JP3198085B2 - Circuit switching network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an STM (Synchronous
Transfer Mode) Used for communication networks. The present invention uses TCP
−IP (Transmission Control Protocol-Internet Prot
ocol) A technology for transferring data having an address via an STM connection.

[0002]

2. Description of the Related Art The operation and problems of a conventional circuit switching network based on STM will be described with reference to FIGS. FIG.
FIG. 1 is a diagram showing a main part configuration of a conventional circuit switching network based on STM. FIG. 6 is a diagram showing a main part configuration of a conventional subscriber exchange. In an STM communication network, signals on a physical channel are multiplexed into time slots and circuit-switched, so the delay time during communication is extremely short, and an ATM (Asynchronous Transfer Mode) header using virtual paths and cells is used. There is no overhead.

For example, if there is a delay of 20 to 30 ms or more in telephone voice, there is a problem in quality, and an echo canceller is required. In general, it is better to have a small delay not only for telephone calls but also for two-way video meetings. In view of the above, STM is a transfer mode suitable for a digital telephone network.

As shown in FIG. 5, in a conventional circuit-switched network based on STM, a user inputs a telephone number of a destination to a CCITT.
No. defined in the Recommendation The transmission in the STM mode by transmitting to the exchange through the common line signaling network allows the physical transmission to be independent of the E.7. 164 addresses (ITU
-T is mapped to an ISDN address standardized by -T for communication. That is, ST in the STM network
The MTM connection is established, and the user data is transferred to the E.M. 164 addresses and transferred to the destination exchange.

In such a conventional circuit switching network based on STM, switching is performed by exchanging time slots of information multiplexed by 8 bytes on a frame. This operation is realized by, for example, sequential writing and random reading as shown in FIG. That is, the sequential counter CT
R writes data to the data buffer memory DBM at sequential addresses with a sequential address, and the address control memory ACM changes the reading order to perform time slot conversion.

[0006]

SUMMARY OF THE INVENTION Such a conventional ST
As described above, the circuit switching network based on M has the advantages that the delay time is extremely short and that there is no overhead as compared with ATM or the like. However, such a conventional circuit switching network based on STM requires that an STM connection be set in advance from a terminal of a calling user to a terminal of a called user, and data be transferred via the STM connection. is there.

FIG. 7 shows an image of a dedicated STM connection. Therefore, as shown in FIG. 7, there is a problem that the application is used only as a dedicated data line between large-scale offices.

On the other hand, regarding data communication performed by the TCP-IP architecture, a TCP-IP address, which is an identification number of a terminal, is written in a header of a packet and sent to a communication network such as the Internet that supports the TCP-IP. Each router such as an exchange searches for the existence of the address and transfers the datagram without having to set up a connection between two terminals with which communication is desired.
As described above, a dedicated connection is not required, and data can be transferred by a very simple procedure. However, in this case, a delay time is longer than that of a circuit switching network based on STM, and overhead is required.

The inventors have considered constructing a new circuit switching network having both the advantages of the circuit switching network using the STM and the advantages of data communication using the TCP-IP address.

The present invention has been made in such a background, and can be provided only as a mere dedicated line by providing a relay network by STM based on a TCP-IP address used for data communication. Missing S
An object of the present invention is to provide a circuit switching network capable of dynamically providing a TM circuit. An object of the present invention is to provide a circuit switching network having a small delay time and a small overhead.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an STM network,
The most important feature is that the CP-IP address is analyzed and routing can be performed in burst units based on the IP address. For this reason, the connection method, the connection method, and the procedure of the connection request from the user to the network are different from those of the conventional technology.

That is, the present invention relates to a circuit switching network,
A plurality of subscriber exchanges accommodating one or more terminals, and a relay exchange for connecting the subscriber exchanges to each other;
The subscriber exchange and the transit exchange are connected via an STM network and are circuit switching networks provided with a signal network for establishing an STM connection between the exchanges.

Here, a feature of the present invention resides in that the subscriber exchange comprises a TCP-I signal coming from the terminal.
Means for receiving burst data having a P address;
Means for managing the TCP-IP address of the terminal accommodated therein, and TCP-IP
Means for acquiring information on a time slot assigned to a subscriber exchange accommodating a terminal serving as a destination of the burst data in accordance with an IP address, and the STM network according to the information on the time slot obtained by the acquiring means. And means for transferring the burst data via the.

The means for acquiring includes means for transferring information on the TCP-IP address of the arriving burst data to another subscriber exchange via the signal network.
The subscriber exchange that has received the information of the P-IP address,
The TCP-I that the TCP-IP address manages
In the case of a P address, a means for returning information on the time slot assigned to the P-address to the local exchange which transmitted the information on the TCP-IP address via the signal network may be provided. it can. Thereby, the obtaining unit can obtain the information of the time slot.

Alternatively, an STM connection is set in advance between each of the plurality of subscriber exchanges, and a table in which information of a time slot corresponding to the STM connection is recorded is provided. It may be configured to include means for acquiring the information of the time slot by referring to the table. In this case, since the time for transferring the information of the TCP-IP address to another subscriber system exchange can be omitted, the information of the time slot can be obtained at a high speed.

At this time, there is provided means for monitoring the use status of the STM connection, and the monitoring means transmits a signal requesting release of the STM connection when there is an STM connection which has not been used for a predetermined time. It can be configured to include means for performing As a result, an STM that is not used for a long time in a preset STM connection.
The TM connection can be released and the network resources can be effectively used.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a circuit switching network according to an embodiment of the present invention. FIG. 2 is a block diagram of a subscriber exchange according to the first embodiment of the present invention. FIG. 3 is a diagram for explaining a route table according to the second embodiment of the present invention. FIG. 4 is a block diagram of a subscriber exchange according to a third embodiment of the present invention.

As shown in FIG. 1, the present invention comprises a plurality of subscriber exchanges LS accommodating one or more terminals, and a relay exchange TS for connecting the subscriber exchanges LS to each other. System switch LS and transit switch TS
No. 2 according to the CCITT recommendation for establishing an STM connection between the local exchange LS and the transit exchange TS. It is a circuit switching network provided with seven signal networks.

Here, the feature of the present invention is that, as shown in FIG. 2, the subscriber exchange LS is a means for receiving burst data having a TCP-IP address coming from the terminal. Store BDS,
IP address database DB as a means for managing the TCP-IP address of the terminal accommodated therein
And a control circuit CON, which is means for acquiring information on a time slot assigned to a subscriber exchange LS accommodating a terminal serving as a destination of the burst data in accordance with a TCP-IP address of the arriving burst data,
This control circuit CON transfers the burst data via the STM network according to the obtained information of the time slot.

In the first embodiment of the present invention, the control circuit CON
Indicates the information of the TCP-IP address of the arriving burst data as No. 7 through the other signaling system LS
When the control circuit CON of the local exchange LS receives the information of the TCP-IP address, the control circuit CON refers to the IP address database DB, and the TCP-IP address is a TCP-IP address managed by itself. Information of the time slot assigned to the
Subscriber exchange L that is the source of CP-IP address information
No. S 7 Reply via signal network. As a result, the control circuit CON can acquire the information of the time slot allocated to the subscriber exchange LS accommodating the terminal serving as the destination of the burst data.

In the second embodiment of the present invention, as shown in FIG. 3, routes 1 to 3, which are STM connections, are respectively set in advance between a plurality of local exchanges LS. A route table RT in which information of a corresponding time slot is recorded;
The ON acquires the information of the time slot by referring to the route table RT.

In the third embodiment of the present invention, as shown in FIG. 4, there is provided a route monitoring circuit RW which is a means for monitoring the use status of the routes 1 to 3, and this route monitoring circuit RW exceeds a predetermined time. When there are unused routes 1 to 3, a signal requesting release of the routes is transmitted.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described with reference to FIGS. In the circuit switching network of the present invention,
As shown in FIG. 1, there are a subscriber exchange LS and a transit exchange TS. The local exchange LS has a TCP-
E. IP is terminated, and E.100 required for STM network routing is used. 1
Burst data store BD for converting to 64 addresses
S and a control circuit CON are mounted. Each subscriber exchange LS records the TCP-IP address managed by itself in the IP address database DB.

The TCP-IP address of the incoming data is The control circuit CON of the subscriber exchange LS that wants to convert the TCP-IP address into the No. 164 address first. 7 to each local exchange LS via a signaling network.

In the subscriber exchange LS which has received the information of the TCP-IP address, the control circuit CON refers to the IP address database DB, and the TCP which is managed by itself.
If the IP address corresponds to the received information, the control circuit CON transmits the information of the time slot used for the communication by the STM to the control circuit CON of the local exchange LS which transmitted the information of the TCP-IP address. No.
7 Reply via signal network.

The control circuit CON of the subscriber exchange LS, which receives the information, transfers the burst data stored in the burst data store BDS using a predetermined time slot. After the burst transfer,
The assigned time slot is released.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. In the second embodiment of the present invention, E.E. STM by 164
Routes 1 to 3 that are connections are set. Further, each of the subscriber exchanges LS is provided with a route table RT in which routes 1 to 3 and time slot numbers for transferring data to the respective routes 1 to 3 are recorded.

As a result, in the second embodiment of the present invention, the control circuit CON refers to the route table RT to perform the information transfer procedure for acquiring the time slot information as in the first embodiment of the present invention. Is omitted, and information on the time slot for performing communication with the destination subscriber exchange LS can be obtained quickly.

(Third Embodiment) A third embodiment of the present invention will be described with reference to FIG. The third embodiment of the present invention includes a route monitoring circuit RW for monitoring the routes 1 to 3 in the second embodiment of the present invention. As a result, in the second embodiment of the present invention, if there is a route that is not used for a predetermined time set in the timer T among the preset routes 1 to 3, the route is released, and the effective use of the network resources is released. It can be used.

[0030]

As described above, according to the present invention,
Since the burst data transmitted from the user terminal by the TCP-IP address can be relayed through the STM network, the STM network can be operated more dynamically than the data relay based on the idea of a dedicated line.

Further, since data can be relayed via the STM network, delay time is reduced and overhead is reduced. As a comparative example, in the case of the ATM, one cell is 53 bytes, of which 5 bytes are overhead, and there is a possibility that the cost is increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a circuit switching network according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a subscriber exchange according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a route table according to a second embodiment of the present invention;

FIG. 4 is a configuration diagram of a subscriber exchange according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a conventional communication network.

FIG. 6 is a diagram showing a configuration of a conventional line switch.

FIG. 7 is a diagram showing an image of a conventional STM network.

[Explanation of symbols]

 ACM Address control memory BDS Burst data store CON control circuit CTR Sequential counter DB IP address database DBM Data buffer memory LS Subscriber exchange RT route table RW Route monitoring circuit T Timer TS Relay exchange

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-98918 (JP, A) JP-A-7-203085 (JP, A) JP-A-6-112942 (JP, A) Interface Vol. 18 No. 9 “Efficient ISDN Utilization Techniques (1 below)” (1992-9-1) pp. 213-229 [CSNW-1998-20040-009] Interface Vol. 18 No. 5 "4. ISDN and LAN" (1992-6-1) pp. 149-161 [CSNW- 1998-00237-004] (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/56 H04L 12/50

Claims (4)

(57) [Claims] A plurality of subscriber exchanges accommodating one or more terminals; and a transit exchange for connecting the subscriber exchanges to each other. The subscriber exchange and the transit exchange are provided with an STM (Synchronous Switch). Transfer Mode) In a circuit-switched network connected via a network and provided with a signaling network for establishing an STM connection between the exchanges, the subscriber exchange is provided with a TCP-
IP (Transmission Control Protocol-Internet Protocol)
ol) means for receiving burst data having an address, means for managing a TCP-IP address of a terminal accommodated therein, and a destination TCP-IP address of the burst data arriving at the receiving means.
Means for acquiring information on a time slot assigned to a route to a subscriber exchange which manages the TCP-IP address, and the burst according to the information on the time slot obtained by the acquiring means. data
Of the route to forward to the destination terminal
The route to the subscriber exchange which accommodates the circuit-switched network, characterized in that a means to transfer through the STM network. 2. The means for acquiring includes means for transferring information of a TCP-IP address of the arriving burst data to another subscriber exchange via the signaling network, and transmitting the information of the TCP-IP address. The subscriber exchange that has received the TCP-IP address has the T
Means for returning, via the signal network, the information of the time slot assigned to itself to the local exchange which transmitted the information of the TCP-IP address if the address is a CP-IP address. 1. The circuit switching network according to 1. 3. A system according to claim 1, wherein said plurality of subscriber-based exchanges include:
A table in which STM connections are respectively set in advance, and information of time slots corresponding to the STM connections are recorded, and the obtaining means includes means for obtaining the information of the time slots by referring to the table. Item 2. The circuit switching network according to Item 1. 4. A means for monitoring the use status of the STM connection, wherein the means for monitoring the status of the STM connection that has not been used for more than a predetermined time.
4. A system according to claim 3, further comprising means for transmitting a signal requesting release of said STM connection when there is a TM connection.
Circuit-switched network as described.