JP2012209638A - Communication control device and communication control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform efficient realtime data communication even if coding schemes used at the communication device of a communication request source and at the communication device of a communication request destination are different.SOLUTION: A communication control device receives coding schemes used by communication devices from the plurality of communication devices; stores communication device identification information associating it with information indicating a coding scheme used by the communication device among multiple coding schemes; receives a call control signal including communication device identification information identifying the communication device of a communication request destination from the communication device of a communication request source; reads out and compares a coding scheme associated with the communication device of the communication request source and a coding scheme associated with the communication device of the communication request destination; and if the compared coding schemes are different, reads out the connection destination of a conversion device performing conversion of different coding schemes, and transmits a call control signal including the connection destination to the communication devices of the communication request source and communication request destination.

Description

  The present invention relates to a technique for controlling communication performed by a predetermined encoding method.

  Research on technologies for communicating data such as voice in real time via an IP (Internet Protocol) network is in progress. For example, VoIP (Voice over Internet Protocol) is a technology in which voice is compressed by a predetermined encoding method, converted into an IP packet, and communicated in real time via an IP network. Thereby, telephone communication via the IP network is realized. A communication device that performs voice communication by VoIP establishes a connection by communicating a call control signal based on a call control protocol such as SIP (Session Initiation Protocol). Then, based on the connection established by the call control signal, the voice is encoded by one of a plurality of predetermined encoding methods by a data transfer protocol such as RTP (Real-time Transport Protocol). Communicate data signals. Non-Patent Documents 1 to 3 define a control protocol for performing such data communication.

“Media Gateway Control Protocol Architecture and Requirements”, [online], [March 4, 2011 search] Internet URL: http://www.ietf.org/rfc/rfc2805.txt “SIP: Session Initiation Protocol”, [online], [searched on March 4, 2011] Internet URL: http://www.ietf.org/rfc/rfc3261.txt “An Offer / Answer Model with the Session Description Protocol (SDP)”, [online], [March 4, 2011 search] Internet URL: http://www.ietf.org/rfc/rfc3264.txt

  However, in such real-time data communication, the communication device encodes data such as voice by any one of a plurality of encoding methods as described above. For this reason, if the encoding method used by the communication request source communication apparatus is different from the communication request destination communication apparatus, the encoded data cannot be decoded and data communication cannot be performed. Here, it is desirable that data communication is possible even when the encoding method used by the communication request source communication apparatus and the communication request destination communication apparatus are different.

  The present invention has been made in view of such circumstances, and communication control for efficiently performing real-time data communication even when the encoding method used by the communication request source communication apparatus and the communication request destination communication apparatus is different. An apparatus and a communication control method are provided.

  In order to solve the above-described problem, the present invention performs control signal communication based on a control protocol, and then encodes data using one of a plurality of encoding methods based on the data transfer protocol. Communication connected to a plurality of communication devices (for example, communication terminal 10-1, communication terminal 10-2, communication terminal 10-3,. A control device (for example, the communication control device 30 in the present embodiment), for each of a plurality of communication devices, communication device identification information for identifying the communication device, and an encoding method used by the communication device among a plurality of encoding methods And a device capability storage unit (for example, the device capability storage unit 31 in the present embodiment) that is stored in association with each other, and any one of a plurality of encoding methods Information indicating a connection destination of a conversion device (for example, the media GW 50-1 or the media GW 50-2 in the present embodiment) that converts the data signal encoded by the encoding into a data signal encoded by another encoding method. Receiving a control signal including information indicating an encoding method used by the communication device from the stored conversion device storage unit (for example, the conversion device storage unit 32 in the present embodiment) and the communication device, and identifying the communication device A device capability registration unit (for example, the device capability management unit 34 in the present embodiment) that associates information indicating the encoding method included in the received control signal with the communication device identification information to be stored in the device capability storage unit, and A receiving unit (for example, a communication unit in this embodiment) that receives a control signal including communication device identification information for identifying a communication device that is a communication request destination from a communication device that is a communication request source. When the control signal is received by the unit 36) and the receiving unit, the device capability storage unit displays the encoding scheme associated with the communication device that is the communication request source and the encoding scheme associated with the communication device that is the communication request destination. If the compared encoding method is different, the connection destination of the conversion device that performs conversion of the different encoding method is read from the conversion device storage unit, and the control signal including the connection destination is communicated with the communication request source. A communication control unit (for example, the communication control unit 38 in the present embodiment) that transmits to the communication device with the request destination.

  In the present invention, information indicating the connection destination of a relay device (for example, the router 60-1 or the router 60-2 in the present embodiment) that relays a data signal without converting the encoding method is stored. A relay device storage unit (for example, the relay device storage unit 33 in the present embodiment), and when the reception unit receives the call control signal, the communication control unit includes an encoding scheme associated with the communication device that is the communication request source. When the encoding method associated with the communication request destination communication device is read from the device capability storage unit and compared, and the compared encoding method matches, the connection destination of the relay device is read from the relay device storage unit Then, a call control signal including the connection destination is transmitted to the communication devices of the communication request source and the communication request destination.

  Further, according to the present invention, a communication request source communication apparatus encodes a data signal using a first encoding system, and a communication request destination communication apparatus uses a second encoding system different from the first encoding system. The communication request source communication device and the communication request destination communication device use the third encoding method different from both the first encoding method and the second encoding method to generate the data signal. Are connected via a network that encodes the data, and the conversion device storage unit includes a first conversion device that converts a data signal according to the first encoding method into a data signal according to the third encoding method, and a second Information indicating a connection destination with a second conversion device that converts a data signal according to the encoding method into a data signal according to the third encoding method is stored, and the communication control unit transmits the information to the communication device that is the communication request source. Send the destination of the first converter, For Shin request destination communication device and transmitting the connection of the second converter.

  Further, according to the present invention, the communication control unit transmits, to the signaling gateway connected to the communication request destination communication device, an internal codec indicating the third encoding method, an external codec indicating the second encoding method, The transmission destination of the second conversion device is transmitted.

  Further, the present invention is characterized in that the connection destination of the second conversion device transmitted by the communication control unit to the signaling gateway is transmitted to the call control server connected to the communication request destination communication device by the signaling gateway. .

  Further, according to the present invention, when the communication control unit transmits the connection destination of the second conversion device to the communication request destination communication device via the signaling gateway and the call control server, the communication request destination communication device receives the call control. The signaling gateway transmits a response signal to the signaling gateway via the server, and receives the response signal. The signaling gateway communicates the data signal to the second conversion device with the communication request destination communication device using the second encoding method. And instructing the communication of the data signal with the first conversion device by the third encoding method, and the communication control unit sends a response signal from the communication device of the communication request destination via the signaling gateway. When received, the signaling gateway connected to the communication requesting communication apparatus transmits an internal codec indicating the third encoding method and an external codec indicating the first encoding method. And transmitting the click, the connection of the first converter.

  In addition, the present invention performs communication of a control signal based on a control protocol, and then performs communication of a data signal in which data is encoded by any one of a plurality of encoding methods based on the data transfer protocol. Communication device identification information for identifying a communication device connected to a plurality of communication devices to be performed for each of the plurality of communication devices, and information indicating an encoding method used by the communication device among a plurality of encoding methods A device capability storage unit that is stored in association with each other and converts a data signal encoded by any one of a plurality of encoding methods into a data signal encoded by another encoding method. A communication control method for a communication control device, comprising: a conversion device storage unit storing information indicating a connection destination of the conversion device, wherein the encoding method used by the communication device is determined from the communication device. Receiving the control signal including the information to be stored, associating the communication device identification information for identifying the communication device with the information indicating the encoding method included in the received control signal, and storing the information in the device capability storage unit; Receiving a control signal including communication device identification information for identifying a communication request destination communication device from a request source communication device; and, upon receiving the control signal, encoding associated with the communication request source communication device If the coding method associated with the communication request destination communication device is read from the device capability storage unit and compared, and the compared coding methods are different, the conversion device storage unit converts the different coding method. And a step of reading a connection destination of the conversion device that performs the processing and transmitting a control signal including the connection destination to the communication devices of the communication request source and the communication request destination.

  As described above, according to the present invention, the communication control device receives the encoding method used by the communication device from the plurality of communication devices, and the communication device among the plurality of encoding methods is the communication device identification information. Information indicating the encoding method to be used is stored in association with each other, and a call control signal including communication device identification information for identifying the communication device of the communication request destination is received from the communication device of the communication request source. The encoding method associated with the communication device and the encoding method associated with the communication device that is the communication request destination are read and compared, and if the compared encoding methods are different, conversion of different encoding methods is performed. Since the connection destination of the conversion device is read and the call control signal including the connection destination is transmitted to the communication device of the communication request source and the communication request destination, the communication device of the communication request source and the communication device of the communication request destination Encoding method used in Even if different, the efficiency can be performed real-time data communication.

It is a block diagram which shows the structural example of the communication system by one Embodiment of this invention. It is a block diagram which shows the structural example of the communication control apparatus by one Embodiment of this invention. It is a figure which shows the data example of the apparatus capability information by one Embodiment of this invention. It is a figure which shows the example of data of the converter information by one Embodiment of this invention. It is a block diagram which shows the structural example of signaling GW by one Embodiment of this invention. It is a figure which shows the operation example by which apparatus capability information is memorize | stored in the communication control apparatus by one Embodiment of this invention. It is a figure which shows the operation example in which the communication terminal by one Embodiment of this invention transmits the call control signal of a communication request to a communication control apparatus. It is a figure which shows the operation example which a communication terminal communicates according to the call control signal of the communication request | requirement transmitted from the communication terminal by one Embodiment of this invention. It is a figure which shows the operation example in which the communication terminal by one Embodiment of this invention transmits the call control signal of a communication request to a communication control apparatus. It is a figure which shows the operation example which a communication terminal communicates according to the call control signal of the communication request | requirement transmitted from the communication terminal by one Embodiment of this invention. It is a figure which compares the communication method by a prior art, and the communication method by one Embodiment of this invention. It is a figure which shows the operation example in which the communication terminal in two networks by one Embodiment of this invention communicates. It is a figure which shows the operation example in which the communication terminal in two networks by one Embodiment of this invention communicates.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a communication system 1 according to the present embodiment. The communication system 1 includes a communication terminal 10-1, a call control server 20-1, a communication control device 30, a signaling GW 40-1, a signaling GW 40-2, and a media GW 50- 1, media GW 50-2, router 60-1, router 60-2, communication terminal 10-2 constituting network b, communication terminal 10-3, and call control server 20-2. Yes. Here, since the functional units having the same names have the same configuration, the communication terminal 10, the call control server 20, the signaling GW 40, The description will be made as the media GW 50, the router 60, and the like.

  Here, the communication terminal 10-1 in the network a communicates with the codec “a” which is the first encoding scheme, and the communication terminal 10-3 in the network b has a second code different from the first encoding scheme. A third code different from both the first encoding method and the second encoding method between the media GW 50-1 and the media GW 50-2 in the network c. Communication is performed using the codec “c”, which is a conversion method. Here, the codec in the network c is called an internal codec, while the codec in the network a and the network b is called an external codec. In addition, when a plurality of communication terminals 10 that perform communication perform communication using the same codec, the common codec is referred to as a direct codec.

  The communication terminal 10 establishes a connection by communicating a call control signal based on a predetermined call control protocol (signaling protocol), and then, based on the established connection, based on a predetermined data transfer protocol, The computer device performs communication of a data signal encoded by any one of a plurality of defined codecs. For example, SIP can be applied as the call control protocol, RTP can be applied as the data transfer protocol, and G. Codecs such as 711 and AMR (Adaptive Multi-Rate) can be applied.

  The call control server 20 (call control server 20-1) associates a telephone number with an IP address based on a predetermined call control protocol, or sends a call control signal transmitted from the communication terminal 10-1 to a communication destination. To the call control server 20 (call control server 20-2). In the present embodiment, the call control server 20 is a SIP server that controls communication based on SIP.

  The communication control device 30 is connected to a plurality of communication terminals 10 via a plurality of networks. Negotiation of device capability between the communication terminals 10 is started before the communication terminal 10 that wants to communicate starts communication. It is a computer apparatus which performs. The communication control device 30 also has a function as the call control server 20 that controls call control signals. FIG. 2 is a diagram illustrating an example of a block configuration of the communication control device 30. The communication control device 30 includes a device capability storage unit 31, a conversion device storage unit 32, a relay device storage unit 33, a device capability management unit 34, a conversion device management unit 35, a communication unit 36, and a call control unit 37. And a communication control unit 38.

  In the device capability storage unit 31, for each of the plurality of communication terminals 10, a device capability in which a communication terminal ID for identifying the communication terminal 10 is associated with information indicating a codec used by the communication terminal 10 among the plurality of codecs. Information is stored. FIG. 3 is a diagram illustrating a data example of the device capability information stored in the device capability storage unit 31. The device capability information includes a telephone number associated with the communication terminal ID, a media type, and a codec (audio codec, video codec,...) Corresponding to the media type. SIP-ID may be applied to the communication terminal ID for identifying the communication terminal. The telephone number is information for identifying a communication source or a communication destination in SIP communication. The telephone number may be a URI (Uniform Resource Identifier). The media type is information indicating the type of communication performed by the associated communication terminal. As the media type, for example, AUDIO which is voice communication, VIDEO which is moving image communication, or the like can be considered. Here, as a codec corresponding to the media type, an audio codec in audio communication and a video codec in moving image communication are shown. Here, an audio codec and a video codec will be described as examples here. However, when other media types exist, information indicating the codec corresponding to the media type can be stored in association with each other. . The audio codec is information indicating the type of audio codec performed by the associated communication terminal. The video codec is information indicating the type of video codec performed by the associated communication terminal. Here, for example, when there are video codecs of the same type but different bands, different types of video codecs can be associated with each band. When the associated communication terminal 10 uses a plurality of types, the media type is associated with a plurality of media types. A plurality of codec types corresponding to a plurality of media types are associated with each other. For example, it is indicated that the communication terminal 10 whose communication terminal ID is “UA (User Agent) 4” uses both “a” and “b” as voice codecs.

  In the conversion device storage unit 32, conversion device information indicating a connection destination of the media GW 50 that codec converts a data signal encoded by a predetermined codec among a plurality of codecs into a data signal encoded by another codec. Is remembered. FIG. 4 is a diagram illustrating a data example of conversion device information stored in the conversion device storage unit 32. The conversion device information is associated with a codec conversion pattern associated with conversion device identification information (M-GW-ID) for identifying the media GW 50 and a logical address. The codec conversion pattern indicates a codec in which the associated media GW 50 performs codec conversion. For example, when the codec conversion pattern is “ac” indicating the conversion pattern of the audio codec, the process of converting the data signal of codec a into the data signal of codec c, and the data signal of codec c as the data signal of codec a To perform the process of converting to. The logical address is information indicating the connection destination of the associated media GW 50, for example, an IP address. In the present embodiment, in this way, the media GW 50-1 converts the data signal based on the codec “a” into the data signal based on the codec “c”, and the media converts the data signal based on the codec “b” into the data signal based on the codec “c”. Information indicating a connection destination with the GW 50-2 is stored.

Returning to FIG. 2, the relay device storage unit 33 stores relay device information indicating the connection destination of the router 60 that relays the data signal transmitted from the communication terminal 10 without codec conversion. The relay device information includes a logical address (IP address) of the connection destination router 60 associated with the router ID for identifying the relay device such as the router 60-1 or the router 60-2.
The device capability management unit 34 receives a call control signal including information indicating the codec used by the communication terminal 10 from the communication terminal 10, and sets the received call control signal to the communication terminal ID that identifies the communication terminal 10. The device capability information associated with the information indicating the codec included is stored in the device capability storage unit 31.

  The conversion device management unit 35 reads or writes the conversion device information stored in the conversion device storage unit 32. For example, when an input device such as a keyboard or a mouse included in the communication control device 30 is operated by the user and conversion device information is input, the conversion device management unit 35 stores the input conversion device information in the conversion device storage unit 32. Remember.

The communication unit 36 communicates with other computer devices connected via a network. For example, the communication unit 36 receives a call control signal including a communication terminal ID for identifying a communication request destination communication terminal 10-3 from the communication request source communication terminal 10-1.
The call control unit 37 performs call control based on a call control signal communicated via the communication unit 36, and performs processing for establishing a session (connection) between the plurality of communication terminals 10.

  The communication control unit 38 negotiates between the communication terminals 10 that perform communication based on the call control signal received by the communication unit 36 from the communication terminal 10 and the conversion device information stored in the conversion device storage unit 32. . For example, when the communication unit 36 receives a call control signal, the communication control unit 38 determines a voice codec associated with the communication terminal 10 that is a communication request source and a codec associated with the communication terminal 10 that is a communication request destination. If the compared codecs are read out from the device capability storage unit 31 and compared, the connection destination of the media GW 50 that performs conversion of the different codec is read out from the conversion device storage unit 32, and the call control including the read out connection destination is included. The signal is transmitted to the communication request source communication terminal 10 and the communication request destination communication terminal 10. For example, since the codec of the communication terminal 10-1 is “a” and the codec of the communication terminal 10-3 is “b”, the codecs are different. The codec of the network c is “c”. Therefore, the communication control unit 38 reads the M-GW-ID of the media GW 50-1 that performs codec conversion between the codec “a” and the codec “c” from the conversion device storage unit 32, and transmits the M-GW-ID to the communication terminal 10-1. In addition, the communication control unit 38 reads the M-GW-ID of the media GW 50-2 that performs codec conversion between the codec “c” and the codec “b” from the conversion device storage unit 32, and transmits the M-GW-ID to the communication terminal 10-3.

  On the other hand, when the codec of the communication request source communication terminal 10 matches the codec of the communication request destination communication terminal 10, the communication control unit 38 reads the connection destination of the router 60 from the relay device storage unit 33 and A call control signal including the connection destination is transmitted to the communication request source communication terminal 10 and the communication request destination communication terminal 10. For example, since the codec of the communication terminal 10-1 is “a” and the codec of the communication terminal 10-4 is “a” or “b”, the codecs match. In this case, the communication control unit 38 reads the connection destinations of the router 60-1 and the router 60-2 that relay the communication between the communication terminal 10-1 and the communication terminal 10-4, and the communication terminal 10-1 and the communication terminal 10 -4. Here, when the communication control unit 38 transmits connection destination information, a NAT (Network Address Translation) function may be used without directly reporting the IP address or the like.

  Returning to FIG. 1, the signaling GW 40 is a gateway device that connects call control signals between different networks. FIG. 5 is a diagram illustrating an example of a block configuration of the signaling GW 40. The signaling GW 40 includes a device capability storage unit 41, a device capability management unit 42, a first communication unit 43, a second communication unit 44, an interwork unit 45, and a communication control unit 46.

The device capability storage unit 41 stores information similar to the conversion device information stored in the conversion device storage unit 32 of the communication control device 30.
The device capability management unit 42 receives the conversion device information transmitted from the communication control device 30 and stores the received conversion device information in the device capability storage unit 41.

The first communication unit 43 communicates with other computer devices connected via a network.
The second communication unit 44 communicates with another computer device connected via a network different from that of the first communication unit 43.
The interwork unit 45 interworkes call control signals of different networks.
The communication control unit 46 controls communication of a call control signal for negotiation transmitted from the communication control device 30.

Returning to FIG. 1, the media GW 50 is a conversion device (gateway device) that performs codec conversion of a data signal transmitted by the communication terminal 10 in cooperation with the signaling GW 40.
The router 60 is a relay device that transfers a data signal transmitted from the communication terminal 10 without codec conversion.

  Next, an operation example of the communication system 1 including the communication control apparatus 30 according to the present embodiment will be described with reference to FIGS. In these drawings, the communication terminal 10 is indicated as “UA”, the call control server 20 and the communication control device 30 are indicated as “SV”, the signaling GW 40 is indicated as “S-GW”, and the media GW 50 is indicated as “M-GW”. And the router 60 is indicated as “R”.

  FIG. 6 is a diagram illustrating an operation example in which device capability information is stored in the communication control device 30. The device capability information registration process shown here is performed, for example, when the communication terminal 10 is connected to the network. The communication terminal 10-1 is assumed to have a communication terminal ID “UA1”, a telephone number “010-1111-1111”, and a codec to be used “a”. The communication terminal 10-3 is assumed to have a communication terminal ID “UA3”, a telephone number “030-3333-3333”, and a codec to be used “b”. Further, it is assumed that the internal codec of the network c to which the communication control device 30 and the signaling GW 40 belong is “c”.

  Based on SIP, the communication terminal 10-1 generates a call control signal of a register including device capability information indicating a codec (codec “a”) used by the communication terminal 10-1 and transmits the call control signal to the call control server 20-1 ( Step S1). The call control server 20-1 transmits the received call control signal to the signaling GW 40-1 (Step S2). When the first communication unit 43 of the signaling GW 40-1 receives the call control signal transmitted from the call control server 20-1, the second communication unit 44 transmits the call control signal via the interwork unit 45. It transmits to the communication control apparatus 30 (step S3). When the communication unit 36 of the communication control device 30 receives the call control signal transmitted from the signaling GW 40-1, the device capability management unit 34 displays the device capability information included in the call control signal received by the communication unit 36 as the device capability. The data is stored in the storage unit 31.

  Similarly, the communication terminal 10-3 generates a call control signal in a register including device capability information indicating a codec (codec “b”) used by the communication terminal 10-3, and transmits the call control signal to the call control server 20-2. Transmit (step S4). The call control server 20-2 transmits the received call control signal to the signaling GW 40-2 (Step S5). When the second communication unit 44 of the signaling GW 40-2 receives the call control signal transmitted from the call control server 20-2, the first communication unit 43 transmits the call control signal via the interwork unit 45. It transmits to the communication control apparatus 30 (step S6). When the communication unit 36 of the communication control device 30 receives the call control signal transmitted from the signaling GW 40-2, the device capability management unit 34 displays the device capability information included in the call control signal received by the communication unit 36 as the device capability. The data is stored in the storage unit 31. In this way, the device capability information of the communication terminal 10 connected to the network is stored in the communication control device 30.

FIG. 7 is a diagram illustrating an operation example in which the communication terminal 10-1 transmits a call control signal of a communication request with the communication terminal 10-3 as a communication request destination to the communication control apparatus 30.
When the telephone number (030-3333-3333) of the communication terminal 10-3 that is the communication request destination is input, the communication terminal 10-1 determines the codec (codec “a”) used by itself based on SIP. An INVITE call control signal in which the indicated information is described by SDP (Session Description Protocol) is generated and transmitted to the call control server 20-1 (step S11). When receiving the call control signal transmitted from the communication terminal 10-1, the call control server 20-1 transmits the received call control signal to the signaling GW 40-1 (step S12). The signaling GW 40-1 transmits the received call control signal to the communication control device 30 (step S13). When the communication unit 36 of the communication control device 30 receives the call control signal transmitted from the signaling GW 40-1, the codec “a” of the communication terminal 10-1 is read from the received call control signal. Then, the call control unit 37 of the communication control device 30 reads the communication terminal ID “UA3” of the communication terminal 10-3 indicated by the telephone number that is the communication request destination from the correspondence table stored in its own storage area. .

  Further, the device capability management unit 34 reads the device capability (voice codec) corresponding to the communication terminal ID “UA3” of the read communication terminal 10-3 from the device capability storage unit 31. Here, the codec “b” corresponding to the communication terminal ID “UA3” is read. The communication control unit 38 compares the codec “b” read by the device capability management unit 34 with the codec “a” that is the codec of the communication terminal 10-1 that is the communication request source. Here, since the codec “b” of the communication terminal 10-3 and the codec “a” of the communication terminal 10-1 do not match, the conversion device management unit 35 uses the M-GW- of the media GW 50 to convert both codecs. The ID is read from the conversion device storage unit 32. Here, the M-GW-ID (M-GW1-2) of the media GW 50-1 that converts the external codec “a” and the internal codec “c”, the external codec “b”, and the internal codec “c” are converted. The M-GW-ID (M-GW2-3) of the medium GW50-2 to be converted is read out.

FIG. 8 is a diagram illustrating an operation example in which the communication terminal 10-1 and the communication terminal 10-3 perform communication in accordance with a communication request call control signal transmitted from the communication terminal 10-1.
The communication control apparatus 30 includes an internal codec “c”, an external codec “b”, and an M-GW-ID “M-GW2-3” indicating the medium GW 50-2 to which the communication terminal 10-3 is read. Are transmitted to the signaling GW 40-2 (step S21). When receiving the call control signal transmitted from the communication control device 30, the signaling GW 40-2 sets an RTP path for the call control server 20-2 and the communication terminal 10-3 via the media GW 50-2. To instruct. That is, the signaling GW 40-2 transmits a call control signal describing the M-GW-ID “M-GW2-3” indicating the media GW 50-2 to the call control server 20-2 (step S22). The call control server 20-2 transmits the call control signal received from the signaling GW 40-2 to the communication terminal 10-3 (step S23).

  Upon receiving the call control signal transmitted from the call control server 20-2, the communication terminal 10-3 generates and transmits a call control signal describing “200 OK” in accordance with the received call control signal ( Step S24). The call control server 20-2 transmits the call control signal transmitted from the communication terminal 10-3 to the signaling GW 40-2 (Step S25). Upon receiving the call control signal transmitted from the call control server 20-2, the signaling GW 40-2 sets the RTP path of the network c based on the internal codec “c” for the media GW 50-2, Instructs to set the RTP path of the network b based on the external codec “b”. Further, an instruction is given to perform codec conversion between codec “b” and codec “c” (step S26).

  Further, the signaling GW 40-2 transmits a call control signal to the communication control device 30 (step S27). The communication control apparatus 30 includes an internal codec “c”, an external codec “a”, and an M-GW-ID “M-GW1-2” indicating the medium GW 50-1 to which the read communication terminal 10-1 is connected. Are transmitted to the signaling GW 40-1 (step S28). When the signaling GW 40-1 receives the call control signal transmitted from the communication control device 30, the signaling GW 40-1 sets the RTP path of the network c based on the internal codec “c” for the media GW 50-1, while the external codec Instructs to set the RTP path of network a based on “a”. Further, an instruction is given to perform codec conversion between codec “a” and codec “c” (step S29).

  The signaling GW 40-1 transmits a call control signal to the call control server 20-2 (Step S30). When the call control server 20-2 receives the call control signal transmitted from the signaling GW 40-1, the call control server 20-2 transmits the received call control signal to the communication terminal 10-1 (step S31). Thereby, the connection between the communication terminal 10-1 and the communication terminal 10-3 is established, and the communication terminal 10-1 and the communication terminal 10-3 are connected to the RTP via the media GW 50-1 and the media GW 50-2. Communicate. Here, since the media GW 50-1 and the media GW 50-2 perform codec conversion between the internal codec and the external codec, respectively, even when the communication terminal 10-1 and the communication terminal 10-3 use different codecs, the communication is performed. It can be performed.

FIG. 9 is a diagram illustrating an operation example in which the communication terminal 10-1 transmits a communication request call control signal with the communication terminal 10-4 as a communication request destination to the communication control device 30. Here, it is assumed that the communication terminal 10-4 performs encoding of the codec “a”.
Here, similarly to the processing described in FIG. 7, when the telephone number (030-3333-4444) of the communication terminal 10-4 that is the communication request destination is input, the communication terminal 10-1 is based on SIP. Then, an INVITE call control signal in which information indicating its own codec (codec “a”) is described in SDP is generated and transmitted to the call control server 20-1 (step S41). When receiving the call control signal transmitted from the communication terminal 10-1, the call control server 20-1 transmits the received call control signal to the signaling GW 40-1 (step S42). The signaling GW 40-1 transmits the received call control signal to the communication control device 30 (step S43). When the communication unit 36 of the communication control device 30 receives the call control signal transmitted from the signaling GW 40-1, the codec “a” of the communication terminal 10-1 is read from the received call control signal. Then, the call control unit 37 of the communication control device 30 reads the communication terminal ID “UA4” of the communication terminal 10-4 indicated by the telephone number that is the communication request destination from the correspondence table stored in its own storage area. .

  Further, the device capability management unit 34 reads the device capability (voice codec) corresponding to the communication terminal ID “UA4” of the read communication terminal 10-4 from the device capability storage unit 31. Here, the codec “a, b” corresponding to the communication terminal ID “UA4” is read. The communication control unit 38 compares the codec “a, b” read by the device capability management unit 34 with the codec “a” that is the codec of the communication terminal 10-1 that is the communication request source. Here, since the codec “a” of the communication terminal 10-4 matches the codec “a” of the communication terminal 10-1, the communication control unit 38 sets the router address of the router 60 that relays both transmissions to the relay device. Read from the storage unit 33. Here, the router address of the router 60-1 and the router address of the router 60-2 are read out.

FIG. 10 is a diagram illustrating an operation example in which the communication terminal 10-1 and the communication terminal 10-4 perform communication in accordance with a communication request call control signal transmitted from the communication terminal 10-1.
The communication control device 30 performs data signal communication with the opposite call control server (call control server 20-1, call control server 20-2) using the matching codec “a” without using the media GW 50. To instruct. That is, the communication control device 30 sends a call control signal in which the direct codec “a” and the router address indicating the router 60-2 to which the communication terminal 10-4 is read are described in the SDP to the signaling GW 40-2. (Step S51). When receiving the call control signal transmitted from the communication control device 30, the signaling GW 40-2 sets an RTP path based on the direct codec “a” for the call control server 20-2 and the communication terminal 10-3. To instruct. That is, the signaling GW 40-2 transmits a call control signal describing the router ID indicating the router 60-2 to the call control server 20-2 (step S52). The call control server 20-2 transmits the call control signal received from the signaling GW 40-2 to the communication terminal 10-4 (step S53).

  Upon receiving the call control signal transmitted from the call control server 20-2, the communication terminal 10-4 generates and transmits a call control signal describing “200 OK” in accordance with the received call control signal ( Step S54). The call control server 20-2 transmits the call control signal transmitted from the communication terminal 10-4 to the signaling GW 40-2 (Step S55). When receiving the call control signal transmitted from the call control server 20-2, the signaling GW 40-2 sets an RTP path between the communication terminal 10-4 and the communication terminal 10-1 for the router 60-2. (Step S56).

  Further, the signaling GW 40-2 transmits a call control signal to the communication control device 30 (step S57). The communication control apparatus 30 transmits a call control signal in which the direct codec “a” and the router address indicating the router 60-1 to which the communication terminal 10-1 is connected are described in SDP to the signaling GW 40-1 ( Step S58). When the signaling GW 40-1 receives the call control signal transmitted from the communication control apparatus 30, the signaling GW 40-1 sends the communication terminal 10-1 and the communication terminal 10-4 to the router 60-1 based on the direct codec “a”. An instruction is given to set the RTP path (step S59).

  The signaling GW 40-1 transmits a call control signal to the call control server 20-2 (Step S60). When the call control server 20-2 receives the call control signal transmitted from the signaling GW 40-1, the call control server 20-2 transmits the received call control signal to the communication terminal 10-1 (step S61). As a result, the connection between the communication terminal 10-1 and the communication terminal 10-4 is established, and the communication terminal 10-1 and the communication terminal 10-4 do not pass through the media GW 50, and the router 60-1 and the router 60- 2 to perform RTP communication.

  In this case, the codec of the originating terminal that is the communication request source and the destination terminal that is the communication request destination are the same, and the codec in the relay network that relays communication between the originating terminal and the terminating terminal is different. However, communication can be performed efficiently. For example, FIG. 11A is a diagram illustrating a communication example in the related art in such a case. Here, the calling terminal and the called terminal communicate control signals based on SIP via the child control server. Further, it is assumed that codec a (for example, AMR) is adopted as the codec for the data signal between the calling terminal and the called terminal, and codec b (for example, G.711) is adopted as the codec in the relay network. In this way, it is conceivable that codec conversion is performed by the media GW in the relay network even if the codec of the calling terminal and the called terminal are the same. Here, the data signal transmitted from the calling terminal and encoded by the codec a is converted to the codec b by the medium GW on the outgoing network side in the relay network, and then converted to the codec a by the medium GW on the destination network side. And transmitted to the destination terminal. By performing such a conversion process, it is possible that a delay occurs or voice quality deteriorates.

  On the other hand, (b) of FIG. 11 is a figure which shows the example of communication in the case of applying the communication control apparatus 30 of this embodiment. Here, when the calling terminal and the called terminal negotiate in advance, RTP communication is performed not through the media GW 50 that performs codec conversion but through the router 60 that performs relay without performing codec conversion. This eliminates the need for codec conversion in the relay network and enables efficient communication.

  In the above-described example, an example in which there are three networks has been described. However, two networks may be connected. FIG. 12 is a diagram illustrating an operation example in which the communication terminal 10-1 and the communication terminal 10-3 in two networks perform communication. Here, an example is shown in which the codec of the communication terminal 10-1 and the codec of the communication terminal 10-3 are different. However, the communication control device 30 also functions as the signaling GW 40 and the media GW 50. When the communication terminal 10-1 transmits a call setting (INVITE) with the communication terminal 10-3 as a connection destination (steps S71 and S72), the communication control device 30 transmits a call control signal transmitted from the call control server 20-1. Receive. The communication control device 30 compares the codec of the communication terminal 10-1 with the codec of the communication terminal 10-3. If the codecs do not match, the communication control device 30 calls the call control signal in which the address of the media GW 50 (here, the address of the communication control device 30 itself) that performs conversion between the codec “a” and the codec “b” is described in the SDP. Is transmitted to the communication terminal 10-3 via the call control server 20-2 (steps S73 and S74). When the communication terminal 10-3 transmits a call control signal for calling the terminal to the communication terminal 10-1 (steps S75 and S76), the communication control apparatus 30 communicates the call control signal for calling the terminal including the address of the media GW 50. It transmits to the terminal 10-1 (steps S77, 78). The communication terminal 10-3 transmits a call control signal in response to the communication terminal 10-1 via the call control server 20-2 or the like (steps S79 to S82), and the communication terminal 10-1 A response call control signal is transmitted to (steps S83 to 86). Thereby, the connection between the communication terminal 10-1 and the communication terminal 10-3 is established, and the communication terminal 10-1 and the communication terminal 10-3 perform RTP communication via the media GW 50 that performs codec conversion.

  FIG. 13 is a diagram illustrating an operation example when the codec of the communication terminal 10-1 and the codec of the communication terminal 10-2 match. When communication terminal 10-1 transmits call setting (INVITE) with communication terminal 10-2 as the connection destination (steps S91, 92), communication control device 30 transmits the call control signal transmitted from call control server 20-1. Receive. The communication control device 30 compares the codec of the communication terminal 10-1 with the codec of the communication terminal 10-2. If the codecs match, the communication control apparatus 30 transmits a call control signal in which the address of the communication terminal 10-1 is described in the SDP to the communication terminal 10-2, and instructs to perform communication using the codec “a” ( Step S93, 94). The communication terminal 10-2 transmits a call control signal for calling a terminal to the communication terminal 10-1 (steps S95 to S98). The communication terminal 10-2 transmits a response call control signal including the address of the communication terminal 10-2 to the communication terminal 10-1 via the communication control device 30 or the like (steps S99 to 102). Communication terminal 10-1 transmits a call control signal for confirmation to communication terminal 10-2 (steps S103 to S106). Thereby, the connection between the communication terminal 10-1 and the communication terminal 10-2 is established, and the communication terminal 10-1 and the communication terminal 10-2 perform RTP communication directly without using the media GW 50.

  As described above, according to the present embodiment, even when the encoding request used by the communication request source communication terminal and the communication request destination communication terminal are different, efficient real-time data communication can be performed. Also, when the encoding methods used by the communication request source communication terminal and the communication request destination communication terminal match, unnecessary real-time data communication can be performed without performing unnecessary codec conversion or the like.

  Note that a program for realizing the function of the processing unit in the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to perform communication control. May be. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 1 Communication system 10 Communication terminal 20 Call control server 30 Communication control apparatus 31 Apparatus capability memory | storage part 32 Conversion apparatus memory | storage part 33 Relay apparatus memory | storage part 34 Apparatus capacity management part 35 Conversion apparatus management part 36 Communication part 37 Call control part 38 Communication control part 40 Signaling GW
41 device capability storage unit 42 device capability management unit 43 first communication unit 44 second communication unit 45 interwork unit 46 communication control unit 50 media GW
60 routers

Claims (7)

After performing control signal communication based on the control protocol, a plurality of communication devices that perform communication of data signals encoded by one of a plurality of encoding methods based on the data transfer protocol A communication control device connected via a network,
Device capability in which communication device identification information for identifying the communication device and information indicating an encoding method used by the communication device among the plurality of encoding methods are stored in association with each other for each of the plurality of communication devices. A storage unit;
Information indicating a connection destination of a conversion device that converts the data signal encoded by any one of the plurality of encoding methods into the data signal encoded by another encoding method is stored. A conversion device storage unit,
The control signal including information indicating the encoding method used by the communication device is received from the communication device, and the encoding method included in the received control signal is included in the communication device identification information for identifying the communication device. A device capability registration unit that associates information to be stored in the device capability storage unit, and
A receiving unit that receives a control signal including communication device identification information for identifying the communication device that is a communication request destination from the communication device that is a communication request source;
When the receiving unit receives the control signal, the device capability is set to the encoding scheme associated with the communication request source communication device and the encoding scheme associated with the communication request destination communication device. Control that includes the connection destination by reading the connection destination of the conversion device that performs the conversion of the different encoding method from the conversion device storage unit when the compared encoding methods are different from each other by reading from the storage unit A communication control unit that transmits a signal to the communication device of the communication request source and the communication request destination;
A communication control apparatus comprising: A relay device storage unit storing information indicating a connection destination of a relay device that relays the data signal without converting the encoding method;
When the receiving unit receives the call control signal, the communication control unit includes the encoding scheme associated with the communication request source communication device and the code associated with the communication request destination communication device. Call control including a connection destination of the relay device by reading out the connection destination of the relay device from the relay device storage unit when the compared encoding methods match. The communication control device according to claim 1, wherein a signal is transmitted to communication devices of the communication request source and the communication request destination. The communication request source communication device encodes a data signal using a first encoding method, and the communication request destination communication device uses a second encoding method different from the first encoding method. And the communication request source communication device and the communication request destination communication device use a third encoding method different from both the first encoding method and the second encoding method. Connected via a network that encodes the signal,
The conversion device storage unit includes a first conversion device that converts a data signal according to the first encoding method into a data signal according to the third encoding method, and a data signal according to the second encoding method. Information indicating a connection destination with a second conversion device that converts to a data signal according to the third encoding method is stored;
The communication control unit transmits the connection destination of the first conversion device to the communication device that is the communication request source, and the connection destination of the second conversion device to the communication device that is the communication request destination. The communication control device according to claim 1 or 2, wherein The communication control unit includes, in a signaling gateway connected to the communication request destination communication device, an internal codec indicating the third encoding method, an external codec indicating the second encoding method, and the second codec. The communication control apparatus according to claim 3, wherein a connection destination of the conversion apparatus is transmitted. The connection destination of the second conversion device transmitted by the communication control unit to the signaling gateway is transmitted by the signaling gateway to a call control server connected to the communication request destination communication device. Item 5. The communication control device according to Item 4. When the communication control unit transmits the connection destination of the second conversion device to the communication request destination communication device via the signaling gateway and the call control server, the communication request destination communication device The signaling gateway that has transmitted the response signal to the signaling gateway via the control server and received the response signal transmits the response signal to the second conversion device and the communication request destination communication device by the second encoding method. Instructing the communication of the data signal between the first conversion device and the first encoding device by performing the communication of the data signal between,
When the communication control unit receives a response signal from the communication request destination communication device via the signaling gateway, the third encoding method is added to the signaling gateway connected to the communication request source communication device. The communication control apparatus according to claim 5, wherein an internal codec to be displayed, an external codec to indicate the first encoding method, and a connection destination of the first conversion apparatus are transmitted. After performing control signal communication based on the control protocol, a plurality of communication devices that perform communication of data signals encoded by one of a plurality of encoding methods based on the data transfer protocol For each of the plurality of communication devices, communication device identification information for identifying the communication device is associated with information indicating an encoding method used by the communication device among the plurality of encoding methods. And the device capability storage unit that is stored and the data signal encoded by any one of the plurality of encoding methods is converted into the data signal encoded by another encoding method A communication control method of a communication control device, comprising: a conversion device storage unit storing information indicating a connection destination of the conversion device
The control signal including information indicating the encoding method used by the communication device is received from the communication device, and the encoding method included in the received control signal is included in the communication device identification information for identifying the communication device. Associating information to be stored in the device capability storage unit;
Receiving from the communication request source communication device a control signal including communication device identification information for identifying the communication request destination communication device;
When the control signal is received, the encoding method associated with the communication request source communication device and the encoding method associated with the communication request destination communication device are read from the device capability storage unit. If the compared encoding methods are different, the connection destination of the conversion device that performs the conversion of the different encoding method is read from the conversion device storage unit, and the control signal including the connection destination is transmitted to the communication device. Transmitting to the communication device of the request source and the communication request destination;
A communication control method comprising:

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