JPH09116989A - Highly reliable communication system and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select a direction in the most reliable state for the communication request of a high level such as an important conference and to set a system to be highly reliable by selecting the direction of the level fitted to a direction selection level in accordance with a bypass condition. SOLUTION: A bypass condition storage means (b) storing the condition for selecting a bypass direction, a direction selection level storage means (d) which previously inputs the direction selection level corresponding to the level at the time of registration or transmission and stores the direction selection level and a direction decision/channel acquisition means (g) selecting the direction of the level fitted to the direction selection level are provided. When highly reliable communication is required, the high direction selection level is designated. Thus, two D-channels select healthy directions. Even if a fault occurs in one D-channel during communication, the other D-channel can be used at present, and communication by a B-channel can be continued. Thus, communication can be set highly reliable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly reliable communication system and a communication control method for achieving highly reliable route selection in ISDN to which a backup D channel system is applied. In a network adopting a common line signaling system, acquisition control of a plurality of B channels is performed using the D channel, but the B channel is forcibly disconnected due to the failure of the D channel. So one D
A backup D channel system is known in which, when a channel fails, the backup D channel is switched to the backup D channel and the B channel acquisition control is continued, and further improvement in reliability is desired.

[0002]

2. Description of the Related Art FIG. 23 is a schematic explanatory view of an exchange, and comprises a plurality of line system card mounting shelves 101, a control system card mounting shelf 102, and a power supply related section 103. The power supply related section 103 is provided in each section. It supplies a stabilized power supply, and the control system shelf 102 has an IO (input / output interface) card, MM (main memory) card, CPU (processor) card, NW (network) card, FD ( A floppy disk), HD (hard disk), etc. are installed.

Further, the line card-equipped shelf 101 is provided with, for example, a plurality of I's corresponding to the routes 1, 2, 3 ,.
An SDN card is installed and a backup D-channel type exchange of 2D + 64B configuration is configured. In this case, one of the two D channels is in use and the other is in standby, and the route acquisition of 64 B channels is performed using the in-use D channel.

For example, in the route 3, one of the two D channels is currently in use, 64 B channels are captured and controlled, and when a failure occurs in the D channel, the other D channel is recovered from the standby state. 64 by switching to the current
The acquisition control of the B channels will be continued. In this case, if the backup D channel configuration is not applied, if one D channel fails, the
The channel is forcibly disconnected. Therefore, the backup D channel configuration can improve the reliability of communication.

FIG. 24 is a diagram for explaining the D channel switching sequence. D1 and D2 indicate the D channel between the PBX (private branch exchange) and the opposite station (subscriber exchange), and (IS).
Indicates the in-service or working side, and (STBY) indicates the standby or standby side. Working D on the PBX side
When the failure occurrence of the channel D1 is detected, the disconnection request message DISC (DISCONNECT) by the layer 2
To the game side.

On the other side, the disconnection request message DIS
When C is received, UA (Unnumbered Ackno) is sent to the PBX side.
wledgement) response is sent, and the PBX side sends this U
SABME (Set Asynchronous) for A response
Balancing Mode Extended) command is sent, and the D channel D1 in which the failure has occurred is out of service (OOS).
And Against this SABME command, the game side is U
The A response is transmitted, and the D channel D1 between the player side and the PBX side is switched to the spare (STBY) side.

For the spare D channel D2, P
The BX side sends a SERV command to the game side by layer 3, the game side sends a SERV response, and the PBX
The side receives D-channel D by receiving this SERV response.
2 is switched to the working (IS) side, and an affirmative response SERV A
Send CK to the game side, and the game side also acknowledges SERVA
CK is sent to the PBX side and the D channel D2 is currently used (I
Switch to S) side.

[0008]

When capturing the B channel in the route of the backup D channel configuration, the active B channel is used to selectively capture the empty B channel in the route. In that case, when all the B channels of the selected route are in use, the busy process is performed or the bypass connection is made to another preset route. In the B channel configuration of such a backup D channel configuration, even if one of the working D channel and the backup D channel has a failure, if there is an empty B channel, that route is selectively captured. .

Therefore, if the B channel in the path where one of the D channels has a failure occurs is captured during an important conference or important data communication, the other D channel is obtained during the conference or the data communication. If a failure also occurs, the two D channels will be in a failure state, and the active and standby D channels cannot be switched.
The channel will be forcibly disconnected. As a result, there was a problem that an important conference had to be interrupted and important data communication was disconnected during the communication. The present invention
For high-level communication requests such as important conferences, the purpose is to select the route with the highest reliability and to make the system highly reliable.

[0010]

The highly reliable communication system of the present invention comprises: (1) a plurality of B channels using a dual D channel for working and protection in a network to which a common line signaling system is applied. In a communication system of a backup D channel configuration for performing selective acquisition, a detour condition storage means b for storing a condition for selecting a detour route, and a level indicating the reliability of the route corresponding to the state of the duplicated D channel. Is set, a route selection level corresponding to this level is input in advance at the time of registration or transmission, and the route selection level storage means d for storing this route selection level and the route selection level are stored in the selected route. Route determining / channel capturing means g for selecting a route having a level that matches the route selection level in accordance with the detour condition stored in the detour condition storage means when the level is higher than the level. .

(2) Also, the level indicating the reliability of the route corresponding to the state of the duplicated D channel is set to the highest level when all D channels are healthy, and a failure occurs in one of the D channels. Then, when the other D channel is healthy, the next level is set, and when one D channel is out of service due to maintenance and the other D channel is healthy, the next level is set.

(3) Further, the level indicating the reliability of the route corresponding to the state of the duplicated D channel may be set to be high for a route having a small number of fault occurrences according to the state statistics and low for a route having a large number of faults. it can.

(4) Further, in the route selection level storage means d,
A route selection level registration / change means c having a function of registering / changing the route selection level by a maintenance operation command or from the terminal device of the caller can be provided.

(5) Further, the detour condition storage means has a structure for storing detour conditions including whether or not the detour connection is necessary and a time zone for the detour connection.

(6) The route determining / channel capturing means g is
The terminal device type of the caller is identified, the route selection level corresponding to the terminal device type is determined, and the route is determined according to the detour condition stored in the detour condition storage means b.

(7) Further, in the communication control method of the present invention, in the high reliability communication system having the backup D channel configuration, when both the duplicated D channels are sound, the highest level is set to the D channel state. When the level indicating the reliability of the corresponding route is set, the detour condition in the route selection is set, and the route selection level requested by the caller is higher than the level of the route according to the outgoing information, It includes a process of selecting a route satisfying the detour condition and having a route level which is equal to or higher than the route selection level to make a detour connection.

(8) When the originator cannot select a route of a level corresponding to the designated route selection level, the originator is notified of that fact and the originator is allowed to re-designate the route selection level. The method may include selecting a route of a level corresponding to the re-designated route selection level.

[0018]

1 is a functional block diagram of an embodiment of the present invention, in which a is a detour registration means (P-104), b is a detour condition storage means (P-103), and c is a route selection level registration.・
Change means (P-105), d is route selection level storage means (P-109), and e is route selection level display means (P-1).
06) and f are route selection level recognition means (P-110, P
-111), g is route determination / channel acquisition means (P-1)
01, P-102, P-107, P-107, P-10
8, P-112, P-113), and the route selection level registration / change means c and the route selection level display means e can be functions of the terminal device of the subscriber.

The detour registration means a is means for registering a detour condition such as a detour route or a detour time zone by a maintenance operation command by a maintenance person or a subscriber's terminal device, and the detour condition storage means b is a detour registration. The memory includes a detour table that stores detour conditions by the means a and is configured by a memory.
The route selection level registration / change means c indicates a means for registering or changing the route selection level corresponding to the importance of communication by the maintenance operation command by the maintenance person or the subscriber's terminal device. The selection level storage means d is composed of a memory for storing the route selection level registered or changed by the route selection level registration / change means c.

Further, the route selection level display means e is a display control means for displaying guidance, registration or change contents when the route selection level is registered or changed, and a display means such as a liquid crystal panel. Further, the route selection level recognition means f refers to the route selection level storage means d to identify the route selection level corresponding to the sender. Further, the route determination / channel acquisition means g selects a route by referring to the route selection level recognized by the route selection level recognition means f and the detour condition stored in the detour condition storage means b. The B channel on the route is selectively captured and can be realized by the processing function of the processor controlling the exchange.

The above-mentioned route selection level is, for example, D1 (or D2) = in service, D2 for the D channel.
(Or D1) = “1” for standby, D1 (or D2) = in-service, D2 = (or D1) “2” for out-of-service, D1 (or D2) = in-service, D2 (or D1) = “3” in the case of maintenance out of service, and the level indicating the reliability of the route can have a relationship of “1”>“2”> “3”.

When the subscriber makes a call to a route having a backup D channel configuration, designation of the route selection level of the subscriber,
Alternatively, the system selects a route based on the route selection level automatically determined by the system according to the type of the terminal device or the communication mode and the level corresponding to the state of the D channel such as soundness or failure, and Selective acquisition of an empty B channel on the route is performed.
For example, when a route selection level "1" is designated when an important conference is started, a route of level "1" in which one D channel is in use and the other D channel is in a standby state is selected. As a result, when a failure occurs in the working D channel, it is switched to the backup D channel and communication by the B channel is continued, so that highly reliable communication can be performed.

FIG. 2 is a system explanatory view of an embodiment of the present invention. 1 is a communication network (NW), 2 is a processor (CPU), 3 is a main memory, 4 is a program section,
5 is a program function block, 6 is a data part, 7 is a data block, 8 is a telephone, 9 is a data terminal device, 10 is an image terminal device, 11 is a line terminal part of an ISDN line, 12
Is an exchange network such as a public network or a private network.

By the processor 2 and the main memory 3,
The functions of the detour condition storage means b, the route selection level storage means c, the route selection level recognition means f, and the route determination / channel acquisition means g of FIG. 1 are realized. Further, at the time of making a call from a subscriber terminal device such as the telephone set 8, the data terminal device 9, the image terminal device 10, etc., the processor 2 identifies the type of the calling terminal device and outputs to the receiving terminal device based on the information element of the call setting message. A route is selected, and an empty B channel on that route is selected and captured.

FIG. 3 is an explanatory diagram of the program function block of the embodiment of the present invention, showing the main part of the program function block 5 of the program unit 4 formed in the main memory 3 of FIG. 2, and the ISDN trunk acquisition control unit. (P-101)
, The detour control unit (P-102), and the state control unit (P-1
03), a route selection command section (P-104), a route selection setting special number control section (P-105), a route selection multi-function telephone display section (P-106), and a special number control section when making a call. (P-
107), a time zone route selection control unit (P-108),
Terminal type route selection control unit (P-109), ISDN terminal route selection control unit (P-110), route manual selection control unit (P-111), and route waiting control unit (P-11)
2) and the state statistics part (P-113).

(P-101) to (P-113) of each part
Shows a program corresponding to the inside of parentheses in each means of FIG. For example, the detour condition registration means a in FIG. 1 can be realized by the function of the route selection command section (P-104),
Further, the route determination / channel capturing means g includes a trunk capture control unit (P-101), a detour control unit (P-102), a calling special number control unit (P-107), and a route queuing control unit (P).
-112), and the function of the state statistics part (P-113).

FIG. 4 is an explanatory view of the data block of the embodiment of the present invention, showing the main part of the data block 7 of the data part 6 formed in the main memory 3 of FIG. 2, and the D channel state table (D- 101), D channel detour table (D-10
2), detour level table (D-103), detour level control table (D-104), detour time zone control table (D-105), detour terminal type registration table (D-106), detour monitoring control table (D)
-107), a state statistical table (D-108), and the like.

FIG. 5A is the above-mentioned D channel state table (D-101), and FIG. 5B is the D channel detour table (D-10).
2), the D channel state table of (A) stores the states of the D channels D1 and D2 in the area corresponding to the subscriber's terminal logical number ENT. The working D channel is set to "1" indicating in-service, and the backup D channel is set to "2" indicating standby. Further, "3" indicating out-of-service is set to the D channel in which the failure has occurred. If maintenance is in progress, "4" indicating maintenance out of service is set. Also, "5" to "7" are spares, and "0" indicates that they are not installed. Therefore, according to the D channel state table, D1 (D2)
= “1”, the level of the route of D2 (D1) = “2” is “1”, D1 (D2) = “1”, D2 (D1) =
The level of the route of "3" is "2", D1 (D2) = "1"
Then, the level of the route of D2 (D1) = “4” becomes “3”.

In the D channel detour table of (B), unregistered "0" and state control "1" of D1 and D2 of the D channel.
And a detour control type setting area for TIME control “2” and a next terminal logical terminal number “NEXT ENT” are stored in correspondence with the terminal logical number.

FIG. 6A shows the above-mentioned detour level table (D-
103) and (B) show an example of the detour level control table (D-104), and the detour level table of (A) is the D channel D.
No detour “0” or detour “1” is set for 1 and D2. With detour "1" is set,
A detour route corresponding to the designated route selection level and according to other detour conditions is selected. In the detour level control table (B), the link terminal logical number LINK ENT is stored based on the D channel D1 having the terminal logical number ENT and the D channel D2 having the D channel D1.

FIG. 7A shows a detour time zone control table (D-1).
05) and (B) show an example of the detour terminal type registration table (D-106), and the detour time zone control table of (A) shows the terminal logical number ENT and Sunday to Saturday "0" to "6". , The detour level LEVEL, which is one of the detour conditions, is stored based on the times “0 to 23”. Although the case of setting the day of the week and the time is shown, it is also possible to set the month and day and the time, and it is also possible to set the month and day. Further, the detour terminal type registration table of (B) shows that the terminal type TYP, TI
The detour level LEVEL is stored based on D.

FIG. 8A shows a bypass monitoring control table (D-10).
7) and (B) show an example of the state statistical table (D-108), and QHT of the detour monitoring control table of (A) is a queuing head table, and as shown by a dotted arrow, a detour waiting The start address of the first data is indicated, and QTT is a queuing tail table, and as indicated by a dotted arrow, indicates the start address of the last data of the detour wait. Also, NEXT QL indicates an address linked to the next queue. In addition, the status statistical table of (B) shows the terminal logical number EN
The failure occurrence count COUNT is stored in an area based on T and the bypass level LEVEL. Number of times this failure has occurred
The level indicating the reliability of the route can be determined by T.

FIG. 9 is a diagram for explaining the operation of the embodiment of the present invention, in which the routes 1 to 3 each have a backup D channel configuration having a plurality of B channels and two D channels D1 and D2. In each of the routes 1 to 3, one of the two D channels is currently used and a plurality of B channels are selectively captured. Some exchanges may include a route that does not have a backup D channel configuration.

For example, one D channel D1 is in service (IS), and the other D channel D2 is out of service (OOS) in route 1 due to a failure.
In the meanwhile, when the routes 2 and 3 are in the standby (STBY) state, the level of the route 1 is “2”, and the levels of the routes 2 and 3 are “1”. Then, if the detour condition is set from the route 1 to the route 2, when the communication request of the route selection level “1” is issued from the terminal device, the empty B is available in the route 1.
Even if the channel exists, since the level of the route 1 is “2”, the level “1” is set according to the set detour condition.
Route 2 is selected. If a time zone is set as the detour condition, the detour route is selected only when making a call in that time zone.

Further, when a communication request of the route selection level "2" is issued from the terminal device, if there is an empty B channel in the route 1 corresponding to the transmission request, the route 1 is selected, An empty B channel is selectively acquired. Moreover, the route 1
When there is no free B channel, the route 2 is selected at a route having the same level as or higher than the route selection level “2” and corresponding to the detour condition.

FIG. 10 is a flow chart of the ISDN trunk acquisition control section of the embodiment of the present invention, and shows the operation of the ISDN trunk acquisition control section (P-101) in the program control block in FIG. First, the D channel detour table of FIG. 5B is read according to the call request (A1), the presence / absence of a free B channel is determined (A2), and if there is no free B channel, it is ended. The presence / absence of reliable communication control is determined (A3), and if there is no request for highly reliable communication, this processing ends.

If the terminal requires high reliability communication, the process (A4) of the detour control unit (P-102) in FIG. 3 is performed to determine whether the high reliability communication control is successful. Shi (A
5) If it is successful, the control result is output (A6), and if it is unsuccessful, it is determined whether or not the secondary reliability communication control is performed (A7). Processing of the route queuing control unit (P-112) in
8) If not, execute the process of the route manual selection control unit (P-111) in FIG. 3 (A9). Therefore, when the route of the designated route selection level is busy, it is possible to capture the B channel by selecting the route of the lower level by changing the route selection level by re-input operation. Become.

FIG. 11 is a flow chart of the detour control unit according to the embodiment of the present invention. The detour control unit (P-1) in FIG.
02), and corresponds to the process of step (A4) in FIG. First, the D channel detour table in (B1) of FIG. 5 is read (B1), and the presence or absence of detour control is determined (B2).
If there is no detour control, this process ends. If there is detour control, it is determined whether or not the detour of the D channel state is necessary (B3),
If no detour is necessary, this process ends. If the detour is necessary, the detour process of the backup D channel configuration is performed (B4). That is, the detour route is selected based on the designated route selection level and the detour condition. Then, it is determined whether or not the bypass control is successful (B5), and if it is successful, the successful control result is output (B6), and if it is unsuccessful, the unsuccessful control result is output (B7).

FIG. 12 is a flow chart of the state control section of the embodiment of the present invention. The state control section (P-1 in FIG. 3).
03), detecting a D-channel state change (C1), and determining whether or not there is a D-channel state change (C1).
2) If there is a status change such as failure occurrence, failure recovery, or maintenance, the changed status is set in the D channel status table of FIG. 5A (C3).

FIG. 13 is a flow chart of the route selection command section of the embodiment of the present invention, which shows the operation of the route selection command section (P-104) in FIG. 3 and shows whether the input information is normal or not. A determination is made (D1), and if abnormal, this processing is ended. If it is normal, it is judged whether it is a command request (D2). If it is a display command, the D channel detour table in FIG. 5B is read (D3) and the display output format is edited (D4). .

In the case of a setting command, it is set in the D channel detour table, detour level table and detour level control table (D
5). Then, the display output format is edited to display the setting contents (D6). In the case of the delete command, the D channel detour table is deleted (D7), and the display output format editing for displaying the deleted result is performed (D7).
8). The information obtained by editing the display output format is displayed on the display unit of the sender's terminal device or the display unit of the maintenance console operated by the maintenance person.

FIG. 14 is a flowchart of the route selection setting special number control unit according to the embodiment of the present invention, showing the operation of the route selection setting special number control unit (P-105) in FIG. It is judged whether the input information by the special number from the device is normal (E1), and if normal, the D channel detour table (see FIG. 5).
(See (B)) is set (E2), and the setting service completion sound transmission control is performed upon completion of the setting (E3). If the input information is abnormal, the setting service failure sound transmission control is performed (E4).

FIG. 15 is a flow chart of the route selection multifunction telephone control unit of the embodiment of the present invention, showing the operation of the route selection multifunction telephone control unit (P-106) of FIG. It is determined whether the device is a multi-function telephone (F1). This can be easily determined by the information element of the call setup message. In the case of a multi-function telephone, it is determined whether the input information is normal (F2), and if it is normal, the D channel detour table (see (B) of FIG. 5) is read (F3) and output editing control is performed. (F4), the setting service completion display transmission control is performed (F5). If the input terminal is not a multifunctional telephone or if the input information is abnormal, the setting service failure display transmission control is performed (F6). Note that setting input can be made possible from a terminal device other than the multifunction telephone.

FIG. 16 is a flow chart of the calling special number control unit of the embodiment of the present invention, showing the operation of the calling special number control unit (P-107) in FIG. 3 and performing the inputted special number analysis processing (G1 ), It is determined whether the special number analysis result is normal (G2), the condition check process of the backup D channel configuration is performed (G3), and it is determined whether the result of the condition check is normal (G4). In the case, the B channel acquisition process is performed (G5), it is determined whether the B channel acquisition process is normally performed (G6), and if it is normal, the transmission process is performed (G7). If the special number analysis result is abnormal or if the condition check result is abnormal, transmission failure processing is performed (G8).
The route special level control unit (P-107) can set the route selection level and the detour condition by the special number at the time of calling.

FIG. 17 is a flow chart of the time zone route selection control section of the embodiment of the present invention, showing the operation of the time zone route selection control section (P-108) of FIG. H1), the time zone level extraction processing is performed with reference to the detour time zone control table of FIG. 7 (A) (H2), the state of the D channel corresponding to that level is checked (H3), and the D
Whether or not there is a channel is determined (H4), and if there is that D channel, the ISDN trunk acquisition processing unit (P-10 in FIG. 3).
The process is passed to 1) (H5). If the D channel does not exist, the ISDN trunk acquisition failure process is performed (H
6).

FIG. 18 is a flow chart of the terminal type route selection control unit of the embodiment of the present invention, showing the operation of the terminal type route selection control unit (P-109) of FIG. 3 and FIG. 7B.
The detour terminal type registration table is read (I1), the level extraction processing corresponding to the terminal type is performed (I2), the D channel state corresponding to this level is checked (I3), and the presence or absence of the D channel is determined ( I4), if there is the D channel, ISDN trunk acquisition control unit (P-101) in FIG.
The process is passed to (I5). If the D channel does not exist, the ISDN trunk acquisition failure process is performed (I6).
This terminal type route selection control unit (P-109) can set a route selection level corresponding to the originating terminal device type.

FIG. 19 is a flow chart of the ISDN terminal route selection control section of the embodiment of the present invention.
The operation of the terminal route selection control unit (P-110) is shown, the information element of the call setup message SETUP is analyzed (J1),
Check the information transfer ability in the information element (J2),
The level corresponding to the bearer capability is checked (J3), the state of the D channel corresponding to the level is checked (J4), the presence or absence of the D channel is determined (J5), and if there is the D channel, the ISDN trunk of FIG. Capture control unit (P-10
The process is passed to 1) (J6). If the D channel does not exist, the ISDN trunk acquisition failure processing is performed (J
7). This ISDN terminal route selection control unit (P-110)
As a result, it is possible to selectively capture the number of B channels corresponding to the communication capacity of the transmitting terminal device.

FIG. 20 is a flow chart of the route manual selection control unit of the embodiment of the present invention, showing the operation of the route manual control unit (P-111) in FIG. 3 and performing the route selection level input processing. (K1), perform analysis processing corresponding to the input level (K
2) Determine whether there is a required level of D channel (K
3) If there is the D channel, the process is passed to the ISDN trunk acquisition control unit (P-101) in FIG. 3 (K4). If there is no D channel, it is judged whether or not there is a re-level input request (K5), and if there is, a shift is made to step (K1),
If there is not, ISDN trunk acquisition failure processing is performed (K
6). With this route manual control unit (P-111), the route selection level can be changed by a re-input operation.

FIG. 21 is a flow chart of the route queuing control unit of the embodiment of the present invention, showing the operation of the route queuing control unit (P-112) in FIG. ), If the waiting request is checked, the D channel state monitoring process corresponding to the level is performed (L2), and it is determined whether the D channel can be captured (L3). If the D channel can be captured, the B channel is captured. Processing is performed (L4), it is determined whether or not the acquisition of the B channel is normal (L5), and if it is normal, transmission processing is performed (L4).
6). If the D channel cannot be captured, or if the B channel is abnormal, the process proceeds to step (L1). If there is no waiting request check, call failure processing is performed (L7).

FIG. 22 is a flow chart of the state statistic section of the embodiment of the present invention. The state statistic section (P-113) of FIG.
Of the backup D channel configuration, it is judged whether or not it is the state statistical processing in the backup D channel configuration (M1). In the case of the state statistical processing, the level statistical information check processing is performed (M1).
2) The acquisition target D channel extraction processing is performed (M3), and the control is passed to the ISDN trunk acquisition control unit (P-101) in FIG. 3 (M4). If it is not state statistical processing, level statistical information totaling processing is performed (M5). This status statistics section (P
The reliability of each route can be obtained from the number of times of occurrence of a fault corresponding to the route according to (113). That is, D corresponding to the route
The level of the route can be determined by a combination of the state of the channel and the number of times of failure occurrence.

The route selection level registering / changing means c shown in FIG. 1 can be realized by using the telephone 8 shown in FIG. 2 as a multifunction telephone. By dialing "special number + level number", The processor 2 of the exchange is a "special number"
The registration of the route selection level is identified by and the route selection level according to the "level number" is registered. In addition, the registration contents or the registration result can be displayed on the route selection multifunction telephone display (P
-106) (see FIGS. 3 and 15), the data can be edited and transmitted in a format that can be displayed on the multifunction telephone.

When the above-mentioned route selection level is registered as, for example, "1" and a call is made from the multi-function telephone, the exchange will select a route at the level "1" in which the two D channels are sound. In that case, when one of the D channels is in failure, the level of the route becomes “2”, and when the detour condition is set, the detour condition is satisfied and the route of the level “1” is satisfied. A selection is made. Therefore, in the communication in which the route selection level is set to "1", since the two D channels are always sound, even if the failure of one D channel is switched to the other D channel, the communication is continued. As a result, highly reliable communication becomes possible.

In this case, the D channel state table (see FIG. 5A), the D channel detour table (see FIG. 5B) formed in the data block 7 of the data section 6 of the main memory 3, Detour level table (see FIG. 6A), detour level control table (see FIG. 6B), detour time zone control table (see FIG. 7A), detour terminal type registration table (FIG. 7) (See (B) of FIG. 8) and the bypass monitoring control table (see (A) of FIG. 8), the processor 2 performs the bypass control corresponding to the route selection level.

Further, the route selection level can be requested by adding "special number + level number" and dialing when making a call. In this case, the processor 2 sends the special number control unit (P-107) at the time of transmission of the program function block 5.
According to (see FIGS. 3 and 16), the "special number" is analyzed as in the case of registration, and the route having the level suitable for the required route selection level is selected.

Further, the route determination / channel acquisition means g (see FIG. 1)
In the reference), based on the information element of the call setup message,
The terminal device type (telephone, fax terminal, data terminal, image terminal, etc.) of the caller is identified. For example, if the calling terminal device type is a telephone and it is not a conference call request, the route selection level is set to 2 and route selection is performed. In the case of a conference call request, it can be determined that high reliability is required, and the route selection level can be set to 1 for route selection.

Further, the case where the level of the route is set to 1 to 3 is shown. For example, the level is set to 1 to 6 and the state statistics part (P-113)
The level can be determined according to the statistical contents according to (see FIGS. 3 and 8B). In that case, for example, even if two D channels are healthy, a route with a large number of fault occurrences is set to level 2 and a route with a zero or few fault occurrences is set to level 1 and a fault occurs in one D channel. As for the route that is being used, the route having a small number of past failures can be set to level 3 and the route having a large number of failures can be set to level 4. Similarly, even when one D channel is being maintained, the route having the least number of fault occurrences in the past can be set to level 5, and the route having many failures can be set to level 6.

As a result, the route selection level designated by the sender is set to "1" to "6", and for communication requiring the highest reliability, the level 1 with the smallest number of failures occurs.
The B channel can be captured by selecting the route (1), and higher reliability can be achieved.

When the required route selection level can be varied depending on the time zone, the time zone route selection control unit (P-108) (see FIGS. 3 and 17) allows the detour time zone control table ( The route is selected with reference to FIG. 7B.

If all the routes of the route selection level designated by the sender are busy, the route queuing control unit (P-112) (see FIG. 21) checks the route queuing request. , If a message is sent to the caller to re-input or change the specified route selection level, and the caller changes the route selection level accordingly, the route selection is made based on the changed route selection level. It can be performed.

The present invention is not limited to the above-mentioned embodiments, but the embodiments may be combined with each other or with other means. In the backup D channel configuration, the number of B channels combined with two D channels can be arbitrarily selected according to the system configuration.

[0061]

As described above, the highly reliable communication system and communication control method of the present invention determines the level of the route in accordance with the state of the D channel in the backup D channel configuration, and achieves high reliability. When communication is required, by specifying a high route selection level, two D channels select a healthy route, so that even if one D channel fails during communication, the other D channel fails. There is an advantage that the D channel becomes the active channel, the communication by the B channel can be continued, and the reliability of the communication can be improved.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a system according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of program function blocks according to the embodiment of this invention.

FIG. 4 is an explanatory diagram of data blocks according to the embodiment of this invention.

FIG. 5 is an explanatory diagram of a D channel state table and a D channel detour table according to the embodiment of this invention.

FIG. 6 is an explanatory diagram of a bypass level table and a bypass level control table according to the embodiment of this invention.

FIG. 7 is an explanatory diagram of a detour time zone control table and a detour terminal type registration table according to the embodiment of this invention.

FIG. 8 is an explanatory diagram of a bypass monitoring control table and a status statistical table according to the embodiment of this invention.

FIG. 9 is an operation explanatory diagram of the embodiment of the present invention.

FIG. 10 is a flowchart of an ISDN trunk acquisition control unit according to the embodiment of this invention.

FIG. 11 is a flowchart of a detour control unit according to the embodiment of this invention.

FIG. 12 is a flowchart of a state control unit according to the embodiment of this invention.

FIG. 13 is a flowchart of a route selection command unit according to the embodiment of this invention.

FIG. 14 is a flowchart of a route selection setting special number control unit according to the embodiment of this invention.

FIG. 15 is a flowchart of a route selection multifunction telephone display unit according to an embodiment of the present invention.

FIG. 16 is a flow chart of a special code control unit during transmission according to the embodiment of this invention.

FIG. 17 is a flowchart of a time zone route selection control unit according to the embodiment of this invention.

FIG. 18 is a flowchart of a terminal type route selection control unit according to the embodiment of this invention.

FIG. 19 is a flowchart of an ISDN terminal route selection control unit according to the embodiment of this invention.

FIG. 20 is a flowchart of a route manual selection control unit according to the embodiment of this invention.

FIG. 21 is a flowchart of a route queuing control unit according to the embodiment of this invention.

FIG. 22 is a flow chart of a state statistic section according to the embodiment of the present invention.

FIG. 23 is a schematic explanatory diagram of an exchange.

FIG. 24 is an explanatory diagram of a D channel switching sequence.

[Explanation of symbols]

 a detour condition registration means b detour condition storage means c route selection level registration / change means d route selection level storage means e route selection level display means f route selection level recognition means g route determination / channel capture means

Claims (8)

[Claims] 1. A backup D channel configuration communication system for selectively capturing a plurality of B channels by using dual D channels for working and protection in a network to which a common line signaling system is applied. A detour condition storage unit that stores a condition for selecting a route and a level indicating the reliability of the route corresponding to the state of the duplicated D channel are set, and the route selection level corresponding to the level is registered in advance or Route selection level storage means for inputting at the time of calling and storing the route selection level; and a detour stored in the detour condition storage means when the route selection level is higher than the level of the selected route. A high reliability communication system, comprising route determination / channel acquisition means for selecting a route of a level that matches the route selection level according to a condition. 2. The level indicating the reliability of the route corresponding to the state of the duplicated D channel is set to the highest level when all D channels are healthy, and a failure occurs in one of the D channels, The next level is set when the other D channel is healthy, and is set to the next lower level when one D channel is out of service due to maintenance and the other D channel is healthy. The highly reliable communication system according to 1. 3. The level indicating the reliability of the route corresponding to the state of the duplicated D channel is set to be high for a route having a small number of fault occurrences according to state statistics and low for a route having a large number of faults. The highly reliable communication system according to claim 1 or 2. 4. The route selection level storage unit is provided with a route selection level registration / change unit having a function of registering / changing the route selection level by a maintenance operation command or a caller's terminal device. The highly reliable communication system according to claim 1, wherein the communication system is highly reliable. 5. The high reliability communication system according to claim 1, wherein the detour condition storage means is configured to store a detour condition including whether or not the detour connection is necessary and a time zone for the detour connection. . 6. The route determining / channel capturing means identifies the terminal device type of the caller, determines a route selection level corresponding to the terminal device type, and stores the detour stored in the detour condition storage means. The highly reliable communication system according to claim 1, further comprising a configuration for determining a route according to a condition. 7. Control of a highly reliable communication system having a backup D channel configuration for performing route acquisition of a plurality of B channels by using dual channels of working and protection channels in a network to which a common line signaling system is applied. A method, wherein a level indicating the reliability of the route corresponding to the state of the D channel is set as the highest level when both of the duplicated D channels are healthy, and a detour condition in the route selection is set. However, when the route selection level requested by the caller is higher than the level of the route according to the outgoing information, the detour condition is satisfied, and the level of the route is the same as the route selection level or higher. A communication control method comprising the step of selecting a higher route and making a bypass connection. 8. When the caller cannot select a route of a level corresponding to the specified route selection level, the caller is notified of that fact, and the caller is allowed to re-designate the route selection level, 7. The communication control method according to claim 6, further comprising a step of selecting a route of a level corresponding to the re-designated route selection level.