Network determination apparatus, network determination method, network determination program, and connection network information providing system

Abstract

To determine a network to which a telephone terminal on a called side is connected after transition from an interconnection system via a public switched telephone network (PSTN) to an interconnection system of IP-IP connection.SOLUTION: A type of a network to which a telephone terminal is connected is determined based on a combination of a code of a response in a response message to an INVITE request including an SDP parameter for an NGN network, a code of a response in a response message to an INVITE request including an SDP parameter for a fixed telephone network, and tag information before being converted by a home gateway 51 to which a network determination device 10 is connected.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a technique for determining a network to which a telephone terminal on the incoming call side is connected.

Background Art

[0002] As a conventional technique for determining telephone number information of a telephone terminal on the incoming call side, there is a telephone number information determination device using a computer server connected to a plurality of terminals via the Internet network, which includes a database for storing usage history information of a plurality of telephone numbers, a search information reception means for receiving authentication information from a terminal and receiving a telephone number as search information from the terminal on condition that an authentication means permits login, a database is searched using the telephone number received by the search information reception means, and it is analyzed whether there are a plurality of histories of transition from the subscribed state to the missing number state in the telephone number history information or a missing number change in the field of the telephone number, and / or it is analyzed whether there are a plurality of histories of transition from the missing number state to the subscribed state in the telephone number history information or a valid change in the field of the telephone number, and the unaccumulated history of the telephone number history information, the latest investigation record of the telephone number history information is a missing number history, the investigation record one before the latest investigation record is a missing number history, and a plurality of call stop histories existing in the telephone number history information are referred to, and history determination information for determining a predetermined subscriber number for the telephone number of the search information is generated, and a system control means for displaying this history determination information to the terminal via the Internet network is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in PSTN migration (PSTN: Public Switched Telephone Networks), the interconnection method between the originating IMS network (IMS: IP Multimedia Subsystem) and the terminating IMS network switches from the interconnection method via the public switched telephone network (PSTN) to the IP-IP connection (IP: Internet Protocol) interconnection method.

[0005] Here, there is a transition period for the switch from the interconnection method via the public switched telephone network (PSTN) to the IP-IP connection interconnection method. Therefore, for example, in order to accurately grasp the usage status of the telephone numbers of the telephone terminals connected to the terminating IMS network, especially during the transition period, it is necessary to determine for each terminating fixed IMS network and terminating mobile IMS network whether the IP-IP connection between the originating fixed IMS network and the terminating fixed IMS network or the terminating mobile IMS network has started (in other words, whether the interconnection method has switched to the IP-IP connection interconnection method).

[0006] In addition, with the migration from the public switched telephone network (PSTN) to the NGN (Next Generation Network), the inter-carrier interconnection interface changes from the common line signaling system SS7 (Signaling System No. 7) to the IP-based SIP (Session Initiation Protocol). Therefore, specific SIP messages from the originating terminal will reach the IMS network, NGN network, and VoIP network (VoIP: Voice over Internet Protocol).

[0007] Note that IMS is a standard for realizing IP-based and integrated multimedia services such as services that have been provided in fixed networks and mobile communications. Mobile communication systems and NGNs are systems built in accordance with this standard.

[0008] Furthermore, the method of establishing communication between the transmitting terminal / device and the receiving terminal / device differs depending on the type of communication network to which the receiving terminal / device is connected. Therefore, if it is possible to pre-determine the type of communication network to which a terminal / device with a certain telephone number is connected, it will be useful information, for example, when conducting an investigation on the usage status of a telephone number of a telephone terminal.

[0009] Therefore, in one aspect, an object of the present invention is to provide a technology capable of determining the network to which a receiving telephone terminal is connected after the transition from the interconnection method via a public switched telephone network (PSTN) to the IP-IP connection interconnection method.

Means for Solving the Problems

[0010] In order to solve the above problems, a network determination device according to the present invention is a network determination device connected to at least one of a telephone terminal connected to a home fixed IMS network and a telephone terminal connected to a visited IMS network via the home fixed IMS network, and includes a message exchange control unit that attaches SDP parameters to an INVITE request for a telephone terminal to be investigated, transmits the INVITE request to the home fixed IMS network, and receives a response message via the home fixed IMS network, and a connection network determination unit that determines the network to which the telephone terminal to be investigated is connected according to the response message. The message exchange control unit transmits an INVITE request including SDP parameters for an NGN network in which the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law, and then transmits an INVITE request including SDP parameters for a fixed telephone network in which the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722. The connection network determination unit determines the network to which the telephone terminal is connected based on a combination of the response code in the response message for the INVITE request including the SDP parameters for the NGN network, the response code in the response message for the INVITE request including the SDP parameters for the fixed telephone network, and the tag information before conversion by the home gateway to which the network determination device is connected.

[0011] In the network determination device according to the present invention, the connection network determination unit may determine that the telephone terminal to be investigated is connected to a metal housing device when the response message for the INVITE request including the SDP parameters for the NGN network has a code 488 Not Acceptable Here and a warn-code of 302 and the tag information is a to-tag value related to the metal housing device.

[0012] In the network determination device according to the present invention, when the response message for the INVITE request including the SDP parameter for the NGN network has a code 488 Not Acceptable Here, a warn-code of 300, 304, or 305, and the tag information is a to-tag value related to the originating fixed IMS network, and further, when the response message for the INVITE request including the SDP parameter for the fixed telephone network is a code 180 Ringing response and the tag information is a to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it may be determined that the telephone terminal under investigation is connected to the VoIP network.

[0013] In the network determination device according to the present invention, when the response message for the INVITE request including the SDP parameter for the NGN network has a code 488 Not Acceptable Here and the warn-code is any one of 300, 304, and 305 and the tag information is not a to-tag value related to the originating fixed IMS network, or when the response message for the INVITE request including the SDP parameter for the fixed telephone network is a code 180 Ringing response and the tag information is not a to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it may be determined that the telephone terminal under investigation is connected to the NGN network.

[0014] In addition, the network determination method according to the present invention is a network determination method for determining the network to which a telephone terminal to be investigated is connected, using at least one of a telephone terminal connected to the originating fixed IMS network and a telephone terminal connected to the terminating IMS network, via the originating fixed IMS network. The apparatus includes: a step of attaching SDP parameters to an INVITE request for the telephone terminal to be investigated and transmitting the INVITE request to the originating fixed IMS network; a step of receiving a response message via the originating fixed IMS network; and a step of determining the network to which the telephone terminal to be investigated is connected according to the response message. As the step of transmitting the INVITE request, an INVITE request including SDP parameters for an NGN network, where the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law, is transmitted. Next, an INVITE request including SDP parameters for a fixed telephone network, where the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722, is transmitted. In the step of determining the network, the network to which the telephone terminal is connected may be determined based on a combination of the response code in the response message for the INVITE request including the SDP parameters for the NGN network, the response code in the response message for the INVITE request including the SDP parameters for the fixed telephone network, and the tag information before being converted by the home gateway to which the apparatus is connected.

[0015] In the step of determining the network, the network determination method according to the present invention may be configured to determine that the telephone terminal under investigation is connected to a metal housing device when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here, the warn-code is 302, and the tag information is the to-tag value related to the metal housing device.

[0016] In the step of determining the network, the network determination method according to the present invention may be configured to determine that the telephone terminal under investigation is connected to a VoIP network when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here, the warn-code is 300, 304, or 305, the tag information is the to-tag value related to the originating fixed IMS network, and further, the response message to the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is the to-tag value related to the terminating fixed VoIP network as the terminating IMS network.

[0017] In the step of determining the network, the network determination method according to the present invention may be configured to determine that the telephone terminal under investigation is connected to the NGN network when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here, the warn-code is any one of 300, 304, and 305, and the tag information is not the to-tag value related to the originating fixed IMS network, or when the response message to the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is not the to-tag value related to the terminating fixed VoIP network as the terminating IMS network.

[0018] In addition, the network determination program according to the present invention causes a computer connected to at least one of a telephone terminal connected to the originating fixed IMS network and a telephone terminal connected to the terminating IMS network via the originating fixed IMS network to perform at least a process of attaching SDP parameters to an INVITE request for a telephone terminal to be investigated and transmitting the INVITE request to the originating fixed IMS network, a process of receiving a response message via the originating fixed IMS network, and a process of determining the network to which the telephone terminal to be investigated is connected according to the response message. In the process of transmitting the INVITE request, an INVITE request including SDP parameters for the NGN network, in which the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law, is transmitted. Next, an INVITE request including SDP parameters for the fixed telephone network, in which the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722, is transmitted. In the process of determining the network, the network to which the telephone terminal is connected is determined based on the combination of the response code in the response message for the INVITE request including the SDP parameters for the NGN network, the response code in the response message for the INVITE request including the SDP parameters for the fixed telephone network, and the tag information before being converted by the home gateway to which the computer is connected.

[0019] In the step of determining the network, the network determination program according to the present invention may be configured to determine that the telephone terminal under investigation is connected to the metal housing device when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here, the warn-code is 302, and the tag information is the to-tag value related to the metal housing device.

[0020] In the step of determining the network, the network determination program according to the present invention may be configured to determine that the telephone terminal under investigation is connected to the VoIP network when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here, the warn-code is 300, 304, or 305, the tag information is the to-tag value related to the originating fixed IMS network, and further, the response message to the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is the to-tag value related to the terminating fixed VoIP network as the terminating IMS network.

[0021] In the step of determining the network, the network determination program according to the present invention may be configured to determine that the telephone terminal under investigation is connected to the NGN network when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here, the warn-code is any one of 300, 304, and 305, and the tag information is not the to-tag value related to the originating fixed IMS network, or when the response message to the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is not the to-tag value related to the terminating fixed VoIP network as the terminating IMS network.

[0022] In addition, the connection network information providing system according to the present invention includes the network determination device described above and a user terminal. When the network determination device receives a connection network information providing request for a telephone terminal from the user terminal, the network determination device includes a network interface unit that transmits, via an IP network, the connection network of the telephone terminal determined by the connection network determination unit to the user terminal that has made the connection network information providing request. This may be done.

Advantages of the Invention

[0023] According to the present invention, on one aspect, after the transition from the interconnection method via the public switched telephone network (PSTN) to the interconnection method of IP-IP connection, it becomes possible to determine the network to which the incoming telephone terminal is connected.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0026] (Network connection form) FIG. 1 is a schematic diagram showing a network connection form of a network determination device 10 according to an embodiment as an example of a specific configuration mode of the network determination device according to the present invention.

[0027] The network determination device 10 is a device that functions as a fixed-type telephone terminal (specifically, an IP telephone terminal), and is connected to the originating fixed IMS network 20 via a home gateway (HGW: Home GateWay) 51 and an optical line termination device (ONU: Optical Netowork Unit) 52. Specifically, the home gateway 51 is arranged on the side of the network determination device 10, and the optical line termination device 52 is arranged on the side of the originating fixed IMS network 20.

[0028] The originating fixed IMS network 20 is an NGN network. The originating fixed IMS network 20 includes an SIP server 21, and the operation of the originating fixed IMS network 20 is managed and controlled by the SIP server 21.

[0029] Between the network determination device 10 and the home gateway 51, and between the home gateway 51 and the optical line termination device 52, UNI (User Network Interface) connections are respectively ensured. The UNI connection between the home gateway 51 and the optical line termination device 52 is referred to as "UNI-1", and the UNI connection between the network determination device 10 and the home gateway 51 is referred to as "UNI-2".

[0030] Between the network determination device 10 and the originating fixed IMS network 20 with the home gateway 51 and the optical line termination device 52 intervening, according to the SIP signal method (in other words, the SIP protocol), a specific SIP message (details will be described later) transmitted from the network determination device 10 is transmitted to the originating fixed IMS network 20.

[0031] The network determination device 10 dials the telephone number of the telephone terminal on the receiving side as the telephone number of the telephone terminal connected to the IMS network on the receiving side. In other words, the network determination device 10 communicates with (or attempts to establish communication with) the telephone terminal connected to the IMS network on the receiving side.

[0032] Specifically, the IMS network on the receiving side is a fixed IMS network to which a fixed telephone terminal is connected and a mobile IMS network to which a mobile telephone terminal (e.g., a mobile phone) is connected. In the description of the present invention, these fixed IMS network and mobile IMS network on the receiving side are collectively referred to as the "IMS network on the receiving side" (note that the reference numeral is 30).

[0033] The IMS network 30 on the receiving side includes an SIP server 31, and the operation of the IMS network 30 on the receiving side is managed and controlled by the SIP server 31. In the example shown in FIG. 1, only one IMS network 30 on the receiving side is illustrated, but in reality, the IMS network 30 on the receiving side is constructed for each communication carrier (i.e., a plurality of networks are constructed), and telephone terminals are connected to each network (specifically, for each fixed IMS network or mobile IMS network on the receiving side; in other words, for each contracting carrier) via the SIP server 31 that each manages and operates.

[0034] The originating fixed IMS network 20 and the receiving IMS network 30 (specifically, the fixed IMS network and the mobile IMS network) are constructed for each communication carrier (i.e., a plurality of networks are constructed), and the connection between the originating fixed IMS network 20 and the receiving IMS network 30 is an IMS interconnection between carriers.

[0035] During the transition period from the interconnection method via the public switched telephone network (PSTN) to the IP-IP connection interconnection method for the communication mode (in other words, the communication specification) between the network determination device 10 and the IMS network 30 on the receiving side, for the inter-carrier interconnection interface, two types, the existing common line signaling system SS7 (Signaling System No. 7) and the newly established IP-based SIP, coexist simultaneously.

[0036] Specifically, for a communication path where the inter-carrier interconnection interface is SS7 of the common line signal system, the originating fixed IMS network 20 and the terminating IMS network 30 are connected via the public switched telephone network (PSTN) 40. This corresponds to a state where the inter-carrier IMS interconnection between the communication carrier of the originating fixed IMS network 20 and the communication carrier of the terminating IMS network 30 has not yet switched to the IP-IP connection interconnection method and remains in the interconnection method via the public switched telephone network.

[0037] The originating fixed IMS network 20 and the public switched telephone network 40 are interconnected with each other in the ISUP signal system of SS7 (ISUP: Integrated Services for digital network User Part) via the public switched telephone network gateway (PSTN-GW) 22 on the originating fixed IMS network 20 side and the public switched telephone network gateway (PSTN-GW) 41 on the public switched telephone network 40 side.

[0038] The public switched telephone network 40 and the terminating IMS network 30 are interconnected with each other in the ISUP signal system of SS7 via the gateway (GW) 42 on the public switched telephone network 40 side and the gateway (GW) 32 on the terminating IMS network 30 side.

[0039] The gateway 42 on the public switched telephone network 40 side and the gateway 32 on the terminating IMS network 30 side are interconnected with each other via the STM-POI (Synchronous Transfer Mode-Point Of Interface) 43 which is an interconnection point for connecting these line networks.

[0040] On the other hand, for a communication path where the inter-carrier interconnection interface is SIP of the IP system, the originating fixed IMS network 20 and the terminating IMS network 30 are directly connected. This corresponds to a state where the inter-carrier IMS interconnection between the communication carrier of the originating fixed IMS network 20 and the communication carrier of the terminating IMS network 30 has already switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method.

[0041] The originating fixed IMS network 20 and the terminating IMS network 30 are specifically interconnected in an IP-based SIP signaling manner via the IBCF (Inter-connection Border Control Function) 23 on the originating fixed IMS network 20 side and the IBCF 33 on the terminating IMS network 30 side.

[0042] The IBCF 23 on the originating fixed IMS network 20 side and the IBCF 33 on the terminating IMS network 30 side are interconnected via an IP-POI (Internet Protocol-Point Of Interface) 34 which is an interconnection point for connecting these line networks to each other.

[0043] And during the transition period from the interconnection method via the public switched telephone network (PSTN) to the IP-IP connection interconnection method, the STM-POI 43 and the IP-POI 34 exist simultaneously as interconnection points for connecting the line networks to each other. The STM-POI 43 corresponds to the SS7 ISUP signaling method, and the IP-POI 34 corresponds to the IP-based SIP signaling method.

[0044] In the interconnection method via the public switched telephone network (PSTN), the IP-based SIP signal called from the originating device (here, the network determination device 10) is converted to an SS7 ISUP signal when passing from the originating fixed IMS network 20 through the public switched telephone network 40. As a result, the SS7 ISUP signal is transmitted between the public switched telephone network 40 and the terminating IMS network 30, and is interworked to an ISDN signal (ISDN: Integrated Services Digital Network) in the terminating IMS network 30. The originating call is specifically a dial call of a telephone number.

[0045] On the other hand, in the IP-IP connection interconnection method, when an IP-based SIP signal is called from the originating device (here, the network determination device 10), the IP-based SIP signal is directly transmitted between the originating fixed IMS network 20 and the terminating IMS network 30, and is also processed as an SIP signal in the terminating IMS network 30.

[0046] (tag information) An information acquisition device 60 is disposed between a home gateway 51 arranged on the side of the network determination device 10 (in other words, to which the network determination device 10 is connected) and an optical line termination device 52 arranged on the side of the originating fixed IMS network 20 (that is, UNI connection: UNI-1).

[0047] The information acquisition device 60 is connected to the line between the home gateway 51 and the optical line termination device 52 (that is, UNI connection: UNI-1), and acquires (in other words, captures) the content of the IP-based SIP signal (specifically, the information of the packet) transmitted between the home gateway 51 and the optical line termination device 52.

[0048] The information of the packet (in other words, the return value; still, it is a SIP signal) transmitted from the destination IMS network 30 side when an IP-based SIP signal is originated from the originating device (here, the network determination device 10), which is acquired by the information acquisition device 60 additionally disposed between the home gateway 51 and the optical line termination device 52 (that is, UNI connection: UNI-1), is the information of the packet not converted by the home gateway 51. That is, the information acquisition device 60 can acquire the information related to the destination IMS network 30 before being converted by the home gateway 51.

[0049] Note that the information of the packet (return value; still, it is a SIP signal) transmitted between the network determination device 10 and the home gateway 51 (that is, UNI connection: UNI-2) when an IP-based SIP signal is originated from the originating device (here, the network determination device 10) and transmitted from the destination IMS network 30 side is the information of the packet converted by the home gateway 51. Therefore, the information related to the destination IMS network 30 cannot be acquired between the network determination device 10 and the home gateway 51.

[0050] FIG. 2 is an example of packet information (return value; note that it is an SIP signal) transmitted from the IMS network 30 side on the receiving side when an IP-based SIP signal is originated from a transmitting device (here, the network determination device 10) and transmitted between the home gateway 51 and the optical line termination device 52. Note that "example3" and "example4" in FIG. 2 correspond to the names of communication carriers (using virtual communication carrier names).

[0051] The part of frame 2a in FIG. 2 (specifically, "SIP from tag:...") represents the information of the transmitting home gateway 51.

[0052] The part of frame 2b in FIG. 2 (specifically, "SIP to tag:...") represents the information of the public switched telephone network gateway 22 or IBCF23 on the transmitting fixed IMS network 20 side.

[0053] In the content of the IP-based SIP signal (specifically, packet information) transmitted between the home gateway 51 and the optical line termination device 52, "SIP from tag:..." and "SIP to tag:..." are referred to as "tag information".

[0054] Tag information in SIP is information for identifying a call session, which is a series of signals exchanged between the transmitting side and the receiving side. Tag information is always generated by the user agents on the transmitting side (From) and the receiving side (To), and its value is unique in a global environment and is generated by an algorithm unique to each user agent.

[0055] Here, as shown in FIG. 3, when the inter-carrier IMS interconnection between the carrier of the originating fixed IMS network 20 and the carrier of the terminating IMS network 30 has not yet switched to the IP-IP connection interconnection method and remains in the interconnection method via the public switched telephone network, the tag information obtained from the content of the IP-based SIP signal transmitted from the terminating IMS network 30 side when an IP-based SIP signal is originated from the originating device (here, the network determination device 10) transmitted between the home gateway 51 and the optical line termination device 52 (i.e., UNI connection: UNI-1) (note that this is the information of the packet not converted by the home gateway 51), the information of the originating home gateway 51 is obtained as the value of "SIP from tag:", and the information of the public switched telephone network gateway 22 on the originating fixed IMS network 20 side is obtained as the value of "SIP to tag:".

[0056] Also, as shown in FIG. 4, when the inter-carrier IMS interconnection between the carrier of the originating fixed IMS network 20 and the carrier of the terminating IMS network 30 has already switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method, the tag information obtained from the content of the IP-based SIP signal transmitted from the terminating IMS network 30 side when an IP-based SIP signal is originated from the originating device (here, the network determination device 10) transmitted between the home gateway 51 and the optical line termination device 52 (i.e., UNI connection: UNI-1) (note that this is the information of the packet not converted by the home gateway 51), the information of the originating home gateway 51 is obtained as the value of "SIP from tag:", and the information of the IBCF 23 on the originating fixed IMS network 20 side is obtained as the value of "SIP to tag:".

[0057] When the destination IMS network 30 is either a destination fixed IMS network or a destination mobile IMS network, and the inter-carrier IMS interconnection between the carrier of the source fixed IMS network 20 and the carrier of the destination IMS network 30 has not yet switched to the IP-IP connection interconnection method and remains in the interconnection method via the public switched telephone network, the value of "SIP to tag:" is composed of a string of only numbers.

[0058] For example, in the example shown in FIG. 2, like the part of frame 2b, the value following "SIP to tag:" is composed of a string of only numbers such as "999486462". In this case, it is determined that the inter-carrier IMS interconnection between the carrier of the source fixed IMS network 20 and the carrier of the destination IMS network 30 has not yet switched to the IP-IP connection interconnection method and remains in the interconnection method via the public switched telephone network.

[0059] On the other hand, when the destination IMS network 30 is either a destination fixed IMS network or a destination mobile IMS network, and the inter-carrier IMS interconnection between the carrier of the source fixed IMS network 20 and the carrier of the destination IMS network 30 has already switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method, the value of "SIP to tag:" is composed of a string starting with a prefix such as two alphabetic characters.

[0060] In the example shown in FIG. 2, for the part of frame 2b, when the value following "SIP to tag:" is composed of a string starting with a prefix of two alphabetic characters such as "gK" like "gK04c0b838", it is determined that the inter-carrier IMS interconnection between the carrier of the source fixed IMS network 20 and the carrier of the destination IMS network 30 has already switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method.

[0061] In addition, when the IMS interconnection between operators has already switched to the IP-IP connection interconnection method, the feature of the value following "SIP to tag:" is not limited to the mode starting with a two-letter alphabet prefix. When the value following "SIP to tag:" is not a string of only numbers, for example, when it includes characters other than numbers such as alphabets or symbols, it is determined that the IMS interconnection between operators has already switched to the IP-IP connection interconnection method.

[0062] (Determination of connection method) When determining the type of network to which the incoming telephone terminal (specifically, a fixed telephone terminal) is connected, first, the network determination device 10 makes an IP-based SIP call to the telephone number under investigation via the originating fixed IMS network 20.

[0063] Next, the information acquisition device 60 acquires (in other words, captures) the content of the IP-based SIP signal transmitted from the terminating IMS network 30 side (that is, the session; specifically, the packet information) when an IP-based SIP signal is called from the originating device (here, the network determination device 10) and transmitted between the home gateway 51 and the optical line termination device 52 (that is, UNI connection: UNI-1).

[0064] The information acquisition device 60 acquires at least the value following "SIP to tag:" in the tag information.

[0065] Then, when the value following "SIP to tag:" has a predetermined feature (for example, a string starting with a two-letter alphabet prefix, or a string including characters other than numbers or symbols, etc.), the information acquisition device 60 determines that the IMS interconnection between operators has switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method.

[0066] The information acquisition device 60 may also make a plurality of calls to a certain telephone number of the investigation target in chronological order, and for each call, obtain the content of the IP-based SIP signal transmitted between the home gateway 51 and the optical line termination device 52 (i.e., UNI connection: UNI-1) (at least the value following "SIP to tag:" in the tag information), and compare the values following "SIP to tag:" in chronological order. Then, when the value following "SIP to tag:" changes, it may be determined that the inter-carrier IMS interconnection has switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method.

[0067] Also, when the inter-carrier IMS interconnection has switched from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method, since the value of "SIP to tag:" is uniquely generated by the unique algorithm of each user agent as described above, when the receiving-side terminals and devices are connected to the same network, they have similar characteristics (for example, a string starting with a two-letter alphabet prefix, or a string containing non-numeric characters or symbols, etc.). Therefore, when the characteristics of the values of "SIP to tag:" are the same for a plurality of telephone numbers, it can be said that the connection modes (for example, the networks to which the receiving-side terminals and devices are connected) of the receiving-side terminals and devices related to these plurality of telephone numbers are the same.

[0068] On the other hand, when the characteristics of the values of "SIP to tag:" are different from each other for a plurality of telephone numbers, it can be said that the connection modes of the receiving-side terminals and devices related to these plurality of telephone numbers are different from each other, and by extension, the contract carriers of the receiving-side terminals and devices are different from each other.

[0069] (Connection mode of the receiving-side device) Regarding the "0ABJ number," which is the phone number of a fixed telephone terminal, when the inter-carrier IMS interconnection switches from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method due to the number portability (LNP) of fixed telephones, it is unclear which of the originating fixed IMS network 20, NGN network 30A, VoIP network 30B, and metal housing device 70 the fixed telephone terminal with this phone number is connected to (see Figure 5). In the example shown in Figure 5, only one IBCF23 on the originating fixed IMS network 20 side is illustrated, but there may be multiple IBCF23s on the originating fixed IMS network 20 side.

[0070] Here, in SIP, in order to perform real-time communication, it is necessary to negotiate between terminals regarding the encoding method of packets containing media information and addresses such as the destinations of the packets. For this negotiation, a description language called SDP (Session Description Protocol) is required, which is defined in TTC standard RFC4566 (TTC: Telecommunication Technology Committee; Information and Communication Technology Committee, Incorporated Association).

[0071] Specifically, in order to establish a session in SIP, first, the originating side sends a request with media information described in the SIP message, and the receiving side returns a response selecting the media that can be supported from among them, thereby sharing the media information to be used for communication between the originating side and the receiving side.

[0072] Describing and sending media information in the SIP message to start a session is called an offer, and returning the corresponding media information in response is called an answer. This offer / answer model is defined in TTC standard RFC3264. Furthermore, the SDP media negotiation procedure in IMS is specified in TTC standard JJ-90.26.

[0073] When the network determination device 10 transmits an SDP offer of the INVITE (invitation) method (referred to as an "INVITE request") to a fixed telephone terminal via the originating fixed IMS network 20, it describes and transmits predetermined SDP parameters in the SDP parameters.

[0074] The SDP parameters included in the INVITE request when transmitting the INVITE request are the network protocol (in other words, the Internet protocol, IP version), media type, transport protocol of the media, and audio codec.

[0075] For the INVITE request, devices related to the establishment of communication between the originating side and the receiving side compare the SDP parameters included in the INVITE request with the SDP parameters that they can use, and according to the result of the comparison (that is, the matching / mismatching situation of the SDP parameters), return a response of a predetermined code in the SIP session as a response message. The basic sequence of operations involving the originating device and the fixed telephone terminal on the receiving side by the INVITE method in IMS interconnection is defined in, for example, TTC standard JJ-90.30, TTC standard JJ-90.26, and TTC standard TR-1088.

[0076] And the content of the SDP parameters differs depending on whether the fixed telephone terminal on the receiving side is connected to any of the originating fixed IMS network 20, NGN network 30A, VoIP network 30B, and metal housing device 70. Therefore, if it is determined in advance to which of the originating fixed IMS network 20, NGN network 30A, VoIP network 30B, and metal housing device 70 a fixed telephone terminal with a certain telephone number is connected, it becomes useful information, for example, when conducting an investigation on the usage status of the telephone number of the fixed telephone terminal.

[0077] Note that the NGN network 30A and the VoIP network 30B are receiving fixed IMS networks in which the IMS interconnection between carriers has switched to an IP-IP connection interconnection method.

[0078] A UNI connection is ensured between the network determination device 10 and the originating fixed IMS network 20. And between the network determination device 10 and the originating fixed IMS network 20, in accordance with the SIP signaling method (that is, the SIP protocol), a specific SIP message (details will be described later) transmitted from the network determination device 10 is sent to the originating fixed IMS network 20.

[0079] The originating fixed IMS network 20 (which is an NGN network) and the NGN network 30A are interconnected by an NNI (Network-Network Interface), which is a mutual connection common interface between IMS operators by IP-IP connection. The NNI between the originating fixed IMS network 20 and the NGN network 30A is compatible with IPv6 for the network protocol (that is, the Internet protocol, IP version) of the SDP parameter of SIP. Note that the NNI is defined in TTC standard JJ-90.30.

[0080] The originating fixed IMS network 20 and the VoIP network 30B are interconnected by an NNI (Network-Network Interface), which is a mutual connection common interface between IMS operators by IP-IP connection. The NNI between the originating fixed IMS network 20 and the VoIP network 30B is compatible with IPv4 for the network protocol (that is, the Internet protocol, IP version) of the SDP parameter of SIP. One of the key points of the present invention is to utilize the fact that it is compatible with IPv4 but not with IPv6 to perform network determination of the terminating fixed IMS network (that is, to pre-determine which of the originating fixed IMS network 20, NGN network 30A, VoIP network 30B, and the metal housing device 70 a fixed-type telephone terminal of a certain telephone number is connected to).

[0081] In addition, the metal housing device 70 connected to the originating fixed IMS network 20 is a subscriber switch related to a landline phone connected to an existing metal cable. That is, the metal IP phone terminal connected to the metal housing device 70 is a phone terminal that continues to use the existing metal cable even after the inter-IMS connection between carriers has shifted from the interconnection method via the public switched telephone network to the IP-IP connection interconnection method, and is provided as a receiver for the landline phone connected to the existing metal cable. And together with the existing metal cable, the subscriber switch continues to be used as a metal housing device.

[0082] A connection is ensured between the originating fixed IMS network 20 and the metal housing device 70 by the ISUP (Integrated Services for digital network User Part) signaling method. Regarding the ISUP protocol, the technical specifications for SIP-TTC ISUP signaling method interconnection are defined in TTC standard JFIETF-RFC3398. Also, the technical information regarding the encapsulation of ISUP information is defined in TTC specification TS-1025.

[0083] (Network determination device) FIG. 6 is a block diagram showing the configuration of the network determination device 10 according to the embodiment.

[0084] The network determination device 10 includes a network interface unit 11, a message exchange control unit 12, a connection network determination unit 13, a connection network history generation unit 14, and a connection network history database 15.

[0085] The network interface unit 11 is responsible for a communication interface for the network determination device 10 to perform communication compliant with the SIP protocol.

[0086] The message exchange control unit 12 transmits an INVITE request including SDP parameters to the phone terminal of the phone number to be investigated, and also receives a message (for example, a response with a predetermined code in the SIP session) from the receiving-side device.

[0087] The connection network determination unit 13 determines, according to a message received via the message exchange control unit 12 (for example, a response with a predetermined code in an SIP session), to which of the originating fixed IMS network 20, NGN network 30A, VoIP network 30B, and metal housing device 70 the telephone terminal of the called party's telephone number to be investigated is connected, and also determines the validity of the telephone number to be investigated (in other words, the usage status of the telephone number). In the present invention, the metal housing device 70 is treated as one of the types of networks (referred to as "connection network") to which the telephone terminal of the called party's telephone number to be investigated is connected.

[0088] The connection network history generation unit 14 constructs a connection network history database 15 by attaching a time stamp indicating the determination date and time to each of the determination results in the connection network determination unit 13 and recording them in chronological order on a recording medium.

[0089] Although the data structure (in other words, the recorded data items) of the connection network history database 15 is not limited to a specific structure or items, the connection network history information regarding the network to which the telephone terminal of the telephone number to be investigated is connected and stored in the connection network history database 15 may include, for example, for each investigation (in other words, for each transmission of an INVITE request), the "telephone number" to be investigated, the determination result of the type of connection network, the "code in the SIP session" returned from a device related to the establishment of communication with the called party, and the "investigation date" (that is, the time stamp). The connection network history information may further include the "existence / missing number determination result".

[0090] Then, for example, when the network determination device 10 determines the type of the network to which the telephone terminal of the telephone number "03-XXXX-XXXX" is connected, the determination results are sequentially recorded in the connection network history database 15 for each determination by the connection network determination unit 13 and accumulated as connection network history information.

[0091] Note that the connection network history database 15 may be implemented in a large-capacity recording medium such as a semiconductor memory, a hard disk, or an optical memory such as a DVD (Digital Versatile Disc).

[0092] The network determination device 10 includes a microprocessor incorporating a memory (not shown) in which a predetermined program (including the network determination program according to the embodiment) is recorded, or a microprocessor with an externally attached memory (not shown) in which a predetermined program is recorded, and an LSI (Large Scale Integration) that performs peripheral control including communication control.

[0093] Then, by sequentially reading and executing a predetermined program (including the network determination program according to the embodiment) recorded in a memory (not shown) by the microprocessor, each of the network interface unit 11, the message exchange control unit 12, the connection network determination unit 13, and the connection network history generation unit 14 is configured, and a predetermined function as the network determination device 10 is realized.

[0094] (Determination of the type of connection network) FIG. 7 is a flowchart showing the processing procedure in the network determination device 10 according to the embodiment.

[0095] The network determination device 10 according to the embodiment is a device connected to at least one of a telephone terminal connected to the originating fixed IMS network 20 and a telephone terminal connected to the terminating IMS network 30 (30A, 30B) via the originating fixed IMS network 20. It includes a message exchange control unit 12 that attaches SDP parameters to an INVITE request for a telephone terminal to be investigated, transmits the INVITE request to the originating fixed IMS network 20, and receives a response message via the originating fixed IMS network 20, and a connection network determination unit 13 that determines the type of network to which the telephone terminal to be investigated is connected according to the response message. The message exchange control unit 12 transmits an INVITE request including SDP parameters for the NGN network, where the network protocol is IPv6, the media type is only multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law. Next, it transmits an INVITE request including SDP parameters for the fixed telephone network, where the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722. The connection network determination unit 13 determines the type of network to which the telephone terminal is connected based on the combination of the response code in the response message for the INVITE request including SDP parameters for the NGN network, the response code in the response message for the INVITE request including SDP parameters for the fixed telephone network, and the tag information before being converted by the home gateway 51 to which the network determination device 10 is connected.

[0096] As an example of a specific configuration aspect of the network determination method according to the present invention, the network determination method according to the embodiment is a network determination method for determining the type of network to which a telephone terminal to be investigated is connected, using at least one of a telephone terminal connected to the originating fixed IMS network 20 and a telephone terminal connected to the terminating IMS network 30 (30A, 30B) via the originating fixed IMS network 20. Specifically, a device (specifically, the network determination device 10) is used. The device (specifically, the network determination device 10) includes steps of attaching SDP parameters to an INVITE request for the telephone terminal to be investigated and transmitting the INVITE request to the originating fixed IMS network 20 (steps S1, S3, S6), receiving a response message via the originating fixed IMS network 20, and determining the type of network to which the telephone terminal to be investigated is connected according to the response message (steps S2, S5, S7). As the step of transmitting the INVITE request, an INVITE request including SDP parameters for the NGN network, where the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law, is transmitted (step S1). Next, an INVITE request including SDP parameters for the fixed telephone network, where the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722, is transmitted (steps S3, S6). In the step of determining the type of network (steps S2, S5, S7), the type of network to which the telephone terminal is connected is determined based on the combination of the response code in the response message for the INVITE request including SDP parameters for the NGN network, the response code in the response message for the INVITE request including SDP parameters for the fixed telephone network, and the tag information before being converted by the home gateway 51 to which the device (specifically, the network determination device 10) is connected.

[0097] The network determination method described below can be implemented, for example, by a computer (specifically, the network determination device 10) executing a network determination program and performing each corresponding procedure according to the program.

[0098] In the description of the network determination method, assume the connection mode of the incoming device as shown in FIG. 5. Note that the information acquisition device 60 in FIG. 5 is specifically connected to the line between the home gateway 51 (not shown in FIG. 5) and the optical line termination device 52 (not shown in FIG. 5) (that is, UNI connection: UNI-1; see FIG. 1). Then, the content of the IP-based SIP signal (specifically, packet information, tag information) transmitted between the home gateway 51 and the optical line termination device 52, which is acquired (alternatively, captured) by the information acquisition device 60, is transmitted and input to the network determination device 10.

[0099] In the description of the network determination method, the value following "SIP to tag:" in the tag information, which is the content of the IP-based SIP signal transmitted between the home gateway 51 and the optical line termination device 52 and is acquired by the information acquisition device 60 for each call of the telephone number under investigation, is referred to as the "to-tag value".

[0100] And in the determination of the type of the connected network, assume that the to-tag values are pre-grouped as follows through prior verification (in other words, assume that the to-tag values corresponding to each of the following groups are pre-acquired). 〈Group A〉 · The originating fixed IMS network (NGN network) of telecommunications carrier X 〈Group B〉 · The terminating fixed IMS network (NGN network) of telecommunications carrier Y · The metal housing device · Other than the originating fixed IMS network of telecommunications carrier X, The communication networks (NGN networks) of telecommunications carrier X and telecommunications carrier Y 〈Group C〉 · The originating fixed IMS network (NGN network) of telecommunications carrier X <D Group> · Fixed on the user side VoIP network (IP-IP connection)

[0101] The A group is classified in detail by referring to the response in the SIP session (specifically, the information of the packet including the to-tag value) returned from the home gateway (HGW; not shown) on the originating fixed IMS network 20 side.

[0102] The B group is classified in detail based on the to-tag value related to the fixed IMS network (NGN network) on the user side of the communication carrier Y, or the to-tag value related to the metal housing device. Specifically, for example, it may be classified by referring to the response in the SIP session (specifically, the information of the packet including the to-tag value) returned from the CA (Call Agent; not shown) accommodated in the originating fixed IMS network 20. Note that the CA controls the interworking between the dedicated IP network and the public switched telephone network, and controls the SG (Signaling Gateway) and the MG (Media Gateway).

[0103] The C group is classified in detail by referring to the response in the SIP session (specifically, the information of the packet including the to-tag value) returned from the SIP server 21 of the originating fixed IMS network 20.

[0104] The D group is classified in detail by referring to the response in the SIP session (specifically, the information of the packet including the to-tag value) returned from the IBCF23 on the originating fixed IMS network 20 side.

[0105] In order to perform the above grouping, the phone number of the phone terminal whose connection network type is known in the prior verification (referred to as the "test number") is dialed (in other words, offered), and the to-tag value for each connection network type is obtained. Specifically, by dialing the test number, the following information from a to o is obtained in advance. a) to-tag value related to the originating fixed IMS network (NGN network) of communication carrier X (specifically, the one returned from the home gateway (HGW) on the originating fixed IMS network 20 side) b) to-tag value related to the terminating fixed IMS network (NGN network) of communication carrier Y c) to-tag value related to the metal housing device d) to-tag value related to the originating fixed IMS network (NGN network) of communication carrier X (specifically, the one returned from the SIP server 21 of the originating fixed IMS network 20) e) to-tag value related to the terminating fixed VoIP network (IP-IP connection; specifically, the VoIP network 30B as the terminating IMS network 30)

[0106] When the to-tag value obtained by the information acquisition device 60 by dialing the telephone number under investigation in the process of determining the type of connection network is the one in a) above, since the information in a) to o) above has been acquired in advance, the telephone terminal of the telephone number is determined to be in Group A.

[0107] Also, when the to-tag value obtained by the information acquisition device 60 by dialing the telephone number under investigation in the process of determining the type of connection network is the one in b) or c) above, the telephone terminal of the telephone number is determined to be in Group B.

[0108] Also, when the to-tag value obtained by the information acquisition device 60 by dialing the telephone number under investigation in the process of determining the type of connection network is the one in d) above, the telephone terminal of the telephone number is determined to be in Group C.

[0109] Also, when the to-tag value obtained by the information acquisition device 60 by dialing the telephone number under investigation in the process of determining the type of connection network is the one in e) above, the telephone terminal of the telephone number is determined to be in Group D.

[0110] Furthermore, in the process of determining the type of connection network, if the to-tag value obtained by dialing the telephone number under investigation and acquired by the information acquisition device 60 is not any of the above a to o, the telephone terminal corresponding to the telephone number is determined to be in Group B.

[0111] The value of "SIP to tag:" (i.e., the to-tag value) is uniquely generated by the unique algorithm of each user agent as described above. Therefore, when the receiving-side terminals and devices are connected to the same network, they have similar characteristics (for example, a string starting with a two-letter alphabet prefix, or a string containing characters or symbols other than numbers, etc.). For this reason, the information of the above a to o is specifically information regarding the characteristics of the to-tag value related to the above a to o. Then, the classification of whether the to-tag value (specifically, the characteristics of the to-tag value) obtained by dialing the telephone number under investigation and acquired by the information acquisition device 60 belongs to any of the above a to o is performed, and based on the classification result, it is determined which of the above Group A to Group D the telephone terminal corresponding to the telephone number belongs to.

[0112] The to-tag value of the receiving-side fixed VoIP network is a unique value for each IBCF23 on the transmitting-side fixed IMS network 20 side.

[0113] The to-tag value for each type of connection network (and thus the information of the above a to o) may be updated appropriately with the latest information by periodically dialing test numbers.

[0114] The SDP parameters included in the INVITE request when the network determination device 10 sends an INVITE request to perform negotiation between terminals are the network protocol (in other words, the Internet protocol, IP version), media type, media transport protocol, and audio codec.

[0115] As a processing procedure for determining the type of connection network, the message exchange control unit 12 of the network determination device 10 first dials the telephone number to be investigated via the originating fixed IMS network 20 and transmits an INVITE request as an offer (step S1).

[0116] At this time, the following are described as SDP parameters included in the INVITE request. The following SDP parameters are referred to as "SDP for NGN network".

[0117] <NGN network SDP> ○ Network protocol (Internet protocol, IP version): IPv6 ○ Media type: Multimedia ○ Media transport protocol: Only RTP / AVPF ○ Voice codec: Including G.711 μ-law

[0118] Regarding the above SDP for NGN network, "Multimedia" of the media type means that at least two of audio, Video, appli, and image are described. Also, "Including G.711 μ-law" of the voice codec means that at least G.711 μ-law is described.

[0119] On the other hand, an answer is returned from the device related to the establishment of communication with the receiving side to the network determination device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20.

[0120] The connection network determination unit 13 of the network determination device 10 determines whether the content of the answer is an error response with a code 488 Not Acceptable Here indicating that the offer is not accepted due to a profile mismatch in the SIP session, the warn-code is 302, and further whether the to-tag value is in group B (step S2).

[0121] Note that for the 488 response, a Warning header is set and a warn-code is set. A warn-code of 302 indicates that the transport protocol set in the offer is not supported. Specifically, for example, when an offer with RTP / AVPF set as the transport protocol is received, but the receiving side only supports RTP / AVP. In this case, the answer is responded by the CA accommodated in the originating fixed IMS network 20 as a device related to the establishment of communication with the calling side.

[0122] When the content of the answer is an error response with a code of 488 Not Acceptable Here, the warn-code is 302, and the to-tag value is in group B (step S2: Yes), the connection network determination unit 13 of the network determination device 10 proceeds with the processing procedure to the processing of step S3.

[0123] Here, the fact that the content of the answer is an error response with a code of 488 Not Acceptable Here, the warn-code is 302, and the to-tag value is in group B corresponds to a situation where although the telephone terminal of the telephone number under investigation is connected to the metal housing device 70, the INVITE request cannot reach the metal housing device 70. Specifically, between the originating fixed IMS network 20 and the metal housing device 70, regarding the SDP parameters, RTP / AVPF is not allowed for the media transport protocol, so the INVITE request cannot reach the metal housing device 70.

[0124] That is, when the INVITE request is sent with NGN network SDP in the processing of step S1, if the telephone terminal of the telephone number under investigation is connected to the metal housing device 70, the content of the answer is an error response with a code of 488 Not Acceptable Here, the warn-code is 302, and the to-tag value is in group B.

[0125] Then, the message exchange control unit 12 of the network determination device 10 dials the phone number to be investigated via the originating fixed IMS network 20 and sends an INVITE request as an offer (step S3).

[0126] At this time, the following are described as SDP parameters included in the INVITE request. The following SDP parameters are referred to as "SDP for fixed telephone network".

[0127] <SDP for fixed telephone network> ○ Network protocol (Internet Protocol, IP version): IPv4 ○ Media type: only audio ○ Media transport protocol: only RTP / AVP ○ Audio codec: including G.711 μ-law and G.722

[0128] Regarding the above SDP for fixed telephone network, "including G.711 μ-law and G.722" for the audio codec means that at least G.711 μ-law and G.722 are described.

[0129] In contrast, an answer is returned from the device related to the establishment of communication with the receiving side to the network determination device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20.

[0130] Based on the result of the process in step S2 (step S2: Yes), the connection network determination unit 13 of the network determination device 10 determines that the telephone terminal of the phone number to be investigated is connected to the metal housing device 70 (step S4). Note that the content of the answer to the INVITE request (where the SDP parameter is the SDP for fixed telephone network) in the process of step S3 also has the to-tag value of group B. Also, in this case, the receiving-side device is a metal IP telephone terminal.

[0131] The connection network determination unit 13 of the network determination device 10 further determines that when the content of the answer to the INVITE request (where the SDP parameter is the SDP for the fixed telephone network) in the process of step S3 is a code 180 Ringing response indicating that a ringing tone is sounding in the SIP session, the telephone terminal with the telephone number under investigation exists and is not busy (that is, the telephone number under investigation exists), or when the content of the answer to the INVITE request (where the SDP parameter is the SDP for the NGN network) in the process of step S1 is an error response of code 488 Not Acceptable Here indicating that the offer is not accepted due to a profile mismatch in the SIP session and the warn-code is any one of 300, 304, and 305, and further determines whether the to-tag value is in group C (step S5).

[0132] Then, the connection network determination unit 13 of the network determination device 10 ends the process of determining the type of the connection network for the telephone number under investigation (END).

[0133] On the other hand, when the result of the determination in the process of step S2 is "No", the connection network determination unit 13 of the network determination device 10 advances the processing procedure to the process of step S5.

[0134] Then, the connection network determination unit 13 of the network determination device 10 determines whether the content of the answer to the INVITE request (where the SDP parameter is the SDP for the NGN network) in the process of step S1 is an error response of code 488 Not Acceptable Here indicating that the offer is not accepted due to a profile mismatch in the SIP session and the warn-code is any one of 300, 304, and 305, and further determines whether the to-tag value is in group C (step S5).

[0135] Note that warn-code 300 is a code indicating non - compliance with the IP version set in the offer. Specifically, for example, it applies when an offer with IPv6 set is received, but the receiving side only supports IPv4. Warn-code 304 is a code indicating non - compliance with the media type set in the offer or that there is an m = line in the plurality of m = lines that is not compliant. Specifically, for example, it applies when an offer with Video set is received, but the receiving side only supports audio. Warn-code 305 is a code indicating non - compliance with any of the audio codecs set in the offer. Specifically, for example, it applies when an offer with G.722 set is received, but the receiving side only supports G.711 μ-law.

[0136] When the content of the answer is an error response with code 488 Not Acceptable Here, the warn - code is any of 300, 304, and 305, and the to - tag value is in the C group (step S5: Yes), the connection network determination unit 13 of the network determination device 10 proceeds with the processing procedure to the processing in step S6.

[0137] Here, when the content of the answer to the INVITE request (where the SDP parameter is the SDP for the NGN network) in the process of step S1 is an error response with the code 488 Not Acceptable Here, and the warn-code is 300, 304, or 305, and the to-tag value is in group C, it corresponds to a situation where the INVITE request cannot pass through the IBCF23 on the originating fixed IMS network 20 side. Specifically, in the IBCF23 on the originating fixed IMS network 20 side connected to the IBCF33 on the VoIP network 30B side, regarding the SDP parameter, IPv6 is not allowed for the network protocol (in other words, the Internet protocol, IP version), only audio is allowed for the media type, and furthermore, RTP / AVPF is not allowed for the media transport protocol, so the INVITE request cannot pass through the IBCF23 on the originating fixed IMS network 20 side.

[0138] Then, the message exchange control unit 12 of the network determination device 10 dials the phone number to be investigated via the originating fixed IMS network 20 and sends an INVITE request as an offer (step S6).

[0139] At this time, the above-mentioned SDP for the fixed telephone network is described as the SDP parameter included in the INVITE request.

[0140] In response to this, an answer is returned to the network determination device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20 from the device related to the establishment of communication with the receiving side.

[0141] The connection network determination unit 13 of the network determination device 10 determines whether the content of the answer is a code 180 Ringing response indicating that the incoming call tone is ringing in the SIP session, and further determines whether the to-tag value is in group D (step S7).

[0142] When the content of the answer is a 180 Ringing response and the to-tag value is the D group (step S7: Yes), the connection network determination unit 13 of the network determination device 10 proceeds with the processing procedure to the processing of step S8.

[0143] Then, based on the result of the processing in step S7 (step S7: Yes), the connection network determination unit 13 of the network determination device 10 determines that the telephone terminal of the telephone number to be investigated is connected to the VoIP network 30B (step S8).

[0144] Furthermore, when the content of the answer to the INVITE request (where the SDP parameter is the SDP for the fixed telephone network) in the processing of step S6 is a 180 Ringing response indicating that the incoming call tone is ringing in the SIP session, the connection network determination unit 13 of the network determination device 10 determines that the telephone terminal of the telephone number to be investigated exists and is not busy (that is, the telephone number to be investigated exists). Or, when the content of the answer is a 404 Not Found response indicating that the media resource requested from the calling side cannot be found in the SIP session, the connection network determination unit 13 determines that the telephone number to be investigated is an unassigned number.

[0145] Then, the connection network determination unit 13 of the network determination device 10 ends the process of determining the type of the connection network for the telephone number to be investigated (END).

[0146] On the other hand, when the result of the determination in the processing of step S5 is "No", specifically, when the content of the answer is an error response of 488 Not Acceptable Here and the warn-code is any one of 300, 304, and 305 and the to-tag value is the A group or the B group, the connection network determination unit 13 of the network determination device 10 proceeds with the processing procedure to the processing of step S9.

[0147] Note that, regarding the SDP parameters, in the originating fixed IMS network 20, IPv6 is allowed in addition to IPv4 for the network protocol (in other words, Internet Protocol, IP version), multimedia is allowed for the media type, RTP / AVPF is allowed for the media transport protocol, and at least G.711 μ-law is allowed for the voice codec. Therefore, the INVITE request can reach the telephone terminal connected to the originating fixed IMS network 20.

[0148] Also, between the originating fixed IMS network 20 and the NGN network 30A, regarding the SDP parameters, IPv6 is allowed in addition to IPv4 for the network protocol (in other words, Internet Protocol, IP version), multimedia is allowed for the media type, RTP / AVPF is allowed for the media transport protocol, and at least G.711 μ-law is allowed for the voice codec. Therefore, the INVITE request can reach the telephone terminal connected to the NGN network 30A.

[0149] And in the above case (that is, step S5: No; still, when the to-tag value is in group C, step S5: Yes and it is excluded), the to-tag value is in group A (that is, the telephone terminal connected to the originating fixed IMS network of the communication carrier X: NGN network) or group B (specifically, the terminating fixed IMS network of the communication carrier Y: the telephone terminal connected to the NGN network).

[0150] In addition, when the INVITE request is sent using the NGN network SDP in the process of step S1, if the telephone terminal of the telephone number under investigation is connected to the NGN network 30A, the answer content is an error response with the code 488 Not Acceptable Here, the warn-code is 300, 304, or 305, and the to-tag value is in group B.

[0151] Furthermore, even when the result of the determination in the process of step S7 is "No", the connection network determination unit 13 of the network determination device 10 proceeds with the processing procedure to the process of step S9. In this case, the to-tag value belongs to Group A.

[0152] Note that the situation where the result of the determination in the process of step S7 becomes "No" after the processes of steps S1, S2, S5, and S6 corresponds to the situation where the telephone terminal of the telephone number to be investigated is connected to the originating fixed IMS network 20. And in this case, the to-tag value becomes Group A.

[0153] Specifically, when an INVITE request is sent with the NGN network SDP in the process of step S1, if the telephone terminal of the telephone number to be investigated is UNI-connected to the originating fixed IMS network 20 (which is an NGN network), the content of the answer is an error response with code 488 Not Acceptable Here and the warn-code is 300, 304, or 305, and the to-tag value is Group A (step S5: No) or Group C (step S5: Yes). Also, if the telephone terminal of the telephone number to be investigated is connected to the VoIP network 30B, the content of the answer is an error response with code 488 Not Acceptable Here and the warn-code is 300, and the to-tag value is Group C (step S5: Yes). Therefore, when the warn-code is 300, it is impossible to specify whether the telephone terminal of the telephone number to be investigated is connected to the originating fixed IMS network 20 or the VoIP network 30B.

[0154] In such a case, by further sending an INVITE request with the SDP for the fixed telephone network (step S6), it is possible to identify that the telephone terminal of the telephone number under investigation is connected to the originating fixed IMS network 20 (which is an NGN network) when the to-tag value in the answer is in group A (step S7: No). On the other hand, when the to-tag value is in group D (step S7: Yes), it is possible to identify that the telephone terminal of the telephone number under investigation is connected to the VoIP network 30B. In the process of step S7, when the result of the determination is "No", specifically, it is the case where the content of the answer is the 180 Ringing response with code 180 and the to-tag value is in group A.

[0155] Based on the result of the process in step S5 (step S5: No) or the result of the process in step S7 (step S7: No), the connection network determination unit 13 of the network determination device 10 determines that the telephone terminal of the telephone number under investigation is connected to the NGN network 30A or the originating fixed IMS network 20 (step S9).

[0156] Furthermore, when the content of the answer to the INVITE request (where the SDP parameter is the SDP for the NGN network) in the process of step S1 is an error response with code 488 Not Acceptable Here indicating that the offer is not accepted due to a profile mismatch in the SIP session, the connection network determination unit 13 of the network determination device 10 determines that the telephone number under investigation exists. Or, when the response is a 404 Not Found response with code 404 indicating that the media resource requested from the originating side cannot be found in the SIP session, it is determined that the telephone number under investigation is an out-of-service number.

[0157] Although the INVITE request can reach the telephone terminal connected to the originating fixed IMS network 20 or the NGN network 30A as described above, if the telephone terminal does not support IPv6, it will be rejected by the home gateway (HGW) between the originating fixed IMS network 20 and the telephone terminal or between the NGN network 30A and the telephone terminal. Therefore, it is an error response with the code 488 Not Acceptable Here and the warn-code becomes 300. Accordingly, the error response with the code 488 confirmed in the process of step S9 means that the telephone terminal corresponding to the telephone number under investigation exists.

[0158] Then, the connection network determination unit 13 of the network determination device 10 ends the process of determining the type of the connection network regarding the telephone number under investigation (END).

[0159] (Network Determination Program) As an example of a specific configuration aspect of the network determination program according to the present invention, the network determination program according to the embodiment is a program installed in a computer (specifically, the network determination device 10) connected via the originating fixed IMS network 20 to at least a telephone terminal connected to the terminating IMS network 30 (30A, 30B).

[0160] The network determination program according to the embodiment causes a computer (specifically, the network determination device 10) connected via the originating fixed IMS network 20 to at least one of the telephone terminal connected to the originating fixed IMS network 20 and the telephone terminal connected to the terminating IMS network 30 (30A, 30B) to execute at least the following processes: adding SDP parameters to an INVITE request for the telephone terminal under investigation and transmitting the INVITE request to the originating fixed IMS network 20; receiving a response message via the originating fixed IMS network 20; and determining the network to which the telephone terminal under investigation is connected according to the response message.

[0161] Then, in the process of sending an INVITE request, the network determination program according to the embodiment sends an INVITE request including SDP parameters for the NGN network, where the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law. Next, it sends an INVITE request including SDP parameters for the fixed telephone network, where the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722. Also, in the process of determining the network, based on the response code in the response message for the INVITE request including SDP parameters for the NGN network, the response code in the response message for the INVITE request including SDP parameters for the fixed telephone network, and the combination of tag information before being converted by the home gateway 51 to which the computer (specifically, the network determination device 10) is connected, it determines the network to which the telephone terminal is connected.

[0162] (Connection Network Information Providing System) FIG. 8 is a system configuration diagram of the connection network information providing system 100 according to the embodiment, as an example of a specific configuration mode of the connection network information providing system according to the present invention.

[0163] The connection network information providing system 100 according to the embodiment includes one or more user terminals 90 and a network determination server (specifically, the network determination device 10) that is connected to the user terminals 90 via the IP network 80 and is also connected to a network (for example, the originating fixed IMS network 20) not shown in the figure.

[0164] The connection network information providing system 100 according to the embodiment includes a network determination server (specifically, the network determination device 10) and a user terminal 90. When the network determination server (specifically, the network determination device 10) receives a request for providing information about the network to which a telephone terminal is connected from the user terminal 90 (referred to as a "connection network information providing request"), the network interface unit 11 transmits, via the IP network 80, information about the network to which the telephone terminal determined by the connection network determination unit 13 of the user terminal 90 to which the connection network information providing request was made is connected (specifically, connection network history information including the type of communication network) (see FIG. 6).

[0165] When the network determination server (specifically, the network determination device 10) receives, via the IP network 80, a connection network information providing request regarding the telephone number to be investigated from the user terminal 90, it refers to a recording medium (specifically, the connection network history database 15) in which connection network history information in which a timestamp indicating the determination date and time is assigned to each determination result of the type of network to which the telephone terminal of the telephone number to be investigated is connected is stored in chronological order, and transmits the connection network history information to the user terminal 90 to which the connection network information providing request was made via the IP network 80.

[0166] The recording medium (specifically, the connection network history database 15) in which the connection network history information is stored may be distributed individually to necessary users. The recording medium (connection network history database 15) in which the connection network history information is stored is, for example, a recording medium generated by the network determination device 10 connected via a dedicated line to a communication carrier network and recording the type of network to which the telephone terminal is connected, and may be used for searching in the distribution destination system.

[0167] The recording medium (specifically, the connection network history database 15) in which the connection network history information is stored is an aggregate of the results of determining the type of network to which the incoming telephone terminal (specifically, a fixed telephone terminal) is connected. For example, a timestamp indicating the determination date and time is assigned to each determination result and recorded in chronological order.

[0168] The distribution of the recording medium (specifically, the connection network history database 15) storing the connection network history information is not limited to the distribution in the form of a database recorded on a DVD or a hard disk, and also includes the distribution using a communication line.

[0169] (Function and effect) According to the network determination device 10, the network determination method, the network determination program, and the connection network information providing system according to the embodiment, it is possible to determine the network to which the incoming telephone terminal is connected after the transition from the interconnection method via the public switched telephone network (PSTN) to the IP-IP connection interconnection method.

[0170] As described above, the embodiments of the present invention have been described. However, the specific configuration mode of the present invention is not limited to the above embodiments, and forms in which modifications and changes within the scope not departing from the gist of the present invention are added to the above embodiments are also included in the present invention.

[0171] For example, in the above embodiment, in addition to determining the type of the network to which the telephone terminal of the telephone number to be investigated is connected, the existence / absence of the telephone number to be investigated is determined. However, in the present invention, the determination of the existence / absence of the telephone number to be investigated is not an essential configuration, and the determination of the existence / absence of the telephone number to be investigated may not be performed.

Explanation of reference numerals

[0172] 10 Network determination device 11 Network interface unit 12 Message exchange control unit 13 Connection network determination unit 14 Connection network history generation unit 15 Connection network history database 20 Originating fixed IMS network 21 SIP server 22 Public switched telephone network gateway (PSTN-GW) 23 IBCF 30 Terminating IMS network 30A NGN network 30B VoIP network 31 SIP Server 32 Gateway (GW) 33 IBCF 34 IP-POI 40 Public Switched Telephone Network 41 Public Switched Telephone Network Gateway (PSTN-GW) 42 Gateway (GW) 43 STM-POI 51 Home Gateway (HGW) 52 Optical Line Termination Equipment 60 Information Acquisition Device 70 Metal Containment Device 80 IP Network 90 User Terminal 100 Connection Network Information Provision System

Claims

1. A network determination device connected to at least one of a telephone terminal connected to a transmitting-side fixed IMS network and a telephone terminal connected to a receiving-side IMS network via the transmitting-side fixed IMS network, A message exchange control unit that attaches SDP parameters to an INVITE request for a telephone terminal to be investigated, transmits the INVITE request to the transmitting-side fixed IMS network, and receives a response message via the transmitting-side fixed IMS network, A connection network determination unit that determines the network to which the telephone terminal to be investigated is connected according to the response message, and is provided with, The message exchange control unit, Transmits an INVITE request including SDP parameters for an NGN network in which the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law, Next, an INVITE request including SDP parameters for a fixed telephone network in which the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.722 is transmitted, The connection network determination unit, Based on the combination of the response code in the response message for the INVITE request including the SDP parameters for the NGN network, the response code in the response message for the INVITE request including the SDP parameters for the fixed telephone network, and the tag information before being converted by the home gateway to which the network determination device is connected, determines the network to which the telephone terminal is connected, A network determination device characterized by the above.

2. When the response message for the INVITE request including the SDP parameters for the NGN network has a code 488 Not Acceptable Here and a warn-code of 302 and the tag information is a to-tag value related to a metal housing device, the connection network determination unit determines that the telephone terminal to be investigated is connected to the metal housing device, The network determination device according to claim 1, characterized by the above.

3. When the response message for the INVITE request including the SDP parameters for the NGN network is Code 488 Not Acceptable Here and the warn-code is 300, 304, or 305 and the tag information is the to-tag value related to the originating fixed IMS network, and further, when the response message for the INVITE request including the SDP parameters for the fixed telephone network is a Code 180 Ringing response and the tag information is the to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it is determined that the telephone terminal under investigation is connected to the VoIP network. The network determination device according to claim 1, characterized in that.

4. When the response message for the INVITE request including the SDP parameters for the NGN network is Code 488 Not Acceptable Here and the warn-code is any one of 300, 304, and 305 and the tag information is not the to-tag value related to the originating fixed IMS network, or when the response message for the INVITE request including the SDP parameters for the fixed telephone network is a Code 180 Ringing response and the tag information is not the to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it is determined that the telephone terminal under investigation is connected to the NGN network. The network determination device according to claim 1, characterized in that.

5. A network determination method for determining the network to which a telephone terminal to be investigated is connected, using a device connected via the originating fixed IMS network to at least one of a telephone terminal connected to the originating fixed IMS network and a telephone terminal connected to the terminating IMS network. The device is a step of attaching SDP parameters to an INVITE request for a telephone terminal to be investigated and transmitting the INVITE request to the originating fixed IMS network. a step of receiving a response message via the originating fixed IMS network. a step of determining the network to which the telephone terminal to be investigated is connected according to the response message, and includes as the step of transmitting the INVITE request, Send an INVITE request containing SDP parameters for an NGN network, where the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law. Next, send an INVITE request containing SDP parameters for a fixed telephone network, where the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.

722. In the step of determining the network. Determine the network to which the telephone terminal is connected based on the combination of the response code in the response message for the INVITE request containing the SDP parameters for the NGN network, the response code in the response message for the INVITE request containing the SDP parameters for the fixed telephone network, and the tag information before being converted by the home gateway to which the device is connected. A network determination method characterized by the above.

6. In the step of determining the network, when the response message for the INVITE request containing the SDP parameters for the NGN network has a code 488 Not Acceptable Here and a warn-code of 302 and the tag information is a to-tag value related to a metal housing device, determine that the telephone terminal under investigation is connected to the metal housing device. The network determination method according to claim 5, characterized by the above.

7. In the step of determining the network, when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here and the warn-code is 300, 304, or 305 and the tag information is the to-tag value related to the originating fixed IMS network, and further, when the response message to the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is the to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it is determined that the telephone terminal under investigation is connected to the VoIP network. The network determination method according to claim 5, characterized in that.

8. In the step of determining the network, when the response message to the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here and the warn-code is any one of 300, 304, and 305 and the tag information is not the to-tag value related to the originating fixed IMS network, or when the response message to the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is not the to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it is determined that the telephone terminal under investigation is connected to the NGN network. The network determination method according to claim 5, characterized in that.

9. On a computer connected via the originating fixed IMS network to at least one of a telephone terminal connected to the originating fixed IMS network and a telephone terminal connected to the terminating IMS network, a process of attaching SDP parameters to an INVITE request for the telephone terminal under investigation and transmitting the INVITE request to the originating fixed IMS network; a process of receiving a response message via the originating fixed IMS network; and a process of determining the network to which the telephone terminal under investigation is connected according to the response message, are at least executed. In the process of transmitting the INVITE request, Send an INVITE request containing SDP parameters for an NGN network where the network protocol is IPv6, the media type is multimedia, the media transport protocol is only RTP / AVPF, and the voice codec includes G.711 μ-law. Next, send an INVITE request containing SDP parameters for a fixed telephone network where the network protocol is IPv4, the media type is only audio, the media transport protocol is only RTP / AVP, and the voice codec includes G.711 μ-law and G.

722. In the process of determining the network. Determine the network to which the telephone terminal is connected based on the response code in the response message for the INVITE request containing the SDP parameters for the NGN network, the response code in the response message for the INVITE request containing the SDP parameters for the fixed telephone network, and the combination of tag information before being converted by the home gateway to which the computer is connected. A network determination program characterized by the above.

10. In the step of determining the network, when the response message for the INVITE request containing the SDP parameters for the NGN network has a code 488 Not Acceptable Here and a warn-code of 302 and the tag information is the to-tag value related to the metal housing device, determine that the telephone terminal under investigation is connected to the metal housing device. The network determination program according to claim 9, characterized by the above.

11. In the step of determining the network, when the response message for the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here and the warn-code is 300, 304, or 305 and the tag information is the to-tag value related to the originating fixed IMS network, and further, when the response message for the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is the to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it is determined that the telephone terminal under investigation is connected to a VoIP network. The network determination program according to claim 9, characterized in that.

12. In the step of determining the network, when the response message for the INVITE request including the SDP parameters for the NGN network is code 488 Not Acceptable Here and the warn-code is any one of 300, 304, and 305 and the tag information is not the to-tag value related to the originating fixed IMS network, or when the response message for the INVITE request including the SDP parameters for the fixed telephone network is code 180 Ringing response and the tag information is not the to-tag value related to the terminating fixed VoIP network as the terminating IMS network, it is determined that the telephone terminal under investigation is connected to the NGN network. The network determination program according to claim 9, characterized in that.

13. A network determination device according to any one of claims 1 to 4, and a user terminal, and when the network determination device receives a request for providing connection network information about a telephone terminal from the user terminal, the network determination device includes a network interface unit that transmits the connection network of the telephone terminal determined by the connection network determination unit to the user terminal having made the request for providing connection network information via an IP network. A connection network information providing system, characterized in that.

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