JP5743936B2 - Signal conversion apparatus, exchange, and signal conversion method - Google Patents

Description

  The present invention relates to a signal conversion apparatus, an exchange having the signal conversion apparatus, and a signal conversion method.

  With the widespread use of communication devices using the IP (Internet protocol) protocol, a VoIP (voice over IP) system that transmits telephone voice over an IP line has become widespread. FIG. 6 is a diagram showing a configuration of a VoIP system 400 related to the present invention. In the VoIP system 400 shown in FIG. 6, exchanges 403 and 404 to which telephones 401 and 402 are respectively connected are connected via a VoIP network 405. The VoIP network 405 is a network based on an IP protocol including, for example, LANs (local area networks) 406 and 407 and a WAN (wide area network) 408. The VoIP network 405 may be configured with an IP leased line independent of the Internet.

  The exchanges 403 and 404 include voice IP modules 409 and 410, respectively. Voice IP modules 409 and 410 convert voice signals into IP packets at the exchanges 403 and 404, respectively, and output them to the VoIP network 405. Also, the voice IP modules 409 and 410 convert the IP packet received from the VoIP network 405 into a signal form that can be processed by the exchange 403 or 404. That is, the voice IP modules 409 and 410 are NICs (network interface cards) of the exchange 403 or 404 for the VoIP network 405.

  In a system using IP packets, a port mirroring function of a network device for collecting IP packets for analyzing a communication state on the VoIP network 405 is known. The port mirroring function is a function of copying to a port to which a device (packet monitoring device) that monitors packets passing through the network is connected in a network device such as a switching hub or a router. The packet monitoring apparatus receives the copied packet from the port of the network device and analyzes it.

  In relation to the present invention, Patent Document 1 discloses a configuration for monitoring a packet of a device that is a target of voice monitoring arranged in a distributed manner at a designated point using IP routing. . Patent Document 2 discloses a private branch exchange apparatus having a port mirroring function.

JP 2004-248192 A JP 2010-183235 A

  As described in Patent Document 1, in general, in order to monitor an IP packet, it is necessary to connect a packet monitoring device to a device inside the IP network. However, in recent years, from the viewpoint of ensuring information security of the IP network, there are cases where it is restricted to connect network devices that are not normally used inside the IP network. In particular, when an IP leased line is used to ensure high security, the connection of the packet monitoring apparatus to devices inside the IP leased line network is often restricted.

  On the other hand, even if the connection of the packet monitoring device is permitted, the network device constituting the IP network does not necessarily have the port mirroring function. In addition, since a large number of network devices are connected to the VoIP network, there are cases where the network devices do not have available ports for outputting packets copied by the port mirroring function to an external packet monitoring device. In order to connect the packet monitoring device in such a case, it is necessary to newly connect a network device having a port mirroring function on the line. However, in order to connect a network device having a port mirroring function when there is no available port in the network device, it is necessary to temporarily disconnect the IP line in use, and packet communication is temporarily interrupted at that time There is a problem that it ends up.

  For this reason, in the VoIP system, there is a technology that enables monitoring of voice IP packets without disconnecting an IP line in use and without directly connecting an external device to a device in an IP network through which voice data passes. is necessary.

(Object of invention)
An object of the present invention is to provide a technique for enabling an IP packet transmitted in an IP network to be monitored without disconnecting a line and without connecting a device inside the IP network. .

  The signal conversion device of the present invention converts the input first signal into a packet signal and outputs the packet signal, and converts the packet signal into a second signal including the packet signal information. Second signal converting means for outputting.

  In the signal conversion method of the present invention, the input first signal is converted into a packet signal and output, and the packet signal is converted into a second signal including the packet signal information and output.

  The present invention makes it possible to monitor a packet transmitted through a packet network without disconnecting the line and without connecting a device inside the packet network.

It is a figure which shows the structure of the VoIP system of the 1st Embodiment of this invention. It is a figure which shows the operation | movement flow of the VoIP system of 1st Embodiment. It is a figure which shows the structure of the digital exchange used by the modification of 1st Embodiment. It is a figure which shows the structure of the VoIP system of the 2nd Embodiment of this invention. It is a figure which shows the structure of the signal converter of the 3rd Embodiment of this invention. It is a figure which shows the structure of the VoIP system relevant to this invention.

  Next, the best mode for carrying out the invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a VoIP system 1 according to the first embodiment of this invention. The VoIP system 1 includes analog switches 100 and 110, a VoIP network 200, a packet monitoring device 210, and a console device 220. The VoIP system 1 is a system that implements a call with the telephones 161 and 162 using the VoIP network 200.

  The analog switch 100 accommodates an analog telephone line and includes a voice IP module 101, a NIC 102, and a line switch unit 103. The circuit switching unit 103 connects the lines accommodated by the analog switch 100. The analog switch 100 also accommodates lines connected to the voice IP module 101 and the NIC 102, respectively.

  The voice IP module 101 is an interface for connecting the analog switch 100 and the VoIP network 200. The voice IP module 101 includes a packet converter 151 and a modem 104. The packet converting unit 151 converts the analog telephone signal output from the circuit switching unit 103 into an IP packet and outputs the IP packet to the VoIP network 200. Further, the packet conversion unit 151 converts a telephone signal that has been received as an IP packet from the VoIP network 200 into an analog telephone signal and outputs the analog telephone signal to the circuit switching unit 103. The analog switch 100 also has a function of controlling the circuit switching unit 103 by processing calls and calls of analog telephone lines. However, since the function of the call switching in the telephone switch is well known, the description is omitted. To do.

  The modem 104 converts the IP packet that the voice IP module 101 transmits / receives to / from the VoIP network 200 into an analog signal that is an interface of the circuit switching unit 103 and outputs the IP packet. The input of the modem 104 is branched from between the packet conversion unit 151 and the VoIP network 200. Therefore, the IP packet that the voice IP module 101 transmits / receives to / from the VoIP network 200 is copied and input to the modem 104 as it is. The modem 104 is, for example, a DSL (digital subscriber line) modem. However, the specification of the modem 104 is not limited to this.

  The voice IP module 101 may be operated by a console device 220 connected to the analog switch 100. The console device 220 controls each part of the analog switch 100 by the operation of the network administrator.

  On the other hand, the analog switch 110 includes a voice IP module 111 and a circuit switching unit 112. Analog switch 110 also accommodates a telephone line including telephone 162. The voice IP module 111 is an interface for connecting the analog switch 110 and the VoIP network 200. The voice IP module 111 converts the analog telephone signal output from the circuit switching unit 112 into an IP packet and outputs the IP packet to the VoIP network 200. Also, the voice IP module 111 converts the IP packetized telephone signal received from the VoIP network 200 into an analog telephone signal and outputs it to the circuit switching unit 112. The function of the circuit switching unit 112 is the same as that of the circuit switching unit 103 provided in the analog switch 100.

  The VoIP network 200 is an IP network that connects the voice IP modules 101 and 111.

  The NIC 102 is disposed between the circuit switching unit 103 and the packet monitoring device 210. That is, the NIC 102 is not directly connected to the VoIP network 200. The NIC 102 includes a modem 105 that demodulates an analog telephone signal received from the circuit switching unit 103. The modem 105 is a modem having the same specifications as the modem 104 of the voice IP module 101. The modem 105 demodulates the IP packet modulated by the modem 104 and outputs it to the packet monitoring device 210. The IP packet demodulated by the modem 105 is the same as the IP packet before being modulated by the modem 104.

  The packet monitoring device 210 connected to the NIC 102 has a function of analyzing an input IP packet, recording the content of the IP packet, and displaying it on a screen. The packet monitoring device 210 is used, for example, when monitoring an IP packet on an IP network and analyzing a failure.

  In FIG. 1, only one voice IP module 101 and NIC 102 are shown, but the number of voice IP modules 101 and NIC 102 connected to the analog switch 100 is not limited. For example, the network administrator may select one specific unit from the plurality of voice IP modules 101 and the NIC 102 using the console device 220. The circuit switching unit 103 may connect the circuit so that the IP packet is transferred from the selected voice IP module to the selected NIC. The voice IP module 101 performs call processing (dial-up) on the analog telephone line to the NIC 102 or the packet monitoring device 210 via the modem 104, so that the voice IP module 101 and the packet monitoring device 210 are connected. May be connected.

  By operating the circuit switching unit 103 by telephone line calling processing, it is possible to keep a record of the start and end times of packet monitoring and the telephone line used for monitoring. As a result, the presence or absence of an illegally connected monitoring device can be investigated based on the record.

  Each of these means operates as follows. The operation flow described below is an example, and other operations are not excluded from the embodiment.

  When a voice call using the VoIP network 200 is performed between the analog switch 100 and the analog switch 110, the IP switch is performed between the voice IP module 101 and the voice IP module 111 via the VoIP network 200. Transmitted voice packets are transmitted and received.

  The console device 220 generates setting information for the voice IP module 101 so that the copied IP packet is modulated by the modem 104 and the modulated signal is output to the NIC 102 via the circuit switching unit 103. . The NIC 102 demodulates the received signal by the modem 105 and reproduces the IP packet before being modulated by the modem 104.

  As a result, the NIC 102 can output to the packet monitoring device 210 an IP packet that the voice IP module 101 transmits / receives to / from the VoIP network 200. As a result, it is possible to monitor IP packets transmitted and received between the VoIP network 200 and the voice IP module 101 using the packet monitoring device 210. Hereinafter, the operation flow of the present embodiment will be described in more detail.

  FIG. 2 is a diagram illustrating an operation flow of the VoIP system 1 according to the first embodiment. First, the network administrator designates the voice IP module 101 that monitors the IP packet and the NIC 102 that is the transfer destination of the IP packet in the console device 220. The console device 220 creates setting information so that an IP packet passing through the voice IP module 101 designated by the network administrator is transferred to the NIC 102 (step S1 in FIG. 2). The setting information is transmitted from the console device 220 to each part of the analog switch 100 (S2).

  The voice IP module 101 copies the IP packet transmitted / received to / from the VoIP network 200 based on the setting information received from the console device 220 and modulates it by the modem 104 (S3). Then, the voice IP module 101 outputs the IP packet modulated by the modem 104 to the circuit switching unit 103 (S4).

  The circuit switching unit 103 connects the voice IP module 101 and the NIC 102 based on the setting information received from the console device 220 (S5). As a result, the modulation signal modulated by the modem 104 is received by the NIC 102 via the circuit switching unit 103 (S6). Note that the connection (S5) between the voice IP module 101 and the NIC 102 in the circuit switching unit 103 is performed by a calling process when the IP packet modulated by the voice IP module 101 is output to the circuit switching unit 103 (S4). It may be done.

  The NIC 102 demodulates the received modulation signal to reproduce the IP packet (S7), and outputs the IP packet to the port to which the packet monitoring device 210 is connected (S8).

  The packet monitoring device 210 receives the regenerated IP packet from the NIC 102 and analyzes it (S9). In this way, it becomes possible to monitor the IP packet transmitted / received in the voice IP module 101 by the packet monitoring device 210.

  As described above, in the VoIP system 1 of the first embodiment, the voice IP module 101 copies and modulates an IP packet transmitted over the VoIP network 200 and transfers it to the NIC 102. The NIC 102 demodulates the transferred signal and reproduces the IP packet. Here, the packet monitoring device 210 is connected to the outside of the VoIP network 200 and is not directly connected to the VoIP network 200.

  For this reason, in the VoIP system 1, it is not necessary to disconnect the IP packet transmission path transmitted between the voice IP modules 101 and 111 inside the VoIP network 200 in order to install the packet monitoring device 210. . In addition, it is not necessary to secure a port for connecting the packet monitoring device to devices constituting the VoIP network 200 in order to monitor IP packets.

  That is, the VoIP system of the first embodiment can monitor a packet transmitted through the packet network without disconnecting the line and without connecting a device inside the packet network.

  In the VoIP system 1, since the packet monitoring device is not directly connected to the VoIP network 200, there is no concern about a decrease in network security due to other devices connected to the VoIP network 200.

  In the VoIP system 1 of the first embodiment, the IP packet modulated by the modem 104 is transferred to the NIC 102 via the circuit switching unit 103 using the circuit switching function of the analog switch 100. Therefore, even if the NIC 102 and the packet monitoring device 210 are arranged under another switch that can be connected from the voice IP module 101, the packet modulated in the modem 104 can be transferred to the NIC and the packet monitoring device.

  Further, the voice IP module 101 may have a function of simply copying the IP packet generated by the packet conversion unit 151 into a signal of another format and outputting it to the outside of the analog switch 100. When a packet monitoring device having an IP interface can be used in the vicinity of the analog switch 100, the copied IP packet can be used as it is for monitoring by the packet monitoring device.

(Modification of the first embodiment)
Here, a modification of the first embodiment will be described. FIG. 3 is a diagram showing a configuration of a digital switch 120 used in place of the analog switch 100 in the first embodiment. The digital switch 120 shown in FIG. 3 includes a voice IP module 121, a NIC 122, and a digital circuit switch unit 123.

  The voice IP module 121 is an interface with the VoIP network 200 of the digital exchange 120. A digital voice signal input / output to / from the digital circuit switching unit 123 and an IP packet input / output from / to the VoIP network 200 are mutually converted.

  The voice IP module 121 includes a packet conversion unit 126. The packet conversion unit 126 converts the digital voice signal output from the digital circuit switching unit 123 into an IP packet and outputs the IP packet to the VoIP network 200. Furthermore, the voice IP module 121 and the NIC 122 include TAs (terminal adapters) 124 and 125. The TAs 124 and 125 encapsulate IP packets and convert them into signals that can be processed by the digital circuit switching unit 123. The TAs 124 and 125 may further have a function of a DSU (digital service unit).

  The digital line switching unit 123 has a digital line switching function. For example, the digital circuit switching unit 123 has an ISDN (Integrated Services Digital Network) circuit switching function. Then, the TA 124 copies an IP packet transmitted / received to / from the VoIP network 200 and converts it into a form that can be transmitted through the ISDN line. The TA 125 included in the NIC 122 restores the IP packet from the ISDN signal generated by the TA 124. The restored IP packet is input to the packet monitoring device 210 connected to the NIC 122.

  That is, in the configuration in which the digital circuit switching unit 123 has the function of an ISDN switch, the IP packet input / output to / from the packet conversion unit 126 is converted into an ISDN signal by the TA 124. The IP packet converted into the ISDN signal is received by the NIC 122 via the circuit switching unit 123. Then, the TA 125 included in the NIC 122 restores the IP packet from the received ISDN signal. Here, the digital circuit switching unit 123 connects the TA 124 and the TA 125 by dial-up processing of the ISDN signal.

  Even if the digital exchange 120 having such a configuration is applied to the VoIP system described with reference to FIG. 1, it is obvious that the same effects as those of the first embodiment can be obtained. That is, the VoIP system using the digital exchange 120 can monitor IP packets transmitted through the IP network without disconnecting the line and without connecting a device to the inside of the IP network. In the VoIP system using the digital exchange 120, there is no concern about a decrease in network security due to other devices connected to the VoIP network 200 when monitoring IP packets.

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 is a diagram showing a configuration of the VoIP system according to the second embodiment of this invention. Referring to FIG. 4, the VoIP system 2 according to the second embodiment includes a terminal 300 capable of VoIP communication, a packet monitoring device 310, a VoIP network 320, and a terminal 330.

  The terminal 300 includes a voice IP module 301 and a terminal function unit 302. The terminal function unit 302 realizes basic functions of the terminal 300 such as a telephone function. The voice IP module 301 is an interface between the terminal function unit 302 and the VoIP network 320. The terminal 330 is a partner terminal with which the terminal 300 communicates via the VoIP network 320.

  The terminal function unit 302 has an analog telephone function. By combining the terminal function unit 302 and the voice IP module 301 that converts an analog telephone signal into an IP packet, the terminal 300 can be configured as an IP telephone.

  The voice IP module 301 is an interface module for connecting the terminal function unit 302 to the VoIP network 320. The voice IP module 301 includes a packet conversion unit 303 and a signal conversion unit 304. The packet conversion unit 303 converts the analog telephone signal output from the terminal function unit 302 into an IP packet and outputs the IP packet to the VoIP network 320. Further, the packet conversion unit 303 converts the IP packetized telephone signal received from the VoIP network 320 into an analog telephone signal and outputs it to the terminal function unit 302.

  The input of the signal conversion unit 304 is branched from between the packet conversion unit 303 and the VoIP network 320. Therefore, the IP packet transmitted / received between the voice IP module 301 and the VoIP network 320 is directly copied and input to the signal conversion unit 304. The signal conversion unit 304 converts the IP packet transmitted / received by the voice IP module 301 into a signal of another form different from the IP packet, and outputs it from an interface different from the interface with the VoIP network 320. In the second embodiment, the signal conversion unit 304 converts the copied IP packet into a serial interface signal format. The IP packet converted into the signal format of the serial interface is output to the packet monitoring device 310 from an interface different from the interface with the VoIP network 320.

  The packet monitoring device 310 receives the IP packet converted into the serial interface signal from the voice IP module 301. The packet monitoring device 310 restores and analyzes the IP packet from the received serial interface signal. By providing such a configuration, the terminal 300 can monitor a packet that the terminal 300 transmits and receives in the voice IP module 301.

  In the VoIP system 2 of the second embodiment, the packet monitoring device 310 is connected to the outside of the VoIP network 320. For this reason, it is not necessary to disconnect the line between the terminal 300 and the terminal 330 when monitoring the IP packet. And in the VoIP system 2 of 2nd Embodiment, in order to monitor an IP packet, it is not necessary to provide the port for connecting a packet monitoring apparatus to the apparatus which comprises the VoIP network 320. FIG. Furthermore, in the VoIP system of the second embodiment, since the packet monitoring device 310 is not directly connected to the VoIP network 320 when monitoring IP packets, there is a security risk caused by connecting other devices to the VoIP network 320. Can be reduced.

  Then, the voice IP module 301 includes the signal conversion unit 304, so that the IP packet can be converted into another signal format and output. By combining the signal format that can be converted by the signal conversion unit 304 with the signal format that can be processed by a device (for example, a packet monitoring device) to which the converted signal is input, IP packets can be transferred to devices of various interfaces. Is possible.

  That is, the VoIP system according to the second embodiment also monitors packets transmitted through the packet network without disconnecting the line and without connecting a device inside the packet network, as in the first embodiment. Is possible.

  In the second embodiment, the configuration in which the signal conversion unit 304 converts the copied IP packet into a serial interface signal has been described. However, the signal format in which the IP packet is converted in the signal conversion unit 304 is not limited to the serial interface signal. For example, the voice IP module 301 and the VoIP network 320 may be connected by wire, and the signal conversion unit 304 and the packet monitoring device 310 may further include a wireless signal transmission / reception function. With the wireless signal transmission / reception function, the signal conversion unit 304 can transmit the copied IP packet to the packet monitoring apparatus 310 as a wireless signal.

  Note that the voice IP module 301 may have a function of copying the IP packet generated by the packet converter 303 without converting it into a signal of another format and outputting the signal to the outside of the terminal 300. If a packet monitoring device having an IP interface is available in the vicinity of the terminal 300, the copied IP packet can be used as it is and monitored by the packet monitoring device.

  In the second embodiment, the terminal 300 has the function of an IP telephone. However, the function of the terminal 300 is not limited to the IP telephone. For example, the terminal 300 can be applied to an IP voice gateway. An IP voice gateway is a device that relays between a telephone network and an IP network in a VoIP system. By configuring the IP voice gateway to include the voice IP module 301 described above, IP packets transmitted and received between the VoIP network and the telephone network can be monitored in the IP voice gateway.

(Third embodiment)
Subsequently, a third embodiment of the present invention will be described. FIG. 5 is a diagram showing a configuration of a signal conversion apparatus 500 according to the third embodiment of the present invention. The signal conversion apparatus 500 includes a first signal conversion unit 501 and a second signal conversion unit 502. The first signal converter converts the input first signal into a packet signal and outputs the packet signal. The second signal conversion unit converts the packet signal output from the first signal conversion unit into a second signal and outputs the second signal. Here, the signal converted by the second signal converter includes all the information of the packet signal output from the first signal converter. That is, it is assumed that the packet signal output from the first signal converter can be restored by performing the reverse process of the process in the second signal converter on the second signal.

  The signal conversion device 500 outputs the packet signal output from the first signal conversion unit, and the packet signal is also output in a form converted to the second signal. The packet signal is transmitted to the original communication destination via the packet signal network.

  On the other hand, the signal conversion apparatus 500 can transfer the packet signal to another communication destination by using the second signal without going through the packet signal network. Therefore, the second signal is transferred to another communication destination on another network by setting the signal format of the second signal to a format suitable for the network between the signal conversion apparatus 500 and another communication destination. be able to.

  For example, when it is desired to monitor a packet using a packet monitoring device connected to the signal conversion device 500 via an analog telephone network, a modem may be used as the second signal conversion unit. By modulating a packet signal using a modem and transmitting it as an analog signal over an analog telephone network and demodulating the packet signal with a packet monitoring device, the packet signal can be monitored with a remote packet monitoring device.

  At this time, it is not necessary to disconnect the packet signal from the original communication destination in order to connect the packet monitoring device. Further, it is not necessary to provide a port for connecting the packet monitoring device to a device between the signal conversion device 500 and the original communication destination of the packet signal.

  Further, when monitoring a packet output from the signal conversion device 500, it is not necessary to connect the packet monitoring device directly to the network between the signal conversion device 500 and the original communication destination of the packet signal. Therefore, when the signal conversion apparatus 500 monitors a packet, there is no fear of a decrease in network security due to connection of another device on a communication path with the original communication destination.

  As described above, the signal conversion apparatus according to the third embodiment can realize a system for monitoring packets transmitted through the packet network without disconnecting the line and without connecting a device to the inside of the packet network. And

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

1, 400 VoIP system 100, 110 Analog switch 101, 111, 121, 301, 409, 410 Voice IP module 102, 122 NIC
103, 112 Circuit switching unit 104, 105 Modem 120 Digital switching system 123 Digital circuit switching unit 124, 125 TA
126, 151, 303 Packet conversion unit 210, 310 Packet monitoring device 220 Console device 300, 330 Terminal 302 Terminal function unit 304 Signal conversion unit 161, 162, 401, 402 Telephone 403, 404 Switch 200, 320, 405 VoIP network 406, 407 LAN
408 WAN
500 Signal converter 501 First signal converter 502 Second signal converter

Claims (5)

A packet conversion means for converting the input first signal into an IP (Internet protocol) packet signal and outputting the signal to the external network ;
The signal conversion means for converting the IP packet signal into a second signal including information of the IP packet signal and outputting the second signal;
Packet restoration means for restoring the IP packet signal from the second signal and outputting the restored IP packet signal;
A circuit switching means for transferring an input signal as the first signal to the packet conversion means and transferring the second signal input from the signal conversion means to the packet restoration means;
An exchange equipped with . The input signal and the first signal are analog telephone signals transmitted over an analog telephone line ;
The signal conversion means is a modem that converts the IP packet signal into a signal that can be transmitted through the analog telephone line ;
The circuit switching means is a switching circuit of the analog telephone line;
The exchange according to claim 1. 3. The exchange according to claim 2, wherein the modem is a DSL (digital subscriber line) modem. The first signal is a signal transmitted through an ISDN (integrated services digital network) line,
The signal conversion means is a TA (terminal adapter) that converts the IP packet signal into a signal that can be transmitted through the ISDN line .
The circuit switching means is a switching circuit for the ISDN circuit;
The exchange according to claim 1 . The circuit switching means transfers the input signal as the first signal to the packet conversion means,
The packet conversion unit converts the first signal into an IP (Internet protocol) packet signal and outputs the packet signal to the signal conversion unit and an external network.
The signal converting means converts the IP packet signal into a second signal including the information of the IP packet signal and outputs the second signal,
The circuit switching means transfers the second signal to the packet restoration means,
The packet restoration means restores the IP packet signal from the second signal,
Outputting the restored IP packet signal;
How to control the exchange.

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