JP2002051046A - Clad apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CLAD(Cell assembly and disassembly) apparatus that can simplify path changeover processing. SOLUTION: The CLAD apparatus 10 is provided with: a cell assembling and disassembling processing section 12 that assembles cells from data received by various terminals 100-103 and disassembles cells sent through an ATM network 700 or an ISDN 701; a VPI/VCI setting section 14 that fixedly assigns the value of VPI/VCI to be used by the cell assembling and disassembling section 12, a conversion table storage section 16 that stores conversion tables respectively denoting correlations between VPI/VCI values that are assigned and VPI/VCI values that are used when connected to connection destinations of networks 700/701 presumed in advance, and a VPI/VCI conversion section that uses the conversion table corresponding to the connection destination at that point in time to convert the VPI/VCI values fixedly assigned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CLAD (Cell Assembly and Disassembl) for assembling (cell-forming) and disassembling (de-celling) cells transmitted and received via an ATM network.
y) The present invention relates to a device, and particularly to a control unit for setting a virtual path identifier / virtual channel identifier (hereinafter, referred to as VPI / VCI) to be set at the time of celling / decelling.

[0002]

2. Description of the Related Art CLAD of ATM cells in the prior art
The device 10 accommodates various terminal devices such as a PBX (voice terminal) 100, a data terminal device 101, a frame relay terminal device 102, and a LAN 103 as shown in FIG. 1, and is used as an ATM network 700 or a backup line. Via the ISDN line 701
It is connected to the AD device 10 and realizes communication between various terminal devices.

The CLAD device 10 has a device configuration as shown in FIG. 2, for example, and the PBX 100 and the data terminal device 101 communicate with each other via the voice interface unit 200 and the data interface unit 201 of the CLAD device 10. / Data control unit 300 is connected.
The frame relay router 102 is connected to the AAL5 processing control unit 301 via the frame relay interface unit 202. Further, the LAN 103 has an IP
(Internet Protocol) Interface Unit 20
3 after being connected to the IP control unit 302 through the AAL
5 connected to the processing control unit 301.

In the CLAD device 10, a voice / data control unit 300 controls a PBX 100 and a data terminal device 101, which are voice terminal devices, and transmits / receives data from both terminal devices to an ATM cell by a cell / decellulation unit 12. Assembled and disassembled into a cell transmission / reception controller gate array 4
Cell transmission / reception is performed for 00. AAL5 control unit 30
1 implements control of the frame relay terminal 102 and the frame relay terminal 102 and the LAN 103
The transmission / reception data transmitted through the ATM cell is assembled and disassembled into ATM cells by the cell / decellulation unit 12, and the cells are transmitted / received to / from the cell transmission / reception control unit gate array 400.

[0005] The cell transmission / reception control unit gate array 400 includes:
Voice / data control unit 300 or AAL5 control unit 301
Bridge the cells transmitted and received by the relay control unit 500.
The relay control unit 500 includes the ATM network interface unit 60
0 or via the ISDN network interface unit 601;
Through the connection line selected according to the line status, etc.
The cell is transmitted / received to / from the ATM network 700 or the ISDN network 701.

[0006]

The above-mentioned prior art CLA
In the D device 10, the low-speed line on the terminal device side and the relay line on the relay network side are connected in a 1: 1 connection or n: m (n and m are arbitrary natural numbers), and the data transmitted / received from the terminal device is transmitted. Cellularization and decellularization were controlled on the low-speed line side.

For example, when the connection destination of a relay line is changed by a relay backup service, a relay bypass service, or the like,
Voice / data control unit 300 and AAL5 control unit 301
In response to the instruction to change the line connection destination sent from the overall control unit 11 of the CLAD device 10, the celling / decelling using the combination of the VPI / VCI values indicated by the change instruction is performed. Predetermined VPI / VCI in each control unit
A change sequence is performed.

More specifically, the VPI / VCI table storing all possible combinations of VPI and VCI values of the ATM cell is stored in the voice / data control unit 300 and the AAL5 control unit 301. The combination of the values of VPI / VCI indicated by the change instruction stored in advance in the unit 13 is stored in the VPI / VC
VPI / VCI stored in the I table storage unit 13
The VPI / VCI of the cell is changed by specifying the VPI / VCI using the table and using the specified value of the VPI / VCI in the celling / decellulating unit 12.

However, the change sequence as described above is
This must be performed for each control unit that performs cellization and decellularization, which is one of the factors that takes a long time to change the connection destination. Further, in the CLAD device 10 that performs the above change sequence, there is a problem that the line setting time in the call control becomes long.

[0010] The present invention has been made in view of the above points, and an object of the present invention is to simplify a connection destination switching process in a relay network and complete a connection destination change process in a relay network in a shorter time. An object of the present invention is to provide a CLAD device.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for assembling cells from data received from a terminal device, sending the assembled cells to a relay network, and disassembling the cells sent through the relay network. CLA for transmitting data to the terminal device
A local VPI / VCI setting unit for fixedly assigning a virtual path identifier (VPI) and a virtual channel identifier (VCI) to be used in assembling and disassembling a cell to each of the terminal devices; VPI / VCI conversion means for converting the values of VPI and VCI set by the local VPI / VCI means according to the connection destination.

In the CLAD apparatus according to the present invention, the local VPI / VCI setting means includes a cell-forming / de-celling unit for assembling and disassembling a cell, and a cell-assembling and disassembling performed by the cell-forming / decellulating unit. VPI to be used in
And a VPI / VCI setting unit for setting the values of VCI and VCI to a predetermined specific value for each connected terminal device.

[0013] In the CLAD device of the present invention, the conversion means is connected to VPI and VCI values fixedly assigned to each terminal device and a connection destination of the relay network assumed in advance. In a case, the correspondence information indicating the correspondence between the VPI and the VCI value to be used for each terminal device is stored for a plurality of assumed connection destinations. VPI / VCI that selects the correspondence information to be used in accordance with the connection destination of the cell, and converts the VPI and VCI values of the fixedly assigned cells using the selected correspondence information.
It is preferable to include a conversion unit.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention adopts a communication control means for fixedly assigning VPI / VCI of a line connected to an interface with a terminal device in a CLAD device. The operation is performed in consideration of the VPI / VCI with the network.

An embodiment of the present invention will be described below with reference to FIGS.

The CLAD apparatus 10a of this embodiment is different from the conventional CLAD apparatus 10 shown in FIG. 2 in that a virtual path identifier (V
PI) / virtual channel identifier (VCI) value is fixedly assigned according to the terminal equipment to be connected, and the fixedly assigned VPI / VCI is assigned to the connection destination in the relay network at that time on the trunk line side. It is converted according to.
In the following description, the same components as those of the CLAD device in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, for example, a CLAD device 10a according to the present embodiment
Data interface unit 201, frame relay interface unit 202, IP interface unit 20
3. Voice / data control unit 300a, AAL5 control unit 30
1a, IP control section 302, cell transmission / reception control section gate array 400, relay control section 500a, ATM network interface section 600, ISDN network interface section 601,
And an overall control unit 11a.

Voice / data control unit 300a and AAL
5 controller 301a assembles ATM cells from data sent from the terminal device side,
A sent from the network 700 or the ISDN network 701
The system includes a celling / decelerating unit 12 for decomposing TM cells, and a VPI / VCI setting unit 14 for setting a VPI / VCI value to be used in the celling / decellularizing unit 12 to a predetermined fixed value. .

The relay control section 500a includes an ATM cell assembled by the voice / data control section 300a and the cellization / decellulation section 12 of the AAL5 control section 301a;
A VPI / VCI conversion unit 15 for converting a VPI / VCI value of an ATM cell transmitted from the TM network 700 or the ISDN network 701 or a combination of the values;
A conversion table storage unit 16 for storing a plurality of conversion tables to be used for conversion by the I / VCI conversion unit 15; Further, the relay control unit 500a determines that the VPI / V
A VPI / VCI table storage unit 13 for storing the VPI / VCI table for determining whether the value of the VPI / VCI converted by the CI conversion unit 15 is valid is provided.

When it is necessary to change the connection destination such as a line backup service or a line detour service, the overall control unit 11a sends a change instruction to the relay control unit 500a,
By switching the conversion table to be used by the I / VCI conversion unit 15, a V corresponding to the changed connection destination is obtained.
A conversion process of the PI / VCI value is realized.

A VPI / VCI conversion method in the CLAD device 10a of the present embodiment will be described with reference to FIG. The figure located above FIG. 4 shows a normal state, and shows a path form in which communication is performed on the ATM network 700. In addition, the lower diagram of FIG. 4 shows a path form in which communication is performed using the ISDN 701 as a backup line while the backup service is being implemented. It should be noted that the values of VPI / VCI used in the drawings are examples, and the values of VPI / VCI in the present invention are not limited to these.

In the path state in the normal state shown in the upper part of FIG. 4, the PBX path extends to the relay control unit 500a in the CLAD device 10a.
Cell transmission / reception is performed with 0/56 or VPI / VCI = 0/57. The relay control unit 500a converts it into a VPI / VCI contracted with the network, for example, as shown below.

VPI / VCI = 0 / 56-> VPI / VCI = 1/30 (Equation 1) VPI / VCI = 0 / 57-> VPI / VCI = 1/31 (Equation 2) Similarly, the data path , The frame relay path is also
VPI / VCI = 0/60 or VPI / VCI fixedly determined up to the relay control unit 500a in the AD device 10a
Cell transmission / reception is performed with = 0/08. Relay control unit 500a
Then, it is converted to VPI / VCI contracted with the network.

VPI / VCI = 0 / 56-> VPI / VCI = 1/40 (Equation 3) VPI / VCI = 0 / 08-> VPI / VCI = 1/50 (Equation 4) In the CLAD device 10a of the present embodiment,
Fixed V for each interface unit for each terminal device
A PI / VCI value (local VPI / VCI) is allocated, and the VPI / VCI conversion unit 15 of the relay control unit 500a performs the conversion table (for example, Conversion table #i)
Is selected from the conversion table storage unit 16, and the VPI / VCI value is converted using the selected conversion table.

On the other hand, in the case of the communication path in the backup state using the ISDN line shown in the lower part of FIG.
The BX path is connected to the relay control unit 50 in the CLAD device 10a.
VPI / VCI fixed to 0a = 0/56
Alternatively, cell transmission / reception is performed with VPI / VCI = 0/57.
The relay control unit 500a determines that V
Conversion to PI / VCI is performed as follows.

VPI / VCI = 0 / 56-> VPI / VCI = 5/40 (Equation 5) VPI / VCI = 0 / 57-> VPI / VCI = 5/41 (Equation 6) Similarly, data path , The frame relay path is also
VPI / VCI = 0/60 or VPI / VCI fixedly determined up to the relay control unit 500a in the AD device 10a
Cell transmission / reception is performed with = 0/08. Relay control unit 500a
Converts it to the VPI / VCI contracted with the network.

VPI / VCI = 0 / 56-> VPI / VCI = 5/50 (Equation 7) VPI / VCI = 0 / 08-> VPI / VCI = 5/60 (Equation 8) CLAD of the present embodiment According to the device 10a, even when the connection destination of the line is changed as in the case of a backup service or the like, instead of the conversion table #i, the VPI / VCI conversion as shown in Expressions 5 to 8 is performed. The conversion table (for example, conversion table #j) is stored in the conversion table storage unit 1.
6 and the VPI / VCI value is simply converted using the newly selected conversion table, thereby completing the connection destination changing process.

Therefore, according to the present embodiment, since each interface unit and control unit on the terminal device side does not need to be aware of VPI / VCI to the network, easy control is possible.

In the present embodiment, an example is shown in which a conversion table is used in the VPI / VCI conversion processing, but the conversion processing in the present invention is not limited to this example. For example, instead of the conversion table, an algorithm for determining a conversion method may be set in advance, and the VPI / VCI after conversion may be set using the algorithm. In the present invention, the method of implementing the conversion processing is not particularly limited, and may be configured by software, a hardware logic circuit, or a combination thereof.

VP performed by VPI / VCI converter 15
Details of the I / VCI conversion will be described with reference to FIG.

FIG. 5 shows the basic format of an ATM cell.
(A). The ATM cell has a 5-byte header and 4
It comprises a payload of an area for storing 8-byte user information. The cell header includes VPI, V identifying the path type.
It is composed of CI, HEC, etc. for recognizing cell errors.

FIG. 5B shows an example of the format of a cell generated by the celling / decellulating section 12 of each control section provided on the terminal device side. Here, VPI = 0, VC
An example where I = 56 is shown, and it is assumed that HEC (A) corresponds to these VPI and VCI values. In the present embodiment, the VPI value and / or the fixed value are fixed according to the type of the terminal device (voice terminal, data terminal, frame relay terminal, IP terminal, etc.), the type of the path, or the interface unit.
Alternatively, a VCI value is set.

The VPI / VCI conversion unit 15 of the relay control unit 500a uses the VP of the cell header shown in FIG.
I and VCI are converted into values as shown in FIG.
The data is transmitted to a line such as an ATM network 700 or an ISDN network 701. In the cell format shown in FIG. 5C, a portion indicated by a bold frame is a portion to be converted. Here, the VPI is converted from 0 to 1, the VCI is converted from 56 to 30, and the converted VP
An example of conversion to HEC (B) corresponding to I and VCI is shown.

In the conventional CLAD device 10 (FIG. 2) and the CLAD device 10a (FIG. 3) of the present embodiment, a device internal path and a VPI / VCI table used for changing the setting of VPI / VCI are stored. VPI /
FIG. 6 shows the location where the VCI table storage unit 13 is provided.
Shown in Here, FIG. 6A shows a conventional CLAD device 10.
FIG. 6B shows the case of the CLAD device 10a of the present embodiment.

As is apparent from FIG. 6, by converting the VPI / VCI only on the trunk line side as in the present embodiment, the number of VPI / VCI tables to be owned is also reduced. Is simplified. further,
The reduction in the number of VPI / VCI tables to be used means not only simplification of the configuration, but also simplification of the control sequence to be executed when changing the path connection destination.

FIG. 7 shows a CLAD device 10a of the present embodiment.
An example of a VPI / VCI list fixedly assigned by the VPI / VCI setting unit 14 of FIG. FIG. 7 shows the VP
An example is shown in which I / VCI values are assigned according to used paths.

In this embodiment, the CLAD device 10a has a fixed low-speed line as an example. However, in the case of a device configuration in which a low-speed line can be added, the local VPI / VCI value to be assigned is , Accommodation slot
A configuration in which a fixed value is created from a port or the like may be adopted.

[0038]

According to the present invention, the switching process of the connection path is simplified, so that the change process can be performed in a shorter time as compared with the conventional method of controlling the terminal device to an arbitrary VPI / VCI. Can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a connection mode of a CLAD device.

FIG. 2 is a block diagram showing a configuration example of a conventional CLAD device.

FIG. 3 is a block diagram illustrating a configuration example of a CLAD device according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram for explaining a VPI / VCI conversion method according to the present invention.

FIG. 5A is an explanatory diagram showing a basic format of an ATM cell. FIG. 5B is an explanatory diagram showing a specific example of a cell format generated on the terminal device side. FIG. 5 (c): VPI / V in the CLAD device of the present invention
FIG. 3 is an explanatory diagram showing a specific example of a cell format subjected to CI conversion.

FIG. 6A is an explanatory diagram showing a device internal path and a VPI / VCI table possession point in a conventional CLAD device. FIG. 6B is an explanatory diagram showing the device internal path and the VPI / VCI table possession point in the CLAD device of the present invention.

FIG. 7 is a table showing a list of internal VPI / VCIs which are fixedly assigned in the present invention.

[Explanation of symbols]

Reference Signs List 100 voice terminal such as electronic exchange (PBX) 101 serial data terminal 102 frame relay router 103 LAN 200 voice terminal interface such as electronic exchange (PBX) 201 serial data terminal interface 202 frame relay router interface 203 LAN interface (Internet Protocol: IP) 300: Voice terminal such as an electronic exchange (PBX) / serial data control unit 301: AAL5 control unit 302: LAN control unit 400: Cell transmission / reception control unit Gate array 500: Relay control unit 600: ATM network interface 601 ... ISDN network interface 700 ... ATM network line 701 ... ISDN network line.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Fujita 94, Kojiyama-shi, Fukushima Prefecture, Funachi, Nippon Telecom Technology Co., Ltd. F term in telecom technology (reference) 5K030 GA01 HA10 HB14 HB29 HC14 HD03 JA06 JA13

Claims (3)

[Claims] 1. A CLAD apparatus for assembling cells from data received from a terminal device and transmitting the assembled cells to a relay network, disassembling cells transmitted through the relay network, and transmitting data to the terminal devices. Local VPI / V for fixedly assigning a virtual path identifier (VPI) and a virtual channel identifier (VCI) to be used at the time of
CI setting means, and the local VPI / V according to a connection destination of the relay network.
CLAD apparatus comprising VPI / VCI conversion means for converting VPI and VCI values set by CI means. 2. The CLAD device according to claim 1, wherein said local VPI / VCI setting means comprises: a cell-forming / de-celling unit for assembling and disassembling a cell; And a VPI / VCI setting unit for setting the values of VPI and VCI to be used in the assembling and disassembling of the terminal to a predetermined specific value for each connected terminal device.
AD device. 3. The CLAD device according to claim 1, wherein said conversion means connects to VPI and VCI values fixedly assigned to each terminal device and a connection destination of said relay network assumed in advance. VP to be used for each terminal device
The correspondence information indicating the correspondence between the values of I and VCI is
For a plurality of assumed connection destinations, a correspondence information storage unit, and from the correspondence information storage unit, select correspondence information to be used according to the connection destination at that time, using the selected correspondence information, A CLAD device comprising: a VPI / VCI conversion unit that converts VPI and VCI values of a fixedly assigned cell.