing at the layer 2 or layer 3 level, and switches the destination of data input / output between the physical interface unit 10 and the AAL function unit 30. The routing table 22 stores routing information (for example, a MAC address and an IP address) necessary for the routing process performed by the switch unit 20.

The AAL function unit 30 performs processing corresponding to the AAL. The AAL function unit 30 divides user information and signaling messages of an upper layer into 48-byte data handled in the ATM layer, and conversely handles it in the ATM layer. The data is assembled in 48-byte units to generate upper layer user information and signaling messages.

For this purpose, the AAL function unit 30
Layer 31, buffer 32, UNI (User-Network
Interface) It includes a signaling generation / processing unit 33 and a VC management unit 36. AAL layer section 31
Is the common part convergence sublayer (CPCS: Co
mmon Part Convergence Sublayer) 34
Assembly sublayer (SAR: Segmentation And Reassem
bly Sublayer) section 35.

Common part convergence sublayer part 34
Is the user information received from the upper layer (CPCS
-Padding PA in SDU (Service Data Unit)
D (Padding) and trailer are added. The padding PAD is a redundant bit inserted so that the length from the user information to the trailer is an integral multiple of 48 bytes. In addition, the trailer has a CPCS-UU (Comm
on Part ConvergenceSublayer-User to User Indicatio
n), CPI (Common Part Indicator), Length, CR
C-32 is included. The CPCS-UU is a CPCS inter-user display field that transparently transfers information used in an upper layer. The CPI is a field for displaying the type of the common part. “Length” is a field for displaying the length of the user information. CRC-32 is C
This is a field for performing an error check on the entire PCS-PDU. In the common part convergence sublayer part 34,
The data unit (CPCS-PDU) in which the padding PAD and the trailer described above are added to the user information passed from the upper layer is transferred to the lower cell division / assembly sublayer unit 35. Alternatively, a process of extracting only the user information from the data unit received from the lower cell division / assembly sublayer unit 35 and passing it to the upper layer is performed.

The cell division / assembly sublayer unit 35 divides the data unit received from the common unit convergence sublayer unit 34 into 48-byte units.
Alternatively, 4 input from outside the AAL layer unit 31
By assembling data in units of 8 bytes, a data unit to be input to the common unit convergence sublayer unit 34 is generated.

The buffer unit 32 has a storage area different for each VC, and stores data divided in units of 48 bytes by the cell division / assembly sublayer unit 35 in the AAL layer unit 31 for each VC. . When the VPs are different, there may be a plurality of the same VCIs. Therefore, when a plurality of VPs are set corresponding to the WAN line 450 accommodated in the physical interface unit 12 on the ATM network side, Classifying for each combination of VPI and VCI,
The data in units of 48 bytes passed from the cell division / assembly sublayer unit 35 may be stored. Also,
The buffer unit 32 prepares for each VC corresponding to each time slot when data of a predetermined length (for example, 1 byte) corresponding to each time slot included in the multiplexed data is sequentially output from the TDM function unit 50. This output data is sequentially stored in the designated area.

UNI / signaling generation / processing unit 33
Is a switched virtual connection (SVC: Switched V)
Processing related to signaling messages required for establishing and releasing an irtual channel). The setting of a call using the switched virtual connection and the operation of transmitting and receiving data will be described later.

The VC management unit 36 performs a process of dynamically changing the correspondence between VCs and time slots. The detailed operation of the VC management unit 36 will be described later. The QoS determining unit 40 determines the QoS for each VC. For example, each V
The required communication band is determined for each C.

The TDM function unit 50 in the AAL function unit 30 performs time-division multiplexing on data divided into 48 bytes for each VC and separates multiplexed data sent via the WAN line 450. I do. To this end, the TDM function unit 50 includes a rotary switch unit 51, a traffic flow monitoring unit 52, a VC-time slot mapping table 53, and a time slot management unit 54.

When performing the multiplexing process, the rotary switch unit 51 reads out the data stored in the buffer unit 32 in the AAL function unit 30 for each VC corresponding to each time slot. For example, time slot 1 (TS
When VC1 corresponds to 1) and VC2 corresponds to time slot 2 (TS2), data is read from the storage area corresponding to VC1 of the buffer unit 32 at the timing corresponding to time slot 1. VC2 of the buffer unit 32 at the timing corresponding to the next time slot 2.
Is read from the storage area corresponding to. In addition,
The data length read corresponding to each time slot is fixed, for example, one byte of data corresponds to one time slot.

When performing the separation process, the rotary switch unit 51 divides the input multiplexed data into each time slot, and prepares the buffer unit 32 prepared for each VC corresponding to each time slot. Output to. The traffic flow monitoring unit 52 monitors the amount of untransmitted data stored in the buffer unit 32 in the AAL function unit 30 (the usage rate of the buffer unit 32) for each VC, and
The data traffic of each C is monitored. In the VC-time slot mapping table 53, each time slot and V
Information indicating the correspondence with C is included.

FIG. 5 is a diagram showing a specific example of the VC-time slot mapping table. In FIG. 5, "or
iginal VCI "is the original VCI used for various data communications when the multiplexing process in the present embodiment is not performed.
CI (Virtual Channel Identifi)
er), for example, each of a1 to a6 is used. Hereinafter, these original VCs are referred to as “original VCs”.
It will be described. “Service categories”
Is a service category corresponding to each original VC, and "constant" is set for a fixed bandwidth type, and "best-effort" is set for a best effort type. “T
ime-slot # "indicates a time slot number corresponding to each original VC. For example, three time slots of numbers" 1 "," 6 ", and" 11 "correspond to an original VC whose VCI is a1. .

The time slot management section 54 performs the following based on the contents of the VC-time slot mapping table 53.
The control of the rotary switch unit 51 is performed. For example, considering the case where multiplexing processing is performed based on the table shown in FIG.
An instruction to read 1-byte data from the storage area of the buffer unit 32 corresponding to the original VC of a1 is output from the time slot management unit 54 to the rotary switch unit 51. Next, corresponding to time slot “2”,
An instruction to read 1-byte data from the storage area of the buffer unit 32 corresponding to the original VC whose VCI is a2 is output from the time slot management unit 54 to the rotary switch unit 51. Hereinafter, similarly, an instruction to read the data of the original VC corresponding to each time slot is output from the time slot management section 54 to the rotary switch section 51 in the same manner.

The ATM layer section 60 performs processing corresponding to the ATM layer, and adds a header to the multiplexed data output from the rotary switch section 51 in the TDM function section 50 in units of 48 bytes. To generate an ATM cell. Alternatively, the ATM layer unit 60 performs a process of extracting 48 bytes of user information excluding the header portion from the ATM cells included in the physical layer frame.
In this header, a VPI (virtual path identifier; Virtual Path Identifier) defined in a contract with a telecommunications carrier providing an ATM network
Path Identifier) and VCI are set. In addition,
This VCI value is stored in the AAL function unit 30 or the TDM function unit 5.
It may overlap with the VCI of the original VC used in 0 (a1, a2, etc. in the table shown in FIG. 5).

FIG. 6 is a diagram showing a format of a general ATM cell. The ATM cell is composed of a 5-byte header followed by user information contained in a 48-byte user area. The first 4 bits of the header are general flow control GFC (Generic Flow Control)
Used as a field, the next byte is VP
I contains VCI in the next two bytes. Next, a 3-bit payload type PT (Payload Typ
e) 1-bit cell loss priority indication CLP (Cell Loss P
riority) 1 byte header error control HEC (Header
Error Check). The payload type PT indicates whether the ATM cell is a user cell or an OAM (Operat
ion Administration And Maintenance) cell, and “000” to “011” are user cells,
“100” and “101” correspond to OAM cells.
“110” and “111” are reserved. The cell loss priority indication CLP is a cell discard priority bit, and makes it possible to make a difference in the discard priority within the same VC. The header error control HEC is used for error detection / correction of a header and cell synchronization. If there is a bit error in the header, the bit error is corrected or, depending on the state, the ATM cell is discarded.

The physical interface unit 12 accommodates the WAN line 450 and performs processing corresponding to the physical layer. The frame structure corresponding to the physical layer is, for example, a synchronous digital hierarchy SDH (Synchronous Digital Hierarchy).
erarchy) Standard synchronous transport module STM
In the case of (Synchronous Transport Module) -1, as shown in FIG. 4, it is configured by an SDH overhead composed of a section overhead SOH, a pointer (pointer), and a path overhead POH, followed by a payload. Cells output from the ATM layer unit 60 are arranged in the payload in the order of input.

In a general ATM, when there is no user information to be transmitted, an empty cell (Id) generated in the physical layer is added to the payload of the SDH frame.
le Cell) and an unassigned cell (Unassigned Cell) generated in the ATM layer are inserted and cells are arranged so that there is no gap. In the present embodiment, each of the 48 bytes of user information in each cell is Since a byte corresponds to a specific time slot, it is not preferable to appropriately insert these empty cells and unallocated cells into the payload of the SDH frame. Therefore, in the present embodiment, TD
The data corresponding to each time slot is constantly output from the rotary switch unit 51 in the M function unit 50 (dummy data is output when there is no transmission data), and the ATM layer unit 60 stores this output data in 48 bytes. A cell is generated by dividing the unit and adding a predetermined header. In this way, cells having a clear relationship between each byte of the 48-byte user information and the time slot are arranged in order in the payload of the SDH frame of the physical layer.

The above-described AAL function unit 30 is used as the first and second data generating means, the TDM function unit 50 is used as the multiplexing means, and the demultiplexing means is used as the ATM layer unit 60, and the physical interface unit 12 is used as the data transmitting means. V
The C-time slot mapping table 53 corresponds to the first and second tables, respectively. In addition, the time slot management unit 54 serves as a time slot variable unit, the traffic flow monitoring unit 52 serves as a traffic monitoring unit, the VC management unit 36 serves as a first, second, and third table changing unit.
The buffer unit 32 corresponds to a data storage unit, the UNI signaling generation / processing unit 33 corresponds to first and second connection setting / release units, and the ATM layer unit 55 corresponds to a detection unit. Further, the original VC is a VC in which an ATM cell to which a header portion is added by the ATM layer portion 60 to the first and fourth connections is actually transmitted and received.
Correspond to the second and third connections, respectively.

The WAN nodes 200 and 210 of this embodiment
Has such a configuration, and its operation will be described next. For example, it is assumed that data is transmitted from each terminal device 300 connected to one WAN node 200 to any one of the terminal devices 310 connected to the other WAN node.

Operation of WAN Node on Transmitting Side First, various data input from the terminal device 300 is
The operation of the WAN node 200 on the transmission side for transmitting the data to the other WAN node 210 via the TM network will be described.

The data output from terminal device 300 is L
When the data is input to the WAN node 200 via the AN line 400, the data is transferred to the AAL function unit 30 via the physical interface unit 10 and the switch unit 20. A
The AL function unit 30 transmits A to the upper layer data.
A predetermined process related to the AL is performed to generate data in units of 48 bytes, and store the data in an area of the buffer unit 32 for each original VC. In the case where there are a plurality of data of the above-described upper layer, or when a signaling message different from such data is generated, the operation of storing the data of each original VC in the buffer unit 32 is performed in parallel. Done.

Next, the time slot management unit 54 in the TDM function unit 50 controls the switching state of the rotary switch unit 51 according to the contents of the VC-time slot mapping table 53, and stores the original VC corresponding to each time slot. Reads data in 1-byte units.

When data corresponding to each time slot is sequentially output from the rotary switch unit 51, the ATM layer unit 60 divides the output data in units of 48 bytes, and divides the output data into 48 bytes. An ATM cell is generated by adding a predetermined header including VPI and VCI. This ATM cell is the physical interface unit 1
2 is converted to an SDH frame by the WAN line 4
Sent out through the line 50.

In this manner, different VCs as in the prior art
An ATM cell to which a header portion having I is added is generated and sent to a WAN line 450, instead of a specific VC using one VCI previously determined by a contract with a communication carrier or the like. Data transmission is performed.

Operation of WAN Node on Receiving Side Next, the other WAN node 210 receives data transmitted from one WAN node 200 via the ATM network.
Will be described. The SDH frame transmitted from one WAN node 200 is
When input to the AN node 210, the physical interface unit 12 establishes synchronization of the frame, extracts cells included in the payload of the frame, and passes the cells to the ATM layer unit 60.

The ATM layer unit 60 performs error detection / correction on the cells sequentially input from the physical interface unit 12 with cell synchronization, and then extracts 48 bytes of user information included in each cell. To the TDM function unit 50. Next, the time slot management unit 54 in the TDM function unit 50 controls the switching state of the rotary switch unit 51 according to the contents of the VC-time slot mapping table 53. With this control, the 48-byte data input from the ATM layer unit 60 to the TDM function unit 50 stores the original V data corresponding to each time slot.
The data is stored in a corresponding area in the buffer unit 32 prepared for each C.

Next, the AAL layer unit 31 in the AAL function unit 30 reads out the data of the buffer unit 32 stored for each original VC and performs processing for assembling the data of the upper layer. The data of the upper layer is transmitted to any one of the physical interface units 10 via the switch unit 20.
To the terminal device 310 via the LAN line 410.
Sent to

In this way, the data received via a specific VC can be returned to the upper layer data corresponding to the original VPI and VCI. Thus, in the present embodiment, in the WAN node 200 on the transmission side,
Data corresponding to a plurality of original VCs can be transmitted through one VC by performing time-division multiplexing processing by associating each time slot with the original VC. Further, in the WAN node 210 on the receiving side, the multiplexed data received through this one VC is
By performing the separation process so as to maintain the same relationship between each time slot and the original VC as in the multiplexing process, the data can be divided into data corresponding to a plurality of original VCs. Therefore, the contract with the carrier
Since communication can be performed for a single VC, communication costs that would have been charged for each original VC can be reduced. Further, in the ATM network, the number of remaining VCs that can be set corresponding to the same VP increases, so that network resources can be effectively used.

By the way, in the communication using the general ATM, synchronization is established for the SDH frame corresponding to the physical layer, but the position of the ATM cell included in the payload of this frame is determined for each frame. Since they are different (since the capacity of the payload (2340 bytes) is not an integral multiple of the cell size (53 bytes)), the position of the time slot cannot be adjusted only based on the synchronization position of the frame. For example, in the simplest case, it is conceivable to associate the time slots "1", "2", "3",... In units of 1 byte from the head position of the payload of the frame. In some cases, the units may be arranged, and since this relationship changes for each frame, it is not possible to simply associate the frame synchronization state with the time slot number count state.

Hereinafter, a specific example of a method of establishing time slot synchronization in the WAN nodes 200 and 210 will be described. Synchronization Establishment Method 1 As described above, the payload included in the SDH frame has a capacity of 260 × 9 bytes, so that 2340/53 53-byte cells can be included. This corresponds to 44 cells and 8-byte data as a fraction. Therefore, the number of cells that do not span two frames is 44 when the number is large and 43 when the number is small. Also, since synchronization of each cell can be established by using the header error control HEC included in the header, the time slot management unit 54 in the TDM function unit 50 detects the head position of the frame, The bytes of the user information included in the cell first inserted into the payload of this frame (excluding the cell straddling the immediately preceding frame) may correspond to the time slot “1” in order. Considering that the number of cells included in the payload is 43 when the number of cells included in the payload is small,
The number of time slots can be set up to 2064 (= 43 × 38).

In the WAN node 210 on the receiving side,
The time slot management unit 54 in the TDM function unit 50 may detect the head position of the frame and start counting the time slot number when detecting the head position of the cell. By the way, in the SDH frame, since one frame including overhead is transmitted in 125 μs,
The communication band corresponding to 1-byte data included in the payload is 8 [bit] / (125 × 10 ⁻⁶ ) = 64 [kbps].
Becomes Therefore, when two time slots correspond to a predetermined original VC, the original VC
Is 128 [kbps]. If it is necessary to secure more communication bands, the number of time slots corresponding to the original VC may be increased.

Method of Establishing Synchronization The synchronization of the time slots may be established using the synchronization position of the cell separately from the synchronization of the two frames. For example, in the simplest case, the number of time slots is set to “48” or its common divisor (such as “24” or “16”), and the leading position of the 48-byte user information of each cell is set to time slot “1”. You may make it match. In this case, the time slot management unit 54 in the TDM function unit 50
In this case, the switching operation by the rotary switch unit 51 may be controlled in synchronization with the data division / assembly operation in units of 48 bytes in the ATM layer unit 60.

Although slightly more complicated, the same method can be used to set the number of time slots to more than "48",
A value other than 48 common divisors can also be set. For example, in this case, a plurality of cells are grouped into one group, and time slots are sequentially allocated from the head position of the user information included in the head cell of each group. However, the WAN on the receiving side
At node 210, the first cell of each group needs to be identified. This identification can be performed, for example, by storing a spare “111” in the payload type PT included in the header of the cell. For example, when three cells form one group, a maximum of 144 (=
48 × 3) time slots can be set.

The relationship between each time slot and the communication band in this case is as follows. For example, if 48 time slots are set corresponding to 48 bytes of user information of each cell, 234 in the SDH frame are set.
In a 0 (= 260 × 9) byte payload, 53
One byte included in the byte cell is allocated to the same time slot. Frame transmission interval 12
Considering 5 μs, the communication band of this original VC when a predetermined original VC is made to correspond to one time slot is 2340 × (1/53) × 8 [bit] /
(125 × 10 ⁻⁶ ) = 2.83 [Mbps]. Similarly, when 96 time slots are made to correspond to two cells, a predetermined original V
The communication band of this original VC when C is made to correspond is 2340 × (1/106) × 8 [bit] / (125
× 10 ^-6 ) = 1.41 [Mbps]. in this way,
By increasing the number of cells that make one round of the time slot number count, a smaller communication band can be associated with each time slot.

When changing the time slot assignment
Modified Example (Part 1) By the way, in the above-described embodiment, as shown in FIG. 5, the operation in the case of providing a fixed band service (for example, a fixed bit rate CBR) using each original VC has been described. When providing a best-effort service corresponding to a variable bit rate VBR or an unspecified bit rate UBR, the communication band of each original VC is not completely fixed but is variable according to the actual communication amount. It is desirable to do.

FIG. 7 is a diagram showing a modification of the VC-time slot mapping table. For example, it is assumed that the service categories of three original VCs with original VCIs a2, a3, and a4 are set to the best effort type. In FIG. 7, “assignable time-
slot # ”is allowed to be lent to another original VC in the time slot corresponding to the best-effort original VC, that is, other original VCs
Indicates the number of a time slot in which the allocation can be changed for the original VC when the traffic volume of the original VC increases. “Threshold (upper)” is an upper limit value serving as a criterion for determining whether to increase the time slot allocation. “Threshold (lower)” is a lower limit that serves as a criterion for determining whether to reduce the allocation of time slots.

The traffic flow monitoring unit 52 in the TDM function unit 50 monitors the traffic of the original VC whose service category is set to the best-effort type, and monitors the traffic of the original VC whose actual traffic is smaller than the set value. Conversely, when there are original VCs whose actual traffic is larger than the set value, an instruction to dynamically change the set value of the traffic of these original VCs is sent to the VC management unit 36 in the AAL function unit 30. send. VC management unit 36 receiving this instruction
Is necessary to change the contents of the VC-time slot mapping table 53 in the WAN node 210 as well as the contents of the VC-time slot mapping table 53 in the WAN node 210 to which data is to be transmitted. Generate a new mapping information change notification frame. This mapping information change notification frame has the WA
In order to send various notifications from the N node 200 to the WAN node 210, the notification is transmitted by using an original VC set exclusively. For example, as shown in FIG.
Is used to transmit the mapping information change notification frame.

FIG. 8 is a format diagram of a mapping information change notification frame generated by the VC management unit 36. In FIG. 8, in the “Frame Type” field,
Information indicating that this frame is a mapping information change notification frame is stored. The “Length” field stores the data length of the mapping information change notification frame. “Original VPI” field and “Origi
The “nal VCI” field stores the VPI and VCI necessary to specify the VP and VC whose contents of the corresponding time slot are to be changed.
The “ts” field stores information on a new time slot corresponding to the original VC specified using the “Original VCI” field.
In the "-slots" field, the allocation can be changed in the time slot set in the "New Time-slots" field. That is, when the communication volume of another original VC increases, the allocation is changed for the original VC. If there is a plurality of original VCs whose correspondence with the time slots is to be changed, the above-mentioned “Original V” is stored.
The process from the “PI” field to the “Assign-able Time-slots” field is repeated for this number.

FIG. 9 is a flowchart showing the operation procedure of the WAN node on the transmitting side, and mainly shows the operation procedure relating to the change of the contents of the VC-time slot mapping table 53. In the transmitting WAN node 200, the TDM
The traffic flow monitoring unit 52 in the function unit 50 checks the usage rate of the buffer unit 32 corresponding to each original VC whose service category is set to the best effort type, and
“Thresh” in the time slot mapping table 53
It is monitored whether or not there is any exceeding the predetermined upper limit set in the "old (upper)" field (step S10).
0). When there is no original VC whose usage rate of the buffer unit 32 exceeds the upper limit, this monitoring state is maintained.

If there is an original VC whose usage rate of the buffer unit 32 exceeds the upper limit, the traffic flow monitoring unit 52 sets a buffer corresponding to another original VC whose service category is set to the best effort type. The usage rate of the unit 32 is checked, and it is determined whether or not there is a value lower than a predetermined lower limit value set in the “threshold (lower)” field in the VC-time slot mapping table 53 (step S101). If there is no original VC whose usage rate of the buffer unit 32 is lower than the lower limit, the process returns to step S100 described above, and the monitoring state of the usage rate of the buffer unit 32 is continued.

If there is an original VC whose usage rate of the buffer unit 32 is lower than the lower limit, information on the original VC whose usage rate of the buffer unit 32 exceeds the upper limit and the original VC whose usage rate is lower than the lower limit is stored in the VC management. Part 36
Sent to Next, the VC management unit 36 changes the content of the VC-time slot mapping table 53 based on the transmitted information (step S102), and a mapping information change notification frame including the changed content (FIG. 8). Generate This mapping change notification frame is
It is stored in a buffer unit 32 corresponding to a specific original VC set in advance for notification of various communication items between WAN nodes, time-division multiplexed together with data of other original VCs, and transmitted to the WAN node 210 on the receiving side. It is sent (step S103).

In the receiving WAN node 210, the AAL
The VC management unit 36 in the function unit 30 monitors the contents of the buffer unit 32 corresponding to the specific original VC described above, and upon confirming the reception of the mapping change notification frame, based on the information included in this frame. , VC-time slot mapping table 53 is updated. Thereafter, the time slot management unit 54 controls the switching state of the rotary switch unit 51 based on the VC-time slot mapping table 53 having the updated contents.

The traffic flow monitoring unit 52 in the TDM function unit 50 of the WAN node 200
The usage rate of the original VC whose usage rate falls below the lower limit and the correspondence relationship with the time slot is changed is continuously monitored, and it is determined whether the usage rate exceeds the lower limit (step S104). ). When the usage rate exceeds the lower limit, the VC management unit 36 performs a process of restoring the correspondence between the changed original VC and the time slot (step S105). Specifically, the VC management unit 36 sets the VC-time slot mapping table 53
, And generate a mapping information change notification frame required to undo this change,
The message is transmitted to the WAN node 210 side.

As described above, when there is an original VC having a larger traffic than the set value and an original VC having a smaller traffic than the set value, the WAN node 200 on the transmitting side has the TDM function 50 Of the VC-time slot mapping table 53 is changed, and the WAN change node 210 on the receiving side also transmits a mapping change notification frame in order to reflect this change. As a result, both the sender and the receiver WAs
In the N nodes 200 and 210, the VC-time slot mapping table 53 is set so that the number of time slots corresponding to the original VC with a large traffic increases and the number of time slots corresponding to the original VC with a small traffic decreases. Since the content is changed and the communication band of each original VC suitable for the actual communication volume can be secured, network resources can be effectively used.

A switch-type virtual connection (SVC)
In the case where data transmission / reception is performed using a switched virtual connection, when a signaling procedure for performing call setup is executed, a change in the VC-time slot mapping table is received from the WAN node 200 on the transmission side. Side WAN
It may be sent to the node 210.

FIG. 10 is a diagram showing a signaling procedure related to call setup. FIG. 11 is a format diagram of the UNI signaling message. 12 and 13 are format diagrams showing specific contents of information elements (IEs) included in the signaling message shown in FIG. In particular, the information element shown in FIG. 13 includes the same information as the frame shown in FIG. 8 (information such as the correspondence between the original VC to be set and the time slot).

When user data corresponding to SVC is input from the terminal device 300 on the transmitting side to the WAN node 200, the UNI signaling generation / processing unit 33 in the AAL function unit 30 starts processing in the connection setting phase. First, the UNI signaling generation / processing unit 33 generates a call setup message (SETUP) and inputs it to the AAL layer unit 31. This message includes an information element (FIG. 12) for specifying a connection required to specify a call to be set, and an information element (FIG. 12) including information on a time slot corresponding to the original VP and the original VC. 13) is added. This call setup message is divided into 48-byte units by the SAR unit 35 and stored in the buffer unit 32 corresponding to the original VCI specially used for the signaling message.
The ATM layer unit 60 thus operates the buffer unit 32
Is read out in units of 48 bytes, and an ATM cell is generated by adding a header part.
Sent to

In parallel with the setting process of such a new original VC, the VC management unit 36 changes the contents of the VC-time slot mapping table 53. For example, when there is a vacant time slot and this time slot is made to correspond to the newly set original VC, the contents of the VC-time slot mapping table 53 are added so that information on this correspondence is added. Be updated. Further, when a part of the used time slot is made to correspond to the newly set original VC (for example, “assignable time-slot #” shown in FIG. 7).
Is added to the original V
C), the information on the correspondence is added, and the VC-time slot mapping table 53 is changed so that a part of the contents up to that point is changed.
Is updated.

In the receiving WAN node 210,
The UNI signaling generation / processing unit 33 returns a call setup message (CALL PROCEEDING) or a response message (CONNECT) to the WAN node 200 according to the normal signaling procedure shown in FIG. 10, and is included in the call setup message. The extracted information element (FIG. 13) is extracted, and an instruction to change the table is sent to the VC management unit 36. VC
When receiving this instruction, the management unit 36
The contents of the VC-time slot mapping table 53 in 0 are updated.

As described above, in the connection setting phase corresponding to SVC, by transmitting information elements necessary for updating the VC-time slot mapping table from one WAN node 200 to the other WAN node 210, Two Ws are included so as to include the correspondence between the newly added original VC and the time slot.
The content of each VC-time slot mapping table 53 in the AN nodes 200 and 210 can be updated and matched. Therefore, when the connection setting phase ends and the process shifts to the data transfer phase, data communication by time division multiplexing using time slots becomes possible. In particular, by updating the contents of the VC-time slot mapping table using the signaling message in such a connection setup phase,
Data communication by time division multiplexing can be efficiently performed in both PVC and SVC.

Modification when Compatibility with Conventional Device is Considered
By the way, some of the WAN nodes connected to the ATM network do not have functions such as the multiplexing processing of the WAN nodes 200 and 210, so that multiplexed data is used between these WAN nodes. It is necessary to secure the same communication operation as before. In such a case, VC-
It is sufficient that the time slot mapping table 53 includes information on the original VC for which the multiplexing process is not performed.

FIG. 14 is a diagram showing a modification of the VC-time slot mapping table. For example, the term “TDM service” is added to the VC-time slot mapping table shown in FIG. “TD
“M service” indicates whether or not to perform multiplexing processing on the corresponding original VC, and is “ON” or “O”.
FF "is set. If this item is set to" OFF ", the multiplexing process is not performed by the TDM function unit 50, and the buffer unit 32 corresponding to the original VC is set.
Is directly input to the ATM layer unit 60. AT
In the M layer unit 60, for this input data,
A header portion corresponding to the original VC is added in units of 48 bytes. Therefore, the physical interface unit 12 transmits a conventional SDH frame.

When changing the time slot assignment
Modified Example (Part 2) As described above, by changing the contents of the VC-time slot mapping table 53, the communication band of each original VC can be dynamically changed. Some original VC
Can be dynamically changed.

FIG. 15 is a diagram showing a partial configuration of the WAN node, and the T node in WAN node 200 shown in FIG.
The configuration of a TDM function unit 50A that can be replaced with the DM function unit 50 is shown. This TDM function unit 50A is configured as shown in FIG.
In the TDM function unit 50 shown in FIG.
It has a configuration in which a header section of a TM cell is added, and an ATM layer section 55 for performing a process of deleting the header section of the ATM cell from the data of the specific original VC output from the rotary switch section 51 is added. .

The traffic flow monitoring unit 52 in the TDM function unit 50A checks the usage rate of the buffer unit 32 corresponding to the original VC whose service category is set to the best-effort type, and exceeds the predetermined upper limit (when the traffic amount exceeds the predetermined upper limit value). Many)
It monitors whether or not there is an original VC and an original VC that is less than a predetermined lower limit (the communication amount is small).

When these two types of original VCs are present, the time slot management unit 54 uses a part or all of the time slots corresponding to the original VCs with a small traffic amount to use the other original VCs with a large traffic amount. Control for transmitting VC data is performed.

For example, in the example shown in FIG. 7, the communication volume of the original VC with the VCI of a2 (referred to as “VC2”) is small.
3)), when the traffic is large, V
Three time slots “2”, “7”, corresponding to C2,
By using “12”, a part of the data of the VC3 having a large communication amount is transmitted.

Time slot management section 54 temporarily transmits VC3 data to rotary switch section 51 and ATM layer section 55 using three time slots "2", "7", and "12". Send instructions. In response to this instruction, the ATM layer unit 55
48-byte data is read from the area corresponding to C3, and a predetermined header portion corresponding to VC3 is added to this data to generate a 53-byte ATM cell. Further, the rotary switch unit 51 converts the 53-byte ATM cell output from the ATM layer unit 55 into three time slots “2”, “7”, “1” newly associated with VC3.
2 ".

Also, T in the WAN node 210 on the receiving side is
In the DM function unit 50A, the ATM layer unit 55 monitors the content of data for each original VC output from the rotary switch unit 51, and determines whether or not the header portion of the ATM cell is included. I have. As mentioned above,
In a state where the relationship between the original VC and the time slot based on the VC-time slot mapping table 53 is maintained, the header output of the ATM cell is not added to the data output from the rotary switch unit 51, but the data is temporarily stored. When transmitting data by borrowing a time slot of another original VC, the original original VC
Is added, the ATM layer 55 extracts only the 48-byte user information following the header, and corresponds to the original VC specified by the VCI included in the header. Buffer unit 3
The extracted user information is stored in a storage area in the storage area 2.

As described above, data of another original VC having a large traffic can be transmitted using the time slot corresponding to the original VC having a small traffic, so that network resources can be effectively used. it can. Further, even when data is temporarily transmitted using a time slot corresponding to another original VC, the WAN node 210 on the receiving side identifies the data and treats it as original VC data. Can be.

In the above-described example, the header used in the ordinary ATM cell is added to the ATM layer 55 in the TDM function unit 50A. The header is included in the WAN node 210 on the receiving side. As long as it can be recognized by the ATM layer unit 55 in the TDM function unit 50, a dedicated header unit having a minimum length that can recognize the original VC may be used.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the embodiment described above,
Although a case has been described in which data of one byte unit is associated with each time slot, data of a plurality of bytes may be associated with each time slot, or data of less than one byte may be associated with each time slot.

In the above-described embodiment, the multiplexing process and the demultiplexing process are performed in the WAN nodes 200 and 210. For example, the multiplexing process is performed in the ATM terminal device, and the multiplexed data is transmitted to the WAN node. You may do so. The data to be multiplexed is A
Not only the TM cell but also other packet data or the like may be used.

In the above-described embodiment, data corresponding to a plurality of original VCs is multiplexed to form one VC.
, The multiplexed data may be transmitted via two or more VCs. (Supplementary Note 1) First data generation means for generating data addressed to a plurality of first connections, and data generated by the first data generation means corresponding to each of the plurality of first connections. A communication apparatus comprising: a multiplexing unit that performs multiplexing processing by allocating to a time slot; and a data transmitting unit that transmits multiplexed data output from the multiplexing unit to a second connection.

(Supplementary Note 2) In Supplementary Note 1, the multiplexing unit has a first table indicating a correspondence between each of the plurality of first connections and the time slot. A communication device for performing multiplexing processing based on contents.

(Supplementary note 3) In Supplementary note 2, when the plurality of first connections include a service corresponding to a best-effort service category, the multiplexing unit may handle the first connection. A communication device comprising a time slot variable unit for variably controlling the number of the time slots.

(Supplementary Note 4) In Supplementary Note 3, the multiplexing unit performs a process of variably controlling the number of the time slots without changing the contents of the first table.
A communication apparatus for performing multiplexing processing including connection identification information indicating which of the plurality of first connections corresponds to the data, when the contents of the first table are contrary to the contents of the first table.

(Supplementary note 5) In Supplementary note 2, the traffic monitoring means for monitoring the traffic of data corresponding to each of the plurality of first connections, and the first communication means may be provided based on a monitoring result by the traffic monitoring means. A first table changing means for dynamically changing the contents of a table.

(Supplementary note 6) In Supplementary note 5, further comprising data storage means for storing the data output by the first data generation means in correspondence with each of the plurality of first connections, and The communication device monitors the amount of data stored in the data storage device before reading.

(Supplementary Note 7) In the supplementary note 5, the first table changing means may be arranged so that the plurality of first connections include two or more services corresponding to a best-effort service category, The contents of the first table are changed when one of these first connections has a data traffic volume below a predetermined lower limit value and a data communication volume exceeding a predetermined upper limit value. Communication device.

(Supplementary Note 8) In the supplementary note 2, a first connection setting / release means for performing additional setting or partial release of the first connection by performing predetermined connection setting processing and connection release processing;
A second dynamically changing the contents of the first table when the contents of the plurality of first connections are changed by the processing of the first connection setting / release means;
And a table changing unit.

(Supplementary note 9) In Supplementary note 2, the first table includes information indicating whether or not each of the plurality of first connections is a target of multiplexing processing by the multiplexing means. The multiplexing means performs multiplexing processing on corresponding data for a part of the plurality of first connections based on the contents of the first table, and converts corresponding data for the rest. A communication device characterized by outputting without multiplexing.

(Supplementary Note 10) A data receiving means for receiving the multiplexed data transmitted through the third connection, and a plurality of fourth multiplexed data received by the data receiving means for each time slot. A demultiplexing unit for demultiplexing in accordance with one of the connections; and a second data generating unit for generating data for each of the plurality of fourth connections separated by the demultiplexing unit. Communication device.

(Supplementary Note 11) In Supplementary Note 10, the demultiplexing unit has a second table indicating a relationship between each of the plurality of fourth connections and the time slot, and the contents of the second table are provided. A communication device for performing a separation process based on a communication device.

(Supplementary Note 12) In Supplementary Note 11, the demultiplexing unit may be configured to separate the multiplexed data when the identification information for specifying the fourth connection is added to the data obtained by separating the multiplexed data. Communication means for detecting data, wherein the second data generation means generates data by giving priority to the fourth connection specified based on the identification information. apparatus.

(Supplementary Note 13) In the supplementary note 11, by performing predetermined connection setting processing and connection release processing, a second connection setting / release means for performing additional setting or partial release of the fourth connection; And a third table changing means for dynamically changing the contents of the second table when the contents of the plurality of fourth connections are changed by the processing of the second connection setting / release means. A communication device characterized by the above-mentioned.

(Supplementary Note 14) In Supplementary Note 11, the second table includes information indicating whether or not each of the plurality of fourth connections is a target of separation processing by the separation processing unit. The demultiplexing unit performs a demultiplexing process on a part of the plurality of fourth connections based on the content of the second table, and separates the corresponding data on the rest of the plurality of fourth connections. A communication device characterized by outputting without performing any processing.

[0104]

As described above, according to the present invention, each data originally transmitted separately through each of the plurality of first connections is subjected to a multiplexing process on this data. By doing so, transmission can be performed via one second connection, so that communication costs can be reduced. In addition, since the number of connections for actually transmitting and receiving data can be reduced, network resources can be effectively used.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a network including a WAN node as a communication device according to an embodiment.

FIG. 2 is a diagram illustrating a state of data transmitted and received between WAN nodes.

FIG. 3 is a diagram showing a detailed configuration of a WAN node.

FIG. 4 is a diagram showing details of disassembly / assembly of a cell performed in a WAN node.

FIG. 5 is a diagram showing a specific example of a VC-time slot mapping table.

FIG. 6 is a diagram showing a format of an ATM cell.

FIG. 7 is a diagram showing a modified example of the VC-time slot mapping table.

FIG. 8 is a format diagram of a mapping information change notification frame generated by a VC management unit.

FIG. 9 is a diagram illustrating an operation procedure of the WAN node on the transmission side when the assignment of the time slot is changed.

FIG. 10 is a diagram showing a signaling procedure regarding call setup.

FIG. 11 is a format diagram of a UNI signaling message.

FIG. 12 is a format diagram showing specific contents of information elements included in a signaling message.

FIG. 13 is a format diagram showing specific contents of information elements included in a signaling message.

FIG. 14 is a diagram showing a modification of the VC-time slot mapping table.

FIG. 15 is a diagram showing a partial configuration of a WAN node.

[Explanation of symbols]

 10, 12 Physical interface (I / F) unit 20 Switch unit 22 Routing table 30 AAL function unit 31 AAL layer unit 32 Buffer unit 33 UNI signaling generation / processing unit 36 VC management unit 40 QoS determination unit 50 TDM function unit 51 Rotary switch Unit 52 Traffic flow monitoring unit 53 VC-time slot mapping table 54 Time slot management unit 55, 60 ATM layer unit 200, 210 WAN node 300, 310 Terminal device 400, 410 LAN line 450 WAN line

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04L 29/14 H04L 13/00 307A 313 F term (reference) 5K028 AA06 AA11 KK01 KK03 LL11 LL12 PP04 RR02 5K030 GA19 HA10 HB14 HC01 HC14 HC15 HD07 LB02 LB03 LB19 MB09 5K033 AA01 AA04 CB01 CB08 DA01 DA06 DB12 DB17 5K034 AA14 AA17 BB06 EE09 EE10 HH01 LL01 LL02 LL07 TT02 5K035 AA05 EE25

Claims (5)

[Claims] A first data generation unit for generating data addressed to a plurality of first connections; and a data generated by the first data generation unit corresponding to each of the plurality of first connections. A communication apparatus comprising: a multiplexing unit that performs multiplexing processing by allocating to a time slot to be multiplexed; and a data transmitting unit that transmits multiplexed data output from the multiplexing unit to a second connection. 2. The multiplexing means according to claim 1, wherein the multiplexing means has a first table indicating a correspondence relationship between each of the plurality of first connections and the time slot, and a content of the first table. A communication device for performing a multiplexing process based on a communication device. 3. The first table according to claim 2, wherein a traffic monitoring unit that monitors a traffic volume of data corresponding to each of the plurality of first connections, and the first table based on a monitoring result by the traffic monitoring unit. And a first table changing means for dynamically changing the content of the communication table. 4. The first connection setting / release means according to claim 2, wherein said first connection setting / release means performs additional setting or partial release of said first connection by performing predetermined connection setting processing and connection release processing; The contents of the first table are dynamically changed when the contents of the plurality of first connections are changed by the processing of the connection setting / release means of the second.
And a table changing unit. 5. A data receiving means for receiving multiplexed data transmitted via a third connection, and transmitting the multiplexed data received by the data receiving means to a plurality of fourth connections for each time slot. A communication unit comprising: a demultiplexing unit that separates data corresponding to any one of them; and a second data generation unit that generates data for each of the plurality of fourth connections separated by the demultiplexing unit. apparatus.