JPH04217149A - Autonomous setting system for communication channel in decentralized exchange network - Google Patents

Abstract

PURPOSE:To suppress the signal delay and to autonomously set a communication channel to each exchange node by suppressing the block-up of the traffic which changes momentarily and at the same time to decrease the number of relaying exchange nodes provided between the outgoing and incoming side exchange nodes. CONSTITUTION:A reader 4 reads the identification information on an input terminal 1 for the block signal with header received from an in-route link set at the subscriber network side and the identification information on an input terminal 3 for the block signal with header received from an in-route link set in a decentralized exchange network respectively. Then a duty identifier 5 identifies the setting of a route, the transfer of data or the release of a route based on a duty identification information signal. Then the different identification information signals read out according to each identification result are connected to a route setting out-route link number pointing device 6, a data transfer out-route link number pointing device 7 or a route releasing out-route link number pointing device 8. Thus a communication route is autonomously set to each exchange node.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a packet communication system, A
In contrast to header-attached block transfer methods such as TM (asynchronous transfer mode) communication methods, communication route autonomy within a distributed switching network autonomously sets a communication route from an originating switching node to a destination switching node using a distributed switching network. Regarding the setting method.

0002

[Prior Art] In research on the next generation BISDN (high-speed broadband service integrated digital network), data transfer is
There is a trend towards the TM system, a trend toward hierarchical network configurations, and a trend towards virtual path systems in which call settings select semi-fixed, preset logical paths for each call. In these trends, only switching nodes called access nodes have the right to select virtual paths, so traffic monitoring within the network and routing tables are required.
The major problem is to immediately search for an adaptive route and select a logical path when a blockage, failure, or congestion occurs. In addition, in the virtual path method, it is not possible to distinguish the originating switching node of the header-attached block that passes through a relay switching node called a cross-connect, so calls that have already been set up have priority over calls that are set up later, and the buffer overflows. There is no protection from discarding the header block due to the header block being discarded.

[0003] Compared to the traffic in conventional communication networks, the traffic in the information communication networks of the next generation advanced information society will be diverse and dynamic due to multimedia services, and will be intensively handled by hierarchical networks. It is expected that network management will not be able to cope with the traffic, and a distributed switching network has been proposed that can adapt to diverse and dynamic traffic at any time without requiring centralized network management. (For example, Osatake Makoto, Tanaka Hidehiko: "Distributed Exchange Network", IEICE Theory, 51-A, 6, pp. 230-237 (Showa 43-
06). Makoto Osatake: “On Communication Networks in the Advanced Information Age,” IEICE Journal, 65, 3, pp. 230-233 (1984)
-03). )

0004

[Problem to be solved by the invention] As mentioned above, the next generation B
In the future, when ISDN is put into practical use, it is predicted that hierarchical networks will reach their limits in their ability to handle traffic, and that a transition to distributed switching networks will be inevitable. However, because a distributed switching network has a completely different network structure from a conventional hierarchical network, there has been little research into call setup and route setup methods in distributed switching networks.

[0005] The present invention is designed to prevent blockage and congestion from occurring in a distributed switching network in response to traffic that changes from moment to moment in various ways, and to avoid blockages, failures, and congestion once they have occurred, and to switch from the originating switching node to the destination switching node. The purpose of this invention is to allow each relay switching node to autonomously set a communication path for a header-attached block transfer method so as to suppress signal delay by minimizing the number of relay switching nodes leading to a node.

[0006]

[Means for Solving the Problems] FIGS. 2 and 3 are schematic plan views of portions of a honeycomb network and a lattice network, respectively, which are typical examples of a distributed switching network. Each switching node in FIGS. 2 and 3 is configured to autonomously set a communication path.

An example of connecting a distributed switching network (honeycomb network) and a subscriber network is shown in FIG. 4 in a three-dimensional schematic diagram. The same applies to lattice nets, etc.

FIGS. 8 and 9 show blockages and blockages occurring on the outgoing link side of each exchange node in FIGS. 2 and 3, respectively.
It is a schematic diagram of a route for notifying other exchange nodes of identification information regarding a failure (including identification information indicating that the blockage/failure has been recovered). For a link where a failure has occurred, the identification information of the switching node that has the link on the outgoing path and the fact that there is a link failure, etc. are sent from the adjacent switching node and to the switching node where the failure has occurred. Notifies the identification information and the fact that there is a node failure from the adjacent exchange node to each node on the straight path passing through the point of occurrence of the failure, etc.

[0009] Here, a straight path is defined as having a diameter r centered around an exchange node or an exchange node directly connected to a link.
When the straight line is rotated by half a rotation, among the routes along the straight line passing through this exchange node, the total physical length of the links is the route that is closest to r. An example of a straight path in a honeycomb network is shown in FIG. 7(c).

In FIGS. 8 and 9, B1, B2, . ．． is a straight route, and in the honeycomb network, the type (B1, B2, B3) according to the direction of the straight route is also notified as part of the identification information regarding the blockage/failure. In a grid network, the type (B1, B
2) is understood.

The above objects of the present invention are achieved by the means described below. Each switching node in the distributed switching network is
For a header block signal with identification information indicating a routing mission, the identification information of the destination switching node that it carries and the information that occurred ahead of the straight path via the outgoing link of each switching node. Based on the identification information regarding the blockage/failure and the order of the outgoing links with a large flow margin based on the detection results of each flow (the number of block signals with headers flowing through the link per unit time) of the multiple outgoing links. , autonomously selects the outgoing link of its own node that forms the shortest route (a route that minimizes the number of stages of relay switching nodes) to the destination switching node of the header-attached block signal, and updates the route setting table of its own node. The outgoing route link number and identification information of the originating and destination switching nodes are registered as a pair in the (routing table).

[0012] If the autonomous selection does not include a detour in response to a blockage or failure, the header-attached block signal is connected to the selected outgoing route link, and the detour (Figs. 10 and 1
1), the header-attached block signal is given identification information necessary for detouring, and then connected to the selected outgoing route link and transmitted to the next relay switching node. If the received header-attached block signal responsible for the route setting task has identification information necessary for the detour, the detour route is maintained based on the identification information until the point of occurrence of the blockage/failure is avoided. The node autonomously selects the outgoing link of its own node.

[0013] By repeating these operations at each relay switching node until the header-attached block signal arrives at its destination switching node, a communication path is autonomously established.

[0014] Each switching node in the distributed switching network responds to a block signal with a header having identification information indicating a data transfer mission by itself based on the identification information of the originating and destination switching nodes it has. The registered outgoing route link number to be connected is read from the route setting table (routing table) of the node, and if the outgoing route link is not blocked or has a failure, the number attached with the read number is Connect the block signal with the header to the outgoing route link,
If a blockage or failure occurs, it autonomously selects the outgoing link of its own node that forms the shortest route (see Figures 12 and 13) that avoids the point of occurrence, and uses the identification information necessary for the detour. is added to the header-attached block signal, and then connected to the selected outgoing route link and transmitted to the next relay switching node.

[0015] When the blockage/failure is recovered, the route autonomously returns to the path before the blockage/fault occurred. In addition, if the received header-attached block signal responsible for the data transfer mission has identification information necessary for the detour, based on the identification information, the route is returned to the route before the blockage or failure through the shortest detour. Autonomously selects the outgoing link of the own node so that the node reaches the node.

Data transfer is achieved autonomously by repeating these operations at each relay switching node until the header-attached block signal arrives at its destination switching node.

[0017] Each switching node in the distributed switching network responds to a block signal with a header having identification information indicating a path release mission by itself based on the identification information of the originating and destination switching nodes it has. Read out the outgoing route link number to be connected from the routing table of the node, and match the identification information of the originating and destination exchange nodes registered in the routing table with the outgoing route link number to be connected. At the same time as deleting the group, if the outgoing route link has not caused any blockage or failure, connect the block signal with the header to the outgoing route link with the read number and cause the blockage or failure to occur. If it is, the connection to the outgoing route link with the read number is made to stand by in the block signal with the header until the blockage/failure is restored, and identification information indicating that it is on standby is sent. Have it. When the blockage/failure is restored, the header-attached block signal that has been put on standby is connected to its output route and transmitted to the next relay switching node.

[0018] If the received header-attached block signal responsible for the route release mission has the identification information indicating that it is on standby, the identification registered in the route setting table of its own node is determined based on the identification information. whether the information is used by the header block signals responsible for data transfer;
Alternatively, it identifies whether or not it has been updated by a block signal with a header that is responsible for a new route setting mission, and if it has not been used and updated, it is deleted in the same way as above, but if it has been used, it is deleted from the route release mission. It is assumed that a new route has been set while the header-attached block signal that is responsible is on standby, and the header-attached block signal that has the role of route release is discarded.

By repeating these operations at each relay switching node until the header-attached block signal arrives at its destination switching node, the path is autonomously released.

[0020] When each switching node in the distributed switching network receives a connection request for a call with its own node as the originating side, only if a communication route to the destination switching node of the call has not been set. , Prior to connection of a call, a communication path is established by transmitting a header-attached block signal having identification information indicating the route setting task to the next relay switching node, and there are no calls to the destination switching node. At that point, calls are set up and released, respectively, by sending a header block signal with identification information informing the route release mission to the next relay switching node.

Under this call setup and release method, when the header-attached block signal having identification information indicating the route setup task is connected to the outgoing route link of the originating switching node, the own node's Refer to the route setting table, count the number of registered pieces of identification information that differ from the originating and destination exchange nodes of the header-attached block signal that is already using the outgoing route link, and determine whether that number is connected to the outgoing route link. When the maximum possible number is approached, by rejecting the connection request for the call originating from the own node, the call that is already connected is prevented from discarding the header-attached block signal due to the buffer overflow of the header-attached block signal. Achieve protection autonomously.

[0022] The above-mentioned object of the present invention is achieved by the autonomous communication route setting system within a distributed switching network characterized as described above.

[0023]

FIGS. 10 and 11 are schematic diagrams of the shortest path, including detours for blockages and failures, between originating and destination switching nodes in a honeycomb network and a lattice network, respectively. The straight lines in FIGS. 10 and 11 represent the straight line path described above.

[0024] When setting a route, there is no blockage or failure between the originating exchange node and the destination exchange node, and a straight path exists that directly connects the originating exchange node and the destination exchange node. If a block signal with a header is connected to that route, if that straight route does not exist, it is routed along the two nearest straight routes that sandwich the originating exchange node from among the straight routes passing through the destination exchange node. The shortest path (intermediate switching node It is possible to set a route that minimizes the number of

[0025] A blockage/failure has occurred between the originating switching node and the destination switching node, and the above-mentioned shortest path exists from the originating switching node to the destination switching node without passing through the point of occurrence. If such a route does not exist, connect a block signal with a header to that route, and if there is no such route, move from a straight route passing through the point of occurrence of the blockage/failure to a parallel route via one link. , after avoiding the point of origin,
By connecting a header-attached block signal to the route leading to the destination switching node, the shortest route can be set.

[0026] In case of a blockage/failure on the outgoing link side (outgoing link or an adjacent switching node directly connected to the outgoing link) in each switching node, By connecting the header-attached block signal to a route that avoids the generation point, the shortest route can be set. Examples of this detour route are shown in FIGS. 12 and 13.

In any of the above cases, each switching node can autonomously select an outgoing link forming the shortest route based on the geometric properties of the distributed switching network.

[0028]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of an embodiment of the present invention for one of a plurality of incoming links of a switching node in a distributed switching network. Input terminal 1 of the block signal with (inserted) header from the ingress link on the Canadian network side in Fig. 1;
From the header-attached block signal applied to the input terminal 3 of the header-attached block signal from the ingress route link in the distributed switching network, an identification information reader 4 reads the identification information possessed by the header-attached block signal.
The mission identifier 5 identifies from the mission identification information signal whether the mission is a route setting mission, a data transfer mission, or a route release mission. The identification information signal is connected to one of the outgoing route link number indicator 6 for route setting, the outgoing route link number indicator 7 for data transfer, and the outgoing route link number indicator 8 for route release, respectively.

At the same time, a signal instructing which of the mission-specific buffers provided in the header-attached block switch 20 should store the header-attached block signal is sent as a mission-specific buffer instruction signal according to the identification result by the mission identifier 5. It is generated by the generator 9 and applied to the input terminal 21 of the block exchanger 20 with header. The header block signal applied to the input terminal 23 of the header block switch 20 is stored within the switch in a mission buffer gated by the mission buffer instruction signal.

When there is a call connection request from the subscriber network side, a block signal with a header having route setting mission identification information is applied to the input terminal 1, and at the same time, a block signal with a header having route setting mission identification information is applied to the input terminal 1, and at the same time, a block signal with a header having route setting mission identification information is applied to the input terminal 1. It is added to the input terminal 2 for the call connection request signal, and sends the call connection request signal to the call request identifier 10 and the header-attached block standby/connection instruction signal generator 12. The header-equipped block standby and connection instruction signal generator 12 is
A header-attached block standby signal is generated, and in addition to the input terminal 21 of the header-attached block switch 20, the input gate of a calling buffer provided inside the header-attached block switch 20 is opened. The header-attached block signal having the route setting mission identification information applied to the input terminal 23 of the header-attached block exchange 20 is stored in a call originating buffer in which the input gate is opened, inside the header-attached block exchange 20. .

At the same time, the call request identifier 10 to which the call connection request signal has been added receives an identification signal including the outgoing route link number information output from the output terminal 31 of the outgoing route link number indicator 6 for route setting. The information signal is connected to the calling connection identifier 11 . The calling connection identification determiner 11 determines whether connection is possible based on the number of logical paths accommodated in the link with the outgoing route link number at that time, based on the connection possibility signal from the link accommodation path counter 14. When notified and connection is possible, the identification information signal including the outgoing route link number information is connected to the header-attached block standby and connection instruction signal generator 12, and information indicating connection is possible is further added to the identification information. Generate a block connection signal with header. When a connection failure notification is received, the identification information signal including the outgoing route link number information is connected to the header-attached block discard instruction signal generator 15, and the outgoing route link number information is sent to the header-attached block discard instruction signal generator 15. Generates an identification information signal replaced with information.

The header-equipped block connection signal includes the output route link number, the originating side, the destination side node identification information write signal generator 13, the input terminal 22 of the header-equipped block exchanger 20,
and is applied to input terminal 21. The identification information signal applied to the input terminal 21 causes the header-attached block signal waiting in the calling buffer inside the exchange to be outputted from the buffer, and the outgoing route link number information applied to the input terminal 22 is output from the buffer. It is connected to the outgoing link to which the outgoing link number is attached by the included identification information signal. Outgoing route link number, originating side, destination side node identification information writing signal generator 1
3 registers the identification information including the outgoing route link number information in the route setting table (routing table) 16.

The header-attached block discard signal is applied to the input terminal 21 of the header-attached block exchanger 20, and causes the header-attached block signal waiting in the calling buffer inside the exchanger to be discarded.

If no call connection request signal is added (that is, in the case of a block signal with a header having a route setting task received from an ingress link in the distributed switching network), the call request identifier 10 detects the egress link. An identification information signal including number information is sent to the outgoing route link number, originating side, and destination node identification information writing signal generator 13, and the identification information is registered in the route setting table (routing table) 16, and the output direction is The identification information including path link number information is applied to the input terminal 22 of the header-equipped block switch 20, and the header-equipped block signal stored in the route setting task header-attached block signal buffer inside the exchange is outputted from the buffer. Connect to the outgoing link with the outgoing link number.

The route setting table 16 stores the registered outgoing route link numbers in the link accommodation path counter 14, the outgoing route link number indicator 7 for data transfer, and the outgoing route link number indicator 8 for route release. Notify. Further, the route setting table 16 notifies the registered route use discriminator 103 shown in FIG. 19 whether or not the outgoing route link corresponding to the registered identification information is being used.

The link accommodation path counter 14 always counts the number of pieces of different identification information of the originating and destination exchange nodes registered in the route setting table 16 for each outgoing route link, and the number is When the maximum number of logical paths that can be connected to each outgoing route link is approached, the connection impossible signal is generated, and when the number is within the allowable number, the connection possible signal is generated.

The blockage fault identification signal buffer 17 receives the notification signal of the occurrence of outgoing link blockage from the flow margin detector 19 and the blockage fault identification signal from the straight path in the distributed switching network applied to the input terminal 24. is constantly updated and accumulated, and the identification information of the blockage failure of each outgoing route link, and the identification information of the switching node that is located in front of the straight route that has caused the fault congestion, for each straight route passing through each outgoing route link. , and the identification information of the exchange node directly connected to the link in which the blockage fault has occurred, the type of direction of the straight route, the type of blockage fault, etc., to the outgoing route link number indicator 6 for route setting, and data transfer. The signal is sent to the outgoing route link number indicator 7 for route release, the outgoing route link number indicator 8 for route release, and the flow margin detector 19, and at the same time, the function to transfer the header-attached block signal into the distributed switching network is completely lost. The identification information of the exchange node currently being used is registered in the discard registration table 18.

Further, the blockage fault identification signal buffer 17 transmits the constantly updated and accumulated blockage fault identification signal to the switching node behind the straight path via the incoming route link (see FIG. 8).
and 9) (this device is not shown in FIG. 1). Note that one type of blockage failure is the loss of the forwarding function of the own node (header-attached block signals can be branched to the network, but all outgoing links in the distributed switching network have blockage failures). The state (which cannot be transferred to an adjacent switching node because of the current status) is autonomously identified by the signal output from the output terminal 38 in FIG.

Further, the discard registration table 18 also allows discards from the outgoing route link number indicator 7 for data transfer even when the own node completely loses the function of transferring header-attached block signals within the distributed switching network. The identification information of the own node is registered using the registration signal. In order to discard the header-attached block whose destination switching node is the exchange node of the registered identification information, the discard registration table 18 sends the identification information signal to the outgoing route link number indicator 6 for route setting and for data transfer. Send it to the outgoing route link number indicator 7.

The flow margin detector 19 always detects the flow (the number of block signals with headers flowing through the link per unit time) for each outgoing link in the grid network, and detects the flow of each outgoing link. To obtain a margin, the blockage fault identification signal buffer 17 is notified of the number of the blocked (flow margin zero) outgoing route link. When the flow margin detector 19 receives a notification from the blocking failure identification signal buffer 17 that a failure has occurred on the outgoing route link side, the flow margin detector 19 sets the flow margin of the notified outgoing route link to zero. Based on the obtained flow margin, the flow margin detector 19 sends order information signals of links with large flow margins to the outgoing route link number indicator 6 for route setting and the outgoing route link number indicator 7 for data transfer. send.

[0041] Note that the number of outgoing links of the exchange nodes in the lattice network and the honeycomb network is usually 3 and 2, respectively. In a switching node, the number of outgoing links can be less than or equal to two. The number of outgoing links is 2
In the flow margin detector 19 described below, the function of detecting blockage of each outgoing route link is sufficient.

The block switch with header 20 selects the input terminal 2 based on the identification information signal applied to the input terminal 21.
The header-added block signal added to step 3 is stored in either the mission-specific buffer or the call-output buffer, and the buffers and the stored header-added block signal are controlled. Also, based on the identification information signal applied to the input terminal 22, a header-attached block signal is output from the buffer, and the header-attached block signal is connected to the output route link indicated by the output route link number information. The other parts and functions of the header-equipped block switch 20 are similar to those of a BISDN cross-connect or other switch.

FIG. 14 is a schematic diagram of an embodiment of the outgoing route link number indicator 6 for route setting in a switching node of a distributed switching network. The discard identifier 48 compares the identification information signal applied to the input terminal 28 with the identification information signal of the destination switching node registered in the discard registration table 18 added to the input terminal 27. If it matches, input terminal 28
The identification information signal added to the header is connected to the header-attached block discard instruction signal generator 49, which generates an identification information signal in which the discard instruction information is added to the identification information, and outputs the identification information signal from the output terminal 32 to the header-attached block discard instruction signal generator 49. Output.

If the comparison by the discard identifier 48 does not match, the identification information signal is connected to the destination switching node coordinate difference unit 50, and the coordinates in the distributed switching network of the own node and the destination switching node are The coordinate difference between the coordinates in the distributed switching network (see FIGS. 2 and 5 or 3 and 6) is calculated, and the coordinate difference information is added to the identification information signal to determine the outgoing route link for setting the shortest route. Send to number selection table 51. It goes without saying that this distributed switching network coordinate itself can be used as the switching node identification information.

Outgoing route link number selection table 5 for shortest route setting
1 is based on the coordinate difference information, if the own node is a Y-shaped node in the honeycomb exchange network (see FIG. 7).

[Table 1] If the own node is an inverted Y-shaped node in the honeycomb exchange network (see Figure 7), then

[Table 2] , if the own node is an exchange node in a grid exchange network, then

By referring to [Table 3], it is possible to determine whether the destination switching node of the header-attached block signal is the own node (corresponding to symbol D in these tables), or whether the destination switching node of the header-attached block signal is the own node (corresponding to symbol D in these tables). is an adjacent node directly connected to the selected outgoing link (corresponding to the symbol N in the table), or the selected outgoing link is a destination exchange of the header block signal with the own node. Form a straight path connecting the nodes (in the case of a honeycomb exchange network, Δx = ±Δxo
or Δy=0, in the case of a lattice network, either Δx=0 or Δy=0), or neither of these, and the output to which the header-attached block signal should be connected. The identification information signal in which the coordinate difference information is replaced with a route link number (including symbol D),
Depending on the identification result, it is connected to either the output terminal 31, the adjacent route selector 52, the straight route selector 53, or the general route selector 54, respectively.

[0046] When referring to Tables 1 and 2, shape identification information indicating whether the destination exchange node is Y-shaped or inverted Y-shaped is required, but this information is This can be achieved either by having it as part of the identification information of the destination switching node held by the network, or by providing each switching node with a shape identification table for all switching nodes in the network.

FIG. 15 is a schematic diagram of an embodiment of the adjacent route selector 52 in the outgoing route link number indicator for route setting. The identification information signal added to the outgoing route link number information applied to the input terminal 55 and the blockage fault identification signal applied to the input terminal 57 are compared by the blockage fault discriminator 70, and the Even if there is no blockage failure and the adjacent node directly connected to the outgoing link is unable to forward the header block signal into the distributed switching network due to blockage of all outgoing links of that node, the subscriber network If it is possible to branch to the subscriber network, an identification information signal to which outbound route link number information (symbol D) to the subscriber network is added is connected to the output terminal 58.

[0048] As a result of the collation by the blockage fault discriminator 70, if the outgoing route link has caused a blockage fault, the identification information signal to which the outgoing route link number information has been added is transmitted to the maximum flow margin link number discriminator. Connect to 71. In a grid-like switching network, the maximum flow margin link number identifier 71 contains number information of the link with the maximum flow margin among all the outgoing route links (the link with the notified outgoing route link number has a flow margin of zero). Therefore, the notified outgoing route link number information is necessarily excluded), and sends an identification information signal replacing the outgoing route link number information to the output terminal 58,
In the honeycomb switching network (since there are only two outgoing links), an identification information signal in which the outgoing link number information is replaced with the other link number information is sent to the output terminal 58;
When all outgoing route links are blocked (flow margin is zero), the header-attached block discard instruction signal generator 72 changes the outgoing route link number information to header-attached block discard instruction information. Output terminal 5 for identification information signal
Send to 9.

[0049] Further, as a result of the collation by the blockage failure discriminator 70, even if an adjacent node directly connected to the outgoing route link has a node failure, the identification information signal to which the outgoing route link number information is added is detected. is sent to the header-attached block discard instruction signal generator 72, and an identification information signal in which the outgoing route link number information is replaced with the header-attached block discard instruction information is sent to the output terminal 59.

FIG. 16 is a schematic diagram of an embodiment of the straight route selector 53 in the outgoing route link number indicator for route setting. The identification information signal added with the outgoing route link number information applied to the input terminal 60 and the blockage fault identification signal applied to the input terminal 62 are collated by the blockage fault discriminator 73, and the If there is no blockage failure, the identification information signal to which the outgoing route link number information is added is connected to the output terminal 63. If a blockage fault occurs in front of the straight route, the point of occurrence is further determined from the coordinates of the notified point of blockage fault occurrence, the coordinates of the own node, and the coordinates of the destination exchange node. Identify whether or not the station is located between the station and the station. If it is not located between the own node and the destination exchange node, select the outgoing route link indicated in the table. If the node is located between the own node and the destination switching node, the identification information signal to which the outgoing route link number information is added is connected to the maximum flow margin link number identifier 74.

The flow margin maximum link number identifier 74 is
Number information of the link with the largest flow margin among all the outgoing links (especially if the outgoing link itself has a blockage failure, the link with the notified outgoing link number will be the one with the largest flow margin) Since the margin is zero, both the notified outgoing route link number information is necessarily excluded) signal and the identification information signal to which the outgoing route link number information is added are used as the outgoing route link number. Connected to the verifier 75, if all outgoing links are blocked (flow margin is zero),
The identification information signal to which the outgoing route link number information has been added is connected to a header-attached block discard instruction signal generator 76. The header-attached block discard instruction signal generator 76 sends to the output terminal 64 an identification information signal in which the outgoing route link number information is replaced with header-attached block discard instruction information.

The outgoing route link number verifier 75 verifies the notified number information of the link with the maximum flow margin and the outgoing route link number information included in the identification information signal, and if they match, the outgoing route The identification information signal to which the route link number information is added is sent to the output terminal 63, and if they do not match, the identification information is connected to the detour identification information writer 77. The detour identification information writer 77 replaces the outgoing route link number information added to the identification information signal with the number information of the link with the largest flow margin, and further indicates that the header-attached block signal is taking the detour route. After writing the detour identification information that informs the exchange node into the identification information signal, it is sent to the output terminal 64.

If you do not insist on the shortest detour route, the outgoing route link number collation unit 75 is omitted, and the flow margin maximum link number identifier 74 determines the maximum flow margin among all outgoing route links. It is also conceivable to send to the output terminal 63 an identification information signal in which the outgoing route link number information is replaced with the link number information. With this method as well, the header-attached block signal responsible for route setting autonomously sets a route to the destination switching node while avoiding the point where a blockage failure occurs. However, the shortest route is not guaranteed.

FIG. 17 is a schematic diagram of the configuration of one embodiment of the general route selector 54 in the outgoing route link number indicator for route setting. The detour discriminator 7 determines whether the header-attached block signal is taking a detour route based on the identification information signal added with the outgoing route link number information applied to the input terminal 65.
8, and if a detour route is taken, that identification information signal is connected to the detour outgoing route link number selection table 79, and if a detour route is not taken, that identification information signal is selected. It is connected to the path number discriminator 80.

[0055] The detour output route link number selection table 79 sends an identification information signal to the header-attached block discard instruction signal generator 85 when all output route links have a blockage failure. If not, based on the detour identification information, if the own node is a Y-shaped node in the honeycomb exchange network (see Figure 7),

[Table 4] If the own node is an inverted Y-shaped node in the honeycomb exchange network (see Figure 7), then

[Table 5] , if the own node is an exchange node in a grid exchange network, then

By referring to Table 6, an identification information signal in which the outgoing route link number information is replaced with the outgoing route link number information indicated by each table is sent to the output terminal 68.

In particular, in the case of I in Tables 4 and 5, the detour output route link number selection table 79 further includes the detour identification information and the blockage fault identification signal added to the terminal 67. When the location of the blockage failure point specified by both sides matches (the end of the detour route)
In this case, an identification information signal in which information instructing deletion of the detour identification information included in the header-attached block signal is added to the identification information of the header-attached block signal is sent to the output terminal 69.

On the other hand, since the identification information signal applied to the input terminal 65 may have two outgoing route link number information (see Tables 1, 2, and 3), the selected outgoing route number discriminator 80 If it has one outgoing route link number, it is connected to the blockage fault discriminator 81, and if it has two outgoing route link numbers, it is connected to the blockage fault discriminator 82. Connecting.

The blockage fault discriminator 81 identifies whether or not a blockage fault has occurred in front of the straight path passing through the link with the one outgoing route link number, and if no blockage fault has occurred, sends the identification information signal to which the outgoing route link number information is added to the output terminal 68, and connects it to the maximum flow margin link number identifier 84 if a blockage failure has occurred. In a grid-like switching network, the maximum flow margin link number identifier 84 contains number information of the link with the maximum flow margin among all the outgoing route links (the link with the outgoing route link number where the blockage failure has occurred is the link with the highest flow margin). is zero, so it is inevitably excluded), an identification information signal with the outgoing route link number information replaced is sent to the output terminal 68. If all the outgoing links are blocked (flow margin is zero), an identification information signal in which the outgoing link number information is replaced with the other link number information is sent to the output terminal 68. , is connected to the header-attached block discard instruction signal generator 85. The header-attached block discard instruction signal generator 85 sends to the output terminal 69 an identification information signal in which the outgoing route link number information is replaced with header-attached block discard instruction information.

The blockage fault discriminator 82 identifies whether or not a blockage fault has occurred in front of the straight path passing through the links to which the two outgoing route link numbers are attached, respectively. If a blockage failure occurs in front of the straight route that passes through only one of the route links, the identification number information is replaced with the number attached to the other route link. An information signal is generated and sent to output terminal 68. In addition, if no blockage fault has occurred in the front of the straight path passing through the two outgoing route links, or if a blockage fault has occurred in both, the connection is made to the maximum flow margin link number identifier 83. do. The maximum flow margin link number identifier 83 generates an identification information signal in which the outgoing route link number information is replaced with the number assigned to the link with the largest flow margin among the two outgoing route links, It is sent to the output terminal 68. In particular, if both of the two outgoing links themselves have a blockage failure, they are connected to the maximum flow margin link number identifier 84. The operation of the maximum flow margin link number identifier 84 is as described above.

FIG. 18 is a schematic diagram of an embodiment of the outgoing link number indicator 7 for data transfer in a switching node of a distributed switching network. The identification information signal applied to the input terminal 35 and the identification information signal of the destination exchange node registered in the discard registration table 18 added to the input terminal 33 are compared by the discard discriminator 86, and if they match, the is connected to the header-attached block discard instruction signal generator 87, generates a header-attached block discard instruction signal in which the header-attached block discard instruction information is added to the identification information, and outputs it from the output terminal 41 to the header-attached block discard instruction signal. do. Disposal identifier 86
If there is no match, the identification information signal is connected to the registration identifier 88.

The registered identifier 88 compares the identification information signal with the identification information signal registered in the route setting table 16 added to the input terminal 34, and if they match, outputs the identification information signal. connection to the path link number reader 89. If they do not match, the header-attached block signal is taking a detour route, so it is connected to the detour direction discriminator 90.

The outgoing route link number reader 89 adds outgoing route link number information read from the registration information signal applied to the input terminal 34 from the route setting table 16 based on the identification information to the identification information signal. and sends it to the outgoing route link blockage fault discriminator 91. The outgoing route link blockage failure identifier 91 compares the outgoing route link number information with the outgoing route link blockage failure identification information received through the input terminal 37, and if they match, a detour is required. The identification information signal to which the outgoing route link number information is added is connected to the alternative outgoing route link number identifier 92. If they do not match, it is connected to the detour identifier 93.

The detour identifier 93 identifies whether or not the header-attached block is taking a detour route from the identification information signal. If the detour route is not taken, an identification information signal to which outgoing route link number information is added is sent to the output terminal 40. If a detour is being taken, the identification information signal to which the outgoing route link number information is added is connected to the detour start tag discriminator 94.

The detour start tag identifier 94 is connected to the input terminal 34.
The detour start tag is identified from the registration information signal of the route setting table 16 added to the route setting table 16, and if the detour start tag is registered (it has gone around the blockage failure point), outgoing route link number information is added. The generated identification information signal is connected to a header-attached block discard instruction signal generator 95. If the detour start tag is not registered (the detour route has ended), an identification information signal to which outgoing route link number information is added is sent to the output terminal 40 and connected to the detour identification information deletion signal generator 96. do. The detour identification information deletion signal generator 96 generates instruction information for deleting the detour identification information from the header-attached block signal stored in the header-attached block switch internal buffer.
It is added to the identification information signal and sent to the output terminal 41.

In the grid-like switching network, the alternative outgoing route link number identifier 92 selects the outgoing route link (
If the proximity is the same, the number information of the link with a larger flow margin is used. In a honeycomb switching network, the number information of the link that is closer to the (Since only two exist), an identification information signal in which the outgoing route link number information is replaced with the other link number information is sent to the output terminal 40. At the same time, the detour start tag registration signal generator 97 generates a signal for registering the detour start tag in the route setting table and sends it to the output terminal 39, and also sends an identification information signal to which outgoing route link number information is added. It is connected to the detour direction identification information write signal generator 98. Further, when all the outgoing route links are blocked (flow margin is zero), it is connected to the header-equipped block discard instruction signal generator 95.

Header-attached block discard instruction signal generator 95
sends an identification information signal in which the outgoing route link number information is replaced with header-attached block discard instruction information to the output terminal 41, and also sends it to the output terminal 38 in order to register the identification information of the own node in the discard registration table. . This signal represents the loss of the forwarding function of its own node and is also sent to the device that notifies other switching nodes of the occurrence of a blockage failure.

The detour direction identification information write signal generator 98 detects the alternative outgoing path link based on the fact that the side of the outgoing path link before the occurrence of the blockage fault matches the side where the point of occurrence of the blockage fault is located. , identifies the left and right positions of the blockage fault occurrence point with respect to the direction of movement of the header-attached block signal, and sends an identification information signal to which left and right information is added to the output terminal 41;
The detour direction identification information is written to the header-attached block signal stored in the header-attached block switch internal buffer.

The detour direction discriminator 90 reads the detour direction identification information from the identification information signal, and adds the number information of the leftmost or rightmost link among the outgoing route links to the identification information signal according to the left and right information. and sends it to the outgoing link blockage fault discriminator 99. The outgoing route link blockage fault identifier 99 compares the outgoing link number information with the outgoing link blockage fault identification information added to the input terminal 37, and if they match, a detour is required. The identification information signal to which the outgoing route link number information is added is connected to the alternative outgoing route link number identifier 100. If they do not match, an identification information signal to which outgoing route link number information is added is sent to the output terminal 40.

In the grid-like switching network, the alternative outgoing route link number identifier 100 uses the honeycomb-like switching network to determine the number information of the link that is closer to the outgoing route link before the occurrence of the blockage fault among all the outgoing route links. Then (since there are only two outgoing links), an identification information signal is sent to the output terminal 40 in which the outgoing link number information before the occurrence of the blockage fault is replaced with the other link number information. When all the outgoing route links are blocked (flow margin is zero), it is connected to the header-attached block discard instruction signal generator 95. The operation of the header-attached block discard instruction signal generator 95 is as described above.

[0070] Since the alternative outgoing route link numbers specified by the alternative outgoing route link number identifiers 92 and 100 are not registered in the route setting table 16, after the blockage fault is recovered, the route before the blockage fault occurs becomes autonomous. is set.

FIG. 19 is a schematic diagram of an embodiment of the outgoing route link number indicator 8 for route release in a switching node of a distributed switching network. The outgoing route link number reader 101 reads the outgoing route link number information read from the registration information signal applied to the input terminal 42 by the route setting table 16 based on the identification information signal applied to the input terminal 43. It is added to the identification information signal and sent to the standby identifier 102. Based on the identification information signal, the standby discriminator 102 identifies whether or not the header-attached block signal has a history of waiting due to encountering a blockage failure at an exchange node on the way to its own node, and determines whether the block signal with a header has a history of waiting. If there is a history, it is connected to the registered route usage discriminator 103, and if there is no history of the samurai machine, the identification information signal to which the outgoing route link number information is added is connected to the outgoing route link blockage fault discriminator 104. At the same time, the registered identification information deletion signal generator 105 generates an identification information signal in which the outgoing route link number information is replaced with information instructing the deletion of the identification information registered in the route setting table 16.
send to

The outgoing route link blockage fault discriminator 104 receives the identification information signal to which the outgoing route link number is added and the input terminal 4.
4 is compared with the blockage fault identification signal added to step 4, and it is determined whether or not the link to which the outgoing route link number is attached is experiencing a blockage fault. If a blockage failure has occurred, the identification information signal to which the outgoing route link number is added is connected to the standby identification information write signal generator 106. The standby identification information write signal generator 106 sends standby information (indicating that there is a history of standby to the preceding exchange node) to the header-attached block signal stored in the header-attached block buffer of the header-attached block exchanger 20. A signal for writing the identification information (identification information for notification) and outgoing route link number information is generated and sent to the output terminal 47.

The header block signal stored in the route release mission header block buffer of the header block exchanger 20 is sent to the standby unit provided inside the header block exchanger 20 at the time of receiving the standby identification information write signal. The data is transferred to a parallel buffer for waiting for recovery from the blockage failure. When this header-attached block signal is notified of recovery from a blockage failure, it reads the outgoing route link number information written therein and connects to the outgoing route link with that number.

The registered route use discriminator 103 determines whether the identification information registered in the route setting table 16 is used by the header-attached block signal responsible for data transfer duty or for the header-attached block signal responsible for route setting duty. Registered route usage identification information indicating whether the registered route has been updated by the signal is read from the registration information added to the input terminal 42, and the usage has been updated (the header-attached block signal responsible for the route release task is the relay switching node in front of If a new route is set while waiting at Connecting. Block discard instruction signal generator with header 107
In order to discard the header-attached block signal stored in the route release header-attached block signal buffer in the header-attached block exchange 20, the output path link number information of the identification signal is converted into header-attached block discard instruction information. A changed identification information signal is generated and sent to the output terminal 47. The operation of the outgoing route link blockage fault discriminator 104 is as described above.

[0075]

Effects of the Invention As described in detail above, according to the present invention, the geometrical feature of a distributed switching network is the large number of routes that can be selected between the originating switching node and the destination switching node. By taking advantage of this, each relay switching node between the originating switching node and the terminating switching node can create a route with less traffic by using as few relay stages as possible while avoiding points where blockages, failures, and congestion occur within the network. Since it is configured autonomously, it is possible to adaptively equalize traffic within the network that changes from time to time in various ways, suppressing the occurrence of blockages and the spread of congestion, and immediately achieving detours in the event of failures after call setup. This has the effect of autonomously providing preferential protection for calls that are currently in use.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of an embodiment of a switching node in a distributed switching network.

[Figure 2] Schematic plan view of a distributed (honeycomb) exchange network

[Figure 3]
Planar diagram of a distributed (lattice-like) exchange network

[Fig. 4] Schematic diagram of an example three-dimensional display connecting a distributed switching network and a subscriber network.

FIG. 5: Schematic diagram of an example of coordinate assignment for exchange nodes in a distributed (vertical honeycomb arrangement) exchange network.

FIG. 6: Schematic diagram of an example of coordinate assignment for exchange nodes in a distributed (lattice-like) exchange network.

[Figure 7] Abbreviations of exchange nodes in a honeycomb exchange network and a schematic diagram of an example of a straight path

FIG. 8 is a schematic diagram of switching nodes and routes for disseminating identification information signals regarding node fault congestion and link blockage faults to other switching nodes in a distributed (honeycomb) switching network;

FIG. 9 is a schematic diagram of switching nodes and routes for disseminating identification information signals regarding node fault congestion and link blockage faults to other switching nodes in a distributed (lattice-like) switching network;

Figure 10: Schematic diagram of the shortest path including detours in a distributed (honeycomb) exchange network

[Figure 11] Schematic diagram of the shortest path including detours in a distributed (lattice-like) switching network

[Figure 12] Schematic diagram of a detour route in case of blockage failure on the outgoing link side in a distributed (honeycomb) switching network

[Figure 13]
Schematic diagram of a detour route in case of blockage failure on the outgoing link side in a distributed (lattice-like) switching network

FIG. 14 is a schematic diagram of the configuration of an embodiment of an outgoing route link number indicator for route setting in a switching node of a distributed switching network;

FIG. 15 is a schematic diagram of the configuration of an embodiment of the adjacent route selector in the outgoing route link number indicator for route setting.

FIG. 16 is a schematic diagram of the configuration of an embodiment of the straight route selector in the outgoing route link number indicator for route setting.

FIG. 17 is a schematic diagram of the configuration of an embodiment of the general route selector in the outgoing route link number indicator for route setting.

FIG. 18 is a schematic diagram of the configuration of an embodiment of an outgoing link number indicator for data transfer in a switching node of a distributed switching network;

[Figure 19
] Schematic diagram of the configuration of an embodiment of an outgoing route link number indicator for route release in a switching node of a distributed switching network

[Explanation of symbols]

1 Input terminal for a (inserted) header-attached block signal from the ingress link on the subscriber network side 2 Input terminal for a call connection request signal from the ingress link on the subscriber network side 3 Ingress route in the distributed switching network Input terminal for block signal with header from link 4 Identification information reader 5 Mission identifier 6 Outgoing route link number indicator for route setting 7 Outgoing route link number indicator for data transfer 8 Outgoing route link number for route release Indicator 9 Mission-specific buffer instruction signal generator 10 Call request identifier 11 Call connection identifier 12 Block standby with header, connection instruction signal generator 1
3 Outgoing route link number, originating side, destination side node identification information write signal generator 14 Link accommodation path counter 15 Block with header discard instruction signal generator 16
Route setting table 17 Blockage fault identification signal buffer 18 Discard registration table 19 Flow margin detector 20 Block exchanger with header 21 Buffer input terminal in block exchanger with header 2
2 Input terminal for the outgoing link number signal to the block switch with header 23 Input terminal for the block signal with header to the block switch with header 24 Input terminal for blockage fault identification signal from the straight path in the distributed switching network 25 Distributed Output terminal 26 for outputting a block signal with a header to an outgoing link in the switched network 27 Output terminal 27 for a block signal with a (branch) header to an outgoing link on the subscriber network Identification information registered in the discard registration table Signal input terminal 28 Input terminal 29 for identification information signal possessed by header-attached block signal Input terminal 30 for flow margin identification signal Input terminal 31 for blockage fault identification signal Outgoing route link number signal to subscriber network and distributed switching network Output terminal 32 Signal output terminal 33 for header-attached block exchange internal buffer Input terminal 34 for identification information signal registered in the discard registration table Input terminal 35 for registration information signal in the route setting table
Input terminal 36 for the identification information signal of the header-attached block Input terminal 37 for the flow margin identification signal Input terminal 38 for the outgoing route link blockage identification signal 38 Output terminal 39 for the header-attached block discard instruction signal Output terminal for the detour start tag registration signal 40 Output route link number signal output terminal 41 Signal output terminal to header-attached block switch internal buffer 42 Input terminal 43 for route setting table registration information signal
Input terminal 44 for identification information signal included in header-attached block signal Input terminal 45 for blockage fault identification signal Output terminal 46 for registered identification information deletion signal Output terminal 47 for outgoing route link number signal Signal output to buffer in header-attached block switch Terminal 48 Discard identifier 49 Block discard instruction signal generator with header 50
Destination side exchange node coordinate difference unit 51 Outgoing route link number selection table 52 for shortest route setting
Adjacent route selector 53 Straight route selector 54 General route selector 55 Input terminal 56 for identification information signal to which output route link number information is added Input terminal 57 for flow margin identification signal Input terminal 58 for blockage fault identification signal Output Output terminal 59 for route link number signal; Signal output terminal 60 for header-equipped buffer in the block exchange; Input terminal 61 for identification information signal with outgoing route link number information; Input terminal 62 for flow margin identification signal; Input terminal 62 for blockage fault identification signal. Input terminal 63 Output route link number signal output terminal 64 Signal output terminal to header-attached block switch internal buffer 65 Input terminal 66 for identification information signal to which output route link number information is added Input terminal 67 for flow margin identification signal Input terminal 68 for blockage fault identification signal Output terminal 69 for output link number signal Signal output terminal 70 for header-attached block buffer in the exchanger Blockage fault identifier 71 Maximum flow margin link number identifier 72 Header-attached block discard instruction signal generation blockage fault identifier 74 flow margin maximum link number identifier 75 outgoing route link number collation device 76 header-attached block discard instruction signal generator 77
Detour identification information writer 78 Detour identifier 79 Detour output route link number selection table 80 Selected output route number identifier 81 Blockage fault identifier 82 Blockage fault identifier 83 Maximum flow margin link number identifier 84 Maximum flow margin link Number identifier 85 Block with header discard instruction signal generator 86 Discard identifier 87 Block with header discard instruction signal generator 88
Registration identifier 89 Outgoing route link number reader 90 Detour direction identifier 91 Outgoing route link blockage failure identifier 92 Alternative outgoing route link number identifier 93 Detour identifier 94 Detour start tag identifier 95 Header-attached block discard instruction signal generator 96
Detour identification information deletion signal generator 97 Detour start tag registration signal generator 98 Detour direction identification information write signal generator 99 Outgoing route link blockage fault identifier 100 Alternative outgoing route link number indicator 101 Outgoing route link number reader 102 Standby identifier 103 Registered route use identifier

Claims (5)

[Claims] Claim 1: In a distributed switching network consisting of a plurality of switching nodes, at least identification information of an originating switching node, identification information of a destination switching node, and one of a route setting mission, a data transfer mission, or a route release mission. Each switching node in the distributed switching network autonomously selects an optimal route from the originating switching node to the destination switching node in response to a header-attached block signal having identification information indicating one of the missions. An autonomous setting method for communication routes within a distributed switching network, which is characterized by selecting and relaying connections. 2. The originating side and the relay switching node to transmit the header-attached block signal having the identification information indicating the route setting task to the next relay switching node are configured to transmit the header block signal to the next relay switching node.・In order to bypass the failure point and suppress the occurrence of blockage due to the selection itself, the outgoing route link that forms the communication route to the destination switching node with the minimum number of relay switching nodes is autonomously created. 2. The autonomous communication route setting method in a distributed switching network according to claim 1, wherein 3. In response to the header-attached block signal having the identification information that informs the data transfer mission, the originating side and the relay switching node send an outgoing route link side (outgoing route link side) forming the already set communication route. When a blockage/failure occurs in a route link or an adjacent exchange node directly connected to an outgoing route link, the route link is replaced with the outgoing route link, bypassing the point of occurrence of the blockage/failure, and the point of occurrence of the blockage/failure is caused by the selection itself. The distributed type according to claim 1, characterized in that the outgoing route link that forms a communication route to the destination switching node with a minimum number of relay switching node stages is autonomously selected so as to suppress the occurrence of blockage. An autonomous communication route setting method within a switched network. 4. In response to the header-attached block signal having identification information informing the route release mission, the originating side and the relay switching node block the outgoing route link side forming the already set communication route.・When a failure occurs,
Until the blockage/failure is restored, the connection of the header-attached block signal to the outgoing route link is kept on standby, and upon the restoration, the release of the communication path to the destination switching node is autonomously resumed. 2. The autonomous communication path setting method in a distributed switching network according to claim 1. 5. The originating switching node that has received a call connection request performs the route setting task only when a communication route to the destination switching node of the call has not been set. The communication route is set up by transmitting the header-attached block signal having identification information informing the next relay switching node, and when there are no calls to the destination switching node, the route release mission is performed. Call setup and release are performed by transmitting the header-attached block signal having the identifying information to the next relay switching node, respectively, and at the originating switching node,
At the time when a block signal with a header having identification information indicating a route setting mission is connected to an outgoing link of the switching node, the total number of the communication paths connected to the outgoing link is equal to the number of the outgoing link. When the number of connections approaches the maximum number that can be connected to the switching node, the connection request for the call originating from the switching node is rejected, and the header-attached block signal is discarded due to the header-attached block signal buffer overflow. 2. The autonomous communication route setting system in a distributed switching network according to claim 1, wherein the autonomous communication route setting method in a distributed switching network protects calls.