JPH08186578A - Switching processing control method for atm network - Google Patents

Abstract

PURPOSE: To reduce processing relating to the decision of VPI/VCI and the setting of a cell header conversion table and to improve the throughput of an ATM switching machine by performing only the reservation/release of the band of a cell when communication between network elements housed in an ATM network is started and completed. CONSTITUTION: A terminal 101 holds communication With a terminal 106 with high frequency. The terminal 106 is decided as a registration target, and the VPI/VCI used by the cell between the terminals 101 and 106 is decided. The terminal 101 stores the terminal 106 as a (VPI/VCI decided and cell header conversion table set incoming call destination), and also, stores the VPI/VCI in the cell for the terminal 106. Also, the cell header conversion tables of switching machines 107, 109 on the midway are set. For example, the cell conversion table 201 sets input a(7,3), output A(5,4), and informs the fact of registration as an incoming call terminal is informed to the terminal 106. When the communication is completed, the terminal 101 performs the reservation/release of the band by instructing band release to the switching machine 107.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an asynchronous transfer mode (A
TM; Asynchronous Transfer
The present invention relates to a network (hereinafter referred to as an ATM network) for performing data transfer by Mode, and particularly, an ATM network exchange processing control method suitable for reducing the processor load related to VPI / VCI determination, cell header conversion table setting, and bandwidth reservation. It is about.

[0002]

2. Description of the Related Art Broadband ISDN (Integrated Digital Communication Network; Integrated Serre) compatible with communication of multimedia information
vices Digital Network), for example, “Nikkei Communication Separate Volume ISDN Usage Guide” (19
The ATM network control technology described on pages 168 to 177 of Nikkei BP (1988) has been developed. The ATM network will be described below with reference to FIGS.

In FIG. 16, 101 to 106 are terminals,
107 to 109 are ATM exchanges. Transmission links 110-1 are provided between terminals and exchanges and between exchanges.
It is tied by 18. Transmission links 110-118
One or more virtual paths (hereinafter VP; Virtua)
l Pass) and one or more virtual connections (hereinafter referred to as VC; Virtual Connection) are accommodated in the VP. In the ATM network, all information is
It is transferred in fixed-length block units called cells. The cell identifies the VP in the cell header.
I and a VCI that identifies the VC in the VP.
I and VCI identify which VC each cell carries information corresponding to. Also, in the cell header,
There is an area for distinguishing the user information cell from other cells.

The ATM switch is, for example, the ATM shown in FIG.
A cell header conversion table (TBL) 2 for deciding a transfer destination of a cell, as shown by a switch (denoted as Ex in the figure) 107.
01 (also referred to as a mapping table) and a switch (indicated as SW in the figure) for performing an actual cell exchange process 20
2 and a processor (described as CPU in the drawing) 203 for performing signal processing for VPI / VCI determination, cell header conversion table setting, and bandwidth reservation. For example,
16, when communication is performed from the terminal 101 to the terminal 106, it is necessary to determine the VPI / VCI between the terminals, set the cell header conversion table on the exchanges 107 and 109, and reserve the bandwidth between the terminals. Become. This bandwidth reservation is, for example, for a transfer capacity of 150 Mb / s, so that the inflowing cell amount does not exceed it.
The transfer capacity corresponding to the inflow cell amount is secured in advance.

FIG. 1 shows how values are set in the cell header conversion tables of the exchanges 107 and 109 in FIG.
7, shown in FIG. Cell header conversion table 2 in FIG.
01, input transmission links 110-112 are respectively a,
b, c, and output transmission links 113, 114 are A,
In the cell header conversion table 301 of FIG. 18, the input transmission links 113 and 115 are represented by a and b, and the output transmission links 117 and 118 are represented by A and B. In FIG. 16, first, if it is determined that the VPI / VCI value of the cell header is to be output from the terminal 101 to the exchange 107 by, for example, “7” and “3”, the transmission link 110 to the exchange 107 is set.
In the cell header conversion table 201 of FIG. 17 input from the above, reference is made to the (7, 3) number of the input transmission link a,
The VPI / VCI value of the cell header is output to the corresponding output link A as (5, 4). The output link A is actually the transmission link 113, and the cell output here is VPI = 5, VCI for the output transmission link A (that is, the transmission link 117) in the exchange 109 based on the cell header conversion table 301 shown in FIG. = 7 is output. As a result, this cell arrives at the intended terminal 106.

As described above, communication between terminals is performed by performing "VPI / VCI determination", "cell header conversion table setting", and "bandwidth reservation". Generally, in order for unspecified subscribers to communicate with each other, these processes are performed at each communication, and at the end of each communication, "bandwidth release", "cell header conversion table setting cancellation", "VPI / VC"
I release. These processes are performed not only in the ATM layer (providing the function of only transferring cells) but also in the OS.
I (Open Systems Interconnection)
Layer 3 (third layer, network: determines a data transmission path) in (3), and is performed by software by the processors (203, 303).
Note that "VPI / VCI determination" and "cell header conversion table setting" are performed for each communication, but "bandwidth reservation and release"
Has also proposed a technique of generating a "bandwidth reserved cell / released cell" for each burst unit which is a block of cells. In this case, the "bandwidth reservation / release" can be performed in the ATM layer, and can be performed only in hardware without the intervention of a normal processor.

[0007]

The problem to be solved is that the conventional ATM network switching processing control technology is "VPI /
The processing for “VCI determination and cell header conversion table setting” occupies a large part of the processor load. An object of the present invention is to solve these problems of the prior art, reduce and reduce the processing of the processor relating to "VPI / VCI determination, cell header conversion table setting", to make the ATM switch and the ATM network economical, and to improve the ATM switch. An object of the present invention is to provide an ATM network exchange processing control method capable of improving processing capacity.

[0008]

In order to achieve the above object, an ATM network exchange processing control method according to the present invention comprises (1) an AT which performs cell transfer in an asynchronous transfer mode (ATM).
In the switching processing control method for M network, VPI / VC used for transferring cells between two network elements arbitrarily selected in advance.
I is determined and set in the cell header conversion table, and at the start and end of communication between two network elements, the cell that reserves the band and the cell that releases the band are set to the VPI / cell set in the cell header conversion table. VC
It is characterized in that it is flown between two network elements while VPI / VCI conversion is performed according to I, and only bandwidth reservation / release is performed without determining / releasing VPI / VCI and setting / releasing the cell header conversion table. Also, (2) A for performing data transfer in the asynchronous transfer mode (ATM)
In the switching processing control method for the TM network, when the communication between the network elements accommodated in the ATM network is completed, the VPI / VCI
Is not released and the cell header exchange table is not released, but only the bandwidth is released. When starting the next communication between network elements, the cell for which the bandwidth is reserved has already been set in the cell header conversion table in the previous communication. VPI / VCI
It is characterized by flowing between two network elements while performing VPI / VCI conversion according to. (3) In the ATM network exchange processing control method according to (2), when the communication between the two network elements reaches a predetermined number of times, the communication between the two network elements ends. It is characterized in that the exchange processing control is performed only by releasing the band. (4) In the ATM network switching processing control method according to any one of (1) to (3), the network element of the transfer destination of the cell for which the VPI / VCI is determined and the cell header conversion table is set When the VPI / VCI between network elements is determined and the cell header conversion table is set over a predetermined number, the VPI / VCI between network elements is calculated in the order of lowest counted communication frequency. It is characterized in that it is assigned to communication between new network elements. Also, (5) above (1)
In the ATM network exchange processing control method according to any one of (3) to (3), the VPI / VC between network elements exceeds a predetermined number.
When determining I and setting the cell header conversion table, the VPIs between network elements are arranged in the order of earliest communication occurrence date and time.
/ VCI is assigned to communication between new network elements. (6) In the ATM network switching process control method according to any one of (1) to (5) above, each network element monitors a cell flow on each VPI / VCI, and a predetermined time or more When VPI / VCI in which no cell is flowing is detected, a cell for releasing the band of this VPI / VCI is transmitted. Also, (7) above (1)-
In the ATM network exchange processing control method according to any one of (6), each network element monitors a cell flow on each VPI / VCI, and a VPI in which no cell has flowed for a predetermined period or longer.
/ VCI is detected and stored, and when a VPI / VCI shortage occurs for a new communication request between network elements accommodated in the ATM network, the stored VPI / VCI is assigned to the new communication request. It is characterized by (8) In the ATM network switching control method according to any one of (1) to (6), the network element monitors the cell flow on each VPI / VCI, and the cell is monitored for a predetermined time or longer. VPI / VCI that is not flowing is detected and stored, and the stored VPI / VCI is detected.
When the VPI / VCI shortage occurs in response to a new communication request between network elements accommodated in the ATM network while releasing the bandwidth allocated to the / VCI, the stored VPI / VCI is used. One VPI / VCI is selected, the selected VPI / VCI is released and the setting in the cell header conversion table is released, and the released VPI / VCI is released.
/ VCI is assigned to a new communication request. (9) In the ATM network exchange processing control method according to any one of (1) to (6), the network element monitors the cell flow on each VPI / VCI, and the cell is monitored for a predetermined time or more. Is detected every time VPI / VCI is detected,
It is characterized in that the band allocated to the detected VPI / VCI is released, the VPI / VCI is released, and the setting of the cell header conversion table is released. In addition, (1
0) In the switching processing control method for an ATM network according to any one of the above (7) to (9), there is a shortage of VPI / VCI for a new communication request between network elements accommodated in the ATM network. When it occurs, the VPI / VCI used for the oldest communication is selected and assigned to a new communication request.
(11) In the ATM network exchange processing control method according to any one of (1) to (10), the VPI / VC
It is characterized in that an arbitrary amount of band is allocated in advance for each network element for which I and the cell header conversion table are determined and set, and communication between network elements is performed within this allocated band amount. (12) In the ATM network exchange processing control method according to any one of (1) to (11) above,
Each exchange processing control is performed between a calling terminal and a called terminal as network elements. (13) In the ATM network exchange process control method according to any one of (1) to (11), each exchange process control is performed between exchanges as network elements. Also, (14)
In the ATM network exchange processing control method according to any one of the above (1) to (11), each exchange processing control is performed between exchanges as network elements, and a source terminal and a destination terminal as the exchange and network elements. In between, the conventional method is characterized in that the exchange processing control is performed by the upper layer.

[0009]

In the present invention, it is necessary to determine the VPI / VCI and the cell header conversion table prior to the cell transfer in the ATM network. This requires software processing (upper layer), which becomes a processor load. Paying attention to this, for example, “VPI / VCI determination” and “cell header conversion table setting” are performed in advance for specific network elements such as terminals and exchanges that frequently communicate. In addition, in the calling terminal, the called terminal for which “VPI / VCI determination” and “cell header conversion table setting” have been performed in advance is registered as the “registered destination”. Then, in the communication to the registered destination, only the reservation and release of the band, and the hardware processing at the time of the communication request and at the end of the communication are performed. Alternatively, only bandwidth reservation is performed by hardware when a communication request is made, and bandwidth is released by monitoring the network (monitoring whether cells are flowing for a predetermined time or longer). In this way, software processing can be reduced.
Further, this can be expected to increase the amount of communication that can be processed by a single exchange and to utilize high-speed hardware processing.

Further, even in the case of communication by a network element that has not been registered, at the end of the communication according to the conventional technique, only the band is released, the VPI / VCI is not released, and the cell header conversion table is not released. By leaving “VCI determination” and “cell header conversion table setting”, the same processing can be performed for users who are not registered as registered destinations. Further, only when the communication is performed a predetermined number of times, by leaving the “VPI / VCI determination” and the “cell header conversion table setting”, it is possible to efficiently specify the network element to which the present invention is applied. it can.

When the number of registrations exceeds the number that can be registered, the "VPI / VCI determination" and "cell header conversion table setting" for communication with high communication frequency or communication close to the latest communication are always left. . As a result, it is possible to efficiently select a specific net element. In particular, since the selection can be made based on the date and time of communication occurrence, it is effective when the communication partner has a high correlation with the recent communication partner. Also,
By monitoring the cell flow, network elements with low communication frequency can be identified, bandwidth can be released by the destination terminal or exchange, and when VPI / VCI is insufficient, "VPI / VCI release" and "cell header conversion table setting release" Can select the candidate of ", and can always use up VPI / VCI. Further, by performing the exchange processing control of the present invention between the exchanges accommodating the originating side terminal and the receiving side terminal respectively, the processor load of the transit exchange can be reduced and the VPI / VCI can be used more effectively. Further, by dividing the band for each destination node (switch), the band usage efficiency is reduced, but the band reservation and release at the relay node are not required.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 4 are flowcharts showing a first embodiment of an ATM network exchange processing control method according to the present invention.
The operation between the terminals 101 and 106 in the ATM switching network having the configuration shown in FIG. 16 will be described based on FIGS. 1 to 4. In this embodiment, it is assumed that the terminal 101 in FIG. 16 communicates with the terminals 106 at high frequency. First, the terminal 106 is determined in advance as a registration target (step 101), and the cell between the terminals 101 and 106 is determined. Determines the VPI / VCI used (step 102).

For example, as described in the prior art, the number (7, 3) is between the terminal 101 and the exchange 107, and the exchange 101
And (5, 4) between the exchange 109 and (5, 7) between the exchange 109 and the terminal 106. Then, the terminal 101 stores the terminal 106 as “VPI / VCI determined, destination set with cell header exchange table” (hereinafter referred to as registered destination), and the VPI / VCI written in the cell for this terminal 106 is stored. It is stored as shown in FIG. 19 (step 103). Further, the cell header conversion tables 201 and 301 of the exchanges 107 and 109 on the way are set (step 104). For example, the cell header conversion table 201
Input a (7,3), output A (5,4), and cell header conversion table 301 input a (5,4), output A
Set it as (5, 7). Then, the terminal 106 is notified that it has been registered as the destination terminal (step 105).

When the terminal 101 actually communicates with the terminal 106 (incoming call request), the subscriber using the terminal 101 inputs the incoming call address corresponding to the terminal 106 (step 106). The terminal 101 refers to the content of FIG. 19 and determines whether the address is included in the registered destinations (step 107). If not included, communication is performed by the function of the upper layer of the prior art (step 108), but in this example, as shown in FIG. 19, since the terminal 106 is included in the registered destinations, bandwidth reservation is made. Corresponds to the terminal 106 as VPI / VCI for the cell to be performed (distinguished from the user information cell by the cell header) (7, 3)
Is written and sent on the output transmission link 110 (step 109).

Next, the exchange 107 which has received this cell
Recognizes that it is a band reserved cell (step 11
0), read the required bandwidth and VPI / VCI written in a predetermined area of the same cell (step 111), and use the reserved bandwidth value (see FIG. 20) corresponding to the relevant VP on the transmission link 113. If the required bandwidth is added and the value exceeds the VP bandwidth (step 112), a cell notifying that bandwidth reservation is not possible is returned to the terminal 101 (step 113),
If it does not exceed the value, the value is written as a new reserved bandwidth value in the bandwidth management table in the exchange (see FIG. 20) (step 114). After that, according to the cell header conversion table 201 in FIG. 17 (input a “7,3”,
Output A "5,4"), VPI / VCI conversion of band reserved cell,
The data is transmitted to the exchange 109 via the transmission link 113 (step 115).

As described above, the processing from the reception of the band reserved cell to the transmission in the exchange 107 is all performed by hardware without interposing the processor 203. Although the required bandwidth amount is described in the bandwidth reservation cell here, the VC bandwidth may be stored in advance for each registered destination and not described in the bandwidth reservation cell. Next switch 109
In the same way, the same processing from the band reserved cell reception to the transmission as in the exchange 107 is performed (step 116-
119), and sends the band reserved cell to the destination terminal 106 (step 120).

Then, the terminal 10 which has received the band reservation cell
In step 6 (step 121), if the user information can be received (step 122), the receivable cell is transmitted in the opposite direction to the band reserved cell (step 124). Receivable cells are
It is brought to the terminal 101 through the exchanges 109 and 107 (steps 125 and 126). If the cell cannot be received at step 122, the cell notifying that the cell cannot be received is exchange 1
The terminal 101 is notified via 09 and 107 (step 123). The terminal 101 that has received the receivable cell (step 127) flows the user information cell and communicates with the terminal 106 (step 128). At the end of communication, the terminal 101 sends a band release cell (distinguished from a user information cell by a cell header) to the line 110 with VPI = 7 and VCI = 3, thereby instructing the exchange 107 to release the band (step). 129).

Further, the exchange 107 which has received this cell
Recognizes that it is a band release cell (step 13
0), read the release bandwidth amount written in a predetermined area of this cell (if the bandwidth reservation cell has no description of the bandwidth amount, the release cell does not need the bandwidth description) and VPI / VCI (step 131), the value of the reserved bandwidth for the VP on the transmission link 113 is reduced by the released bandwidth, and the exchange 10
It writes in the band management table shown in FIG. 20 in 7 (step 132). Then, according to the cell header conversion table 201 of FIG. 17, this band release cell is VPI / VCI converted,
The data is transmitted to the exchange 109 via the line 113 (step 133). Such band release cell reception to transmission can be performed by hardware without intervention of the processor 203.

Also in the next exchange 109, the exchange 10
The processing from the band release cell reception to the transmission similar to that in 7 is performed (steps 134 to 137). Switch 109
The terminal 106 that has received the band release cell from sends the release end cell in the opposite direction to the band release cell (step 13).
8). The cell is connected to the terminal 1 via the exchanges 109 and 107.
01 (steps 139 to 141). The cell transmission / reception operation by the above processing is shown in FIG.

Next, another embodiment according to the present invention will be described with reference to FIG. FIG. 5 is a flow chart showing a second embodiment of the ATM network exchange processing control method of the present invention. In this example, the band is released by the destination terminal.
~ After the processing in steps 106 to 129 in Fig. 4,
The destination terminal monitors the cell flow (step 20).
1) If cells have not been transferred for a certain period of time (step 202), a band release cell is generated and transmitted,
The bandwidth for communication with the calling terminal is released (step 20).
3).

Next, another embodiment according to the present invention will be described with reference to FIG. FIG. 6 is a flowchart showing a third embodiment of the ATM network exchange processing control method of the present invention. In this example, the bandwidth is released by each exchange, and the VPI / VCI in which cells have not been transferred for a certain period of time is released from the cell header conversion table. In particular,
Terminal 101 in the ATM switching network having the configuration shown in FIG.
Step 1 in FIG.
10 illustrates an operation example when the destination terminal corresponding to the communication request in 07 is not included in the registered destinations.

If the destination terminal corresponding to the communication request is not included in the registered destinations, communication according to the conventional technique is performed (step 306). In that case, the network first determines the VPI / VCI used by the cell between the terminals 101 and 106. For example, as described in the related art, the terminal 101 and the exchange 107 are (7, 3), the exchanges 107 and 109 are (5, 4), and the exchange 109 and the terminal 106 are (5, 7).
It is decided to turn. Then, the cell header conversion tables 201 and 301 of the exchanges 107 and 109 on the way are set. For example, in the cell header conversion table 201, the input a (7,
3), output A (5,4), cell header conversion table 30
At 1, the input is set to a (5, 4) and the output is set to A (5, 7). The terminal 101 refers to the terminal 106 as “registered destination”
(VPI / VCI determined, destination set with cell header exchange table already set), and VPI / VCI to be given to the cell for the same terminal is stored (see FIG. 19). As a result, after the next time, terminal 1
06 is a registered destination.

As described above, when a communication request is made to a destination not included in the registered destinations, VPI / VCI determination and cell header conversion table setting are performed according to the conventional technique. The VPI / VCI release process is not performed after the communication process control by. Therefore V
CI is exhausted. In order to deal with such a problem, as shown in FIG. 6, in the present embodiment, each exchange sets a cell on each VC during each process of step 128 and step 133 described in FIGS. The flow is monitored (step 301), and the cell has not flowed for a certain period of time V
C (step 302) is stored in the processor as a dormant VC list (see FIG. 23) (step 30).
3) Then, the bandwidth of this VC is subtracted from the reserved bandwidth list (see FIG. 20) (step 304). Therefore, a user who does not want to release the band in which the user information is interrupted needs to occasionally send out an OAM cell or the like while not transmitting the user information.

In this way, with the dormant VC list registered, it is assumed that, for example, the VCI with VPI = 5 in the transmission link 113 shown in FIG. 17 has been used up (step 305), and on the exchange 107. Suppose that the paused VC list in step 23 is as shown in FIG. 23 (step 30
7), the transmission link 113 is, as described above, the exchange 1
Since the transmission link is “A” on 07, VCI = 4 for VPI = 5 in this transmission link is a dormant VC. Therefore, the cell header conversion table 201 on the exchange 107 is set.
From the input (a, 7, 3) and output (A, 5, 4) corresponding to the same VCI (step 309),
The released cell of this VC (VCI = 4) is the pure direction of the same VC,
The data is sent in the reverse direction (step 310). In addition, step 3
If the VCI is not insufficient in 05, communication control is performed by the function of the upper layer by the conventional technique (step 306). In step 307, the pause VC
If there is no list, call loss or detour processing is performed (step 308).

The exchange 1 which has received the VC release cell transmitted from the exchange 107 whose VCI is insufficient in step 310.
09, the cell header conversion table 301 shown in FIG.
From the input (a, 5, 4) corresponding to the same VC, output (A,
5 and 7) are deleted and the released cell of the same VC is set to the terminal 1
06 (step 311). The terminal 106 that has received this VC release cell releases the relevant VCI from the registered destination list and returns a release end cell (step 312). This release end cell is notified to the exchange 107 via the exchange 109. (Step 313). still,
In the terminal 101 which has received the VC release cell transmitted from the exchange 107, from the cell header conversion table, the VC
And the destination (the destination 106, VPI
= 7, VCI = 3) is deleted, and a release end cell is transmitted to the exchange 107. As a result, the VP on the transmission link 113
Since VCI = 4 in I = 5 becomes available for another VC, the exchange 107 allocates this VCI to a new communication request by the conventional technique.

The above processing operation is also shown in FIG. In the third embodiment, the VCI is released when the VCI becomes insufficient due to a communication request to a destination not included in the registered destinations, but it may be released at regular intervals. . Also, the newly assigned VC
At the end of the communication using I, the terminal 101 sends the band release cell to the terminal 106, as in step 129 in FIG. 3 (at this time, the exchanges 107 and 109 only transfer the band release cell). Alternatively, as in the processing of steps 201 to 203 in FIG.
Monitors the cell flow, detects that no cells are flowing for a certain period, and secures the band. In either case, the exchange does not activate the bandwidth release and VPI / VCI release processing by any notification processing.

Next, another embodiment according to the present invention will be described with reference to FIGS. 7 to 11 show the AT of the present invention.
It is a flowchart which shows the 4th Example of the switching process control method of M network. 7 to 11 are examples of communication according to the present invention between the exchanges 904, 906 and 907 in the ATM switching network having the configuration shown in FIG. A table showing the determined VPI / VCI and the registered destination node is stored on the exchange 904 in FIG. 24 (FIG. 2).
5). The cell header conversion table on the exchange 905 is as shown in FIG. Here, the transmission link 909 is the input transmission link a on the cell header conversion table, the transmission link 910 is the output transmission link A, and the transmission link 912 is the output transmission link B.

Therefore, in the exchange 904, VPI =
1, the cell sent out on the transmission link 909 at VCI = 1 is switched to V on the transmission link 910 at the exchange 905.
It is sent with PI = 1 and VCI = 1 and delivered to the exchange 906. In the exchange 904, VPI = 1, V
The cell transmitted on the transmission link 909 with CI = 3 is transferred to the transmission link 912 at the exchange 905, and VPI =
1, VCI = 1, and sent to the exchange 907.

When a communication request is actually made between the terminals 901 and 903 (step 401), the terminal 901 makes a communication request to the exchange 904 by using the function of the upper layer according to the prior art (step 402). The exchange 904 recognizes that this communication request is a communication request to the terminal 903 (step 403), and the exchange 90 as a destination node.
It is judged that 6 should be selected (step 404), and the registered destination node table is searched (step 405).
Registered destination node is VPI / VC corresponding to exchange 906
One of the I's not in use, eg VPI = 1,
Select VCI = 1 (step 406) and select the VP (VP
It is determined whether or not a value obtained by increasing the value of the reserved band corresponding to I = 1) by the amount of band required for this communication exceeds the VP band, and if it exceeds, a call loss or detour process is performed. (Step 408). If it does not exceed the VP band, the value is newly set as the reserved band value and written in the table (see FIG. 20) for band management in the exchange (step 409).

Then, the selected VPI = 1 and VCI = 1
Is set in the cell header conversion table on the exchange 904 (step 410), and the band reserved cell is set to the transmission link 909.
The data is sent upward with VPI = 1 and VCI = 1 (step 411). FIG. 27 shows the setting contents of the cell header conversion table after the processing of step 410. The exchange 905, which has received this band reserved cell, recognizes that it is a band reserved cell (step 412) and reads the required band amount and VPI / VCI written in a predetermined area of the cell (step 413). ), The relevant VP on the transmission link 910 (VP
If the value obtained by increasing the value of the reserved band corresponding to I = 1) by the amount of band required for this communication does not exceed the VP band (step 414), the value is newly set as the value of the reserved band and the exchange is set. The data is written in a table for bandwidth management (step 416). If it exceeds the VP band, a reservation notifying cell is returned or a time-out is caused by discarding the band reserved cell (step 415).

After that, according to the cell header conversion table,
The band reserved cell is transmitted through the transmission link 910, VPI = 1, VCI.
= 1, the data is transmitted to the exchange 906 (step 417).
The procedure from receiving the band reserved cell to transmitting the band reserved cell is performed by the exchange 9
In 05, software processing by the processor and upper layer processing are not required. The exchange 906 that has received the same band reserved cell (step 418) sends an incoming call request to the terminal 903 using the function of the upper layer according to the conventional technique (steps 419 to 422).

Thereafter, processing based on the conventional technique is performed. That is, the terminal 903 that has received the incoming call request (step 423) determines whether or not the user information can be received (step 424), notifies that reception is not possible (step 425), and accepts when the reception is possible. The availability notification is transmitted (step 426). The exchange 906, which has received the acceptance acceptance notification from the terminal 903, generates a receivable cell and transmits it to the exchange 904 via the exchange 905 (step 427). The exchange 904 that has received the receivable cell transmits a receivable notification to the terminal 901 (step 428). After receiving this receivable notification (step 429), the terminal 901 transmits user information (step 430).

At the end of communication, the terminal 901 notifies the exchange 904 of the end of call by using the function of the upper layer according to the conventional technique (step 431). The exchange 904 analyzes this notification by the processor and recognizes that it is the notification of the end of call (step 432), and the contents “input (a, 1, 1) of the cell header conversion table (see FIG. 27) corresponding to the same VC.
1), output (A, 1, 1) "is canceled (step 43
3), the in-use display of the corresponding portion (switch 906, VPI = 1, VCI = 1) of the registered destination node (see FIG. 25) is returned to "not in use" (0) (step 43).
4). Then, the corresponding VP (VPI on the transmission link 909)
= 1), the value of the reserved bandwidth is reduced by the amount of the released bandwidth, the bandwidth management table is updated (step 435), and the bandwidth released cell is set to VPI = 1, VCI on the transmission link 909.
= 1, and the exchange 905 is instructed to release the band (step 436).

The exchange 905 recognizes that the received cell is a band release cell (step 437), reads the release band amount and VPI / VCI written in a predetermined area of the cell (step 438). The value of the reserved bandwidth for the corresponding VP (VPI = 1) on the transmission link 910 is reduced by the amount of the released bandwidth, and the bandwidth management table (see FIG. 20) is updated (step 439). After that, according to the cell header conversion table, this band release cell is VPI / VCI converted,
The data is transmitted to the exchange 906 (step 440). Switch 9
In 05, from the band release cell reception to the transmission.
Performed without software processing or upper layer processing in the processor.

The exchange 906 receives the band release cell from the exchange 905 (step 441), reads the release band amount and VPI / VCI written in a predetermined area of the cell (step 442), and determines the band. On the management table, the value of the reserved band for the VP on the transmission link 911 is subtracted by the released band value (step 443). After that, the terminal 9
03, the end of call is notified, and the corresponding portion on the cell header conversion table is released (step 44).
4).

Next, another embodiment according to the present invention will be described with reference to FIGS. 12 to 15 are flow charts showing a fifth embodiment of the ATM network exchange processing control method of the present invention. Based on FIGS. 12 to 15, FIG.
Exchanges 904 and 90 in the ATM switching network having the configuration shown in FIG.
6 and 907 will be exemplified. On the exchange 904 in FIG. 24, a table showing the determined VPI / VCI and the registered destination node (see FIG. 25), the total available bandwidth of each VC corresponding to the registered destination node, and the time There is a table (see FIG. 28) that stores the total sum of bandwidths used.

The cell header conversion table on the exchange 905 is as shown in FIG. Here, the transmission link 909 of FIG. 24 is the input transmission link a on the cell header conversion table shown in FIG.
Is the output transmission link A, and the transmission link 912 is the output transmission link B. Therefore, VPI = in the exchange 904
1, the cell transmitted on the transmission link 909 at VCI = 1 is transferred to the transmission link 910 at the exchange 905 by V.
It is sent with PI = 1 and VCI = 1 and delivered to the exchange 906.

When a communication request is actually made between the terminals 901 and 903 (step 501), the function of the upper layer is used by the conventional technique, and the terminal 901 makes a communication request to the exchange 904 (step 502). The exchange 904 recognizes in the processor that this communication request is a communication request to the terminal 903 (step 503), and the exchange 906.
Is selected as the incoming exchange (step 504). Search the registered destination node table (step 50
5), the registered destination node corresponds to the exchange 906
One of VPI / VCI that is not in use, eg VPI
= 1, VCI = 1 is selected (step 506), and the registered destination node is the exchange 9 in the bandwidth management table (see FIG. 28).
If the difference between the usable band and the in-use band corresponding to 06 is greater than or equal to the required band amount of this communication request (step 507), the value of the in-use band is increased by the required band amount of this communication request. The value is updated (step 509) to the cell header conversion table on the exchange 904 as shown in FIG. 27 (step 510). Incidentally, step 50
If the answer is NO in step 7, the call loss or detour process is performed (step 508).

Thereafter, the exchange 904 sends out a band reserved cell (distinguished from the user information cell by the header part) with the terminal 903 on the transmission link 909 according to the cell header exchange table (step 511). The exchange 905, which is a transit exchange, recognizes that this cell is a band reservation cell, and immediately transfers the cell to the exchange 906, which is an incoming exchange, according to the cell header exchange table (step 512). The processing of the exchange 905 can be performed only by hardware. The exchange 906, which has received the cell from the exchange 905, recognizes that this cell is a band reservation cell with the terminal 903 (step 513) and uses the function of the upper layer according to the conventional technique to receive the call to the destination terminal 903. Request (step 514).

The terminal 903 which has received this incoming request (step 515) judges whether or not the user information can be received (step 516), and if it is not, a notification of reception failure (step 517). Acceptable Notification Exchange 906
(Step 518) is performed using the upper layer of the prior art. The exchange 906, which has received the acceptance notification from the terminal 903, generates a receivable cell and transmits it to the exchange 905 (step 519). Exchange 905
Transmits the received receivable cell to the exchange 904 (step 520). The exchange 904, which has received this receivable cell, releases the bandwidth reservation timeout (step 5).
21), the receivability notification is transmitted to the terminal 901 using the upper layer of the conventional technique (step 522). After receiving this receivable notification (step 523), the terminal 901
Transmits user information (step 524).

At the end of communication, the terminal 901 notifies the exchange 904 of the end of call by using the function of the upper layer according to the conventional technique (step 525). The exchange 904 analyzes this notification by the processor, recognizes that it is the notification of the end of call (step 526), cancels the contents of the cell header conversion table corresponding to the same VC (step 527), and confirms the registered destination node. Corresponding part (switch 906, VPI =
1, VCI = 1) is returned to "not in use" (step 528), and the value of the in-use band corresponding to the registered destination node in FIG. It is reduced and stored (step 529). at the same time,
The band release cell is sent to the exchange 905 (step 530), and the exchange 905 transfers the received band release cell to the switch 906 (this is transfer only and can be handled by hardware processing). The exchange 906 that has received this band release cell recognizes that this cell is a band release cell (step 532), and notifies the terminal 903 of the release using the function of the upper layer by the conventional technique (step 533). ).

Next, another embodiment of the present invention will be described with reference to FIG. FIG. 29 is a flow chart showing a sixth embodiment of the ATM network exchange processing control method of the present invention. If there is a communication request (step 601). It is judged whether or not this communication request is to the registered destination (step 602). If not, communication by the function of the upper layer of the conventional technique is started (step 603), and communication of user information is performed (step 604). Then, at the end of communication, it is determined whether or not the destination network element has the function according to the present invention (step 605).

If the result of this determination is negative, the communication is terminated by the function of the upper layer of the prior art (step 606), but it has the function, and this communication allows the same destination network element to be connected. If the number of times of communication has reached a predetermined number (step 607), the band is released only without releasing the VPI / VCI and the cell header conversion table (step 608), and this destination network element is selected. , Is registered as a registered destination (step 609). If the number of registrations is greater than the number that can be registered in the source network element, the destination with the oldest communication history among the registered destinations is deleted, and this destination network element is replaced with the latest one. Register as a communication partner of. In step 602, if the communication request is for the registered destination, the communication history of the registered network element is updated with the latest communication with the destination network element (step 61).
0), and thereafter, the processes from step 109 shown in FIGS. 1 to 4 are performed.

As described above with reference to FIGS. 1 to 29, in the switching processing control method of the ATM network of each embodiment, for example, between specific network elements such as terminals and exchanges that frequently communicate, "VPI / VCI determination" and "cell header conversion table setting" are performed in advance. Then, in the communication to this specific destination (registered destination), only the reservation and release of the band, and the hardware processing at the time of the communication request and the end of the communication are performed. Alternatively, only bandwidth reservation is performed by hardware when a communication request is made, and bandwidth is released by monitoring the network (monitoring whether cells are flowing for a predetermined time or longer). In this way, software processing can be reduced. Further, this can be expected to increase the amount of communication that can be processed by a single exchange and to utilize high-speed hardware processing.

Also, in the case of communication with a network element that has not been registered, when the communication according to the conventional technique is completed, only the bandwidth is released, and the VPI / VCI and the cell header conversion table are not released, and "VPI / VPI / By leaving “VCI determination” and “cell header conversion table setting”, the same processing can be performed for users who are not registered as registered destinations. Further, only when the communication is performed a predetermined number of times, by leaving the “VPI / VCI determination” and the “cell header conversion table setting”, it is possible to efficiently specify the network element to which the present invention is applied. it can.

When the number of registrations exceeds the registrable number, "VPI / VCI decision" and "cell header conversion table setting" are always left for communication with high communication frequency or communication close to the latest communication. . As a result, it is possible to efficiently select a specific net element. In particular, since the selection can be made based on the date and time of communication occurrence, it is effective when the communication partner has a high correlation with the recent communication partner. Also,
By monitoring the cell flow, network elements with low communication frequency can be identified, bandwidth can be released by the destination terminal or exchange, and when VPI / VCI is insufficient, "VPI / VCI release" and "cell header conversion table setting release" Can select the candidate of ", and can always use up VPI / VCI.

Further, by performing the exchange processing control of the present invention between the exchanges accommodating the originating side terminal and the receiving side terminal respectively, the processor load of the transit exchange can be reduced and the VPI / VCI can be used more effectively. Further, by dividing the band for each destination node (switch), the band usage efficiency is reduced, but the band reservation and release at the relay node are not required. The present invention is not limited to the embodiments described with reference to FIGS. 1 to 29, and various modifications can be made without departing from the scope of the invention.

[0048]

According to the present invention, the processing of the processor relating to "VPI / VCI determination, cell header conversion table setting" can be reduced or reduced, and the ATM switch and ATM network can be made economical.
In addition, it is possible to improve the processing capacity of the ATM exchange.

[Brief description of drawings]

FIG. 1 is a quarter part of a flow chart showing a first embodiment of an ATM network exchange processing control method according to the present invention.

FIG. 2 is a 2/4 part of a flow chart showing the first embodiment of the ATM network exchange processing control method of the present invention.

FIG. 3 is a 3/4 part of a flow chart showing a first embodiment of an ATM network exchange processing control method of the present invention.

FIG. 4 is a 4/4 part of a flow chart showing the first embodiment of the switching processing control method of the ATM network of the present invention.

FIG. 5 is a flowchart showing a second embodiment of the ATM network exchange processing control method of the present invention.

FIG. 6 is a flowchart showing a third embodiment of an ATM network exchange processing control method of the present invention.

FIG. 7 is a ⅕ portion of a flow chart showing the fourth embodiment of the ATM network exchange processing control method of the present invention.

FIG. 8 is a second fifth part of a flow chart showing a fourth embodiment of the ATM network exchange processing control method of the present invention.

FIG. 9 is a 3/5 part of a flowchart showing a fourth embodiment of the ATM network exchange processing control method of the present invention.

FIG. 10 is a fourth method of controlling the exchange processing of the ATM network of the present invention.
4/5 part of the flowchart showing the embodiment of FIG.

FIG. 11 is a fourth switching processing control method for an ATM network according to the present invention.
5 is a 5/5 part of the flowchart showing the embodiment of FIG.

FIG. 12 is a fifth method for controlling an ATM network exchange processing according to the present invention.
Is a quarter part of the flowchart showing the embodiment of FIG.

FIG. 13 is a fifth method for controlling an ATM network exchange processing according to the present invention.
2/4 part of the flowchart showing the embodiment of FIG.

FIG. 14 is a fifth method for controlling an ATM network exchange processing according to the present invention.
Is a 3/4 part of the flowchart showing the embodiment of FIG.

FIG. 15 is a fifth method for controlling an ATM network exchange processing according to the present invention.
4/4 part of the flowchart showing the embodiment of FIG.

FIG. 16 is a block diagram showing a first configuration example of an ATM network.

17 is a block diagram showing an example of the internal configuration of an exchange that accommodates the calling terminal in FIG.

FIG. 18 is a block diagram showing an internal configuration example of an exchange that accommodates the receiving-side terminal in FIG. 16;

19 is an explanatory diagram showing an example of registered contents of a registered destination table according to the present invention in the exchange shown in FIG.

20 is an explanatory diagram showing registered contents of a bandwidth management table according to the present invention in the exchange shown in FIG.

FIG. 21 is a sequence diagram showing an example of cell transmission / reception operation in the ATM network having the configuration of FIG. 16 by the processing in FIGS.

22 is an AT having the configuration of FIG. 16 according to the process of FIG.
It is a sequence diagram which shows the example of transmission / reception operation | movement of the cell in M network.

FIG. 23 is an explanatory diagram showing an example of registered contents of a dormant VC list according to the present invention.

FIG. 24 is a block diagram showing a second configuration example of an ATM network.

25 is an explanatory diagram showing an example of registered contents of a registered destination table according to the present invention in the exchange shown in FIG.

FIG. 26 is an explanatory diagram showing an example of setting contents of a cell header conversion table according to the present invention in the exchange shown in FIG. 24.

27 is an explanatory diagram showing another example of setting contents of the cell header conversion table according to the present invention in the exchange shown in FIG. 24. FIG.

28 is an explanatory diagram showing an example of registered contents of a bandwidth management table according to the present invention in the exchange shown in FIG. 24. FIG.

FIG. 29 is a sixth method of controlling the exchange processing of the ATM network of the present invention.
3 is a flowchart showing an example of the above.

[Explanation of symbols]

 101 to 106, 901 to 903 Terminals 107 to 109, 904 to 907 Exchanges 110 to 118, 908 to 913 Transmission link 201, 301 Cell header conversion table 202, 302 Switch 203, 303 Processor

Claims (14)

[Claims] 1. A switching processing control method for an ATM network for performing cell transfer in an asynchronous transfer mode (ATM), wherein VPI / VCI used for transferring the cell between two arbitrarily selected network elements is determined in advance. The cell header conversion table is set, and at the start and end of communication between the two network elements, the cell that reserves the band and the cell that releases the band are set according to the VPI / VCI set in the cell header conversion table. VPI / VC
Flowing between the above two net elements while performing I conversion, the above VP
A switching control method for an ATM network, characterized in that only bandwidth reservation / release is performed without determining / releasing I / VCI and setting / releasing a cell header conversion table. 2. A switching control method for an ATM network which performs data transfer in an asynchronous transfer mode (ATM),
At the end of communication between the network elements accommodated in the ATM network, the VPI / VCI is not released and the cell header exchange table is not released, but only the band is released, and the next communication between the network elements is performed. At the time of starting, the cell for which bandwidth reservation is performed is set to the VPI / VCI according to the VPI / VCI set in the cell header conversion table in the previous communication.
A switching control method for an ATM network, characterized in that it is flowed between the two network elements while being converted. 3. The ATM network switching processing control method according to claim 2, wherein when the number of times of communication between the two network elements reaches a predetermined number, the communication between the two network elements is performed. An exchange processing control method for an ATM network, characterized in that exchange processing control is performed only by releasing a band at the time of termination. 4. The ATM network exchange processing control method according to claim 1, wherein the VPI /
VCI determination and communication frequency to the transfer destination network element of the cell, which has been set in the cell header conversion table, are counted, and the VPI / VCI between the network elements is determined and the cell header conversion table An ATM network exchange processing control method characterized in that, when setting is performed, VPI / VCI between the network elements is assigned to communication between new network elements in the order of lowest counted communication frequency. 5. The ATM network switching processing control method according to claim 1, further comprising determining a VPI / VCI between the network elements and setting a cell header conversion table in excess of a predetermined number. An ATM network exchange processing control method characterized by allocating VPI / VCI between network elements to communication between new network elements in order of earliest communication occurrence date and time, when performing. 6. The switching control method for an ATM network according to claim 1, wherein each network element monitors a cell flow on each VPI / VCI for a predetermined time or more. An ATM network exchange processing control method characterized in that when a VPI / VCI in which no cell is flowing is detected, a cell for releasing the band of the VPI / VCI is transmitted. 7. The switching control method for an ATM network according to any one of claims 1 to 6, wherein each network element monitors a cell flow on each VPI / VCI for a predetermined period or more. When a VPI / VCI in which no cell flows is detected and stored, and when a shortage of VPI / VCI occurs in response to a new communication request between the network elements accommodated in the ATM network, the stored VPI / VCI / An ATM network exchange processing control method characterized by allocating a VCI to the new communication request. 8. The ATM network switching process control method according to claim 1, wherein the network element monitors a cell flow on each VPI / VCI, and a cell is operated for a predetermined time or more. Is detected and stored, and the bandwidth corresponding to the stored VPI / VCI is released, and a new communication request is made between network elements accommodated in the ATM network. On the other hand, VPI / V
When a shortage of CI occurs, the VPI / VCI stored above is stored.
Select one VPI / VCI from the
/ VCI is released and the setting in the cell header conversion table is released, and the released VPI / VCI is assigned to the new communication request. 9. The switching control method for an ATM network according to claim 1, wherein the network element monitors a cell flow on each VPI / VCI, and monitors the cell flow for a predetermined time or more. Each time a VPI / VCI in which no packet is flowing is detected, the band allocated to the detected VPI / VCI is released, the VPI / VCI is released, and the setting of the cell header conversion table is released.
A switching control method for M network. 10. The ATM network exchange processing control method according to any one of claims 7 to 9, wherein:
For new communication requests between network elements accommodated in the network,
A switching control method for an ATM network, characterized in that, when a shortage of the VPI / VCI occurs, the VPI / VCI used for the oldest communication is selected and assigned to the new communication request. 11. The ATM network exchange processing control method according to claim 1, wherein the VP
It is characterized in that an arbitrary amount of band is allocated in advance for each of the network elements for which the I / VCI and the cell header conversion table are respectively determined and set, and communication between the network elements is performed within the allocated band amount. An ATM network exchange processing control method. 12. An ATM network exchange processing control method according to any one of claims 1 to 11, wherein the exchange processing control is performed between a calling terminal and a called terminal as the network elements. A switching control method for an ATM network. 13. An ATM network exchange processing control method according to any one of claims 1 to 11, wherein the exchange processing control is performed between exchanges as the network elements. Exchange control method. 14. An ATM network exchange processing control method according to claim 1, wherein the exchange processing control is performed between exchanges as the network elements, and the exchanges and the network elements are provided. An exchange processing control method for an ATM network, characterized in that a conventional exchange processing control by an upper layer is performed between a calling terminal and a called terminal.