JPH0897823A - Data transfer system and method thereof - Google Patents

Abstract

PURPOSE: To make the permission of new entry and secession possible on a user side by providing a function for judging requests and change controlling routing information at the time of receiving the request of the entry or the secession to/from a call incoming terminal group from a terminal. CONSTITUTION: When the terminal N issues a new entry request to the terminal 1 of the GA supervisor of a group address(GA) 1, the terminal 1 judges whether or not to permit the request. In the case of permitting it, the terminal 1 requests a GA solution function part (GAA) to add the terminal N to the member of the GA 1 and the GAA performs updating corresponding to the request and informs the terminal 1 of the end. Then, the terminal 1 informs all the GA members of the entry of the terminal N to the GA 1 by utilizing multicasting to the GA 1. It is similar for the secession as well and the terminal N recognizes its own entry or secession to/from the GA 1. Thus, the permission of the new entry, the secession and security management are made possible on a user side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transfer system and a data transfer method, and relates to an ATM (Asyncron).
The present invention can be applied to connectionless type communication by means of a ous transfer mode (asynchronous transfer mode) communication method.

[0002]

2. Description of the Related Art In recent years, ATs have been used to realize B-ISDN.
M communication technology is being developed. For example, technical development of an ATM communication system based on a connectionless (CL) system is actively carried out.

(A) For example, in the broadcast communication method of connectionless communication, ITU-T Recommendation I.2 is adopted as a multicast transfer system for each subscriber of the broadcast group. 364
Has proposed the following method.

(1) Centralized control type transfer system: This is a system in which a group address resolution function (GAA) placed in a network centrally transfers a multicast.

This GAA waits for a correspondence table of the group address GA to be processed and the individual addresses of all the terminals included in the GA, uses the table to convert the group address GA into individual addresses, and to each terminal. It has a function of distributing / transferring the protocol data unit PDU.

(2) Centralized control type transfer system by NGAA: This is a system in which a GAA and a nested GA resolution function (NGAA) are used to transfer multicast in stages.

(3) Distributed control type transfer system: This is a system in which GAA placed in each network shares the transfer of multicast.

Among these transfer methods, the specificity of the control mechanism and the ease of management are preferentially taken into consideration, and there are problems in terms of processing load and delay, but the centralized control of (1) above. Form transfer method seems to be the most feasible.

Therefore, a multicast transfer mechanism according to the centralized control transfer method will be described with reference to the network model of FIG. The terminals 1 to 4 are members of the group address GA1.

First, the terminal 1 entered in GA1
Ships a PDU with a group address (GA-PDU). Next, the GA-PDU is once transferred to GAA. Next, the GAA transfers the GA-PDU to all the terminals 2, 3, 4 entered in GA1. At this time, it is not transferred to the terminal 1 which is the sender. still,
GA-PDU from a subscriber who is not entered in GA
Was discarded by the screening function of GAA.

(A) Next, FIG. 3 shows an example of a connectionless communication network. The network has multiple ATM switching functions and connectionless service functions (C
LSF). This ATM switching function provides a PVC connection between the terminal and CLSF or between CLSF and CLSF. In addition, the ATM switching function accommodates a plurality of terminals, and PVC is used between ATM switching devices.
(PermanentVertical Channel
l) consists of a mesh. CLSF is CLNAP-
Provides transfer of PDUs or CLNIP-PDUs.

Further, CLSF is a protocol conversion function (P
CF) and VPI based on the destination address of the PDU
/ VCI is selected. Explaining the routing method of the connection network, CLNAP is between the terminal and CLSF.
-Routed with the destination address of the PDU. CLS
The F-CLSF is routed by the destination address of CLNIP-PDU. One CLSF has one station number as the destination address, and the subscriber address always includes the station number.

According to the routing table, the CLSF is (1) the correspondence between the subscriber address accommodated in the own CLSF and the VC indicating the route of the subscriber, and (2) the CLSF connected to the own CLSF. Station number and CLSF
Has a correspondence relationship of VCs indicating the routes of CLNAP-PDU or CLNIP-based on the information of the routing table.
The PDU is routed.

Therefore, a detailed description will be given using the table contents shown in FIG. First, as an example of routing to terminals in the same station, communication from terminal A to terminal B will be described.

(1) First, the terminal A uses CLNAP- whose destination address is the address (22-0002) of the terminal B.
After the PDU is made into cells, it is sent to the ATM switching function via the communication channel (VC # 2).

(2) Next, the ATM switching function switches the cell to C
The LSF is sent to the LSF, and the CLSF retrieves the VC number (VC # 3) for the destination address from the routing table and replaces the VC number (VC # 2) of the cell.

(3) Next, the ATM switching function sends to the terminal B according to the reassigned VC number.

Communication from the terminal A to the terminal C will be described as an example of routing between terminals of another station.

(4) Terminal A receives the address (55-
After the CLNAP-PDU whose destination address is 0001) is made into a cell, the ATM switching function is provided with a communication channel (VC).
Send with # 2).

(5) The ATM switching function connected to the terminal A sends the cell to CLSF # 0. In CLSF, since the destination address is not registered in the routing table, the VC number (V
C # 1) is taken out and the cell VC number (VC # 2) is replaced.

(6) The ATM switching function sends the cell to the ATM switching function to which the CLSF # 1 with the station number 55 is connected by the VC number thus replaced.

(7) The ATM switching function connected to CLSF # 1 sends a data cell to CLSF # 1. CLSF
# 1 retrieves the VC number (VC # 4) for the destination address from the routing table and replaces the VC number (VC # 1) of the cell.

(8) The ATM exchange function connected to the terminal C sends the ATM exchange function to the terminal C by the reassigned VC number.

It is fully conceivable that this terminal will have to move for some reason. It is also possible that there is a demand for immediate communication at the destination. The ability to communicate immediately at the destination is called the portability function.

Considering a normal telephone routing algorithm, the same telephone number can be used when the destination is within the same office. However, if the station is different at the destination, a new telephone number with the station number is given, and the numbers are different. Therefore, if the number is different at the destination, you cannot communicate unless you tell the other party the changed number.

It is expected that something like a pen personal computer will become a terminal in the future, and it is thought that there is a need to immediately connect to a connectionless (CL) network at work. In this case, such a routing mechanism of a normal telephone is not realistic because the amount of processing for notifying that the number has been changed is huge.

Further, considering that the number is changed every time it moves out of the station, the number resource may run out, which is not desirable. This is because the number that has been used once is generally not used for a certain period of time in order to prevent incorrect calls. Considering this, the number must be able to communicate with the same number at the destination.

[0028]

[Problems to be Solved by the Invention]

(A) The broadcast communication function described in (a) above is one of closed communication functions (a communication function provided to a closed group (a set of specified subscribers for the purpose of sharing information)). .
However, conventionally, network managers are supposed to perform closed-area communication, that is, multicast operation and its security management.

Therefore, there has been a problem that the user cannot easily expand or contract the closed group, and cannot manage the closed group members necessary for preventing the abuse of the information in the closed group.

From the above, there is a demand to provide a "data transfer system that allows the user to permit and withdraw new subscriptions and to allow the user to manage security".

(B) In the network described in (B) above, considering the portability function, the in-house CLS
In the movement within F, the routing is possible by moving the logical channel along with the movement of the physical channel. However, for movement across CLSFs, if the subscriber's number is the same, then routing becomes a problem.

An example of this problem will be described. When the terminal B in FIG. 4 moves from CLSF # 0 to CLSF # 1,
Delete from CLSF # 0 routing table, CL
Register in the routing table of SF # 1. This is shown in FIG.

Explaining with reference to FIG. 5, when the communication is made from the terminal A, the data sent is CL because there is no terminal number (22-0002) in the routing table.
Discarded in SF # 0. When communication is performed from the terminal C, the CLSF is changed by the station number (22-XXXX).
The data flowing to # 0 or the subscriber number of terminal B (22-0
002), it cannot be judged whether the data is on the subscriber side.

Thus, the occurrence of inconsistency in the routing table becomes a factor that hinders the portability function. A routing algorithm to solve this was needed.

From the above, there is a demand for the provision of "a data transfer method in which the terminal number is fixed and the destination terminal can communicate with the same number".

[0036]

[Means for Solving the Problems]

(1) Therefore, the present invention is a data transfer system for transferring data in which a receiving terminal group identification number is set from a calling side terminal to a receiving side terminal based on routing information. A supervisor function unit that determines a request is provided on the terminal side in the system.

When the supervisor function unit receives from the terminal a request to join or leave the called terminal group,
By determining these requests and controlling the change of the routing information, the above problem (a) is solved.

(2) Further, as an invention for solving the above-mentioned problem (i), the present invention is provided with a connectionless function unit for making a connectionless type line connection, and a calling terminal identification number and a called terminal identification are provided. It is a data transfer method of a system in which data in which a number or the like is set is transferred from a calling side terminal to a called side terminal based on routing information, and a terminal connected to the system can move by changing a connection point on the system.

Further, according to the present invention, the number of the moved terminal and the channel of the destination connectionless function unit are registered in the routing table of the connectionless function unit before the terminal is moved, and the connectionless function unit of the destination also Add the mobile terminal number and channel for data delivery to the routing table.

When both the terminal-side delivery channel and the connectionless function section-side delivery channel are registered, the terminal-side delivery channel is preferentially used and controlled. The received data for the moved terminal is delivered to the destination connectionless function section via the connectionless function section before the movement, and the destination connectionless function section sends the data to the terminal side.

[0041]

According to the data transfer system of the invention of the above (1), by providing the supervisor function unit on the terminal side, it is possible to easily join or leave the closed group and to perform flexible closed communication for the terminal. Can provide operations. Also, the processing load on the network side can be reduced.

Therefore, the terminal side permits new subscription,
It is considered that the withdrawal becomes possible and the terminal side can manage the security of the data.

According to the data transfer method of the invention (2), data transfer between the terminals can be performed regardless of which connection point the terminal is moved to and connected to. Further, the routing information of terminals in the station can be updated or added simply by changing the connectionless function unit before moving and the connectionless function unit at the moving destination.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described with reference to the drawings. "First embodiment": The first embodiment is an embodiment according to the first invention. Therefore, in this embodiment, in the data transfer system in which the packet having the header group identification number of the called side sent from the calling side terminal is copied to the called side terminal based on the routing information in the device and is routed, the called party Within the group, one or a plurality of supervisors that examine new joining and leaving requests are configured, and a function that changes routing information based on the registration request and the reduction request from this supervisor is configured to realize the broadcast communication.

FIG. 1 is an explanatory diagram of a network system model of the first embodiment. In FIG. 1, the system includes terminals 1 to N, a group address resolution function unit GAA,
It is composed of networks 11 to 13. In FIG. 1, the operation of the GA member update algorithm in which the terminal N newly joins the member of the group address GA1 in the network model will be described.

Further, FIG. 2 is a sequence diagram for explaining the operation of FIG. This will be described with reference to FIG.

First, in step S1, the terminal N is GA
A new joining request is issued to terminal 1, which is the GA supervisor of No. 1. Next, in step S2, the terminal 1 that received the new joining request examines whether or not to accept the terminal N as a member of GA1, and if it is permitted, adds the terminal N to the member of GA1 to GAA. Request.

Next, in step S3, the GAA operates the terminal 1
In accordance with the request, the update is performed and the terminal 1 is notified of the end of the update. Next, in step S4,
The terminal 1 notifies all GA members that the terminal N has joined the GA1 by using the multicast for the GA1 (step S5). As a result, the terminal N becomes G
I know that I was able to join A1.

Although withdrawal from the GA member is also performed by this algorithm, the GA supervisor needs to notify the withdrawn terminal that the withdrawal procedure has been completed.

(Effects of the first embodiment): According to the above-mentioned first embodiment, it is possible to easily join / leave the closed group and provide the user with a more flexible operation of closed communication. In addition, in the permission system by the GA supervisor, the user can arbitrarily set the permission level according to the purpose of use of the closed group, so that it is considered that the degree of freedom in the use of closed communication is high.

Also, on the network side, the application of this algorithm does not require a complicated control mechanism, so that there is an advantage that the overhead of the processing load can be suppressed.

[Second Embodiment]: This second embodiment is the second
It is an example according to the invention of. In the second embodiment, the number of the moved terminal and the channel addressed to the destination CLSF are registered in the routing table of the CLSF before the movement, and the number of the subscriber and the delivery of the subscriber number are also registered in the routing table in the destination CLSF. When a delivery channel is added to both the subscriber side and the CLSF side in order to add a channel and to avoid a reversion, control is given to give priority to the subscriber side.

Further, the received data for the moved terminal passes through the CLSF before moving, and the CLSF of the moving destination delivered to the CLSF of the moving destination configures the data transfer device so as to send the data to the subscriber side.

Then, the disconnection / connection procedure when moving by the portable routing algorithm of the data transfer device will be described. Here, the case where the terminal B is moved as shown in FIG. 5 will be described by using the network of FIG. 3 as a model.

(1) Regarding "when disconnecting the terminal",
Considering the disconnection procedure, the sequence is as shown in FIG. First, in S10 (disconnection request due to movement), the disconnection request due to movement is issued from the terminal A to the CLSF # 0. Then S
11 (routing table registration deletion) CLS
F # 0 deletes the part of the routing table of the destination address of the mobile terminal in response to the disconnection request due to movement.
Next, in S12 (disconnection completion), the CLSF # 0 issues disconnection completion to the mobile terminal. The terminal receiving this becomes mobile. By such processing, cutting can be performed.

After the disconnection, it is assumed that the terminal A comes to access the terminal B while moving. Data is CLS
It is discarded in F # 0 (step S13). It is considered that the terminal A comes to access many times without knowing that the terminal B is not connected. This results in increased traffic and wasted resources on the connectionless (CL) network.

Therefore, FIG. 7 shows a network model that solves this problem. In FIG. 7, the network includes ATM switching function units 21 to 22 and CLFS.
It is composed of # 0 to # 1, a server 20, and terminals A to D. In FIG. 7, the server 20 having the movement information is provided. Therefore, the server 20 receives the protocol data unit PDU addressed to the moving terminal,
It has a function of transmitting movement information to the source of the PDU.

That is, when a packet is sent to a disconnected terminal, a packet or cell for notifying the calling terminal that the terminal is absent is sent.

Therefore, description will be made with reference to the sequence diagram of FIG. First, in step S20 (disconnection request due to movement), terminal B issues a disconnection request due to movement to CLSF # 0. Next, in S21 (channel registration of server in routing table), CLSF # 0 registers the channel of the server in the routing table corresponding to the destination address of mobile terminal A in response to the disconnection request due to movement.

Next, in S22 (cutting completion), CLSF
# 0 issues a disconnection completion to mobile terminal A. The terminal that receives it becomes mobile. In this way, when an access is made from another terminal while moving, the data is sent to the server (S24) and the movement information is sent to the calling terminal (S25). The movement information includes a movement completion date and time.

(2) When connecting the next moved terminal,
The connection procedure will be described with reference to the sequence of FIG. 11 and the network configuration diagram of FIG. Here, the moved terminal A
When connected to the destination CLSF, the connectionless (CL) communication channel is not set up. Then, it is assumed that a connectionless (CL) communication channel is acquired by using a control channel fixedly assigned. Hereinafter, description will be made step by step.

First, in S30, the terminal A is accommodated in C.
A connection request is issued to LSF # 1. Next, in S31, CLSF # 1 learns that the terminal has moved by a connection request. Depending on the station number of this terminal, C of this station number
Issue mobile connection confirmation to LSF (# 0). Then S32
In CLSF # 0, if the received mobile connection confirmation confirms that the terminal number is registered, CLSF # 0 prepares to rewrite the channel number in the routing table to the accommodated CLSF channel number (if rewritten, The terminal is discarded because it is not connected).

Next, in S33 (permission), CLSF #
0 issues a grant to CLSF # 1. Next, in S34 (routing rewriting instruction), a rewriting instruction is issued to CLSF # 0 (S34), and connection completion (giving a communication channel) is issued to terminal A (S35). It is preferable that this issuance be performed at the same time as much as possible so that data is not discarded.

The function that must be newly added to CLSF is the priority control function of routing. This priority control function is a function of preferentially selecting the channel number if all the terminal numbers match when the same station number exists in the routing table.

That is, when the routing information is searched, both the procedure for searching from all of the called terminal identification numbers and the procedure of searching from the station number of the called terminal identification number are executed, and if both can be searched, the former is the search result. Is output as.

With the above processing, connection can be established and communication is possible.
Describe how the routing is done to actually communicate. First, the routing between the terminal C and the terminal B in the station that currently accommodates the terminal B will be described with reference to FIG.

First, the terminal C determines the address (22-0) of the terminal B.
After the CLNAP-PDU whose destination address is 002) is made into cells, the ATM switching function unit 22 is connected to the communication channel (V
Send with C # 4). Next, the ATM switching function unit 22 sends the cell to CLSF # 1, and CLSF # 1 extracts the VC number for the destination address from the routing table. Since both the station number and the destination address are registered, the VC number (VC
Take out # 6). The VC number of a cell is changed to its VC number (V
Replace with C # 6).

Next, the ATM switching function unit 22 sends the cell to the terminal B by the reassigned VC number. The routing is performed as described above.

To describe the routing with the terminal accommodated in a station different from the terminal B, the data addressed to the terminal B is always sent to the CLSF (# 0) before the movement. The transmitted cell is the CLSF currently accommodated by the routing table of the CLSF before moving according to the destination address.
(# 1). After that, it is the same as the above-mentioned routing method.

The C that was always stored before each move
Via LSF. However, if the movement is repeated many times, C
There is a problem in that the number of LSFs passing through increases and the delay increases. First registered C to solve this
If there is a relay address of the same station number as the number of the moving terminal in the routing table at the time of disconnection after the second movement for the LSF, CL of that station number
In the SF, the channel corresponding to the number of the moving terminal in the routing table is changed to the server that manages the movement information.

The CLSF that is about to disconnect peripherals the registered routing table. As a result, the CLSF passage number is increased by one more than the shortest route. This is unlikely to cause any problems.

(Effects of the Second Embodiment) According to the second embodiment described above, by using the above-described routing mechanism, the terminal number is fixed, and the same number is used even at the destination of the terminal communication. It is possible to communicate regardless of where the terminal moves. In addition, updating / adding the routing information of the terminals in the station to realize the portability function is performed before the CLSF is moved.
This can be realized by a very small process of changing the CLSF of the destination. The data transmission delay is considered to be small enough. It is considered that the high speed of routing is also maintained.

(Other Embodiments) (1) In the above first embodiment, it is also preferable that the supervisor terminals are provided in a plurality of systems.

(2) In the second embodiment, ATM
Switching function unit, connectionless service function unit CLSF
Can be applied even to a system provided with three or more each.

(3) Furthermore, the server 20 of the second embodiment is
It can also be realized by a structure realized by a terminal.

(4) Furthermore, it is considered that the above-mentioned data transfer can be applied to the transfer of variable length packets and the transfer of fixed length packets.

[0077]

As described above, the data transfer system according to the first aspect of the present invention is provided with the supervisor function unit for judging the joining request or the withdrawal request in the incoming terminal group on the terminal side in the system, and the supervisor function unit is When a request for joining or leaving a terminal group is received from a terminal, the request is judged and the routing information change control is performed, so that the user can permit or withdraw from new joining and the user side. It is thought that security management can be enabled by.

In the data transfer method of the second invention, the number of the moved terminal and the channel of the connectionless function unit of the moving destination are registered in the routing table of the connectionless function unit before moving the terminal, Even in the connectionless function unit, if the mobile terminal number and the channel for data delivery are added to the routing table and both the terminal side delivery channel and the connectionless function unit side delivery channel are registered, the subscriber Controls to preferentially use the delivery channel on the side, and the received data for the moved terminal is delivered to the destination connectionless function unit via the connectionless function unit before movement, and the destination connectionless function In the department, by sending data to the subscriber side, the terminal number is fixed without changing and the same at the destination. Data transfer can be performed at issue.

Therefore, according to the above-mentioned invention, it is considered that the functionality of the connectionless communication by the ATM communication system can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a network model according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional example.

FIG. 3 is an explanatory diagram of a conventional example.

FIG. 4 is an explanatory diagram of a conventional example.

FIG. 5 is an explanatory diagram of a conventional example.

FIG. 6 is an explanatory diagram of a processing sequence of the first embodiment.

FIG. 7 is an explanatory diagram of a network model according to a second embodiment.

FIG. 8 is an explanatory diagram of a processing sequence of the second embodiment.

FIG. 9 is an explanatory diagram of a processing sequence of the second embodiment.

FIG. 10 is an explanatory diagram of a network model according to a second embodiment.

FIG. 11 is an explanatory diagram of a processing sequence of the second embodiment.

[Explanation of symbols]

1-N ... Terminals, 11-12 ... Network, 21-22
... ATM switching function unit, CLSF ... Connectionless service function unit, GAA ... Group address resolution function unit, G
A ... Group address.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kazutaka Hanaki 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (2)

[Claims] 1. A data transfer system for transferring data set with a receiving terminal group identification number from a calling terminal to a receiving terminal based on routing information, wherein a joining request or a withdrawal request is judged in a called terminal group. A supervisor function unit that does this is provided on the terminal side in the system, and when the above-mentioned supervisor function unit receives a request to join or withdraw from the called terminal group from the terminal, it judges these requests and controls the change of routing information. A data transfer system characterized by. 2. A connectionless function unit for performing connectionless type line connection, wherein data in which a calling terminal identification number and a called terminal identification number are set is transferred from a calling terminal to a called terminal based on routing information. However, in a system data transfer method in which a terminal connected to the system can move by changing the connection point on the system, the number of the moved terminal is stored in the routing table of the connectionless function unit before the terminal is moved. Register the channel of the connectionless function unit at the destination, add the mobile terminal number and the channel for data delivery to the routing table in the connectionless function unit at the destination as well. If both delivery channels on the function side are registered, The priority is used for control, and the received data for the moved terminal is delivered to the connectionless function unit at the destination via the connectionless function unit before movement, and at the connectionless function unit at the destination. , A data transfer method characterized by sending data to the terminal side.