JP2000031978A - Call control system and call control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly establish a call without being affected by the delay due to a network failure by transmitting a call setting message from a communication equipment to another communication equipment in parallel through plural routes and establishing the call between the communication equipments based on a response message to the call setting message. SOLUTION: When a terminal equipment 20 first sends a call setting request with a terminal equipment 21 to an ATM switch (A) 10, a call setting message transmitting means 1a obtains information about a route from a routing table 3a. Then two SETUP messages for the equipment 21 added with mutually different route information are transmitted in parallel to separate ATM switches (B) 11 and (D) 13. However, transfer can not be performed if a failure takes place between the switch (B) 11 and an ATM switch (C) 12. On the other hand, a call setting message transmitting means 1d of the switch (D) 13 transfers a SETUP message in parallel to the equipment 21 via the switch (C) 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a call control system and a call control method.

[0002]

2. Description of the Related Art FIG. 7 shows, for example, an ATM Forum PN.
NI (Private Network-Network)
1 is a configuration diagram illustrating a network including an ATM switch (an ATM switch having a call control function) that performs a conventional call control based on (k Interface) 1.0.
7, reference numerals 100, 101, 102, and 103 denote ATs.
M switches 110 and 111 are terminal devices.

Next, the call control operation will be described with reference to a sequence diagram shown in FIG. Terminal device 1 in FIG.
When the terminal 10 communicates with the terminal device 111, a route (path) passing through the ATM switches [A] 100, [B] 101, and [C] 102, and the ATM switches [A] 100, [D] 10
3. There are two routes: a route passing through [C] 102. The ATM switch [A] 100 sends a SETUP message (FIG. 8) which is a call setup message from the terminal device 110.
Receiving S101), the route via the above-mentioned ATM switch [B] 101 and the ATM switch [D]
The route information of the route passing through 103 is obtained from the routing table in the own device, and one of the routes, for example, the route passing through the ATM switch [B] 101 is selected. Then, the selected route information is added and SETUP
Message (S102 in FIG. 8)
[B] Transmit to 101. At the same time, a CALL PROC message (CP111 in FIG. 8) indicating that the SETUP message S101 has been received from the terminal device 110 is transmitted to the terminal device 110. This CA
The LLPROC message indicates that the terminal device or the ATM switch that has received the SETUP message indicates that the SETUP message has been received.
This message is a message returned to the terminal device or the ATM switch that transmitted the message, and is a message used for confirming whether the SETUP message has been normally delivered between the two devices. This CALL PROC message is also returned for the SETUP message described below, but the description and illustration are omitted. Next, the ATM switch [B] 101 transfers the SETUP message transmitted from the ATM switch [A] 100 to the ATM switch [C] 102 by referring to the route information added to the message (FIG. 8). S103).
ATM switch that received this SETUP message
[C] 102 sends this SETU to the terminal device 111 which is the destination.
The P message is transferred (S104 in FIG. 8).

The terminal device 111 receives the SETUP message, and transmits a CONNECT (response) message (C105 in FIG. 8) to the terminal device 110 when approving the communication with the terminal device 110. This CONN
The ATM switch [C] 102, [B] 101, [A] 10
0 (C106, C107, C108 in FIG. 8), and the terminal device 110
The terminal device 110 and the terminal device 11 receive the CONNECT message in response to the ETUP message.
A call is established between them.

In the above call control system, when a failure occurs in a route for which a call is to be established and the call cannot be established, the ATM switch which has determined the first route establishes the call with another route. cure. This operation will be described with reference to the sequence diagram shown in FIG. For example, the ATM switches [A] 100, [B] 101, and [C] 102 in FIG.
It is assumed that a call has been attempted to be established through a route passing through, but a failure has occurred in the network between the ATM switches [B] 101 and [C] 102. The terminal device 110 sends a SETUP message to the terminal device 111 (S1 in FIG. 9).
11) is sent. Then, the ATM switch [A] 100 that has received the SETUP message refers to the routing table to the ATM switches [A] 100 and [B].
9 and obtains the route information via [C] 102, adds this route information to the SETUP message, and transmits it to the ATM switch [B] 101 (S1 in FIG. 9).
12). ATM switch [B] 101 is an ATM switch
An attempt is made to transfer the SETUP message transmitted from [A] 100 to ATM switch [C] 102 in accordance with the route information added to this message, but a failure occurs in the network with ATM switch [C] 102. Cannot be transferred. Therefore, ATM switch [B]
101 transmits a RELEASE COMPLETE message (RC113 in FIG. 9) indicating that the call cannot be established to the terminal device 110 that is the transmission source.

The ATM switch [A] 100 that has received the RELEASE COMPLETE message RC113
Are ATM switches [A] 100, [B] 101, [C] 10
ATM switch [A] 10 instead of route via 2
0, a route via [D] 103 and [C] 102 is newly selected, and this route information is added to the SETUP message and transmitted to the ATM switch [D] 103 (FIG. 9).
At S114). Thereafter, the SETUP message is transferred to the terminal device 111 via the ATM switches [D] 103 and [C] 102 (S115 and S1 in FIG. 9).
16). When accepting the communication with the terminal device 110, the terminal device 111 that has received the SETUP message S116 transmits a CONNECT message (C117 in FIG. 9) to the terminal device 110. And this C
ONCONNECT message is ATM switch [C] 102,
It is transferred to the terminal device 110 via [D] 103 and [A] 100 (C118, C119, C12 in FIG. 9).
0), when the terminal device 110 receives the CONNECT message in response to the SETUP message, a call between the terminal device 110 and the terminal device 111 is established.
As a result, although a delay occurs, the terminal device 110 can establish a call with the terminal device 111 without being aware of the occurrence of a failure.

[0007] The call setting operation for one-to-one communication (point-to-point routing) has been described above.
TM Forum PNNI1.0 also defines a call setup method for one-to-many communication (point / multipoint routing). FIG. 10 and FIG. 11 are configuration diagrams showing a network composed of a conventional ATM switch (ATM switch having a call control function) for performing point-multipoint call control according to the ATM Forum PNNI1.0. 10 and 11, reference numerals 120, 121, 122 and 123 denote ATM switches, and reference numerals 130, 131 and 132 denote terminal devices. FIG.
Reference numeral 200 in FIG. 0 and 203 in FIG. 11 are searched route information, and 201, 202 in FIG. 10 and 204, 205, 206 in FIG. 11 are route information added to the call setting message. In addition, P1 to P9
Is an input / output port of each ATM switch.

Next, the operation of point-multipoint call control will be described. Terminal device 130 in FIG.
If the user wants to communicate with the terminal devices 131 and 132, the terminal device 130 sets up a call with the terminal device 131 and then sets up a call with the terminal device 132. First, the operation when the terminal device 130 sets up a call with the terminal device 131 will be described with reference to FIG. First, the terminal device 130 is SE
The TUP message is transmitted to the terminal device 131. ATM switch that received this SETUP message [A]
120 is A based on the address of the terminal device 131 and the like.
A route up to the TM switch [C] 122 is searched, and route information 200 is obtained. The route information added to the SETUP message includes a pointer indicating the position of information to be referred to,
A number indicating the own ATM switch that first determined the route,
An output port number indicating an output destination of the ATM switch, a number indicating an ATM switch to be relayed next,
An output port number indicating an output destination in a TM switch, a number indicating an ATM switch to be relayed next, an output port number indicating an output destination in the ATM switch, and the like, for transmitting a SETUP message to a destination terminal. Number indicating ATM switch to be activated and its ATM
An output port number indicating an output destination in the switch is included. For example, in FIG. 10, the route information 200 includes a pointer “0” indicating a position to be referred to, a number “A” indicating the first ATM switch that has determined a route first, and an output port number “P2” indicating an output destination of the ATM switch. "
The number "B" indicating the next ATM switch to be relayed, the output port number "P4" indicating the output destination of the ATM switch, the number "C" indicating the next ATM switch to be relayed next, and the output at the ATM switch The output port number “0” indicating the destination is included. Here is the final AT
The output port number of the M switch 122 is 0, which indicates that it is the last part in the route obtained by searching. To indicate the output port to the terminal directly connected to the ATM switch,
Such a value is set when the switch determines a route in its own ATM switch. ATM switch [A]
Reference numeral 120 denotes the above-described route information 200 obtained by searching.
, The pointer (value 0) referred to by the own ATM switch is changed to a value “2” indicating the position of the information of the ATM switch to be referred next. ATM switch [A] 12
No. 0 adds the route information 201 after the change to the SETUP message to the next ATM switch [B] 121 and transfers the message.

SETUP with route information 201 added
A received message from ATM switch [A] 120
The TM switch [B] 121 recognizes the number indicating its own ATM switch and the output port number from the information at the position indicated by the pointer (value 2). Then, the ATM switch [B] 121 checks the route information 201 for its own ATM.
Pointer referenced by switch [B] 121 (value 2)
Is changed to a value “4” indicating the position of the information of the ATM switch to be referred next. The ATM switch [B] 121 adds the changed route information 202 to the SETUP message and transfers the route information 202 from the output port “P4” recognized by the route information 201 to the next ATM switch [C] 122. The ATM switch [C] 122 that has received the SETUP message from the ATM switch [B] 121 similarly obtains the number indicating the own ATM switch and the output port number, and since the output port number is “0”, ATM
A route is determined in the switch, and the destination
Send an ETUP message.

Next, an operation for setting a call between the terminal device 130 and the terminal device 132 while a call between the terminal device 130 and the terminal device 131 is set as described above will be described with reference to FIG. explain. First, terminal device 1
An ATM switch 30 sends an ADD PARTY message, which is an additional call setup message, to the terminal device 132.
[A] Transmit to 120. Here, after the call setting between the terminal devices 130 and 131 described in FIG. 11, when the terminal 132 is further added as a connection partner, the same call number is used for a series of call settings between these terminals. However, the ADD PARTY message includes a call number used in a series of point-to-multipoint call setups. The ATM switch [A] 120 first refers to the call number used in the received ADD PARTY message and uses the same call number as the previously set SETUP message. Is S
It recognizes that it belongs to the ETUP message. Thereafter, as in the case of setting a call to the terminal device 131, the route information 20 to the ATM switch [D] 123 is stored.
3, the number indicating the own ATM switch and the output port number are recognized. Then, the ATM switch [A] 120
For the route information 203, the pointer (value 0) referred to by the own ATM switch changes the pointer (value 0) to be referred next.
The value indicating the position of the information of the TM switch is changed to “2”, and the changed route information 204 is changed to the next ATM switch [B].
The message is added to the ADD PARTY message to be sent to the message 121 and transferred.

ADD P added with route information 204
The ATM switch [B] 121, which has received the ARTY message from the ATM switch [A] 120, recognizes that the ATM switch [B] 121 belongs to the previously set SETUP message by referring to the call number. Then, from the information at the position indicated by the pointer (value 2) of the route information 204, the own A
The number indicating the TM switch and the output port number are recognized. Then, the ATM switch [B] 121 changes the pointer (value 2) referred to by the own ATM switch [B] 121 with respect to the route information 204 to the value “4” indicating the position of the information of the ATM switch to be referred next. ”, And the route information 205 after the change is added to the ADD PARTY message to the next ATM switch [C] 122 and transferred.

ADD P to which route information 205 is added
The ATM switch [C] 122 that has received the ARTY message from the ATM switch [B] 121 similarly refers to the call number and recognizes that the ATM switch [C] 122 belongs to the previously set SETUP message. Then, from the information at the position indicated by the pointer (value 4) of the route information 205, the own A
The number indicating the TM switch and the output port number are recognized. Then, the ATM switch [C] 122 changes the pointer (value 4) referred to by the own ATM switch [C] 122 in the route information 205 to the value “6” indicating the position of the information of the ATM switch to be referred next. ”, And the route information 206 after the change is added to the ADD PARTY message to the next ATM switch [D] 123 and transferred.

ADD P added with route information 206
The ATM switch [D] 123, which has received the ARTY message from the ATM switch [C] 122, refers to the call number and (with the ATM switch [C] 122- [D] 123) with the newly set ADD PARTY message. Recognize that there is. Then, the number indicating the own ATM switch and the output port number are obtained from the information at the position indicated by the pointer (value 6) of the route information 206, and the output port number is "0". And transmits an ADD PARTY message to the destination transmitting terminal 132. As a result, a point / multipoint call between the terminal device 130 and the terminal devices 131 and 132 is set.

[0014]

The above-mentioned conventional apparatus sets up a call as described above. If a failure occurs in the route for which the call is to be set up and communication becomes impossible, a new route is set up. Must be selected to perform the call setting operation.
Therefore, there is a problem that an extra delay time is generated from when a failure is discovered to when the setting of the bypass route is completed. In particular, when the scale of the network is large, when the location where the failure has occurred is close to the destination, there is a possibility that the delay time becomes extremely long. Further, since the information of all the relay devices is added to the point / multipoint call setup message, the processing load on each relay device increases as the network scale increases,
There has been a problem that the use efficiency of the network also deteriorates.

[0015]

A call control system according to the present invention sets up a plurality of paths for connecting a plurality of communication apparatuses, and one communication apparatus transmits another communication apparatus in parallel on the set plurality of paths. And a call control means for establishing a call between the communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means. is there.

Further, the call control means includes a call selection means for recognizing a plurality of routes in which a call can be established based on the response message and selecting one of the plurality of routes as a call.

Further, the call control means cancels the call setting for a path other than the path selected by the call selection means.

The call control means recognizes a route other than the route selected by the call selection means as an alternative call.

Further, the call setting message transmitting means transmits the call setting message by adding multi-path transmission information indicating that the call setting message is a call setting message to be transmitted to the same communication device through a plurality of paths. The call control means, when receiving a call setup message to which the multi-path transmission information is added, performs control based on the multi-path transmission information.

Further, the call control system according to the present invention sets a plurality of routes connecting a plurality of communication devices, and sequentially transmits a call setting message from one communication device to another communication device on the set plurality of routes. A call setting message transmitting means for transmitting; a call control means for establishing a call between the plurality of communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means;
(Integer greater than or equal to 2) A route that adds only the route information from the new branch point to the transmission destination to the call setup message in comparison with the route at the time of the call setup before the (n-1) th location at the time of call setup at the location. A call is made based on the information adding means and the route information added by the route information adding means, or the call number used at the time of call setting before the (n-1) th point and the call number of the received call setting message. Call setting message transfer means for transferring a setting message.

Further, according to the call control method of the present invention, a plurality of routes connecting a plurality of communication devices are set, and a call setup from one communication device to another communication device is performed in parallel on the set plurality of routes. A message is transmitted, and a call between the communication devices is established based on a response message to the transmitted call setup message.

Further, according to the call control method of the present invention, a plurality of routes connecting a plurality of communication devices are set, and a call setting message is sequentially transmitted from one communication device to another communication device on the set plurality of routes. And establishes a call between the plurality of communication devices based on a response message to the transmitted call setup message. At the time of call setup for a point-to-multipoint n (an integer of 2 or more) point, the (n-1) th point Only the route information from the new branch point to the transmission destination compared with the route at the time of the previous call setup is added to the call setup message, and the added route information or the call setup before the (n-1) th point is set. The call setting message is transferred based on any information of the used call number and the call number of the received call setting message.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a system configuration diagram showing one embodiment of a call control system according to the present invention. 20 and 21 are terminal devices, and 10 to 13 are ATMs constituting a part of a network to which the terminal devices are connected.
Switch. 1a to 1c set a plurality of different routes (routes) to the same destination, and call setting message transmitting means for transmitting a call setting message on the set route, and 2a to 2c use the call setting message transmitting means 1a to 1c.
The call control means 3a to 3c for setting a call based on the call setting message transmitted by 1c is a routing table for holding the route information referred to when the call setting message transmitting means 1a to 1c sets a route.

In such a system configuration, when the terminal device 20 communicates with the terminal device 21, a route via the ATM switches [A] 10, [B] 11, and [C] 12 is established between these terminals. , ATM switch [A] 10, [D] 1
3. There are two routes: a route via [C] 12. Next, the operation will be described with reference to the sequence diagram shown in FIG. In the present embodiment, a case where a failure occurs in a network between the ATM switch [B] 11 and the ATM switch [C] 12 in FIG. 1 and communication is impossible will be exemplified. First, the terminal device 20 sends a call setup request (SETUP message S1 in FIG. 2) with the terminal device 21 to A.
When the call is sent to the TM switch [A] 10, the call setting message transmitting means 1 a of the ATM switch [A] 10 receives the information and refers to the routing table 3 a for information on the route existing between the terminal devices 20 and 21. It is obtained by doing. Then, two SETUP messages (S2 and S12 in FIG. 2) addressed to the same destination (terminal device 21) to which different route information is added are transmitted in parallel to separate ATM switches [B] 11 and [D] 13 (multicast). ). That is, a plurality of call setup messages are transmitted to the same destination by different routes.

The call setting message transmitting means 1b of the ATM switch [B] 11 transmits the route information added to the SETUP message (S12 in FIG. 2) transmitted by the call setting message transmitting means 1a of the ATM switch [A] 10. By referencing the next transfer destination, this SET
Attempt to transfer the UP message to ATM switch [C] 12. However, this SETUP message cannot be transferred because a failure has occurred in the network between the ATM switch [B] 11 and the ATM switch [C] 12. Then, the call setting message transmitting means 1b of the ATM switch [B] 11 transmits the RELEASE COMPLETE indicating that the call cannot be established to the terminal device 20 which is the transmission source in a direction opposite to the route to which the SETUP message has been transmitted.
An E message (R13 in FIG. 2) is transmitted. This RELEASE COMPLETE message R13
Is first sent to the ATM switch [A] 10, and upon receiving this, the call control means 2a of the ATM switch [A] 10
It recognizes that the terminal device 20 cannot establish a call with the terminal device 21 requested by the route via the TM switches [B] 11 and [C] 12.

On the other hand, in parallel with the above operation, the call setting message transmitting means 1d of the ATM switch [D] 13
The SETUP message (S in FIG. 2) transmitted by the call setting message transmitting means 1a of the switch [A] 10
The next transfer destination is recognized by referring to the route information added to 2), and this SETUP message is transferred to the ATM switch [C] 12 (S3 in FIG. 2). The same operation is performed in the subsequent ATM switch [C] 12, and
The SETUP message is transferred to the terminal device 21 via the ATM switch [C] 12 (S4 in FIG. 2). Then, the terminal device 21 that has received the SETUP message
Transmits a CONNECT (response) message (C5 in FIG. 2) addressed to the terminal device 20 to the ATM switch [C] 12, and the CONNECT message is transmitted to the ATM switch [A] 10 via the ATM switch [D] 13. It is transferred (C6, C7 in FIG. 2).

The call control means 2a of the ATM switch [A] 10 which has received the CONNECT message C7,
ATM switch by this CONNECT message
It recognizes that a call can be established by a route via [A] 10, [D] 13, and [C] 12. On the other hand, as mentioned above, ATM
Since it is recognized that a call cannot be established on the route via the switches [A] 10, [B] 11, and [C] 12, the call control means 2a determines the ATM switch [A ], 10, [D] 13, and [C] 12 determine that the call requested by the terminal device 20 is to be established,
A call between the terminal devices 20 and 21 is established by this route, and a CONNECT message (C8 in FIG. 2)
To the terminal device 20 to notify the establishment of the call. Therefore, the time required to establish a call between the terminal devices 20 and 21 does not become long due to the influence of the network failure between the ATM switches [B] 11 and [C] 12, and a quick call is established. It can be performed.

As described above, a plurality of routes connecting a plurality of communication devices are set, and a call for transmitting a call setting message from one communication device to another communication device in parallel on the set plurality of routes. Setting message transmission means, and call control means for establishing a call between the plurality of devices based on a response message to the call setting message transmitted by the call setting message transmission means, thereby setting up a plurality of calls in parallel. Call can be quickly established without being affected by delay due to a partial network failure.

In particular, when the scale of the network is large,
The effect of the call control system according to the present invention increases when the location where the failure occurs is close to the destination.

In FIG. 1, all the ATM switches
[A] 10, [B] 11, [C] 12, and [D] 13 are examples including the call setup message transmitting means, the call control means, and the routing table. If the call control means and the routing table are provided in at least one ATM switch, the same effect can be obtained. For example, only the ATM switch [A] 10 in FIG. 1 has a call setup message transmitting means, a call control means, and a routing table, and the other ATM switches transfer a call setup message (SETUP message) and a response message (CONNECT message) as in the prior art. / R
The same effect can be obtained even if the transmission of the ELEASE COMPLETE message is performed. Further, the call setting message transmitting means, the call control means, and the routing table need not always be provided in the ATM switch, and may be provided in, for example, a terminal device.
It may be connected to the network independently of the TM switch and the terminal device.

In the present embodiment, the terminal device 21
Although the ONNECT message is returned, the terminal device 21
ATM switch [C] 12 connecting to CONNECT
The same effect can be obtained by returning the T message.

Also, in the present embodiment, the case where one route in which a call can be established and one route in which a call cannot be established has been described. A similar effect can be obtained by selecting one route and establishing a call. Among the ATM switches located on a route that can establish a call other than the selected route, the ATM that has made the final call setup
Since the ATM switch other than the switch is transferring the CONNECT message, it recognizes that a call via the own switch has been set. Formally canceling the call setting (call disconnection) for such a non-selected route can reduce wasteful use of resources in the network in addition to the effect described above. In this case, for routes other than the selected route, the call is disconnected by a call disconnection message. That is, the ATM switch 10 that has transmitted the call setup message through a plurality of routes receives CO
When the NNECT message is returned by a plurality of routes, one of them is selected, and a call disconnection message is transmitted to a route other than the selected route to disconnect the call. Further, since at least one call is set according to the selected route, a CONNECT message is transmitted to the terminal device 20 to establish a call. Also, by setting the selected route as a normally used call (main route) and notifying the other terminal that a route that can establish a call other than the selected route is set as a backup call (backup route). Since the destination terminal can grasp the relationship between the main route and the backup route among the plurality of routes, it is possible to quickly switch to the backup route when a failure occurs in the main route.

Although a plurality of routes are set with reference to the routing table 3a in the present embodiment, the routing table 3a may not be used if the call setting message transmitting means 1a can set a plurality of routes. .

Embodiment 2 In the first embodiment, the case has been described where the call control means in the ATM switch that transmitted the SETUP message through a plurality of routes receives the CONNECT message and selects one of the routes, but in the present embodiment, the SETUP message is transmitted. A case will be described in which the call control means of the destination terminal device that receives the request selects one of a plurality of routes. FIG.
1 is a system configuration diagram showing one embodiment of a call control system according to the present invention. 14 is an ATM switch [A] 10,
This is an ATM switch including the call setting message transmitting means 1e, the call setting means 2e, and the routing table 3e as in [B] 11, [C] 12, and [D] 13. Others are the same as the above embodiment.

In such a system configuration, when the terminal device 20 communicates with the terminal device 21, routes between the terminals via the ATM switches [A] 10, [B] 11, and [C] 12, ATM switch [A] 10, [D] 13,
Route via [C] 12, ATM switch [A] 10,
There are three routes: routes via [E] 14 and [C] 12. Next, the operation will be described with reference to the sequence diagram shown in FIG. In the present embodiment, A in FIG.
A case where a failure occurs in the network between the TM switches [B] 11 and [C] 12 and communication is not possible is illustrated. First, the terminal device 20 sends a call setup request (SETUP message S21 in FIG. 4) with the terminal device 21 to the ATM.
When the call setting message is transmitted to the switch [A] 10, the call setting message transmitting means 1a of the ATM switch [A] 10 refers to the routing table 3a for information on the route existing between the terminal devices 20 and 21. Gain by doing.
Then, three SETUP messages (S22, S32, and S42 in FIG. 4) destined for the same transmission destination (terminal device 21) to which different route information is added are respectively sent to different ATM switches [B] 11, [D] 13, [ E]. At this time, these three SEs
Information indicating that the TUP message is a multicast message is added to each SETUP message.

The call setting message transmitting means 1b of the ATM switch [B] 11 transmits the route information added to the SETUP message (S42 in FIG. 4) transmitted by the call setting message transmitting means 1a of the ATM switch [A] 10. By referencing the next transfer destination, this SET
Attempt to transfer the UP message to ATM switch [C] 12. However, this SETUP message cannot be transferred because a failure has occurred in the network between the ATM switch [B] 11 and the ATM switch [C] 12. Then, the call setting message transmitting means 1b of the ATM switch [B] 11 transmits the RELEASE COMPLETE indicating that the call cannot be established to the terminal device 20 which is the transmission source in a direction opposite to the route to which the SETUP message has been transmitted.
An E message (RC43 in FIG. 4) is transmitted. This RELEASE COMPLETE message RC4
3 is sent to the ATM switch [A] 10, and the call control means 2a of the ATM switch [A] 10 receiving the
It recognizes that the terminal device 20 cannot establish a call with the terminal device 21 requested by the route via the M switches [B] 11 and [C] 12.

On the other hand, in parallel with the above operation, the call setting message transmitting means 1d and 1e of the ATM switch [D] 13 and the ATM switch [E] 14 send the ATM switch [A] 10
SE transmitted by the call setting message transmitting means 1a
The next transfer destination is recognized by referring to the route information added to the TUP message (S22, S32 in FIG. 4), and this SETUP message is transmitted to the ATM switch.
[C] 12 (S23, S33 in FIG. 4).
The two SETUPs transmitted by the call setting message transmitting means 1d and 1e of the ATM switches [D] 13 and [E] 14.
By referring to the information added to the messages S23 and S33, the ATM switch [C] 12 recognizes that the SETUP messages S23 and S33 are multicast messages. ATM switch [C] 12
For example, among these multicast SETUP messages, a SETUP message that has arrived first, or a SETUP message having the highest priority if the SETUP message has a priority, is accepted.
This SETUP message is transferred to the terminal device 21.
In FIG. 4, the S of the route via the ATM switch [E] 14
Upon receiving the ETUP message (S23), the terminal device 2
1 is transferred to the SETUP message (S24).
Then, the terminal device 21 that has received the SETUP message
Transmits the CONNECT message (C25) to the terminal device 2
0, and the CONNECT message is sent to the AT
The data is transferred to the ATM switch [A] 10 via the M switches [C] 12 and [E] 14 (C26 and C2 in FIG. 4).
7).

Further, the SETUP message of the route passing through the ATM switch [D] 13 not accepted by the ATM switch [C] 12 (S33 in FIG. 4).
ATM switch [C] 12 responds to
An EASE COMPLETE message (RC36 in FIG. 4) is returned, and this RELEASE COMPLETE
TE message is AT as RELEASE message
ATM switch [A] 10 via M switch [D] 13
(R37 in FIG. 4). (RELEASE COMPLETE at ATM switch [D] 13
The reason that the RELEASE message is used instead of the message is that the SETUP message S32 is not rejected directly by the ATM switch [D] 13,
This is because, as a result of receiving the LEASE COMPLETE message RC36, it is determined that a call cannot be set up. As described above, the call control means 2c of the destination terminal device 21 selects one of the routes in which the call can be established.

CON via ATM switch [E] 14
ATM switch that has received a NECT message (C27 in FIG. 4) and a RELEASE message (R37 in FIG. 4) via the ATM switch [D] 13
In the call control means 2a of [A] 10, the ATM switches [A] 10, [E] 14, [C] 1 are sent by the CONNECT message.
R2 recognizes that a call can be established on the route through
ATM switch [A] 1 by ELEASE message
It recognizes that a call cannot be established through a route passing through 0, [D] 13, and [C] 12. Based on these situations, the call setting means 2a sets the ATM switches [A] 10, [E] 14, [C] 1
It is determined that the call requested by the terminal device 20 is established on the route passing through the terminal 2, and the call between the terminal devices 20 and 21 is established on this route, and the CONNECT message (C 28 in FIG. 4) is sent to the terminal device 20. Transfer to signal call establishment. In this way, the call control means on the destination terminal side selects one of the routes that can establish a call, so that one route is selected from an early stage. The ATM switch on the route that has not been established recognizes early that its own ATM switch is not used in the established call and can release the resources. Therefore, as described in the first embodiment, a call disconnection message is further transmitted to an ATM switch that recognizes that its own ATM switch is used for a set call upon receiving a CONNECT message. As a result, resources in the network can be used efficiently without notifying the user.

As described above, the call setting message transmitting means adds the multi-route transmission information indicating that the call setting message is transmitted to the same destination through a plurality of different routes to the call setting message and transmits the message. In addition, when the call setting unit receives the call setting message to which the multi-route transmission information is added, by recognizing the multi-route transmission information, it is possible to set up a plurality of calls in parallel. A quick call can be established without being affected by a delay due to a network failure.

In this embodiment, all the ATM switches [A] 10, [B] 11, [C] 12, [D] 13, and [E] are used.
14 shows an example including a call setup message transmitting means, a call control means, and a routing table,
The same effect can be obtained if at least one ATM switch is provided with a call setting message transmitting means, a call control means, and a routing table, and another call control means is connected on a network. For example, in FIG. 3, the call setting message transmitting means 1a of the ATM switch [A] 10 sets a plurality of routes,
[C] The call control means 2c of 12 recognizes the multi-route transmission information indicating that the message is a call setup message transmitted to the same destination by a plurality of different routes, and
[A] The call control means 2a of 10 establishes a call as described above, and other ATM switches transfer a call setup message (SETUP message) and a response message (CONNECT / RELEASE / RELEAS) as in the prior art.
The same effect can be obtained even if the transmission of the E COMPLETE message is performed. In this case, the ATM switch [C] 12 does not necessarily need to have the call setting message transmitting means 1c and the routing table 3c. Further, the call control system according to the present invention is not necessarily provided in the ATM switch, but may be provided in, for example, a terminal device.

In this embodiment, the ATM switch
[C] 12 returns a RELEASE COMPLETE message, but the terminal device 21 selects a call and performs RELEASE COMPLETE for a call other than the selected call.
A similar effect can be obtained by returning a TE message.

In this embodiment, a case is described in which a call is disconnected for a route other than the selected route. However, if a route other than the selected route is secured as a backup call, the above-described effect can be obtained. In addition to the above, when a failure occurs in the selected route, it is not necessary to perform recall setting, and an effect is obtained that a call can be switched to a backup call without delay. In this case, for routes other than the selected route, RELEASE / RELEASE COM
Instead of transmitting the PLETE message, information indicating that the call is a backup call is added to the CONNECT message and transmitted. That is, RELEASE C in FIG.
Instead of the OMPLETE message RC36 and the RELEASE message R37, a CONNECT message to which information indicating a preliminary call is added is transmitted. CONNECT message C2 for the selected route
7 with information indicating that this is a backup call
ATM switch [A] 1 which received the NECT message
0 is usually the selected route (ATM switch [A] 1
0, [E] 14, route via [C] 12)
When a failure occurs in this route, the call is immediately switched to a backup call (a route via the ATM switches [A] 10, [D] 13, and [C] 12).

Embodiment 3 FIG. Next, the operation of point-multipoint call control will be described. 5 and 6, reference numerals 30 to 33 denote ATM switches, 40, 41, and 42.
Is a terminal device. 1a is a call setup message transmitting means for sequentially transmitting a call setup message to the plurality of communication devices on a plurality of set routes, and 2a is a call setup message transmitting means based on a response message to the call setup message transmitted by the call setup message sending means 1a. A call control means for establishing a call between a plurality of communication devices, 3a is a routing table holding route information referred to when the call setting message transmitting means 1a sets a route, and 4a is a one-to-many n (an integer of 2 or more). A) route information adding means for adding only the route information from the newly branched point to the transmission destination to the call setting message in comparison with the route at the time of the call setting before the (n-1) th point when setting up the call at the point; Is the route information added by the route information adding means 4a, or the call number and the received call setting message used at the time of call setting before the (n-1) th point. A call setup message transfer means for transferring the call setup message based on information of either di call number. Although not shown, the other ATM switches [B] 31 to [D] 33 include similar components. Also, 50 in FIG. 5 and 53 in FIG. 6 are searched route information, and 51 and 52 in FIG. 5 and 54, 55 and 56 in FIG. 6 are route information added to the call setting message. In addition,
P1 to P9 are input / output port numbers of each ATM switch.

The terminal device 40 in FIG.
In order to communicate with the terminal device 40, the terminal device 40 sets up a call with the terminal device 41 and then sets up a call with the terminal device 42. First, referring to FIG.
The operation when setting up a call with will be described. First, the terminal device 40 transmits a SETUP message to the terminal device 41. A that received this SETUP message
In the TM switch [A] 30, the call setting message transmitting means 1a searches the routing table 3a for a route to the ATM switch [C] 32 from the address and the like of the terminal device 41 in the SETUP message. The route information adding means 4a adds the information obtained by deleting the information of the own switch from the obtained route information 50 to the SETUP message, and the call setting message transmitting means 1a transmits the SETUP message to which the route information is added. Transfer to the next ATM switch [B] 31.

The route information 50 includes a number “A” indicating the own ATM switch that first determined the route, an output port number “P2” indicating an output destination of the ATM switch,
The number "B" indicating the next ATM switch to be relayed, the output port number "P4" indicating the output destination of the ATM switch, the number "C" indicating the next ATM switch to be relayed next, and the output at the ATM switch The output port number “0” indicating the destination is included. Here is the final AT
The output port number of the M switch [C] 32 is “0”, which indicates that it is the last part in the obtained route. Such a value is set when an output port to a terminal directly connected to the ATM switch is indicated, or when each ATM switch determines a route in its own ATM switch again. In the route information 50, the identification number and the output port number relating to the own ATM switch are unnecessary information for the ATM switch that performs the relay thereafter, so this information is deleted and the route information as shown in the route information 51 is deleted. Is added to the SETUP message and transferred to the next ATM switch [B] 31.

SETUP from ATM switch [A] 30
The call setting message transfer means (not shown) in the ATM switch [B] 31 that has received the message
Refers to the route information added to the message. Then, the route information adding means (not shown) similarly outputs the own ATM.
The switch identification number and the output port number are deleted, and the route information as shown in the route information 52 is added to the SETUP message. The call setup message transfer means (not shown) transmits the SETUP message to the next ATM switch [C ] 32.

SETUP from ATM switch [B] 31
In the ATM switch [C] 32 which has received the message, the call setting message transfer means refers to the route information 52 added to the SETUP message. In the route information 52, the value of the output port is “0”, which indicates that this is the last part in the obtained route. Such a value is set when an output port to a terminal directly connected to the ATM switch is indicated, or when each ATM switch determines a route in the ATM switch again. The call setting message transfer means of the ATM switch [C] 32 determines a route according to this information, and transmits a SETUP message to the destination transmitting terminal 41 in this embodiment.

Next, an operation for setting a call between the terminal device 40 and the terminal device 42 while a call between the terminal device 40 and the terminal device 41 is set as described above will be described with reference to FIG. explain. First, the terminal device 40 sends an ADD which is an additional call setup message addressed to the terminal device 42.
A PARTY message is transmitted to the ATM switch [A] 30. Here, after the call setting between the terminal device 40 and the terminal device 41 described in FIG.
In addition, the same call number is used for a series of call setups between these terminals when 2 is added, but the above ADD PARTY message includes such a point-multipoint series call setup. Contains the call number used. The call setting message transmitting means 1a of the ATM switch [A] 30 firstly receives the received ADD PARTY.
By referring to the call number used by the message, since the same call number as the previously set SETUP message is used, it is recognized that this ADD PARTY message belongs to the previous SETUP message. (The same call number is used in a series of point-to-multipoint call setup as described above). Then, as in the case of setting up a call with the terminal device 41, the ATM switch
The call setting message transmitting means 1a of [A] 30 searches the route information 53 to the ATM switch [D] 33. Here, the route information 53 obtained by the search by the call setting message transmitting means 1a of the ATM switch [A] 30 and the above-mentioned SETU
Comparing with the route information 50 of FIG. 5 at the time of transmitting the P message, it can be seen that the route to the ATM switch [B] 31 is common. Therefore, the route information adding means 4a
ADDs the route information 54 from which the common part information has been deleted.
In addition to the PARTY message, the call setting message transmitting means 1a transmits the ADD message to which the route information 54 is added.
The PARTY message is transferred to the next ATM switch [B] 31.

ADD P from ATM switch [A] 30
ATM switch [B] 31 that has received the ARTY message
, The call setting message transfer means refers to the call number, recognizes that the message belongs to the previously set SETUP message, and then refers to the route information 54, but there is no information on the own ATM switch. Therefore, it recognizes that this ADD PARTY message should be transferred to the same output destination port as the previously set SETUP message. This allows ATM switch [B]
31 adds the route information 54 as it is to the ADD PARTY message as the route information 55, and the call setup message transfer means transmits the SETUP message.
ATM switch [C] 3 at the same output destination port as the message
Transfer to 2.

ADD P from ATM switch [B] 31
ATM switch [C] 32 that has received the ARTY message
The call setup message transfer means recognizes that the call belongs to the SETUP message previously set by referring to the call number, and that the information of the own ATM switch exists by referring to the route information 55. Is recognized, and then the output from the output port is recognized. Then, the route information adding means deletes the identification number and the output port number relating to the own ATM switch and adds the route information shown in the route information 56 to the ADD PARTY.
The call setting message transfer means transfers the ADD PARTY message from the output port P7 to the next ATM switch [D] 33.

ADD P from ATM switch [C] 32
ATM switch [D] 33 that has received the ARTY message
In, the call setup message transfer means refers to the call number and recognizes that it is a newly set ADD PARTY message (between the ATM switches [C] 32- [D] 33). Then, with reference to the added route information 56 and the value of the output port is “0”, the route is determined in the own ATM switch and ADD is sent to the destination transmitting terminal 42.
Send a PARTY message.

As described above, when a series of point-multipoint call setup is performed, a portion of the route information added to the ADD PARTY message that does not overlap the route once set is prevented from being transferred. The network can be used efficiently, and the processing load on the relay device can be reduced.

As described above, a call setup message transmitting means for setting a plurality of routes connecting a plurality of communication devices and sequentially transmitting a call setup message to the plurality of communication devices on the set plurality of routes, A call control means for establishing a call between the plurality of communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means; and a one-to-many n (two or more integer) point call setting. A route information adding unit for adding only the route information from the newly branched point to the transmission destination to the call setting message as compared with the route at the time of the call setting before the (n-1) th point, and the route information adding unit adds the route information. Route information, or n-1
A call setup message transfer means for transferring a call setup message based on either the call number used at the time of the call setup before the location or the call number of the received call setup message, so that the call already set up is provided. Route information that overlaps with the route information of
The network can be used efficiently, and the processing load on the relay device can be reduced.

In FIG. 5, all the ATM switches
[A] 30, [B] 31, [C] 32, and [D] 33 have the same configuration, but the call setup message transmitting means 1a,
At least one ATM switch including a call control unit 2a, a routing table 3a, and a route information adding unit 4a is connected to the network, and the other ATM switches include a call setting message transfer unit and a route information adding unit. Thus, the same effect can be obtained. For example, FIG.
Only the ATM switch [A] 10 includes a call setting message transmitting unit 1a, a call control unit 2a, a routing table 3a, and a route information adding unit 4a, and the other ATM switches include a call setting message transferring unit and a route information adding unit. If provided, a similar effect can be obtained.

Although the operation of returning a CONNECT message is omitted in the present embodiment, the terminal devices 41 and 42
Returns a CONNECT message, or the ATM switch [C] 32 connecting the terminal devices 41 and 42,
In any case where [D] 33 returns a CONNECT message, the same effect can be obtained.

[0057]

As described above, a plurality of routes connecting a plurality of communication devices are set, and a call setup message from one communication device to another communication device is transmitted in parallel on the set plurality of routes. Call setting message transmitting means, and call control means for establishing a call between the communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means, thereby setting up a plurality of calls. Since it can be performed in parallel, a quick call can be established without being affected by delay due to a partial network failure.

Further, the call setting means includes a call selecting means for recognizing a plurality of routes in which a call can be established based on the response message and selecting one of the plurality of routes as a call. Can be set in parallel, so that a quick call can be established without being affected by a delay due to a partial network failure.

Further, the call control means cancels the call setting for a route other than the route selected by the call selecting means, so that a plurality of calls can be set in parallel. A quick call can be established without being affected by a delay due to a failure, and wasteful use of resources in a network can be reduced.

Further, the call control means can set a plurality of calls in parallel by recognizing a route other than the route selected by the call selection means as an alternative call, so that a partial It is possible to quickly establish a call without being affected by a delay due to a network failure, and to quickly switch to a spare call when a failure occurs in a selected call.

Further, the call setting message transmitting means adds multi-path transmission information indicating that the message is a call setting message to be transmitted to the same communication device through a plurality of paths to the call setting message, and transmits the call setting message. When the call control unit receives the call setting message to which the multi-path transmission information is added, by performing control based on the multi-path transmission information, it is possible to set up a plurality of calls in parallel. A quick call can be established without being affected by a delay caused by a temporary network failure.

Further, a call setting message transmitting means for setting a plurality of paths connecting a plurality of communication apparatuses, and sequentially transmitting a call setting message from one communication apparatus to another communication apparatus through the set plurality of paths, A call control means for establishing a call between the plurality of communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means; and a one-to-many n (integer of 2 or more) point call setting. , A path information adding means for adding only the path information from the newly branched point to the transmission destination to the call setting message in comparison with the path at the time of the call setting before the (n-1) th point, and the path information adding means The call setup message is transferred based on the received route information or any one of the call number used in the call setup before the (n-1) th location and the call number of the received call setup message. And a call setting message transfer unit that does not transfer a portion overlapping with the route information of the already set call, so that the network can be used efficiently and the processing of the relay device can be performed. The load can also be reduced.

Further, a plurality of routes connecting a plurality of communication devices are set, and a call setup message from one communication device to another communication device is transmitted in parallel on the set plurality of routes,
By establishing a call between the communication devices based on a response message to the transmitted call setup message,
Since a plurality of calls can be set in parallel, a quick call can be established without being affected by a delay due to a partial network failure.

Further, a plurality of routes connecting the plurality of communication devices are set, and a call setting message from one communication device to another communication device is sequentially transmitted on the set plurality of routes,
A call between the plurality of communication devices is established based on a response message to the transmitted call setup message, and at the time of a call setup at a point-to-multipoint n (an integer of 2 or more) point, a call setup before the (n-1) th point is performed. Only the route information from the new branch point to the destination compared with the route at the time is added to the call setup message, and the added route information or the call number used at the time of the call setup before the (n-1) th point is added. And transferring the call setup message based on any information of the call number of the received call setup message, so that a portion overlapping with the route information of the already set call can be prevented from being transferred. Can be used efficiently, and the processing load on the relay device can be reduced.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment of a call control system according to the present invention.

FIG. 2 is a sequence diagram showing a call setting operation.

FIG. 3 is a system configuration diagram showing an embodiment of a call control system according to the present invention.

FIG. 4 is a sequence diagram showing a call setting operation.

FIG. 5 is a system configuration diagram illustrating the operation of point-multipoint call control.

FIG. 6 is a system configuration diagram illustrating an operation of point-multipoint call control.

FIG. 7 is a diagram showing a network configuration constituted by a conventional ATM switch for performing call control;

FIG. 8 is a sequence diagram showing a conventional call control operation.

FIG. 9 is a sequence diagram showing a conventional call control operation.

FIG. 10 is a network configuration diagram for explaining a conventional point-multipoint call control operation;

FIG. 11 is a network configuration diagram for explaining a conventional point-multipoint call control operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Call setup message transmission means 2 Call control means 3 Routing table 4 Route information addition means 5 Call setup message transfer means 10-14 ATM switch 20,21 Terminal device 30-33 ATM switch 40-42 Terminal device 50-56 Route information S1 To S4, S12 SETUP message C5 to C8 CONNECT message RC13 RELEASE COMPLETE message S21 to S24, S32, S33, S42 SETUP
Message C25 to C28 CONNECT message RC36, RC43 RELEASE COMPLET
E message R37 RELEASE message

Claims (8)

[Claims] 1. A call setting message transmitting means for setting a plurality of paths connecting a plurality of communication apparatuses and transmitting a call setting message from one communication apparatus to another communication apparatus in parallel on the set plurality of paths. And a call control means for establishing a call between the communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means. 2. The method according to claim 1, wherein said call control means recognizes a plurality of call-establishable paths based on said response message, and includes call selection means for selecting one of said plurality of paths as a call. The call control system according to claim 1, wherein 3. The call control system according to claim 2, wherein the call control unit cancels the call setting for a route other than the route selected by the call selection unit. 4. The call control system according to claim 2, wherein the call control unit recognizes a route other than the route selected by the call selection unit as an alternative call. 5. The method according to claim 1, wherein said call setting message transmitting means adds multi-path transmission information indicating that the message is a call setting message to be transmitted to the same communication device through a plurality of paths to said call setting message and transmits said call setting message. 5. The call control system according to claim 2, wherein the call control means performs control based on the multi-path transmission information when receiving a call setup message to which the multi-path transmission information is added. . 6. A call setting message transmitting means for setting a plurality of paths connecting a plurality of communication apparatuses, and sequentially transmitting a call setting message from one communication apparatus to another communication apparatus through the set plurality of paths, A call control means for establishing a call between the plurality of communication devices based on a response message to the call setting message transmitted by the call setting message transmitting means; and a one-to-many n (integer of 2 or more) point call setting. , A path information adding means for adding only the path information from the newly branched point to the transmission destination to the call setting message in comparison with the path at the time of the call setting before the (n-1) th point, and the path information adding means The call setup message is transferred based on the received route information or any one of the call number used in the call setup before the (n-1) th location and the call number of the received call setup message. A call control system comprising: a call setting message transfer unit. 7. A plurality of routes connecting a plurality of communication devices are set, and a call setup message from one communication device to another communication device is transmitted in parallel on the set plurality of routes. A call control method comprising: establishing a call between the communication devices based on a response message to a call setup message. 8. A plurality of routes connecting a plurality of communication devices are set, a call setup message from one communication device to another communication device is sequentially transmitted through the set plurality of routes, and the transmitted call is transmitted. A call between the plurality of communication devices is established based on a response message to the setting message, and a one-to-many n
(Integer of 2 or more) At the time of call setup at the point, only the route information from the newly branched point to the destination is added to the call setup message as compared with the route at the time of the call setup before the (n-1) th point,
The call setup message is transferred based on the added route information or any one of the call number used in the call setup before the (n-1) th point and the call number of the received call setup message. Call control method.