JP2005318145A - Inter-network decentralized control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a processing load from concentrating in an inter-network decentralized control system between a line switching network and an IP network. <P>SOLUTION: The inter-network decentralized control system enabling communication between the Internet and a line switching network is provided with a correspondence table making it possible to select a call control server 2 as a common line signal server 3 by separating functions of an inter-network signaling gateway (SG) for transferring call control signals to the call control server 3 and a common line signal transmitting and receiving server 3 and arranging a plurality of call control servers 2 for the common line signal transmitting and receiving server 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inter-network distributed control system for performing communication between a public switched network (PSTN) (circuit-switched network) and an Internet network (IP: Internet Protocol).

  A call control signal between exchanges in a public switching network (circuit switching network) is transmitted by a common line signaling system (No. 7 signaling system). The transmission format in this system includes a sequence number SN (Sequence Number), a destination station number DPC (Destination Point Code), a source station number OPC (Originating Point Code), a communication line number CIC (Circuit Identification Code), and signal information SIF. (Signaling Information Field) and check code CK (Check Bit) are included. In ISDN (Integrated Services Digital Network), ISUP (ISDN User Part) indicating a call control procedure is introduced. In addition, for example, SIP (Session Initiation Protocol) is applied relatively frequently as VoIP (Voice of Internet Protocol) call control in the Internet network (hereinafter abbreviated as IP network).

The gateway system between the circuit switching network (which is the same as the public switching network, which will be described below in terms of circuit switching network) to which the common line signal system is applied and the IP network has the following functions: It consists of units.
(1). A function that interfaces with a common-line-signal circuit switching network and performs common-line signal transmission / reception such as ISUP for call control.
(2). A function that interfaces with an IP network and transmits and receives common line signals such as SIP signals for call control.
(3). A function that performs media conversion of voice signals between an IP network and a circuit switching network.
(4). A function that interfaces with the media conversion function and performs transmission / reception of MEGACO (Media Gateway Control) or the like for media conversion function control.
(5). A function for performing call control between (1) to (4).

  The media conversion function (3) is a function that performs media conversion between a voice signal of a circuit switching network and an RTP (Realtime Transport Protocol) voice packet of an IP network, and is realized by dedicated hardware. . In addition, since a control protocol that operates on an IP network such as MEGACO is standardized, it is relatively easy to arrange functions separately from the function that controls call control (5). In addition, since the SIP signal of (2) is a signal on the IP network, it can be handled only by installing a general network card NIC (Network Interface Card). The function can be realized by a general-purpose server. The termination of the common line signal in the common line signal system of (1) is realized by dedicated hardware because the physical interface is specific to circuit switching.

  Therefore, the circuit switching network and the IP network have a connection configuration shown in FIG. 5, for example. In the figure, 100 is a circuit switching network, 101 is an IP network, 110 is a PSTN (Public Switched Telephony Network) switch, 111 is a general telephone, 115 is an IP telephone, 112 is an SG (Signaling Gateway) server, and 113 is A media conversion server 114 is a SIP (Session Initiation Protocol) server.

The media conversion server 113 performs conversion between the voice signal on the circuit switching network 100 side and the voice packet on the IP network 101 side, and relay transmission between the media conversion server 113 and the PSTN switch 110 is performed using SDH ( This shows a case where multiplexing is performed by the Synchronous Digital Hierarchy) method. In addition, a case is shown in which packet transmission is performed between the media conversion server 113 and the IP telephone 115 by applying RTP (Realtime Transport Protocol). The SIP server 114 performs session establishment processing based on the SIP signal from the SIP-compatible IP telephone 115. The SG server 112 is between the SIP signal of the IP network 101 and the ISUP signal of the circuit switching network. In this case, the conversion timing control between the RTP packet and the multiplexed audio signal by SDH in the media conversion server 113 is performed by the MEGCO signal.

A plurality of media conversion servers (MG) are provided between the ISDN circuit switching network and the IP network, and a common signaling gateway (SG) is provided between the common line signal network and the IP network of the ISDN circuit switching network. A system has been proposed in which a D channel signal of an ISDN circuit switching network is packetized and transferred between the signaling gateway (SG) and a plurality of media conversion servers (MG) (see, for example, Patent Document 1). ).
JP 2002-208966 A

  In the conventional system, a dedicated interface card for transmitting and receiving common line signals is mounted on the SG server 112. However, when the number of lines increases, the number of interface cards to be mounted also increases. Therefore, since the control and the call control are executed on the same server, there is a problem that the load of the call control is large and smooth control processing is difficult.

  It is an object of the present invention to make the call control server an independent configuration so as not to concentrate the processing load.

  The inter-network distributed control system of the present invention is an inter-network distributed control system for performing communication between an Internet network and a circuit switching network, and has a signaling gateway function for transferring call control signals. Is divided into a call control server and a common line signal transmission / reception server, and a plurality of call control servers are provided for the common line signal transmission / reception server.

  Also, an inter-network distributed control system for communication between an Internet network and a circuit switching network, which functions as a signaling gateway between the networks for transferring call control signals, and a common line signal A configuration is provided in which a plurality of the common line signal transmission / reception servers and a plurality of common line signal transmission / reception servers are arranged separately, and a means for transferring a call control signal is provided between the plurality of common line signal transmission / reception servers. ing.

  The common line signal transmission / reception server includes a correspondence table in which a line number on the circuit switching network side is associated with the plurality of call control servers.

  The common line signal transmission / reception server and the call control server can be separated, the server function can be independent and the physical interface storage of the server can be clearly separated, and the physical interface of the call control server can be unified. Can do. Further, since the common line signal transmission / reception server can be arranged independently of the call control server, it is easy to arrange this common line signal transmission / reception server near the circuit switching network and arrange the call control server at an arbitrary position. In addition, the common line signal network as a dedicated network can be made economical.

  The inter-network distributed control system of the present invention will be described with reference to FIG. 1. The inter-network signaling gateway (SG) 1 function for transferring call control signals is exchanged with the call control server 2 through common line signal transmission / reception. The server 3 is separated from the common line signal transmission / reception server 3, and a plurality of call control servers are provided.

FIG. 1 is an explanatory diagram of a main part of an embodiment of the present invention, showing a configuration of an SG (Signaling Gateway) 1 provided between an IP network and a circuit switching network, 2 is a call control server, 3 is a common line signal A transmission / reception server (No. 7 signal transmission / reception server), 4 is a UDP / IP (User Datagram Protocol / Internet Protocol) processing unit, 5 is a MTP (Message Transfer Part) processing unit, and 6 is a transfer function unit.

  The function of SG1 is separated from the call control server 2 and the common line signal transmission / reception server 3, and the call control server 2 can be installed in any position and in any number with respect to the common line signal transmission / reception server 3. . In addition, transmission / reception processing is performed between the circuit switching network and the MTP processing unit 5 of the common line signal transmission / reception unit 3 by ISUP / MTP, and the call control server 2 and the UDP / IP processing unit 4 of the common line signal transmission / reception server 3 Is transmitted / received by ISUP / UDP, and transmission / reception processing is performed by SIP / UDP between the SIP server (not shown) of the IP network and the call control server 2. The control signal is transferred by MEGACO / UDP to the media conversion server from which is omitted.

  As described above, the common line signal transmission / reception server 3 terminates the overall processing of the MTP layer by the MTP processing unit 5 and receives a call control signal such as an ISUP signal from the MTP layer. Thus, the protocol is changed to a protocol that operates on IP such as UDP, and is transferred to the call control server 2 by the UDP / IP processing unit 4. Further, the ISUP signal is transferred from the call control server 2 side to the circuit switching network side by the processing in the reverse direction described above.

  The common line signal transmission / reception server 3 can configure the processing functions of the layers below the MTP layer with dedicated hardware, and the processing function of the transfer function unit 6 can be realized by software. The processing load 3 is lighter than the processing load of the call control server 2.

  Therefore, as shown in FIG. 2, an inter-network distributed control system in which a plurality of call control servers 2-1 to 2-n are provided for the common line signal transmission / reception server 3 is configured. The common line signal transmission / reception server 3 in this case has the processing functions of the UDP / IP processing unit 4, the MTP processing unit 5, and the transfer function unit 6, similarly to the configuration shown in FIG. A correspondence table 10 for associating (call line number) with a call control server is provided. Therefore, the common line signal transmission / reception server 3 can distribute the call control signal by ISUP / MTP from the circuit switching network to the call control server corresponding to the CIC signal by referring to the correspondence table 10.

  Further, media conversion servers 11-1 to 11-n are arranged between the circuit switching network and the IP network so as to correspond to the plurality of call control servers 2-1 to 2-n, and the call control servers 2-1 to 2-n are arranged. Transfers a control signal based on MEGACO / UDP to the media conversion servers 11-1 to 11-n, respectively, based on the call control signal. In this case, a configuration in which a plurality or a single media conversion server is connected to each of the call control servers 2-1 to 2-n can be employed. Alternatively, the common line signal transmission / reception server 3 may be arranged near the common line signal network for transferring the common line signal of the circuit switching network, and the call control servers 2-1 to 2-n may be arranged in a distributed manner with respect to the IP network. it can.

  Since the common line signal transmission / reception server is provided independently of the call control server, a plurality of common line signal transmission / reception servers can be provided. For example, as shown in FIG. 3, a plurality of common line signal transmission / reception servers 3-1 to 3-m are arranged for a single call control server 2, and the call control server 2 is accommodated in a circuit switching network. Call control signal transfer processing is performed with the common line signal transmission / reception server corresponding to the other terminal. The common line signal transmission / reception servers 3-1 to 3-m each have the configuration shown in FIG. 1, but only the MTP processing unit 5 that performs ISUP / MTP transfer with the circuit switching network is illustrated. ing. The media conversion server is not shown.

  Also, it is possible to configure a distributed network control system by providing a plurality of common line signal transmission / reception servers and call control servers. For example, as shown in FIG. 4, a plurality of call control servers 2-1 to 2-n and a plurality of common line signal transmission / reception servers 3-1 to 3-m are provided. In this case, the common line signal transmission / reception servers 3-1 to 3-m illustrate the MTP processing unit 5 and the correspondence table 10, but as illustrated in FIG. 1, the UDP / IP processing unit 4 and the transfer function. And a configuration including the portion 6.

  The common line signal transmission / reception servers 3-1 to 3-m have a function of identifying the accommodation positions of the IP telephones on the IP network side and the telephones on the circuit switching network side and transferring between the common line signal transmission / reception servers. I have. Thereby, for example, for an IP telephone on the IP network side, the call control signal is transferred by ISUP / UDP between the call control server 2-1 and the common line signal transmission / reception server 3-1, and the telephone on the circuit switching network side In the case where the call control signal is transferred by ISUP / MTP between the common line signal transmission / reception server 3-2 and the common line signal transmission / reception unit of the exchange not shown, the common line signal transmission / reception server 3 -1 or common line signal transmission / reception server 3-2 refers to conversion table 10 and associates the CIC (call line number) with the call control server as described above. That is, the circuit switching network side uses the common line signal transmission / reception server 3-2 to transfer the call control signal to / from the exchange side by ISUP / MTP, and the IP network side transmits / receives the common line signal to / from the call control server 2-1. Call control signals are transferred to the server 3-1 by ISUP / UDP, and call control signals are transferred to the common line signal transmission / reception servers 3-1 and 3-2 by ISUP / UDP. Therefore, even when the system scale is large, an economical distributed control system that can balance the load can be constructed.

It is principal part explanatory drawing of the Example of this invention. It is principal part explanatory drawing which has arrange | positioned multiple call control servers. It is principal part explanatory drawing which arrange | positioned multiple common line signal transmission / reception servers. It is principal part explanatory drawing of a some structure. It is principal part explanatory drawing of a prior art example.

Explanation of symbols

1 SG (Signaling Gateway)
2 Call control server 3 Common line signal transmission / reception server 4 UDP / IP processing unit 5 MTP processing unit 6 Transfer function unit 10 Correspondence table

Claims (3)

In the inter-network distributed control system for communication between the Internet network and the circuit switching network, the signaling gateway function between the network for transferring the call control signal, the common line signal transmission / reception with the call control server A distributed inter-network control system comprising: a plurality of call control servers provided for the common line signal transmission / reception server. In the inter-network distributed control system for communication between the Internet network and the circuit switching network, the signaling gateway function between the network for transferring the call control signal, the common line signal transmission / reception with the call control server A plurality of common line signal transmission / reception servers and a plurality of common line signal transmission / reception servers, respectively, and means for transferring a call control signal between the plurality of common line signal transmission / reception servers. Network distributed control system.   The inter-network distributed control according to claim 1 or 2, wherein the common line signal transmission / reception server includes a correspondence table in which a line number on a circuit switching network side is associated with a plurality of the call control servers. system.

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