JPH07273800A - Communication service switching device - Google Patents

Abstract

PURPOSE:To make the most use of the high speed and economical efficiency of an integrated service digital network(ISDN) and to prevent an incovernience of an inadvertent increase of accounting amount of money because neither connection nor disconnection comes to take place during the prescribed period when the accounting amount of money is constant after the connection of the line exchange service. CONSTITUTION:An information measurement part 2 measures the data communication amount. The calculation value X of the result is compared with a prescribed value alpha or a prescribed value beta. A central control part 3 switches a line exchange service to a packet exchange service when the calculation value X is lower than the prescribed value alpha and switches the packet exchange service to the line exchange service when the calculation value X is higher than the prescribed value beta. In using the line exchange service, it is not switched to the packet exchange service until the measurement time T measured by the information measurement part 2 exceeds the constant time by a timer (t) in a storage device 1 by the connection of the line exchange.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication service switching device for automatically switching between a circuit switching service and a packet switching service in a communication service using an integrated service digital communication network (hereinafter referred to as ISDN as appropriate). is there.

[0002]

2. Description of the Related Art In recent years, in a local area network (hereinafter referred to as LAN) in a company, in order to realize interconnection between a network constructed in a head office and a network constructed in each branch, LAN connection devices such as routers and bridges corresponding to various public lines are increasingly used. The line used in the LAN-to-LAN connection device requires a high-speed data communication function with a low data error rate as a performance factor.
High cost performance is required as an economic factor.

At present, ISDN is widely used to meet such requirements. Normally, two types of ISDN communication services are provided on the same line: a circuit switching service featuring high-speed communication and a packet switching service featuring economics of pay-as-you-go billing.

[0004]

However, the conventional IS
The DN data communication terminal defines whether to use the circuit switching service or the packet switching service at the time of starting communication with the partner station, and uses one switching service until the communication is completed. In general, L
The amount of data per unit time on the AN is not constant, and at some point dozens of data packets are transmitted per second,
At some point, no data packet may be transmitted in 10 minutes. Due to such characteristics of LAN, if only the circuit switching service that is charged according to the connection time is used, when data communication between LANs is not performed for a long time or only a very small amount of data communication is performed. Would increase the idle time of the line, resulting in useless billing.

On the other hand, even a conventional remote router or remote bridge is provided with a so-called timer disconnection function that disconnects the line if no data is transmitted on the line for a certain period of time. It can be avoided. However, if data is generated after the timer is disconnected, the other station will be called.
At this time, the line may become busy if a telephone or facsimile is connected to the partner station. In such a state, data is generated on the LAN of the transmission side, and the relay device does not make a call to the partner station, so that the LA of the transmission side is not connected.
Data communication cannot be performed from the terminal on N.

Further, if only the packet switching service is connected, when the amount of data communication between LANs increases, the traffic increases and the throughput of the system drops significantly.

The present invention has been made in view of the above circumstances, and ISDN can be obtained by selectively using such two types of switching services according to the amount of data communication per unit time of the LAN-to-LAN connecting device. The purpose is to effectively utilize the high speed and economic efficiency of the.

[0008]

In order to solve the above-mentioned problems, the communication service switching device of the present invention comprises a calculating means for calculating the data communication amount per unit time transferred in the integrated service digital communication network, The first data communication per unit time, which serves as a criterion for switching the circuit communication service from the circuit switching service to the packet switching service, and the calculated data communication amount calculated by the calculating means while the data communication by the circuit switching service is being performed. The second data communication amount per unit time, which is a criterion for switching the communication service from the packet switching service to the circuit switching service, while comparing the amount of data and the data communication by the packet switching service. And the calculated data communication amount by the comparison means for comparing While switching the communication service from the circuit switching service to the packet switching service when it is determined that it is less than one data communication amount, the communication service is packetized when it is determined that the calculated data communication amount is greater than the second data communication amount. It is characterized in that it comprises a switching means for switching from the switching service to the circuit switching service.

Further, the communication service switching device further includes a time measuring means for measuring a predetermined time after the circuit switching service is connected, and the comparing means terminates the time measurement of the predetermined time by the time measuring means. After that, the calculated data communication amount is compared with the first data communication amount.

[0010]

In the above structure, when the data communication is started, the calculating means calculates the data communication amount per unit time. Here, when communication is being performed by the circuit switching service, the comparison means compares the calculated data communication amount with the first data communication amount. As a result of the comparison, if it is determined that the calculated data communication amount is smaller than the first data communication amount, the switching unit switches the communication service to the packet switching service. Therefore, when the amount of data communication is small, the packet switching service is automatically switched, so that the fee is charged according to the amount of data communication.

On the other hand, when communication is being performed by the packet switching service, the comparison means compares the calculated data communication amount with the second data communication amount.
As a result of the comparison, when it is determined that the calculated data communication amount is larger than the second data communication amount, the switching unit switches the communication service to the circuit switching service. Therefore, when the amount of data communication is large, high-speed communication can be performed by automatically switching to the circuit switching service.

As described above, according to the above configuration, the communication service suitable for the amount of data communication actually transferred by ISDN is selected. Therefore, it is possible to reduce unnecessary charges during the use of the circuit switching service and suppress a decrease in the throughput of the system during the use of the packet switching service.

Further, if the time measuring means is adopted, the time measuring means measures the predetermined time after the circuit switching service is connected. Then, after this time measurement is completed, the comparison means compares the calculated data communication amount with the first data communication amount. As a result, in the case of the circuit switching service, the charge amount is the same for a certain period after the line is connected, so the connection / disconnection of the communication path will not be repeated repeatedly during that period, and the charge amount will be increased carelessly. That inconvenience is avoided.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS.

The bridge according to this embodiment is a LAN-to-LAN connecting device compatible with ISDN, and as shown in FIG. 1, a storage device 1, an information measuring unit 2, a central control unit 3, and a data relay control module. 4, LAN interface 5,
The ISDN interface 6 is provided.

The storage device 1 has a specified value α as the first data communication amount, a specified value β as the second data communication amount, and a predetermined time (timer t) after the circuit switching service is connected and the connection is maintained. ) And are memorized. The prescribed value α is used as a criterion for switching the communication service from the circuit switching service to the packet switching service, and the prescribed value β is used as a criterion for switching the communication service from the packet switching service to the circuit switching service.

The information measuring unit 2 is adapted to calculate the amount of data communication (calculated value X) per unit time and to measure the time since the circuit switching service was connected. It has the function as. Further, the information measuring unit 2 compares the calculated value X with the specified value α or the specified value β and notifies the central control unit 3 of the comparison result when it is necessary to switch communication services. , Also has a function as a comparison means. Further, the information measuring unit 2 compares the timer t with the measured measurement time T, and when the measured time T exceeds the timer t, notifies the central control unit 3 of the result.

Calculation of the calculated value X in the information measuring section 2
This is done as follows. The amount of data communication per unit time is expressed by the effective transfer rate (bits / second). Specifically, the effective transfer rate = total number of bits of data sent on the line ÷ unit time (seconds) ) Is required.

The unit time is set in advance in the information measuring unit 2 such as 30 seconds or 60 seconds, and is divided based on the elapsed time set to "0" when the exchange service is switched. It has become. The total number of bits of the data transmitted on the line is counted by notifying the information measuring unit 2 how many bits of data are transmitted when the data relay control module 4 relays the data to the line. Therefore, the effective transfer rate is calculated every time a unit time elapses based on the elapsed time and the total number of bits.

For example, if the unit time is set to 30 seconds, and if 128 kilobytes of data are transmitted in a certain 30 seconds, the effective transfer rate of the unit time is 128 × 1024 × 8 ÷ 30 = 34. It becomes 0.95 (kilobits / second).

The central control unit 3 instructs a call control unit 6b, which will be described later, in the ISDN interface 6 to connect / disconnect the line. Further, as a result of the comparison between the calculated value X by the information measuring unit 2 and the specified value α, the central control unit 3 determines that the calculated value X is less than the specified value α, and the communication service is switched from the circuit switching service to the packet. It is designed to switch to an exchange service. Further, when the central control unit 3 determines that the calculated value X is larger than the specified value β as a result of the comparison between the calculated value X and the specified value β by the information measuring unit 2, the communication service is switched from the packet switching service to the line. It is designed to switch to an exchange service. Thus, the central controller 3 has a function as a switching unit.

Further, the central control unit 3 notifies the information measuring unit 2 that the switching has been performed at the time of switching the communication service, and requests initialization of the measurement time T. In addition, the central control unit 3 is adapted to perform system startup processing and termination processing including initialization and reset of peripheral ICs.

The data relay control module 4 is a part for controlling the protocol, and includes the LAN interface 5 and the I interface.
The data transfer with the SDN interface 6 is relayed. Specifically, the data relay control module 4 receives data from the LAN interface 5 and gives an instruction to send data to the ISDN interface 6 when the data is received, and receives data from the ISDN interface 6 and receives the data. When L
It is designed to instruct the AN interface 5 to transmit data.

Further, the data relay control module 4 uses the I
The central control unit 3 confirms the connection status (circuit switching or packet switching) when data is transmitted to the SDN interface 6, and the LAN is ISD
When not connected to N, a connection request is sent to the central control unit 3. In addition, the data relay control module 4 notifies the information measuring unit 2 of the amount of transmitted / received data.

The LAN interface 5 has a data transmitting / receiving section 5a and a physical interface 5b. The data transmission / reception unit 5a is a part responsible for data transmission / reception with the LAN, and when receiving data, notifies the data relay control module 4 of the reception. The physical interface 5b is adapted to perform electrical conversion and mechanical work for sending out bit information representing data to the line.

The ISDN interface 6 includes a data transmitter / receiver 6a, a call controller 6b, and a physical interface 6c.
And have. The data transmission / reception unit 6a is a unit responsible for data transmission / reception with the ISDN, and when data is received, it notifies the data relay control module 4 of the reception. The call control unit 6b is configured to perform call control for ISDN according to an instruction from the central control unit 3. The physical interface 6c is a part having the same function as the physical interface 5b.

By the way, the specified values α and β are set at the effective transfer rate as shown in Table 1.

[0028]

[Table 1]

That is, when the B channel is used for packet switching, the effective transfer rate in circuit switching is 20 kbp.
If it is reduced to s, communication is guaranteed even when switching to packet switching. Therefore, in this case, the specified value α is 20
set to kbps. Similarly, when the D channel is used for packet switching, the specified value α is set to 8 kbps.

However, since the amount of data transferred through the LAN is not constant and fluctuates, if the amount of data increases momentarily, the transfer rate per unit time will exceed the above value. On the other hand, in general, most of the LAN-to-LAN connecting devices have a buffer inside, so that even if the amount of data temporarily increases, the data can be relayed while buffering. Therefore, in this case, it is conceivable to set the value slightly larger than the above value as the specified value α.

However, if the specified value α is set to a value higher than the measured value as described above, and this value is set to the specified value β and both specified values α and β are made equal, it becomes impossible to return to circuit switching. . This is because, when the D channel is used, if the specified value β is set to, for example, 10 kbps, the maximum transfer speed of the D channel is 8 kbps, so that the transfer speed does not exceed the specified value β. .
Therefore, in order to switch from the packet switching service to the circuit switching service, the specified value β must be a value smaller than 8 kbps.

A processing procedure for performing data communication between the LAN and the ISDN using the bridge configured as described above will be described with reference to the flowcharts of FIGS. 2 to 4.

The central control unit 3 performs the processing in the procedure according to the flowchart of FIG. First, when the power of the system is turned on and the system is reset, an initialization process is performed (S1). Here, the setting of the specified values α / β and the timer t for the storage device 1, the LAN / IS
Reset the DN interface 5/6 (peripheral IC),
The information measuring unit 2 and the data relay control module 4 are activated.

Then, the process shifts to a loop process for waiting for data communication from the LAN (S2), and if data arrives during this loop process (S3), the line is connected to the call control unit 6b of the ISDN interface 6. An instruction to perform is output (S4). At this time, both the circuit switching service and the packet switching service are connected. After that, the packet switching service is always connected, while the circuit switching service is connected as needed. When the communication path is secured, the calculated value X and the measurement time T are sent to the information measuring unit 2.
An instruction is output to perform the measurement of (S5).

The data communication is first started from the circuit switching service, but at this time, it cannot be switched to the packet switching service until the measurement time T reaches the timer t. In addition, the packet switching service is always connected first because the line may be busy and not connected when necessary. This is because the packet switching service is not charged unless data is transferred, so that the charge is the same regardless of the timing of connection.

In a state where data communication is possible after the line connection, the information measuring section 2 and the data relay control module 4 operate according to the data communication status, as will be described later in detail. Then, the process moves to a loop process of waiting for the occurrence of an event such as a switching request from the information measuring unit 2 (S6). During this loop processing, the information measuring unit 2 measures the calculated value X based on the amount of transmitted / received data notified from the data relay control module 4, and the calculated value X is calculated every unit time.
Is compared with the specified value α or the specified value β. Then, if an event occurs during the above loop processing, the following three kinds of processing are performed (S7).

When it is determined that the calculated value X is smaller than the specified value α while using the circuit switching service, this is notified as an event from the information processing unit 2, and the disconnection of the circuit switching and the processing associated with the disconnection occur. (S8). At this time, a request for disconnecting the line is sent to the call control unit 6b. As a result, the communication service is switched to the always connected packet switching service.

On the other hand, when the calculated value X exceeds the specified value β during the use of the packet switching service, this is notified as an event from the information processing unit 2, and the circuit switching connection and the processing associated with the connection are performed. (S9). At this time, a line connection request is sent to the call control unit 6b. As a result, the communication service is switched to the circuit switching service.

After the above steps S7 to S9 are repeated, a process for ending the data communication is performed (S10). Further, in the above loop processing, when an event that terminates the system operation occurs, the processing is S1.
Move to 0.

In the data relay control module 4, as shown in the flow chart of FIG. 3, when a predetermined pre-process is performed (S11), a transition is made to a loop waiting for the occurrence of an event such as data communication from the LAN or ISDN ( S1
2). If an event such as arrival of data occurs during this loop processing (S13), the following three kinds of processing are performed.

First, when the data from the LAN is received, it is judged whether or not the line is connected (S14),
If the line is not connected, the central control unit 3 is notified of the data reception and a connection request is sent (S1).
5). As a result, when the line is connected, it is confirmed which exchange service is currently used for data communication (S16), and a transmission request corresponding to the exchange service is sent to the ISDN interface 6 (S17). . If the line is connected in S14, the process proceeds to S16. Then, the amount of transfer data is notified to the information measuring unit 2 (S18).

On the other hand, when the data from the ISDN is received, the transmission request is sent to the LAN interface 5 (S19), and the data is transferred when the LAN is connected to the ISDN. The transfer data amount is notified (S18). After the processes of S14 to S18 or S19 and S18 are repeated, the process of the data relay control module 4 ends.

When an event that terminates the system operation occurs, the process ends as it is.

In the information measuring unit 2, as shown in the flowchart of FIG. 4, when a predetermined preprocessing is performed (S2
1) The process shifts to a loop waiting for line connection (S22). When the line is connected during this loop processing (S23), the elapsed time is set to "0" (S24), and the processing shifts to the loop processing for switching the exchange service (S25).
In this loop processing, the elapsed time is updated (S2
6) When the unit time has elapsed (S27), the calculated value X is obtained (S28), and the exchange mode (type of exchange service)
It is confirmed whether is the circuit switch or the packet switch (S29).

When it is confirmed that the circuit is switched, it is determined whether the measured time T has expired on the timer t (S30). When the measured time T has expired the timer t, it is determined whether the calculated value X is smaller than the specified value α (S31). If the calculated value X is less than the specified value α, a disconnection request is sent (S32).

On the other hand, when it is confirmed in S29 that the packet switching is performed, it is determined whether the calculated value X is larger than the specified value β (S33). When the calculated value X is larger than the specified value β, a connection request is sent (S34), and the elapsed time is set to "0" again (S35).

After the processes of S26 to S35 are repeated, the process of the information measuring section 2 ends.

As described above, the bridge according to this embodiment switches the circuit switching service or the packet switching service according to the amount of data communication to be transferred. As a result, when the amount of data is large, the circuit switching service featuring high-speed communication is selected, while when the amount of data is small, the packet switching service based on the pay-per-use accounting is selected. Therefore, the high speed and economy of ISDN can be fully utilized.

When the circuit switching service is connected, the packet switching service cannot be switched for a certain period (timer t) after the connection. As a result, it is possible to avoid the inconvenience that the connection and disconnection are repeated during that period and unnecessary charges are generated.

Further, since the communication path is always secured by using either one of the two exchange services, the communication between the devices is not interrupted and the reliability of the system can be improved.

Although the bridge has been described in this embodiment, a router other than the bridge can be applied as the LAN connecting device. The difference between a router and a bridge is that the data to be relayed is
rnet frame, which is an IP packet or IPX in the router
It is a network layer datagram such as a packet.

[0052]

As described above, the communication service switching device according to claim 1 of the present invention comprises a calculating means for calculating the amount of data communication per unit time transferred in the integrated service digital communication network, and a circuit switch. The calculated data communication amount calculated by the calculating means when data communication by the service is performed, and the first data communication amount per unit time which is a criterion for switching the communication service from the circuit switching service to the packet switching service. While comparing
A comparing means for comparing the calculated data communication amount when the data communication is being performed by the packet switching service and the second data communication amount per unit time which is a criterion for switching the communication service from the packet switching service to the circuit switching service; When the calculated data communication amount is determined to be smaller than the first data communication amount by the comparison means, the communication service is switched from the circuit switching service to the packet switching service, while the calculated data communication amount is the second data communication amount. And a switching means for switching the communication service from the packet switching service to the circuit switching service when it is determined that the number is larger than the above.

As a result, when the data amount is large, the data communication by the circuit switching service is performed, and when the data amount is small, the data communication is performed by the packet switching service, and the communication service suitable for the data communication amount is selected. It Therefore, it is possible to reduce unnecessary charges during the use of the circuit switching service and suppress a decrease in the throughput of the system during the use of the packet switching service.

Therefore, if the communication service switching device is adopted, it is possible to maximize the high speed and economy of ISDN.

A communication service switching device according to a second aspect of the present invention is the communication service switching device according to the first aspect, further comprising clocking means for timing a predetermined time after the circuit switching service is connected. Therefore, the comparison means compares the calculated data communication amount with the first data communication amount after the predetermined time period measured by the time measuring means is completed.

As a result, in the case of the circuit switching service, the charges for the fixed period after connection are the same,
During that time, unnecessary connections and disconnections will not be repeated. Therefore, there is an effect that it is possible to avoid the inconvenience that the billing amount carelessly increases.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a bridge according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure by a central control unit in the bridge of FIG.

3 is a flowchart showing a processing procedure by a data relay control module in the bridge of FIG.

4 is a flowchart showing a processing procedure by an information measuring unit in the bridge of FIG.

[Explanation of symbols]

 1 Storage Device 2 Information Measuring Unit (Calculating Means, Comparing Means, Clocking Means) 3 Central Control Unit (Switching Means) 4 Data Relay Control Module 5 LAN Interface 6 ISDN Interface

Claims (2)

[Claims] 1. A calculation means for calculating the amount of data communication per unit time transferred in a service integrated digital communication network, and a calculation calculated by the calculation means when data communication by a circuit switching service is being performed. While comparing the data communication amount with the first data communication amount per unit time, which is the criterion for switching the communication service from the circuit switching service to the packet switching service, the calculated data when the data communication by the packet switching service is performed. The comparison means for comparing the communication amount and the second data communication amount per unit time, which is a criterion for switching the communication service from the packet switching service to the circuit switching service, and the data communication amount calculated by the comparison by the comparison device are the first data. When it is determined that the traffic is less than the traffic, the communication service is From the packet switching service to the circuit switching service when it is determined that the calculated data communication amount is larger than the second data communication amount. Communication service switching device. 2. The data communication amount and the first data calculated after the comparison means has timed a predetermined time after the circuit switching service is connected, and the comparison means has finished counting the predetermined time by the timed means. The communication service switching device according to claim 1, wherein the communication service switching device compares the communication amount.