JP2783637B2 - Terminal status notification method - Google Patents

Description

The present invention relates to a network system provided with an adapter device for connecting a terminal device to a packet switching network.
In particular, the present invention relates to a terminal status notification method for notifying a management terminal or the like of the status of a terminal device via an adapter device.

(Prior Art) Generally, in a packet switching network such as an ISDN packet switching network or DDX-P, a packet type terminal device is directly connected to the packet switching network, while a non-packet type terminal is connected to a packet adapter via a terminal adapter. Connected to the switching network. Further, even a packet-type terminal device may be connected to a packet switching network via a terminal adapter for the purpose of multiplexing.

In such a network system, when communication failure / recovery occurs in a terminal device connected to the packet switching network via the terminal adapter, the terminal adapter generates a reset packet and transmits it to the packet switching network. However, it is determined by Recommendation X.25 that the cause codes “01” / “09” indicating the communication failure / recovery of the terminal device cannot be used by the network itself. Therefore, the cause codes "01" / "09"
For example, it is converted to “00” in the packet switching network. Therefore, even if a certain terminal device (A) notifies the state of the terminal to another terminal device (B) connected to the packet switching network using the cause code “01” / “09”, the packet switching network As a result, the cause code was converted to "00", and the status notification could not be correctly sent to the terminal device (B). This problem is based on the recommendation of the packet switching network, and does not basically relate to whether the terminal device is a packet terminal or a non-packet terminal.
This causes many causes that the host computer device or the management terminal misrecognizes the state of the terminal device.

(Problems to be Solved by the Invention) Conventionally, even if the terminal device notifies the other terminal of the state using the cause code “01” / “09”, the state is changed to another code “00” by the packet switching network. Because it was replaced, status notification could not be performed correctly. For this reason, although the cause codes “01” / “09” can be mutually recognized between the terminal devices, in a connection environment via the packet switching network,
There is a problem that the cause code cannot be actually used for the status notification between the terminals.

The present invention has been made in view of such a point, and provides a terminal adapter device for connecting a terminal device to a packet switching network with a function of converting a code format of a cause code,
In this way, the cause code, which cannot be accurately used in the connection environment via the packet switching network and cannot be used in practice, can be used for the status notification of the terminal even in the connection environment via the packet switching network. It is an object of the present invention to provide a terminal status notification method that allows a device to normally grasp the status of a terminal device.

[Constitution of the Invention] (Means for Solving the Problems) A terminal status notification method according to the present invention is a network system provided with an adapter device for connecting a terminal device to a packet switching network. First conversion means for converting a first cause code indicating a communication inability / recovery state of a device into a second cause code having a specific code format and transmitting the converted second cause code to the packet switching network; and transmitting from the packet switching network. And a second conversion unit for converting the second cause code to be converted into the first cause code and transmitting the second cause code to the terminal device. Is notified.

(Operation) In this terminal status notifying method, when the cause code of the terminal device is transmitted to the packet switching network, its code format is converted. When the cause code is received via the packet switching network, the cause code is converted. Is converted back to the original code form. For this reason, the cause code that could not be used conventionally is
It can be used for status notification of all terminal devices, which allows the host computer device and other management terminals to normally grasp the transmission disabled / recovery status of the terminal devices.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows the configuration of a network system for realizing a terminal status notification system according to an embodiment of the present invention. In FIG. 1, an ISDN packet switching network 11 provides various communication services such as telephone, data communication, facsimile, and image communication. Connected to the packet switching network 11 are ISDN-compliant terminals 12, 13 and non-ISDN-compliant terminals 14, 15, which are not ISDN-compliant. The non-ISDN packet type terminals 14 and 15 are non-ISDN compatible packet terminals having no ISDN connection function. Below, non-ISDN packet type terminals
14 and 15 are simply referred to as packet-type terminals.

The packet-type terminals 12 and 13 are directly connected to the ISDN switching network 11, while the packet-type terminals 14 and 15
It is connected to the ISDN switching network 11 via terminal adapters 16 and 17, respectively. Among these terminal devices, the packet terminal 14 functions as a management terminal for managing other terminals.

The terminal adapter 16 is a device capable of multiplexing packets, for example, up to four lines.
It controls data transfer between the switching networks 11. The terminal adapter 16 transmits and receives a cause code indicating a communication disabled / recovery state corresponding to a reset request or a reset instruction between the packet type terminal 14 and the ISDN switching network 11,
The code format of the cause code is converted by a. For example, when transmitting the packets of the cause codes “01” / “09” indicating the communication disabled / recovery state of the packet form terminal 14, the terminal adapter 16 sets the cause codes to “0001”.
/ "0009" and transmits it to the ISDN packet switching network 11. This is a format in which a diagnostic code of “01” / “09” is added to a cause code of “00”. Further, the terminal adapter 16 transmits “0001” / “0009” from the ISDN packet switching network 11.
Is received, the packet is decrypted, converted to the original cause code "01" / "09", and transmitted to the packet terminal 14.

The terminal adapter 17 is also a device capable of multiplexing packets, for example, up to four lines.
It controls data transfer between the DN exchange networks 11. This terminal adapter 17 disables communication between the packet terminal 15 and the ISDN switching network 11 in response to a reset request or a reset instruction.
When sending and receiving a cause code indicating the recovery state, the code format of the cause code is converted by the code conversion unit 17a in the same manner as in the terminal adapter 16. That is, when transmitting a packet with the cause code “01” / “09” indicating the communication disabled / recovery state of the packet form terminal 15, the terminal adapter 17 converts the cause code into “0001” / “0009”, respectively. Then, the packet is transmitted to the ISDN packet switching network 11. In addition, the terminal adapter 17 transmits “000
When a packet of “1” / “0009” is received, it is decoded, converted to the original cause code “01” / “09”, and transmitted to the packet-type terminal 15.

Next, with reference to FIG. 2, the operation of transferring the cause code between the packet-type terminal 15 and the packet-type terminal 14 functioning as the management terminal will be described. FIG. 2A corresponds to the case where the terminal adapter 17 detects the communication disabled state of the packet-type terminal 15, and FIG. 2B corresponds to the case where the terminal adapter 17 detects the communication recovery state of the packet-type terminal 15. If you do.

As shown in FIG. 2 (A), when the terminal adapter 17 detects that the packet form terminal 15 cannot communicate, the terminal adapter 17 converts the reset request packet with the cause code "RQ01" to "RQ0001". Then, the packet is transmitted to the ISDN packet switching network 11. As a result, the reset instruction packet “RI0001” is transmitted from the ISDN packet switching network 11 to the terminal adapter 16. This reset instruction packet “RI0001” is decoded by the terminal adapter 16 and the reset instruction packet “RI0” having the cause code “01” is read.
It is converted to “1” and transmitted to the packet form terminal 14. In this way, the packet with the cause code "01" indicating the communication disabled state of the packet-type terminal 15 is transmitted to the packet-type terminal 14 which is the management terminal of the packet-type terminal 15, and the packet-type terminal 15 Can be normally grasped that the communication is disabled.

Further, as shown in FIG. 2B, the packet transfer of the cause code "09" is performed in the same manner as the case of the cause code "01". That is, when the terminal adapter 17 detects the communication recovery state of the packet-type terminal 15, the terminal adapter 17 converts the reset request packet with the cause code "09" into "RQ0009" and transmits it to the ISDN packet switching network 11. Thereby, the ISDN packet switching network 11
Sends a reset instruction packet “RI0009” to the terminal adapter 16. This reset instruction packet “RI0009” is decoded by the terminal adapter 16, converted into a reset instruction packet “RI09” having the cause code “09”, and transmitted to the non-ISDN packet type terminal 14. In this manner, the packet with the cause code “09” indicating the communication recovery state of the packet-type terminal device 15 is transmitted to the packet-type terminal 14 that is the management terminal, whereby the packet-type terminal 15 It can be normally grasped that the communication has been restored.

As described above, the cause codes "01" / "09" are converted to "00" as the conversion method of the cause codes by the terminal adapters 16 and 17.
"01" / "0009" and the cause code "01"
A method of converting / "09" to "81" / "89" can also be used. In this case, as shown in FIG. 3 (A), the reset request packet “RQ01” indicating the communication disabled state of the
"0" is added and converted to "RQ81", which is transmitted to the ISDN packet switching network 11. As a result, the reset instruction packet “RI81” is transmitted from the ISDN packet switching network 11 to the terminal adapter 16. The reset instruction packet “RI81” is decoded by the terminal adapter 16 and the reset instruction packet “RI0” having the cause code “01” is read.
It is converted to “1” and transmitted to the packet form terminal 14.

As shown in FIG. 3B, the reset request packet "RQ09" indicating the communication recovery state of the packet type terminal 15 is converted into "RQ89" by the terminal adapter 17 and transmitted to the ISDN packet switching network 11. Sent. This allows the ISDN packet switching network 11 to connect to the terminal adapter 16
, A reset instruction packet “RI89” is transmitted.
The reset instruction packet “RI89” is decrypted by the terminal adapter 16, converted into a reset instruction packet “RI09” having the cause code “09”, and transmitted to the packet-type terminal 14.

In this way, the cause codes “01” / “09” to “81” / “8
Even if the conversion to "9" or the reverse conversion is performed, the communication failure / recovery state of the packet terminal 15 can be normally grasped by the packet terminal 14.

As described above, in this embodiment, the terminal adapters 16 and 17 are provided with the function of converting the code format of the cause code, so that the cause code “01” which could not be used conventionally can be used.
/ "09" can be used for status notification of a terminal device connected to a packet switching network via a terminal adapter, so that the host computer device or management terminal cannot communicate / recover the terminal device. The state can be grasped normally.

[Effects of the Invention] As described above, according to the present invention, the communication disabled / recovery state of the terminal device connected to the packet switching network via the terminal adapter is normally transmitted to the host computer device and other management terminal devices. Can be notified.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a network system for realizing a terminal status notification system according to an embodiment of the present invention, and FIG. 2 is a diagram showing causes of a terminal adapter provided in the network system of FIG. FIG. 3 is a diagram showing an example of a code conversion operation, and FIG. 3 is a diagram showing another example of a cause code conversion operation by a terminal adapter provided in the network system of FIG. 11 ISDN packet switching network, 12, 13, 14, 15 ... packet-type terminal, 16, 17 terminal adapter.

Claims (1)

(57) [Claims] In a network system provided with an adapter device for connecting a terminal device to a packet switching network, the adapter device specifies a first cause code indicating a communication disabled / recovery state of the terminal device. Second of sign format
A first conversion means for converting the second cause code transmitted from the packet switching network into the first cause code, and converting the second cause code transmitted from the packet switching network into the first cause code. A terminal status notifying system, comprising: a second conversion unit for transmitting a message; and notifying the terminal device of a communication disabled / recovery status by a cause code conversion operation.