JPH0373696A - Autonomous distributed type route selection system - Google Patents

Abstract

PURPOSE:To calculate a sending disabled time and to simplify its sending processing by determining a fixed time T = t0 at the time of receiving a connection disable response in respect to building block type exchange, and when a response to a connection request sent immediately after the time-out of the fixed time T can not be connected, setting up the fixed time T = t1 (t0<t1). CONSTITUTION:A call receiving part 11 in an input exchange module 10 receives a calling message from a preexchange or a terminal. A call processing part 12 receives the calling message from the call processing part 11, executes a series of processing for call processing such as number translation and selects an output exchange module 20 as the 1st candidate of output exchange modules. A call transmitting/receiving part 13 sends a call connection request to the module 20 through a connection mechanism 30 in accordance with a command from the call processing part 12. A call processing pat 22 in the module 20 adds the status information of 2 bits to a connection disabled response message and sends the added message to the module 10 through a call receiving part 21 when there is no idle line 7 or idle selfmodule processor processing capacity.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an autonomous decentralized route selection method between modules of a building block exchange component. [Prior Art] Conventional route selection is based on When applied to module selection in a building block type switch, it is done as follows.

(1) Candidates for inbound and outbound exchange modules are determined based on the candidates in the route selection table determined during system operation.

(2) The method of observing the usage status of the outgoing exchange module of the incoming exchange module is to have the incoming exchange module observe or receive information from the outgoing exchange module at arbitrary intervals, or to inquire at the place that centrally manages the usage status of the outgoing exchange module. Or let me know.

(3) The method for dynamically determining the outgoing exchange module is to observe the usage status of the target outgoing exchange module, and perform the process in order of usage status with the largest available capacity or randomly for the available outgoing exchange modules. .

(4) The time period during which the call connection request cannot be sent to the outgoing exchange module that sent the connection request failure response is fixed, or the frequency of sending is made low for an arbitrary period of time.

[Problem to be solved by the invention]

The above-mentioned conventional technology has the following problems.

(1) Regarding the method of determining the outgoing exchange module, (1-1)
If the usage status of the outgoing exchange module is observed in one place,
When the number of inquiries increases, there is a limit to the scale of the exchange due to the processing capacity limit of the management section, and reliability is low because processing is concentrated in one place.

(1-2) In a method in which each incoming exchange module performs the process independently, as the number of exchange modules increases, the processing for observing and determining the usage status of the outgoing exchange module increases as the number of selection targets increases, resulting in a decrease in throughput. vinegar.

(1-3) A method in which each incoming exchange module performs independently,
When a connection failure response is received from an outgoing exchange module, the method of fixing a certain period of time and stopping sending connection requests to that outgoing exchange module is difficult to calculate the optimal fixed period of time, and the calculation process is complicated. . Furthermore, even with the method of making the fixed time variable, it is difficult to determine and calculate the optimum variable width.

(1-4) A method in which each incoming exchange module performs independently,
When a connection failure response is received from an outgoing switching module, the sending of call connection requests is stopped for a certain period of time and until the call that has been previously connected to the outgoing switching module is disconnected. The latter places a limit on the upper limit of the amount of calls that can be generated to achieve a high throughput of the line, and in the latter case a low blocking rate of connection requests.

(2) Regarding the method of observing the usage status of outgoing exchange modules, (2-1) In systems that centrally manage the usage status of outgoing exchange modules, the increase in the number of exchange modules causes processing bottlenecks due to a concentration of inquiries to the exchange modules. Limited scale and detailed observations become impossible.

(2-2) When the usage rate of an outgoing exchange module exceeds a specified point, the outgoing exchange module broadcasts a notification to the incoming exchange module, which reduces the amount of messages between modules and the processing of sending and receiving them, compared to periodic notification. However, when the number of call types handled increases, when the number of exchanged modules increases, or when there is a difference in the processing capacity of each module, the above-mentioned reduction effect may be reduced.

(2-3) The method of observing the usage status of the outgoing switching module based on the call connection failure response C from the outgoing switching module involves almost no extra message transfer and processing for observation, but It is unclear whether this is due to the outgoing line usage rate, and it is impossible to control the sending of call connection requests from the incoming switching module in order to maintain a balance between the processor processing capacity of the outgoing switching module and the outgoing line capacity.

(3) Regarding the control speed of route selection, (3-1) The conventional methods of observing the usage status of outgoing switching modules are the method that is performed when a specified time period or a specified point of usage rate is crossed, and the method that is performed when a specified point of the usage rate is crossed, and the method that is performed when a call connection failure response is used. In the constant time period method, half of the time interval is the minimum average control speed, and shortening this observation period is not effective in terms of message transfer and processing required. Also,
The control speed of the method performed when the usage rate crosses the specified point is faster than the former method, but when there is hysteresis at the specified point, the throughput decreases by the amount of hysteresis. The method using unacceptable responses has a fast control speed because it can be performed on a call-by-call basis, but it is impossible to control the sending of call connection requests from the incoming switching module in order to maintain a balance between the processor processing capacity of the outgoing switching module and the outgoing line capacity. .

The purpose of this invention is to solve the above-mentioned conventional problems,
An object of the present invention is to provide an autonomous decentralized route selection system suitable for an exchange that allows easy expansion of the exchange scale (addition of exchange modules).

[Means for solving the problem] Claim (1) of the autonomous decentralized route selection system according to the present invention
), The invention described in (2) is that the outgoing exchange module is determined by an operation center that centrally manages the network before a call occurs, taking into consideration equipment design and statistical traffic in offline processing. ni candidates (ni≧1
．． It has a route selection table (routing table) consisting of i = destination address from 1 to the number of addresses), and in online processing, the route selection table is changed by the inter-module message shown below, and the route selection table is When the message cannot be accepted, the incoming switching module skips the outgoing switching module candidate for a certain period of time and sets the next outgoing switching module candidate as the destination for sending the call setup signal;
When the result is receivable, no skipping is performed, and the skipping is in the method of skipping all calls for a certain period of time and the method of skipping some calls, wherein the certain period of time is T=t+ (to <tx), and When the response to the connection request sent immediately after the fixed time T-tl times out is that connection is not possible, the fixed time T=t2 (tI
t2) and increase the fixed time T, and the fixed time T
When the response to the call connection request sent immediately after the timeout of t3 (t2 x t3)...tn (
tn-s < tn), and after a timeout of a certain time T, sends a connection request to the outgoing exchange module and receives a connection OK response, sets r=to for the certain period of time.

Further, in the invention described in claim (2), the certain period of time is a semi-fixed time, but there is no disconnection of a previously connected call between the incoming switching module and the outgoing switching module during the semi-fixed time. When the capacity is reached, the capacity is set to zero until another call connection is made.

Furthermore, in the invention as set forth in claim (3), the inter-module message is a call acceptance/rejection response from the outgoing switching module in response to the call connection request of the incoming switching module, and the acceptance/rejection message is a response of the processor processing of the outgoing switching module. It is possible to identify whether this is due to a high usage rate or a high usage rate of the outgoing line of the outgoing exchange module.

Further, the invention according to claims (4) and (5) provides that the skipping is performed for each call type in consideration of the outgoing line usage rate and processor usage rate of the outgoing exchange module and the incoming exchange module. The exchange module determines whether

[Effect]

(1) In the outgoing exchange module selection method according to claims (1) to (4) of the present invention, since each incoming exchange module performs selection autonomously, the amount of selection processing that is a problem in a centralized method is reduced. Since it is distributed to each switching module, it can be applied to large-scale switching systems and also improves reliability against failures.

In addition, when each incoming exchange module autonomously selects a route, it is possible to send a routing command to the incoming exchange module in advance.
By setting up a pull and changing the information of the corresponding routing group using the information element indicating the connection failure response and the status of the sub-exchange module in the response, redundant information for the change can be saved. This eliminates the need for extensive inter-module messages, and even if the number of modules increases, it is possible to reduce the increase in processing for observing and determining the usage status of sub-exchange modules.

According to the invention described in claim (1), when a connection failure response is received from the sub-switching module, a -fixed time period during which transmission of a connection request is disabled is provided, and the -fixed time period T=t+(t
o<t□), and furthermore, when the response to the connection request sent immediately after the timeout of the fixed time T=t is not connectable, the fixed time T=t2(t).

t2) and increase the fixed time T, and the fixed time T
When the response to the call connection request sent immediately after the timeout is that connection is not possible, t3 (tz < ts)...tn
(tn-+ < tn), and after a timeout of a certain period of time T, a connection request is sent to the outgoing exchange module and a connection OK response is received, the specified period of time T
= t0.

Further, the invention described in claim (2), when receiving a connection failure response from the sub-exchange module, stops sending the connection request for a certain period of time for a semi-fixed time, and during that semi-fixed time, the incoming exchange module and the sub-exchange module are connected to each other. When a call that was previously connected between switching modules is disconnected, the method of reducing the transmission stop time to zero until the call is reconnected with its capacity is to When a vacancy is created due to the disconnection of a previously connected call, connection requests for subsequently generated calls can be assigned to the switching module.

Furthermore, in the invention described in claim (3), since the method of observing the usage status of the sub-exchange module is carried out autonomously by the incoming exchange module, there is a problem with the method in which the usage status of the sub-exchange module is notified from the out-exchange module or the central management unit. When the number of call types increases, or if there are variations in the processing capacity of the number of sub-exchange modules or the number of incoming exchange modules, and if there are also variations in processor usage, the notification will cause the processing of each processor of each incoming exchange module to increase. It is possible to observe the usage status of the sub-exchange module in accordance with the status of each incoming exchange module without causing a decrease in throughput.

Furthermore, the inventions described in claims (4) and (5) include information on whether the outgoing line usage rate or the processor usage rate of the sub-switching module is over, in the connection failure response, so that the connection request in the incoming switching module is not processed. When sending out calls, the receiver preferentially sends out call types that are likely to be answered.

Note that since these controls are performed for each call, they can be performed at a high control speed.

〔Example〕

An embodiment of the present invention will be described below using the building block switch shown in FIG. 1 as an example. First, the outline of each figure will be explained, and then the operation will be explained.

FIG. 1 shows a block diagram of the part relating to call transmission/reception and call processing of the coupling structure between switching modules in a building-type switch and between a switch and a terminal.

In FIG. 1, 10-1 to 1O-N (hereinafter, simply 10 is used) are incoming exchange modules, each of which includes a call acceptance unit 11 that receives a call connection request from a previous exchange or a terminal; A call processing section 12 performs all call processing other than transmitting and receiving calls received by the section 11 to the next stage, and a call transmitting/receiving section 1 transmits and receives call processing messages between sub-switching modules.
Consists of 3. Reference numerals 20-1 to 20-N (hereinafter simply referred to as 20) are sub-exchange modules, which are connected to the incoming exchange modules 10-1 to 10-N, respectively. 3
0 is a coupling mechanism for transferring user information and inter-module control information between the incoming exchange module 10 and the exchange module 20, and 1 to 7 are lines and information transmission paths. Note that separate exchanges or terminals are generally connected to both sides of the exchange, but these are omitted here.

FIG. 2 shows the selection flow of the invention according to claim (1), in which Δt is the basic unit of transmission-disabled time set smaller than the average holding time, and t1 to t4 are the times after the connection request transmission stop is released. This is the time until a new connection request is sent.

FIG. 3 shows the selection flow of the invention according to claim (2), where tr is a semi-fixed time during which connection requests cannot be sent.

FIGS. 4(a) and 4(b) are diagrams showing the relationship between the output exchange module status and 2 bits of status information according to the invention set forth in claim (3), and diagrams illustrating the contents of a connection failure response.
In the outgoing exchange module 20, a bit Δ indicating whether the processor processing capacity is exceeded or the outgoing line utilization rate is exceeded is a specified point, and when this level is exceeded, it is determined that there is no remaining power. Note that the level of the specified point is determined by taking into consideration the outgoing line capacity, processor processing capacity, call types handled, traffic fluctuation rate, and quality required for the system.

FIG. 5 is a diagram showing the transmission unavailable time for each call type according to the invention described in claim (4), where tr is a semi-fixed connection request transmission unavailable time, t is a symbol indicating the time axis, and low-speed calls are switched to an exchange. refers to calls that have a lower speed than the average speed of calls handled by the service provider. A high speed call refers to a call that has a high speed based on the average speed of calls handled by the switch. The 2 bits of status information is the same as the 2 bits of status information in Figure 4.The meaning (how to find it) of the remaining processor capacity and remaining line in the incoming exchange module status is the same as the remaining processor capacity and remaining line in Figure 4, and the mu is half Indicates that the fixed transmission unavailable time is zero.

Next, the first to fourth embodiments of the present invention (claims (1) to (
Corresponding to claim (4), the fourth embodiment includes claim (5)) will be sequentially explained.

(First Embodiment) A first embodiment according to the present invention is shown in FIG. Here, from the incoming exchange module 10 to the outgoing exchange module 20
This figure shows the procedure for sending messages between modules. The procedure will be described below using both FIG. 1 and FIG. 2.

(1) A calling message is received from a previous exchange or a terminal and is received by the call reception section 11 of the exchange module 10.

(2) The call processing unit 12 receives the calling message from the call reception unit 11, performs a series of call processing such as number translation, and selects the outgoing exchange module 20 as the first candidate for the outgoing exchange module.

(3) The call transmitting/receiving unit 13 sends a call connection request to the outgoing switching module 20 via the coupling mechanism 30 in accordance with the instruction from the call processing unit 12.

(4) In the call processing unit 22 of the outgoing exchange module 20, if there is no free space in the line 7 and the own module processor 1A, the incoming exchange module 10 through the call reception unit 21
Send a connection failure response message to. In addition, if there is a vacancy, the call processing section 22 performs a series of call processing such as selecting a line from among the lines 7, and at the same time sends a call setting message to the next-stage exchange or terminal through the call transmitting/receiving section 23.
A connection response message is sent to the incoming exchange module 10 through the call reception unit 21.

(5) When the call processing unit 12 of the incoming exchange module 10 receives a connection failure response from the selected outgoing exchange module 20 through the call transmitting/receiving unit 13, the call processing unit 12 of the incoming exchange module 10 performs detour processing or disconnection processing, and from then on, the call processing unit 12 of the incoming exchange module 10 performs detour processing or disconnection processing. Stop sending call connection request messages to.

(6) If a call arrives that makes a request to the outgoing switching module 2o, which has stopped sending call connection request messages, the incoming switching module 1o skips the outgoing switching module 20 and sends the second candidate outgoing switching module 2o. A call is set up between switching modules 20 or the call is dropped.

(7) When the stoppage of connection request transmission is released, the same processing as described in (1) and subsequent steps is performed.

(8) If the incoming exchange module 1o subsequently receives a connection failure response from the outgoing exchange module 20 after canceling the connection request transmission stop, the incoming exchange module 1o sets that number of unsentable Δ minutes as a new unsentable time, and no transmissions are performed during this period. , and perform the same processing as from (5) above.

(9) The first transmission-disabled time when a connection-disabled response is received after a connection-enabled response is set to the basic unit Δt.

(Second Example) A second example is shown in FIG. Here, inter-module messages and sending procedures from the incoming exchange module 10 to the outgoing exchange module 20 are shown. The procedure will be described below using both FIG. 1 and FIG. 3.

(1) A call message is received from the previous exchange or terminal and is received by the call acceptance section 11 of the exchange module 10.

(2) The call processing section 12' receives the calling message from the call reception section 11, performs a series of call processing such as number translation, and selects the sub-exchange module 20 as the first candidate for the sub-exchange module.

(3) The call transmitting/receiving unit 13 sends a call connection request to the sub-switching module 20 via the coupling mechanism 30 in accordance with the instruction from the call processing unit 12.

(4) In the call processing section 22 of the sub-switching module 20, if the line 7 and the processing capacity of the own module's processor are full, a connection failure response message is sent to the incoming switching module 10 through the call accepting section 21. In addition, if there is a vacancy, the call processing unit 22 performs a series of call processing such as line selection from among the lines 7, and at the same time sends a call setting message to the next-stage exchange or terminal through the call transmission/reception unit 23. A connection response message is sent to the incoming exchange module 10 through the reception unit 21.

(5) When the call processing unit 12 of the incoming switching module 10 receives a connection failure response from the selected sub-switching module 20 through the call transmission/reception unit 13, the call processing unit 12 of the incoming exchange module 10 handles the following case (6) during the semi-fixed transmission failure time tr. Except for this, sending of the call connection request message to the sub-switching module 20 is stopped.

(6) The incoming switching module 1o cancels the suspension by the amount of disconnected calls that have been previously connected between the sub-switching modules 20 that have suspended the transmission of connection requests.

(7) After the semi-fixed transmission disabled time tr has elapsed, the above (1)
) Repeat the process from then on.

In the second embodiment, only step (6) may be changed as follows.

(6) The incoming switching module 10 cancels the suspension by adding α to the disconnected capacity of the previously connected calls between the sub-switching modules 20 that have suspended the transmission of connection requests. Note that α may have a negative value or a positive value.

(Third example) A third embodiment is shown in FIGS. 4(a) and 4(b).

Here, an example is shown in which the value of the specified point is set to a processor and output line usage rate of 0.7 to 1.0. The explanation will be given below using both FIG. 1 and FIG. 4.

(1) A call message is received from the previous exchange or terminal and is received by the call acceptance section 11 of the exchange module 10.

(2) The call processing unit 12 receives the calling message from the call reception unit 11, performs a series of call processing such as number translation, and selects the sub-switching module 20 as the first candidate for the sub-switching module.
Select.

(3) The call transmitting/receiving unit 13 sends a call connection request to the sub-switching module 20 via the coupling mechanism 30 in accordance with the instruction from the call processing unit 12.

(4) In the call processing unit 22 of the sub-exchange module 20, if there is no free space in the line 7 and the processing capacity of the own module's processor, the call enters through the call reception unit 21 and sends 2 bits of status information shown in FIG. 4 to the exchange module 10 as a connection failure response. Add to message and send. At this time, in order to determine whether the 2-bit status information is due to the processor processing capacity of the sub-switching module 20 or the lack of remaining line capacity, a predetermined value of 70% of 0.7 is set for each. The content of the 2-bit status information is determined based on whether or not the specified point has been exceeded. The specified point is that the total processing capacity and total line capacity are 1 (100
%), it can be set between 0.7 and 1.0, and here it is set to 0.7 (70%).

In addition, if there is a vacancy, the call processing unit 22 performs a series of call processing such as line selection from among the lines 7, and at the same time sends a call setting message to the next-stage exchange or terminal through the call transmission/reception unit 23. A connection response message is sent to the incoming exchange module 10 through the call reception unit 21.

(5) When the call processing unit 12 of the incoming exchange module 10 receives a connection failure response from the selected sub-exchange module 20 through the call transmitting/receiving unit 13, it analyzes 2 bits of status information of the outgoing exchange module 10 contained in the response message. and perform processing based on the results.

(Fourth example) Next, a fourth example will be described.

Embodiment 4-1.4-2 in which the third embodiment is applied to the distributed route selection system of the first embodiment will be shown below using both FIGS. 1 and 5.

(Example 4-1) (1) to (5) are the same as in the third embodiment.

(6) The analysis result of the call processing unit 12 is one of the combinations shown in FIG. At that time, if some calls in the distributed route selection system are to be stopped, the transmission of call types (low-speed calls, high-speed calls) for which the semi-fixed transmission unavailable time tr will be stopped for the semi-fixed unavailable time tr,
Other call types will not stop.

(7) There is a new call in the call processing unit 12, and the first
If the route candidate is the outgoing exchange module 20 that has stopped sending out, that route candidate is skipped and processing proceeds to the second route candidate. Note that the processing for the second route candidate and subsequent routes is also similar to that for the first route candidate. This process causes a call to be lost a certain number of times or when there are no more candidate sub-exchange modules.

(Example 4-2) (1) to (5) are the same as the third embodiment.

(6) The analysis result of the call processing unit 12 is one of the combinations shown in FIG. At that time, the transmission of calls fit (low-speed calls, high-speed calls) whose semi-fixed transmission disabled time tr occurs is stopped after the semi-fixed disabled time Δ, and other call types are not stopped. Note that the call processing unit 12 performs detour processing or call loss processing on the corresponding call type that arrives during the suspension period.

(7) There is a new incoming call in the call processing unit 12, and the sending of the connection request is stopped and a connection request of the same call type as the stopped call type is sent to the released switching module, and the sending switching module 20 sends a connection request of the same call type as the stopped call type. When a connection failure response is received, the semi-fixed transmission failure time tr for that call type is doubled to Δt.

(8) There is a new incoming call in the call processing unit 12, and a connection request of the same call type as the stopped call type is sent to the outgoing switching module 20, where sending of a connection request has been stopped and released, and the outgoing switching module 20 When receiving a connection failure response from , perform connection processing.

(9) When the call processing unit 12 receives a new call and issues a connection request to the same outgoing exchange module 20 as in (8) above and receives a connection failure response, the semi-fixed transmission failure time tr for that call type
is Δt, and the call processing unit 12 performs detour processing or call loss processing.

Next, Example 4-3.4-4 when the third example is applied to the distributed route selection method and autonomous decentralized route selection method of the second example is shown in FIGS. It is shown below along with a diagram.

(Example 4-3) (1) to (5) are the same as in the third embodiment.

(6) The analysis result of the call processing unit 12 is one of the combinations shown in FIG. At that time, the call processing unit 12 stops the transmission of the call type (low speed call, high speed call) for which the semi-fixed transmission disabled time tr occurs for the semi-fixed dispatch disabled time tr, and
If there is a disconnection of a call of the same type as the stopped call that has been previously connected between 0 and the outgoing switching module 20, the suspension is canceled.

(7) There is a new call in the call processing unit 12, and the first
If the route candidate is the outgoing exchange module 20 that has stopped sending out, that route candidate is skipped and processing proceeds to the second route candidate. Note that the processing for the second route candidate and subsequent routes is also similar to that for the first route candidate. This process causes a call to be lost a certain number of times or when there are no more candidate sub-exchange modules.

(Example 4-4) (1) to (5) are the same as in the third embodiment.

(6) The analysis result of the call processing unit 12 is one of the combinations shown in FIG. At that time, the call processing unit 12 stops sending out the call type (low speed call, high speed call) for which the semi-fixed sending disabled time tr occurs for the semi-fixed sending disabled time tr. If there is a disconnection of a call of the same type as the stopped call type that has been previously connected between the two terminals, the suspension of transmission of the same call type is canceled by the capacity of the disconnection. Note that if the same call type is sent for the disconnection capacity during the semi-fixed sending-disabled time tr, the connection request sending is stopped again.

(7) There is a new call in the call processing unit 12, and the first
If the route candidate is the outgoing exchange module 20 that has stopped sending out, that route candidate is skipped and processing proceeds to the second route candidate. Note that the processing for the second route candidate and subsequent routes is also similar to that for the first route candidate. This process causes a call to be lost a certain number of times or when there are no more candidate exchange modules.

Next, FIG. 1 shows Example 4-5 when the autonomous decentralized route selection method of the first example and the third example are applied to the autonomous decentralized route selection method of the second example. It is shown below using the figure and FIG.

(Example 4-5) (1) to (5) are the same as in the third embodiment.

(6) The analysis result of the call processing unit 12 is one of the combinations shown in FIG. At that time, the call processing unit 12 stops sending the call types (low-speed calls, high-speed calls) whose semi-fixed sending disabled time tr occurs during the semi-fixed sending disabled time Δ, and does not stop the other call types. When a call of the same type as the stopped call type, which has been previously connected between the incoming switching module 10 and the outgoing switching module 20, is disconnected, the suspension of transmission of the same call type is canceled by the capacity of the disconnection. Note that if the same call type is sent for the disconnection capacity during the semi-fixed sending-disabled time Δ, the connection request sending is stopped again.

(7) There is a new incoming call in the call processing unit 12, and a connection request of the same call type as the stopped call type is sent to the outgoing switching module 20, where sending of a connection request has been stopped and released, and the outgoing switching module 20 When a connection failure response is received from a call type, the semi-fixed transmission failure time tr for that call type is doubled to Δt.

(8) There is a new call in the call processing unit 12, and the first
If the route candidate is the outgoing exchange module 20 that has stopped sending out, that route candidate is skipped and processing proceeds to the second route candidate. Note that the processing for the second route candidate and subsequent routes is similar to that for the first route candidate.This process results in a call loss when a fixed number of times or when there are no more candidate exchange modules.

(9) There is a new incoming call in the call processing unit 12, and the sending of connection request is stopped and the connection request is sent to the canceled outgoing switching module of the same call type as the stopped call type, and the outgoing switching module connects. When a response is received, connection processing is performed.

(10) There is a new call in the call processing unit 12, and the above (9)
When the same call type issues a connection request to the same outgoing exchange module 20 and receives a connection failure response, the semi-fixed transmission failure time tr for that call type is set to Δt, and the call processing unit 12 performs detour processing or call loss processing. be done.

It goes without saying that the present invention also includes the selection of autonomous decentralized exchanges between converters.

〔Effect of the invention〕

As explained above, the invention according to claim (1) provides a plurality of switching modules having functions equivalent to the incoming line and outgoing line resource management functions, switching functions, and call control functions of an exchange. In a switching system configured by interconnecting the above with an inter-module coupling mechanism for transferring user information and inter-module control information between switching modules, the incoming switching module that receives a call from the preceding switching system or terminal will act as a relay. selects an outgoing switching module that accommodates the transmission path to the next-stage switching equipment or destination terminal, sends a call connection request to that outgoing switching module, and that outgoing switching module returns a response that connection is not possible due to lack of resources. In this case, the incoming exchange module selects another outgoing exchange module candidate and performs the same call processing, and when the process fails a certain number of times or when there are no candidate outgoing exchange modules, the call is lost and connection is not possible. The sending of the call connection request to the outgoing switching module that has returned the response is a distributed route selection method in which all or part of T1 is stopped for a certain period of time, and when the determination of the certain period of time T is received, Let T = t0 for a certain period of time, and when the response to the connection request sent immediately after the timeout is not possible to connect, the specified period T = tl (to
<tt ), and when the response to the connection request sent immediately after the fixed time T-tl times out is unable to connect, the fixed time T is increased sequentially to the fixed time T = t2 (tt <t2), and the fixed time T is t3 when the response to the call connection request sent immediately after the fixed time T has timed out is that connection is not possible
(tz<t3)...tn (tn-1<tn)
When a connection request is sent to the sub-exchange module and a connection OK response is received after a fixed time T has timed out, the fixed time T = to, so the calculation of the transmission disabled time and its sending process are becomes easier.

Furthermore, in the invention described in claim (2), when the release is due to disconnection, the stoppage of transmitting a call connection request to the outgoing exchange module is canceled by the capacity of the disconnection, and subsequent call connection requests are not transmitted again. Since the system is set to a stopped state, when a call that has previously been connected to the outgoing switching module becomes vacant during a semi-fixed time period, a connection request for a call that has occurred since then to the incoming switching module can be assigned. This makes it possible to increase the utilization rate of the outgoing line of the outgoing exchange module. Furthermore, this invention, which allows connection requests to be sent as many times as the call disconnection capacity during the semi-fixed time period, has the advantage that, compared to the conventional method, which allows connection requests to be sent as many times as the disconnection capacity of the call, it is possible to send connection requests from the time of disconnection to the time when the connection is not possible.
Even when a large number of connection requests are generated, connection requests with a high probability of being accepted can be easily sent out, and the system is suitable for the amount of connection requests generated while achieving a low block rate.

Furthermore, the invention described in claim (3) adds an element indicating whether the connection is impossible due to the processor processing capacity of the outgoing exchange module being exceeded or the outgoing line usage rate of the outgoing exchange module is over to the information element of the connection failure response. However, depending on the information added above, the incoming switching module stops sending out call connection requests for a certain period of time when the outgoing switching module exceeds its processor processing capacity, and stops sending out call connection requests when the outgoing switching module exceeds the outgoing line usage rate. I decided not to set a stop, so
Based on the processor processing usage rate of the outgoing exchange module and the incoming exchange module and the line usage rate of each exchange module, the incoming exchange module sets the time during which call connection requests cannot be sent to the outgoing exchange module, and the priority of the outgoing call type by the incoming exchange module is set. The feature is that through control, the throughput of the entire system can be improved. Furthermore, since the usage state information is added to the call connection failure response message and transferred, there is no need to transfer extra messages between modules, there is no setup time, and the call setup time is shortened, and the amount of invalid processing by the processor is reduced. Moreover, since each exchange module can perform the exchange in an autonomous distributed manner, there is no restriction on the exchange scale due to a specific processor processing capacity bottleneck, and reliability is improved by distributing the processing.

In addition, the inventions described in claims (4) and (5) describe the sending of a call connection to the outgoing switching module within a certain period of time after receiving the connection failure response as the outgoing switching module state and the processor processing of the incoming switching module. Since the incoming switching module performs priority control on the connection request sending call type depending on the capacity and the line usage rate between the incoming switching module and the outgoing switching module, the blocking rate of requests can be lowered and the incoming and outgoing switching modules can In addition to reducing invalid processing in the switching module and shortening the call connection time, it also controls the sending of call connection requests in the incoming switching module to maintain a balance between the processor processing capacity of the outgoing switching module and the outgoing line capacity. It has the advantage of being possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the connection configuration between switching modules in a building-type exchange and between the exchange and terminals, especially the parts related to call transmission/reception and call processing, and FIG. 2 is a selection flow diagram showing the first embodiment of the present invention. , FIG. 3 is a selection flow diagram showing the second embodiment, and FIGS. 4(a) and 4(b) are the output exchange module status and 2-bit status information of the third embodiment.
FIG. 5 is an explanatory diagram of the transmission-disabled time for each call type, also showing the fourth embodiment. In the figure, 1 to 7 are lines and information transmission paths, 10-1 to 1
0-N are incoming switching modules, 11 is a call reception unit, 12 is a call processing unit, 13 is a call reception unit, 20-1 to 20-N are outgoing switching modules, 21 is a call reception unit, 22 is a call processing unit ,2
3 is a call receiving section, and 30 is a coupling mechanism. Figure 2 Figure 3 shows call disconnection

Claims (5)

[Claims] (1) A system for transferring user information and inter-module control information between multiple switching modules that have functions equivalent to the incoming and outgoing resource management functions, switching functions, and call control functions of the switching equipment. In an exchange that is configured by interconnecting each other by an inter-module coupling mechanism, an incoming exchange module that receives a call from a previous exchange or terminal connects a transmission path to the next exchange or other terminal for relaying. If an outgoing switching module to be accommodated is selected and a call connection request is sent to that outgoing switching module, and the outgoing switching module returns a response that connection is not possible due to insufficient resources, the incoming switching module transfers the call to another outgoing switching module. Select a candidate, perform the same call processing, and when the above process fails a certain number of times or when there are no candidate switching modules, the call is lost and the call is connected to the calling switching module that returns a connection-unable response. In a distributed route selection method in which the request is stopped completely or partially for a certain period of time T, the certain period of time T is determined as T = t_0 when the connection failure response is received, and immediately after that timeout. When the response to the sent connection request is that connection is not possible, a certain period of time T = t
_1 (t_0<t_1), and further a certain time T=t_
When the response to the connection request sent immediately after the timeout in step 1 is not connectable, the constant time T is increased sequentially such that the constant time T = t_2 (t_1 < t_2), and the constant time T is changed to the constant time T
t_3 (t_2<t_3)...t_
n (t_n_-_1<t_n), and when a connection request is sent to the outgoing exchange module and a connection OK response is received after a timeout of a certain period of time T, the specified period of time T
= t_0. (2) A system for transferring user information and inter-module control information between multiple switching modules that have functions equivalent to the incoming line and outgoing line resource management functions, switching functions, and call control functions of the switching equipment. An exchange configured by interconnecting each other by an inter-module coupling mechanism, where an incoming exchange module that receives a call from a previous exchange or terminal accommodates a transmission path to the next exchange or other terminal for relaying. If an outgoing switching module is selected and a call connection request is sent to the outgoing switching module, and the outgoing switching module returns a response that connection is not possible due to insufficient resources, the incoming switching module selects another outgoing switching module candidate. When the selected call is selected and the same call processing is performed, and the above processing fails a certain number of times or there are no candidate switching modules, the call is lost, and the call connection request to the calling switching module that returns a connection-unable response is Distributed route selection in which all or part of the transmission is stopped, and the suspension of transmission is canceled when a previously connected call between the incoming and outgoing switching modules is disconnected, and after a certain period of time has elapsed. In this autonomous system, when a release is made due to a disconnection, the suspension of sending call connection requests to the outgoing exchange module is canceled for the capacity of the disconnection, and subsequent transmission of call connection requests is again stopped. Distributed route selection method. (3) A system for transferring user information and inter-module control information between multiple switching modules that have functions equivalent to the incoming and outgoing resource management functions, switching functions, and call control functions of the switching equipment. An exchange configured by interconnecting each other by an inter-module coupling mechanism, where an incoming exchange module that receives a call from a previous exchange or terminal accommodates a transmission path to the next exchange or other terminal for relaying. If an outgoing switching module is selected and a call connection request is sent to the outgoing switching module, and the outgoing switching module returns a response that connection is not possible due to insufficient resources, the incoming switching module selects another outgoing switching module candidate. When the selected call is selected and the same call processing is performed, and the above processing fails a certain number of times or there are no candidate switching modules, the call is lost, and the call connection request to the calling switching module that returns a connection-unable response is In a distributed route selection method in which transmission is stopped in whole or in part for a certain period of time T, the information element of the connection failure response indicates that the connection is not possible due to the processor processing capacity of the outgoing exchange module being exceeded or the outgoing line usage rate of the outgoing exchange module is over. Based on the added information, the incoming switching module will stop sending call connection requests for a certain period of time when the outgoing switching module exceeds its processor processing capacity, and the outgoing switching module will An autonomous decentralized route selection method characterized in that the transmission of call connection requests is not stopped when the usage rate is exceeded. (4) In the autonomous decentralized route selection method according to claim (1) or (2), the processor of the outgoing switching module instructs the outgoing switching module to send a call connection to the outgoing switching module within a certain period of time after receiving a response indicating that connection is not possible. The incoming exchange module may An autonomous decentralized route selection method characterized by priority control of call types for sending connection requests. (5) A system for transferring user information and inter-module control information between multiple switching modules that have functions equivalent to the incoming line and outgoing line resource management functions, switching functions, and call control functions of the switching equipment. An exchange configured by interconnecting each other by an inter-module coupling mechanism, where an incoming exchange module that receives a call from a previous exchange or terminal accommodates a transmission path to the next exchange or other terminal for relaying. If an outgoing switching module is selected and a call connection request is sent to the outgoing switching module, and the outgoing switching module returns a response that connection is not possible due to insufficient resources, the incoming switching module selects another outgoing switching module candidate. When the selected call is selected and the same call processing is performed, and the above processing fails a certain number of times or there are no candidate switching modules, the call is lost, and the call connection request to the calling switching module that returns a connection-unable response is The transmission is suspended completely or partially for a certain period of time T, or the transmission suspension is canceled when a call that has been previously connected between the incoming exchange module and the outgoing exchange module is disconnected, and after a certain period of time has elapsed. In the form route selection method, the call connection is sent to the relevant outgoing switching module within a certain period of time after receiving a response indicating that connection is not possible. Autonomous decentralization characterized in that the incoming switching module performs priority control of connection request sending call types depending on the state, the processor processing capacity of the incoming switching module, and the line usage rate state between the incoming switching module and the outgoing switching module. Shape direction selection method.