JP3609905B2 - Interface converter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an interface conversion device that selects a communication line to be used in accordance with the communication speed of a communication terminal device.
[0002]
[Prior art]
Conventionally, in a system in which communication terminal devices are always connected to each other and the communication speed of the communication terminal devices changes (for example, a system using a LAN as a terminal device), the communication terminal devices are accommodated on the relay side of the interface conversion device. It is necessary to match the communication speed of the communication line to the maximum communication speed of the communication terminal device, so that data communication can be performed at the maximum communication speed with the telephone communication company providing the communication line (dedicated line) on the relay side. Has a contract for the communication line.
[0003]
[Problems to be solved by the invention]
In a conventional interface conversion device, it is necessary to draw in a communication line with the maximum communication speed of the communication terminal device so that data communication is always possible at the maximum communication speed. In a system in which the communication speed of the communication terminal device changes Even when data communication does not require the maximum communication speed, since the communication line is fixed at the maximum communication speed, a band (channel) that is not actually used is generated, and the use efficiency of the communication line is reduced. There was a problem that it was not good and required communication cost more than necessary.
[0004]
An object of the present invention is to accommodate (connect) a plurality of types of communication lines (dedicated line, low-speed switching line, high-speed switching line, etc.) in the interface conversion apparatus, and according to the communication speed required by the communication terminal apparatus. It is an object of the present invention to provide an interface conversion device that can efficiently use a bandwidth (channel) of a communication line and selectively reduce a communication cost by selectively connecting communication lines to be used.
[0005]
[Means for Solving the Problems]
The present invention provides an interface unit for connecting a communication terminal device, receiving means for receiving communication speed information used from the communication terminal device via the interface unit, and the communication terminal device using a plurality of communication lines. Connection means for connecting, and connection control means for connecting the communication terminal device to any or all of the communication lines according to information received by the receiving means.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0007]
FIG. 1 is a diagram showing an inter-LAN connection system in which LANs are connected using the interface conversion apparatus of the present invention. In FIG. 1, one LAN 1 includes a plurality of terminal devices 31 and a router 3, and the router 3 is connected to an interface conversion device 5. Further, the relay side of the interface converter 5 is a high-speed digital dedicated line 7 that is always connected, an ISDN basic network 8 that performs line switching with an ISDN basic interface, and an ISDN primary that performs line switching with an ISDN primary group interface. Each of the group networks 9 is connected by a dedicated line 71, an ISDN basic line 81, and an ISDN primary group line 91. The other LAN 2 is the same, and the LAN 2 includes a plurality of terminal devices 41 and a router 4, and the router 4 is connected to the interface conversion device 6. Further, the relay side of the interface converter 6 is connected to the high-speed digital private line 7, the ISDN basic network 8, and the ISDN primary group network 9 through the dedicated line 71, the ISDN basic line 81, and the ISDN primary group line 91, respectively. Has been. The interface converters 5 and 6 perform communication control between the LAN 1 and the LAN 2 via these three types of communication lines.
[0008]
Here, in the present embodiment, the high-speed digital dedicated line 71 is a digital line having a communication speed of 1536 kbps. The ISDN basic interface indicates a digital interface of 64 kbps (B1 channel) +64 kbps (B2 channel) +16 kbps (D channel), and the ISDN primary group interface indicates a digital interface of 1536 kbps (H0 channel). .
[0009]
FIG. 2 is a block diagram illustrating a hardware configuration of the interface conversion apparatus. In FIG. 2, 11 is a system bus, 12 is an upstream and downstream highway having 32 time slots (TS), 14 is a LAN router 3 with a 2 Mbps (2048 kbps) interface compliant with, for example, TTC standard JJ-20.11. 4 is a LAN interface unit for connecting 4, 15 is a high-speed digital line interface unit for connecting a high-speed digital dedicated line 7, 16 is an ISDN basic interface unit for connecting an ISDN basic line 81 from the ISDN basic network 8, and 17 is an ISDN primary group network. 9 is an ISDN primary group interface unit for connecting the ISDN primary group line 91 from 9, 13 is an inter-network delay adjustment unit for matching and adjusting data delay between communication lines, and 10 is a highway 12 and an inter-network delay adjustment unit 13. And interface conversion device, such as settings for each interface A main control unit for controlling the whole.
[0010]
Next, the operation according to the interface conversion apparatus of the present invention will be described.
[0011]
FIG. 5 is a diagram showing a frame configuration in a TTC standard 2 Mbps interface (an interface between a router and an interface converter). In FIG. 5, the 2 Mbps interface is composed of 32 time slots of TS0 to TS31, of which TS0 is a time slot for signals, and TS1 to TS15 and TS17 to TS31 are for voice or data (ch1 to ch30). These time slots and TS16 are defined as time slots that do not regulate their use.
[0012]
Next, the configuration of TS0 (signal time slot) will be described. TS0 is a multi-frame configuration in which one frame is formed by 8 frames. Bit 1 “F” is an 8-kbps frame synchronization bit, bit 2 “MF” is a multi-frame synchronization bit, bit 3 “S” ”Indicates a device alarm bit that gives an alarm to the device when an abnormality such as a signal loss or out of frame detection is detected.“ A1 ”to“ A30 ”in bits 4 to 8 of frames 2 to 8 are TS1 to TS15 and TS17. ˜TS31 is a signal bit assigned to each bit (ch1 to ch30) corresponding to each channel (ch1 to ch30), “X” indicates an unspecified bit.
[0013]
Here, in the present invention, TS0 is used to determine the communication speed of the communication terminal device (router), and is used by ON “1” or OFF “0” of the signal bits “A1” to “A30”. Select and connect the relay line. In addition, TS16, which is not defined in the TTC standard 2 Mbps interface, is used to notify the communication terminal device (router) whether communication is possible or not possible. When TS16 is all bits ON “1”, communication is permitted. This means that when TS16 is all bits OFF “0”, it means that communication is impossible.
[0014]
FIG. 7 is a diagram for explaining the time slot allocation state. In FIG. 7, TS0 to TS31 indicated by a symbol X are time slots of the TTC standard 2 Mbps interface. In the present embodiment, among these time slots, TS0 to TS23 are designated as the high-speed digital leased line 7 indicated by the symbol A, TS24 is designated as the B1 channel of the ISDN basic line 81 indicated by the symbol B, and ISDN basic indicated by the symbol C. The B81 channel of the line 81 is set so as to be assigned to the H0 channel of the ISDN primary group line 91 indicated by the symbol D, TS26 to TS32. The reason why the B1 channel and the B2 channel of the ISDN basic line 81 are separated is that data continuity cannot be maintained.
[0015]
FIG. 6 is a table showing the correspondence between the information of the signal bits A1 to A30 of TS0 and the communication line used on the relay side. In FIG. 5, when only A1 to A22 of TS0 are in the ON “1” state, only the high-speed digital leased line 7 is used, and when A1 to A24 are in the “1” state, the high-speed digital leased line 7 and ISDN are used. When the basic line 81 is used and A1 to A30 are in the ON "1" state (when any of A25 to A30 is additionally set to the ON "1" state), the high-speed digital leased line 7 and the ISDN basic line 81 and ISDN primary group line 91 are set to be used.
[0016]
Next, the communication connection operation of the present invention will be described.
[0017]
FIG. 3 is a sequence diagram showing the operation in the connected state. First, in a state in which the LAN router 3 sends A1 to A22 of TS0 to “1” and sends data to the interface conversion device 5 through the 2 Mbps interface, the amount of transmission data is as shown in FIG. Only the high-speed digital leased line 7 that is always connected is connected to the interface conversion device 5 and the interface conversion device 6 so that the LAN 1 and the LAN 2 are in a data communication state. (S101, S102, S103). At this time, data is not mounted on the TS24 to TS31 of the 2 Mbps interface, and the data of the time slot is invalid data.
[0018]
In such a state, when the amount of data transmitted from the LAN 1 to the LAN 2 increases, the router 3 notifies the interface conversion device 5 so as to increase the number of channels used for the 2 Mbps interface. For example, when the channels used by the 2 Mbps interface are all ch1 to ch30, the router 3 sets all of A1 to A30 of TS0 of the 2 Mbps interface to the ON “1” state, and transmits this to the interface conversion device 5 ( S104). Then, the interface converter 5 recognizes that the amount of transmission data increases, and recognizes the connection line with the interface converter 6 with reference to the table shown in FIG. In this case, since it is necessary to further use the ISDN basic line 81 and the ISDN primary group line 91, processing for resetting the communication line between the interface converter 5 and the interface converter 6 is executed.
[0019]
First, the interface converter 5 sets all the 8 bits of the channel (ch16) of the high-speed digital leased line 7 corresponding to the TS16 of the 2 Mbps interface to OFF “0”, and sends this information to the interface converter 6 on the other side. Notification is made (S105). Then, the interface converter 6 detects OFF “0” of the channel (ch16) of the high-speed digital leased line 7 corresponding to the TS16 of the 2 Mbps interface, recognizes that the communication stop request has been made, and All 8 bits of TS16 of the 2 Mbps interface with the router 4 of the LAN 2 are turned OFF “0”, and the communication stop is notified to the router 4 (S106). As a result, the router 4 recognizes the communication stop and sets so as not to transmit data to the LAN 1 side. When the interface converter 6 notifies the router 4 that the communication has been stopped, all 8 bits of the channel (ch16) of the high-speed digital leased line 7 corresponding to the TS 16 of the transmission data to the interface converter 5 are all OFF “0”. On the contrary, the interface converter 5 is notified that the LAN 2 has been stopped (S107). Then, the interface converter 5 detects OFF “0” of the channel (ch16) of the high-speed digital leased line 7 corresponding to the TS16 of the 2 Mbps interface, recognizes that the communication stop request has been accepted, and Then, all 8 bits of TS16 of the 2 Mbps interface with the router 3 of the LAN 1 are turned OFF “0”, and the communication stop is notified to the router 3 (S108). Thereby, the router 3 recognizes the communication stop and sets so as not to transmit data to the LAN 2 side.
[0020]
In this way, when the communication is stopped, the interface converter 5 next performs a transmission operation according to a predetermined sequence, and performs a call connection with the interface converter 6 through the B1 channel of the ISDN basic line 81. . Briefly explaining this operation, the interface conversion device 5 automatically makes a call to the ISDN basic network 8 and requests that the call connection is made with the interface conversion device 6 by the B1 channel of the ISDN basic line. (S109). As a result, when the interface converter 6 detects an incoming signal (S110), it automatically responds to this and transmits a response signal to the ISDN basic network 8 (S111). On the other hand, the ISDN basic network 8 transmits a response signal to the interface converter 5 in response to this (S112), and connects the interface converter 5 and the interface converter 6 via the B1 channel of the ISDN basic line 81 ( S113).
[0021]
Next, similarly to this, the interface converter 5 performs a transmission operation according to a predetermined sequence, and performs call connection with the interface converter 6 through the B2 channel of the ISDN basic line 81 (S114 to S118). . Further, similarly, a transmission operation is performed to the ISDN primary group network 9 according to a predetermined sequence, and a call connection with the interface converter 6 is performed by the H0 channel of the ISDN primary group line 91 (S119 to S123). .
[0022]
As described above, the interface converter 5 and the interface converter 6 are connected by the high-speed digital dedicated line 7 connected from the beginning, the B1 and B2 channels of the ISDN basic line 81, and the H0 channel of the ISDN primary group line 91. In this way, in order to exchange data from one 2 Mbps interface using a plurality of communication networks (communication lines), a transmission delay between the communication lines (communication networks) is absorbed. Since it is necessary, next, delay adjustment processing between networks / channels is performed (S124). Hereinafter, the delay adjustment processing between networks / channels will be described with reference to FIG.
[0023]
FIG. 8 is a diagram for explaining the outline of the inter-network / inter-channel delay adjustment method. In FIG. 8, first, each of the interface conversion devices 5 and 6 transmits the test data shown in (a) to the communication partner interface conversion device. This test data is data set for each communication network and channel by incrementing 1 from (00) H for each frame.
[0024]
On the other hand, each interface conversion device that has received the test data compares the test data received from the respective communication networks / channels, reconstructs the frame based on the most delayed communication network / channel, and Performs delay adjustment processing between channels. This will be described in detail. Assume that one interface converter transmits the test data shown in FIG. 7A and the other interface converter receives the test data as shown in FIG. Then, the received interface converter includes test data A (TS1 to TS15, TS17 to TS23) from the high-speed digital leased line 7, test data B (TS24) from the B1 channel of the ISDN basic line 81, and the ISDN basic line. Test data C (TS25) from the B2 channel of 81 and test data D (TS26 to TS31) from the H0 channel of the ISDN primary group line 91 are respectively compared. Then, as shown in (b), if the content of the data for an arbitrary frame is A = B = C = D, no delay adjustment between networks / channels is required, and the received data is sent to the router side. Send to 2Mbps interface.
[0025]
Further, when the content of data in an arbitrary frame is, for example, as shown in (d), An, Bn, Cn, Dn + 1, since the test data D is one frame earlier, the test data D is stored in the next frame. Processing for delaying one frame is performed, and as shown in (e), delay adjustment processing between networks / channels is performed so that the content of data of one frame is A = B = C = D. Note that, as shown in (g), even if the content of data in any frame is An, Bn, Cn + 1, Dn + 1, similarly, the test data C and the test data D are delayed by one frame, and (h ), The delay adjustment processing between the networks / channels is performed so that the content of the data of one frame is A = B = C = D, and the exchange with the 2 Mbps interface is performed by the reconstructed frame. To do.
[0026]
Returning to FIG. 4, when the delay adjustment processing between networks / channels (S124) is performed as described above, the interface conversion apparatus 5 next selects the channel (in the high-speed digital leased line 7 corresponding to TS16 of the 2 Mbps interface ( All the 8 bits of ch16) are set to the ON “1” state, and information indicating that the delay adjustment processing is completed is notified to the interface conversion device 6 on the other side (S125). Then, the interface conversion device 6 detects ON “1” of the channel (ch16) of the high-speed digital leased line 7 corresponding to the TS16 of the 2 Mbps interface, completes the delay adjustment processing, and is requested to resume communication. Recognize that. When the delay adjustment processing between the networks / channels using the test data from the interface converter 5 is completed and communication is possible, all 8 bits of the TS16 of the 2 Mbps interface with the router 4 of the LAN 2 are turned ON. 1 ", the router 4 is notified of communication resumption (S126). As a result, the router 4 recognizes that communication is possible and permits data transmission to the LAN 1 side. At the same time, the interface converter 6 sets all the 8 bits of the channel (ch16) of the high-speed digital leased line 7 corresponding to TS16 of the transmission data to the interface converter 5 to ON “1”, and conversely, The interface converter 5 is notified that the delay adjustment processing has been completed and communication is possible (S127).
[0027]
On the other hand, the interface conversion device 5 detects ON “1” of the channel (ch16) of the high-speed digital line 7 corresponding to the TS16 of the 2 Mbps interface, recognizes that the request for resuming communication has been accepted, and All 8 bits of TS16 of the 2 Mbps interface with the router 3 of the LAN 1 are turned ON “1”, and the communication restart is notified to the router 3 (S128). As a result, the router 3 recognizes that communication is possible and permits data transmission to the LAN 2 side.
[0028]
As described above, a communication path is established between the interface conversion apparatus 5 and the interface 6 by the high-speed digital dedicated line 7, the B1 and B2 channels of the ISDN basic line 81, and the H0 channel of the ISDN primary group line 91. Data communication is performed at a speed of 2 Mbps (S129, S130, S131).
[0029]
In the above description, the case of improving the data communication speed has been described as an example, but conversely, the B1 and B2 channels of the ISDN basic line 81 and the H0 channel of the ISDN primary group line 91 are disconnected, and the data Communication speed can also be reduced.
[0030]
That is, when the router 3 sets only A1 to A22 of TS0 to ON “1”, the interface conversion apparatus 5 temporarily stops the communication and performs B1 and IS1 of the ISDN basic line 81 according to a predetermined sequence in the same manner as described above. The B2 channel and the H0 channel of the ISDN primary group line 91 are disconnected, and the communication path between the interface conversion device 5 and the interface conversion device 6 is established only by the high-speed digital dedicated line 7 so that low-speed data communication can be performed. What should I do?
[0031]
If the interface converter 5 and the interface converter 6 are connected by ISDN basic lines of a plurality of ISDN basic networks 8, the communication speed can be set and connected in finer units.
[0032]
【The invention's effect】
According to the present invention, it is possible to selectively connect a communication line to be used according to the communication speed required by the communication terminal device, and to efficiently use the bandwidth of the communication line. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an inter-LAN connection system in which LANs are connected using an interface conversion apparatus of the present invention.
FIG. 2 is a block diagram showing a hardware configuration of an interface conversion apparatus according to the present invention.
FIG. 3 is a sequence diagram showing an operation in a connection state according to the present invention.
FIG. 4 is a sequence diagram showing an operation in a connection state according to the present invention.
FIG. 5 is a diagram showing a frame configuration in a 2 Mbps interface. FIG. 6 is a table showing a correspondence relationship between information of signal bits A1 to A30 of TS0 and a communication line used on a relay side.
FIG. 7 is a diagram for explaining a time slot allocation state;
FIG. 8 is a diagram for explaining an outline of an inter-network / inter-channel delay adjustment method;
[Explanation of symbols]
1, 2 LAN
3, 4 Router 31, 41 Terminal device 5, 6 Interface converter 7 High-speed digital leased line 8 ISDN basic network 9 ISDN primary group network

Claims (1)

An interface unit that connects a communication terminal device according to interface specifications including voice or data communication information, communication speed request information, and communication availability notification information, and a first communication line that is always connected to a communication partner device. The communication speed request information is received from the communication terminal device via the interface unit ; a second connection unit that is connected to the communication partner device via a second communication line that can be arbitrarily connected; The communication terminal device is notified of the communication failure by the communication availability notification information when the connection via the second communication line is required by the communication speed request information received by the receiving device and the communication speed request information received by the reception device. Then, a connection control means for connecting the second communication line by the second connection means, and after the connection control means connects the second communication line, the first communication line is connected. A delay adjusting means for adjusting a delay between the line and the second communication line; and after the delay adjusting means adjusts the delay, the communication terminal apparatus is notified of the communication availability by the communication availability notification information, and the first And a communication restarting means for performing communication of the voice or data communication information through the second communication line and the second communication line .

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