JP2010109738A - Ip key telephone equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accommodate key telephones having various media capabilities, automatically determine an optimal media capability between a key telephone and an IP outside line which supports audio communication and video communication, and allow conversation with the optimal media capability. <P>SOLUTION: An IP key telephone equipment 100 accommodates key telephones 91, 92, ..., and so on having various media capabilities, and allows conversation with the IP outside line which supports audio communication and video communication. A CCU1, when a key telephone originates a call to the IP outside line, performs fallback while mutually exchanging a media capability with the other end equipment in accordance with SIP, thereby selecting a media capability optimal to conversation. Also, the CCU1, when receiving an individual incoming call or a broadcast incoming call from the IP outside line, selects a media capability for conversation while exchanging a media capability with the other end equipment in accordance with SIP using an incoming call handling capability determination table conforming to system data as an algorithm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an IP button telephone device, and in particular, accommodates extension telephones with various media capabilities, and automatically determines the optimum media capability for calls between extension phones and IP external lines that support voice communication and video communication. , IP button telephone device that enables calls with optimal media capabilities.

  The conventional IP external network does not support high-quality voice communication and video communication other than standard sound quality. Therefore, the IP button telephone device interposed between the IP outside line and the extension telephone need only support only standard sound quality voice communication, and does not need to support high sound quality voice communication or video communication. There is no need to perform automatic judgment control of audio and video capabilities.

  The next generation network (NGN) IP external network supports high-quality voice and video communications.

In Patent Literature 1, in a communication control device that controls communication between a plurality of incoming communication terminals and a plurality of incoming communication terminals having the same position information on a communication network, the positional information of the plurality of incoming communication terminals, It is described that there is provided means for storing media receiving capability information and priority receiving terminal information, and a destination terminal control means for selecting an optimal communication terminal device from a plurality of receiving side communication terminal devices with reference to these information. ing.
JP 2005-130287 A

  NGN's IP external network supports high-quality voice and video communications, so it is necessary to support high-quality voice and video communications even with IP button telephones.

  In NGN, IP button telephone equipment, extension telephones with media capability of only standard voice, extension phones with two voice media capabilities of standard sound quality and high sound quality, extension phones with media capability of voice and video only of standard sound quality, standard sound quality It is considered to accommodate extension telephones with various media capabilities, such as two telephones with high audio quality and voice and video media capabilities.

  In addition, there are individual incoming calls and broadcast incoming calls for IP button telephone devices. The individual incoming call is a function for displaying an incoming call only on a specific extension telephone of the number by dial-in, and only the specific extension telephone can receive a call.

  On the other hand, the broadcast incoming call is a function that can display an incoming call to a plurality of grouped extension telephones. In this case, the plurality of extension telephones to be grouped are not limited to those having the same media capability, but may include those having different media capabilities. For incoming calls, you can receive calls from any extension telephone with any media capability in the group. That is, it can be received by any one of a plurality of extension telephones constituting the group.

  When a call is made from the extension telephone of the IP key telephone apparatus to the IP outside line, if the media capability of the destination telephone is known in advance, a call can be made by matching the media capability of the caller extension telephone. However, in some cases, the media capability of the destination telephone is not known. In this case, in order to enable a call between the caller extension telephone and the destination telephone, select an appropriate media capability for each other or one. A mechanism is needed to make calls.

  In addition, when an individual incoming call is received from an IP outside line to the IP button telephone device, the called extension telephone will receive the incoming call. However, even if the calling telephone has a media capability different from that of the called extension telephone, the calling telephone In order to make a call on the destination extension telephone, it is necessary to have a mechanism for making a call by selecting an appropriate media capability with each other or one of them.

  Also, when there is a broadcast incoming call from an IP external line to an IP key telephone device, one of the extension telephones that make up the group will receive the incoming call. May include things with various media capabilities. Under such circumstances, a mechanism for how to receive incoming broadcasts is required.

  An extension telephone can hold a call and transfer it to another extension telephone. When telephones with audio and video media capabilities are talking to each other via an IP external line, if the call is put on hold and transferred to an extension phone with only audio media capabilities, the call is temporarily transferred to the extension telephone. It is also necessary to have a mechanism for how to handle video that is no longer needed.

  The communication control device described in Patent Document 1 is provided as an IP telephone server in an IP telephone network, and receives position information and media reception of a plurality of incoming communication terminals having the same position information on the IP telephone network. Since capability information and priority receiving terminal information are stored, it is necessary to consider the system configuration of the entire network. In addition, this makes it possible to select an optimal communication terminal device from a plurality of incoming communication terminals having the same location information (the same telephone number or ID) on the IP telephone network. The communication terminal device and the receiving communication terminal device do not cooperate to select and communicate the optimum media capability for both.

  The object of the present invention is to accommodate extension telephones with various media capabilities, automatically determine the optimum media capability between the extension phone and the IP external line that supports voice and video communications, and call with the optimum media capability. The object is to provide an IP button telephone device that enables this.

  In order to achieve the above object, the present invention accommodates an extension telephone having various media capabilities and enables an IP external telephone that supports voice communication and video communication to communicate with an external IP line. It is characterized in that a main control unit is provided which allows a telephone call by selecting an optimum media capability between the extension telephone and the other device while exchanging media capabilities with each other.

  In addition, the present invention provides the main control unit that falls back while exchanging media capabilities with each other device by SIP when the extension telephone transmits to the IP outside line, and is optimal for the extension telephone and the other party device. It features the ability to make calls by selecting media capabilities.

  In addition, the present invention provides the main control unit, when there is an individual incoming call from the IP outside line to the extension telephone, the incoming / outgoing determination table according to the system data set in advance in the IP button telephone apparatus as an algorithm with the other party apparatus using SIP. It is characterized in that it is possible to make a call with an optimum media capability between the extension telephone and the counterpart device while exchanging media capabilities with each other.

  In addition, the present invention, when the main control unit receives a broadcast incoming call from the IP outside line to the extension telephone, the incoming / outgoing determination table according to the system data set in advance in the IP button telephone apparatus as an algorithm with the counterpart apparatus in SIP If the media capability is exchanged, if the incoming call is not possible, the incoming call is rejected. If the incoming call is possible, the incoming call is rejected, and a call can be made from any of the grouped extension telephones. .

  Further, the present invention provides a case where an extension telephone having no video capability receives a call state when the main control unit can receive a broadcast incoming call including video and audio from an IP outside line to the extension telephone. Is characterized by discarding video packets from the IP external line and transmitting the muted image as a video packet to the IP external line.

  Further, according to the present invention, the main control unit receives a voice and video broadcast from the IP outside line to the extension telephone, and a hold operation is performed from a video and voice call state on the IP outside line and the extension telephone. When transferred to an extension telephone having only media capability, the video packet from the IP external line is discarded and a mute image is transmitted as a video packet to the IP external line.

  According to the present invention, when an IP external line is transmitted, an individual call is received, a broadcast is received, etc., between an extension telephone with various media capabilities accommodated by the IP button telephone apparatus and an IP external line that supports voice communication and video communication. It is possible to automatically determine the optimum media ability for a telephone call and select the optimum media ability to enable the call.

  Also, when an incoming telephone call is received by an extension telephone that does not have video capability even though video communication is in progress, the phenomenon that the video is not displayed on the other device can be eliminated by transmitting a mute image. it can.

  In addition, after a video / audio call is started, a hold operation is performed on the extension telephone, and when the call is transferred to an extension telephone having only the voice media capability, a mute image is transmitted so that the video communication is in progress. Regardless of this, it is possible to eliminate the phenomenon that the video is temporarily not displayed on the counterpart device.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a functional block diagram showing an embodiment of the present invention. Here, components unnecessary for the description of the present invention are not shown.

  The IP button telephone apparatus 100 according to the present embodiment has an external line such as an analog line, a number display contract line, a network number dial-in line, an analog leased line, a digital leased line, and an ISDN line. ) As well as VoIP lines and NGN (Next Generation Network) lines (IP external lines). Also accommodates not only legacy analog terminals (TDM extension telephones) such as general analog terminals, digital button telephones, ISDN terminals, hotel phones and fax machines as extension telephones, but also IP extension terminals (IP extension telephones) such as IP button telephones, Control calls between each outside line and each extension telephone.

  In IP button telephone apparatus 100, a main control unit (CCU: Central Control Unit) 1 is mounted on a single board, and performs basic operation control (main control) of the entire IP button telephone apparatus according to main control software. In addition, the CCU 1 performs call processing control between an IP external line, an IP extension, a TDM external line, and a TDM extension (including IP extensions and TDM extensions) to enable various calls. The main control software can interpret SIP, which is a protocol for IP external lines, so that IP external lines can be accommodated and IP external lines can be sent and received.

  A TDM system main control unit (TCCU: TDM Central Control Unit) 2 is also mounted on a single board, and transmits / receives control information to / from the CCU 1 to perform TDM system main control. This control includes, for example, control of various dedicated interfaces (TDM control units) of the TDM external line and the TDM internal line.

  A customer edge unit (CEU) 3 has a function as a high-speed broadband router that performs IP communication in which voice information and control information are multiplexed. The voice conversion unit (VCU) 4 sends voice packets according to the media capability selected for the call and the media capability of the extension phone when it is transferred to an extension phone with a different media capability for voice. Convert from high sound quality to standard sound quality or vice versa. Also, a high-quality or standard-quality voice packet is sent to an extension telephone that holds a high-quality sound and a standard sound quality and does not have a hold sound at the time of holding according to the media capability during a call.

  TCCU2 includes legacy terminals (TDM extension telephones) such as fax terminal 81, hotel phone terminal 82, digital key telephone 83, and standalone telephone 84, and legacy external lines such as general external lines, ISDN net lines, analog leased lines, and digital leased lines (TDM external line) can be connected via various dedicated interfaces (TDM control unit) and TDM bus 5 for TDM communication. The TDM bus 5 includes a D channel that transmits and receives control information and a B channel that transmits and receives audio information.

  CCU1 and TCCU2 are connected by two LAN cables, a LAN cable 8 for voice information transmission and a LAN cable 9 for control information transmission. CCU1, CEU3 and VCU4 are also connected by LAN cable. Further, a maintenance computer 95 is connected to the CCU 1 via the LAN cable 10 and a switching hub (HUB) 7 is connected via the LAN cable 6. The HUB 7 is connected to an IP key telephone 91 and an audio conference device 92 via a dedicated interface. The wireless access point (AP) contains an IP cordless phone 93, and a computer 94 on which a soft phone application is installed. Connected.

  CCU1 is CPU 11, DDR memory (RAM) 12, flash memory 13, dedicated chip 14 specialized for packet transfer control, removable compact flash (CF) memory 15 and layer 2 switch (L2SW) 16 Is the main component. The dedicated chip 14 is a custom LSI that functions as a packet transfer circuit.

  When CCU1 is powered on or reset (POWERON / RESET), the boot loader (software) in the flash memory 13 operates first, and the OS stored in the file system of the CF memory 15 is loaded into the DDR memory 12. to start. Next, the OS loads the CF memory 15 application (main control software) into the DDR memory 12 and starts it. As a result, the main control software operates.

  Further, the CF memory 15 has a database (DB) of system data (setting data) of the IP button telephone device, which is taken out as necessary and set as a variable on the DDR memory 12. Thereby, the IP button telephone apparatus operates according to the system data. The system data can be set by the maintenance computer 95.

  TCCU2 includes CPU 21, DDR memory 22, flash memory 23, phi (PHY) 24, highway switch 25 that controls the B channel of TDM bus 5, Dch control signal communication chip 26 that controls the D channel, and DSP (Digital Signal Processor) 27 is the main component. The PHY 24 is an LSI that controls the physical layer of Ethernet (registered trademark) (not shown).

  The CEU 3 includes a CPU 31, a DDR memory 32, a flash memory 33, a dedicated chip 34 specialized for packet transfer control, and an L2SW 35 as main components. The dedicated chip 34 is the same as the dedicated chip 14. The VCU 4 includes a CPU 41, a DDR memory 42, a flash memory 43, an L2SW 44, and a DSP 45 as main components. The DSP 45 converts voice packets from high sound quality to standard sound quality. The reverse conversion is also performed.

  The IP button telephone device 100 of the above embodiment is configured as a multi-CPU system in which CPUs 11, 21, 31, and 41 are distributedly arranged in each of CCU1, TCCU2, CEU3, and VCU4, and these CPUs are linked to perform overall control. Therefore, load distribution can be realized. Various dedicated interfaces (TDM control units) also include a CPU. In addition, since the packet transfer is controlled by the hardware of the dedicated chips 14 and 34 mounted on the CCU1 and CEU3, the processing load on the CPU is reduced.

  In the IP button telephone device 100, for example, when the single phone 84 is made / received via a TDM external line, the TCCU 2 performs control of the TDM system by transmitting / receiving control information via the CCU 1 and the LAN cable 9, and the TDM extension and the TDM Enables transmission and reception of voice information between external lines. The single telephone 84 and the TCCU 2 transmit / receive the PCM-converted voice information through the TDM bus 5 by time division multiplexing communication.

  Further, for example, when the single telephone 84 makes / receives a call via the IP external line, the voice information subjected to PCM conversion is transmitted / received between the single telephone 84 and the TCCU 2 by the time division multiplexing communication on the TDM bus 5. Voice packets are exchanged between the TCCU2 and the CCU1 via the LAN cable 8. The DSP 27 of TCCU2 is used for mutual conversion between voice information TDM and packets. In CEU3, it is connected to the IP external line via L2SW35, and CCU1 and CEU3 exchange voice packets by using their respective dedicated chips 14 and 34.

  Further, for example, when the IP button telephone 91 makes / receives a call via the TDM external line, the routes of the TDM bus 5, TCCU2, CCU1 and HUB7 are established. Further, when the IP key telephone 91 makes / receives a call via an IP external line, the routes of CEU3, CCU1 and HUB7 are established.

  The extension telephones accommodated in the IP key telephone device 100 include extension telephones with media capabilities of only standard voice, extension telephones with two voice media capabilities of standard sound quality and high sound quality, audio and video media with only standard sound quality Extension telephones, two telephones with standard audio quality and high audio quality media and voice extension, and extension telephones with IP / KT (Internet Protocol Key) Telephone), video input (CCD) / output (LCD) function and extension telephone with browser function (A-KT: Advanced Key Telephone), and a button telephone function as an application on a PC connected to a camera, microphone and speaker. There are a wide variety of extension telephones such as extension telephones (Software Key Telephones).

  IP-KT has standard and high-quality audio media capabilities, but does not have video media capabilities. A-KT has media capabilities for standard and high-quality audio, MPEG4 Encoder / Decoder (Simple Profile Level 0 to 3), QVGA (320x240), QCIF (176x144) video size, up to 15fps frame With media capabilities for rate video. Softphone has standard and high-quality audio media capabilities, and MPEG4 Encoder / Decoder (Simple Profile Level 0 to 3), VGA (640x480), QVGA (320x240), CIF (352x288), QCIF (176x144) ) With a video capacity of up to 30fps frame rate.

  In FIG. 1, an IP key telephone 91, an audio conference apparatus 92, an IP cordless phone 93, and a computer 94 are illustrated as IP extension telephones. These IP extension telephones make and receive calls via the IP key telephone apparatus 100 to and from IP external lines that support standard and high-quality voice and video.

  The IP button telephone device 100 is required to have a function of automatically determining and controlling the mutual media capabilities of the extension telephones to be talked and enabling a call using the optimum media. Therefore, the main control software operating on the CCU1 of the IP button telephone device 100 selects the optimum media capability for the extension telephone and the other party device while exchanging media capabilities with the other party device via SIP, and makes a call. Provide functions that enable it.

  First, when an extension telephone makes a call to an IP outside line, CCU1 falls back while exchanging media capabilities with each other device via SIP, and can select and call the optimum media capability between the extension phone and the other device. And

  FIG. 2 is a flowchart showing an example of fallback when an extension telephone makes a call to an IP outside line. When the extension telephone has a video and audio media capability, first, it is checked whether or not a call can be made with the video and audio media capabilities. For this reason, the calling party (SIP-UA) sends out SDP (INVITE (video + audio)) including the video and audio media capabilities to the network (SDP offer). SDP (Session Description Protocol) is a protocol that describes media capabilities and is sometimes described in SIP messages.

  On the other hand, a trial execution message (100 Trying) is returned from the counterpart device, and if the counterpart device has video and audio media capabilities, an incoming call response is returned. In this case, the extension telephone and the partner apparatus select the video and audio media capabilities as the media capabilities for communicating with each other. However, if the counterpart device has only a media capability of either video or audio, a response to reject the incoming call (Not Acceptable Here (warn-code = 304)) is returned from the counterpart device. Since warn-code = 304 is a response that `` There is something that cannot be used with media '', after sending a confirmation message (ACK) from the originating side (SIP-UA), SDP (including audio-only media capability) INVITE (voice)) is sent to the network, and in the same manner as described above, it is checked whether or not it is possible to talk to each other with the voice-only media capability. Here, if an incoming call response is returned from the counterpart device, the extension telephone and the counterpart device select the voice media capability as the media capability to talk to each other. However, if an incoming call rejection response is returned, it is determined that the incoming call is rejected because a call cannot be made even with a voice-only media capability.

  In this way, when making an outgoing call from an extension telephone to an IP external line, the optimum media ability for making a call between the extension telephone and the other device is selected by reducing the SIP media ability and making a call again (fallback). be able to.

  Next, in the case of individual incoming calls and broadcast incoming calls, the CCU 1 determines whether or not incoming calls are possible while exchanging media capabilities with the counterpart device using SIP. For this reason, the main control software operating on CCU1 has system data related to media capability exchange, and finally uses SIP as an incoming / outgoing decision table according to the system data as an algorithm to exchange media capabilities with the other device. Determine the optimum media capability for a call between the other device and the extension telephone. The system data is stored in advance in the CF memory 15 using the maintenance computer 95.

  FIG. 3 shows an example of a call acceptance / rejection determination table according to the system data. In the figure, “O” in “Reception offer video capability analysis result” indicates that the incoming call is acceptable, and “X” indicates that the incoming call is not possible (it is impossible to respond with the presentation capability). In addition, “video cannot be received” means that video communication is restricted.

  The incoming / outgoing permission determination table of this example has two system data regarding video capabilities of “video incoming restriction” and “video size restriction”. The video capability of an extension telephone is defined by the profile level (a parameter that comprehensively presents the maximum capability in terms of video capability) and the video size (a parameter that is individually presented for the corresponding video size). There is 0. Video sizes include VGA, QVGA, and QCIF. Here, VGA> QVGA> QCIF, L4a / VGA> L4a / QVGA> L3 / QVGA> L0 / QCIF> None (voice).

  Set “Yes” or “No” for incoming video restriction in “Video incoming restriction”, and “No video size restriction” for VGA, QVGA mode <standard>, QCIF mode. Set.

  When there is no “video incoming restriction”, broadcast incoming and individual incoming / outgoing are made according to “video size restriction” and “reception offer video capability analysis result” regardless of the video capability of the extension telephone. For example, for broadcast incoming calls, when “Video Size Restriction” is unrestricted (VGA possible), “Reception Offer Video Capability Analysis Result” is SP @ L4a / VGA, SP @ L4a / QVGA, SP @ L3 / QVGA, SP @ Either L0 / QCIF is acceptable. In addition, individual incoming calls will be rejected if the “Received offer video capability analysis result” is SP @ L4a / VGA or SP @ L4a / QVGA when “Video size restriction” is QVGA mode <standard>, but SP @ L3 / QVGA and SP @ L0 / QCIF are acceptable.

  In the case of “video incoming restriction”, broadcast communication is restricted regardless of “video size restriction”, “reception offer video capability analysis result”, and “terminal video capability”. Individual incoming calls to extension telephones that do not have the corresponding video capability are rejected. When the extension telephone does not have video capability but only audio capability, video communication is limited regardless of the “reception offer video capability analysis result”.

  As described above, when there is no “video incoming restriction”, whether or not an incoming call is accepted is determined according to “video size restriction” and “reception offer video capability analysis result” regardless of the video capability of the extension telephone. An extension telephone that does not have video capability for the situation may receive a call. In this case, the video is not displayed on the counterpart device even if the video communication is in progress, and the video is not transmitted to the counterpart device in the video communication mode.

  In order to eliminate this phenomenon, when an extension telephone that does not have video capability for the incoming call status of the incoming call is received, the video packet from the IP external line is discarded and the mute image is used as the video packet. It is preferable to transmit to the outside line. As the mute image, for example, a still image of the characters “Video mode communication in progress. Video charging is in progress” can be used. By transmitting the mute image, it is possible to indicate that the video mode communication is being performed on the video screen of the counterpart device on the IP outside line. The mute image can be generated and transmitted by the VCU 4 of the IP button telephone device. That is, the mute image is stored in the flash memory 43 and developed on the DDR memory 42 at the time of activation. Then, the mute image on the DDR memory 42 is transmitted to the instructed IP address and UDP port according to the command from the CCU 1 in the designated size.

  Also, when an extension telephone with video capability receives a call for a broadcast incoming call, but the extension is put on hold and the call is transferred to an extension telephone with only voice media capability The same phenomenon occurs. In this case as well, it is preferable to discard the video packet from the IP external line and transmit the muted image as a video packet to the IP external line.

  As for voice, an extension telephone having a different media capability may receive the voice. In this case, the VCU 4 converts the voice packet into a high sound quality or a low sound quality in accordance with the selected media capability and the media capability of the extension telephone.

  FIG. 4 is a flowchart showing the operation when the extension telephone makes a call to the IP outside line.

  First, INVITE transmission (S41) is performed from the calling side (SIP-UA) to the counterpart device through the IP external line. This INVITE transmission includes audio: high sound quality, standard sound quality, and video: SP @ L4a 2M VGA 30fps as media capabilities. A response to this INVITE transmission is received (S42), and its type is determined (S43). If 180 Ringing is determined, a 200 OK response is received (S44), an ACK is sent (S45), and voice: high sound quality or standard sound quality (depending on the SDP codec type included in the 200 OK response) ), Video: SP @ L4a 2M VGA 30 fps media call is started (S46). 180 Ringing indicates that a call is being made (a call can be made with the presented media capability). The 200 OK response indicates that the call has been received, and the SDP of the media capability of the response source device is added.

  If it is determined in S43 that 488 Warning 304, ACK is transmitted (S47) and fallback is performed. In other words, although INVITE is transmitted, 488 Warning 304 is a response that “There is no ability to use the offered media type”, so the media capabilities to be included in it are: voice: high sound quality, standard sound quality, video: none (S48 ). A response to this INVITE transmission is received (S49), and its type is determined (S50). If 180 Ringing is determined, a 200 OK response is received (S51), then an ACK is sent (S52), and a call is started with a media capability of voice: high sound quality or standard sound quality, video: none ( S53). However, if it is determined in S50 that 488 Warning 305 or other 4xx response, the process proceeds to S61. Note that 488 Warning 305 is a response “There is no ability to use the codec of the offered media”. Also, the other 4xx responses are “no specific fallback response” responses, so fallback to media capabilities with only standard sound quality is attempted.

  If it is determined in S43 that 488 Warning 305 or 488 Warning 370, ACK is transmitted (S54) and fallback is performed. That is, although INVITE transmission is performed, the media capability included in the transmission is reduced to audio: standard audio quality, video: SP @ L0 48K QCIF 15fps (S55). The 488 Warning 370 is a response “too much for the available bandwidth”. A response to this INVITE transmission is received (S56), and its type is determined (S57). If 180 Ringing is determined, a 200 OK response is received (S58), an ACK is sent (S59), and voice: Standard sound quality, Video: SP @ L0 48K QCIF 15fps media capability Start (S60). However, if it is determined in S57 that there is a 488 Warning 304, 488 Warning 305, 488 Warning 370 or other 4xx response, the process proceeds to S61.

  If it is determined in S43 that the response is another 4xx response, the process proceeds to S61. In S61, ACK is transmitted (S61) and fallback is performed. Next, INVITE transmission (S62) is performed including the minimum media capability of audio: standard sound quality and video: none. A response to this INVITE transmission is received (S63), and the type is determined (S64). If 180 Ringing is determined, a 200 OK response is received (S65), then an ACK is sent (S66), and a call is started with a media capability of voice: standard sound quality and video: none (S67). . However, if it is determined in S64 that the response is another 4xx response, an ACK is transmitted (S68) but not retransmitted (S69). That is, the call cannot be made.

  FIG. 5 is a flowchart showing the operation when there is an individual incoming call from the IP outside line. Fig. 5 (a) shows the operation when the media capability of the caller is not accepted. Receives an INVITE that includes the media capability of SP: L4a 2M VGA 30fps from the IP outside line. In the case of (S70), a response 488 Warning 304 that “there is no ability to use the offered media type” is transmitted (S71). Thereafter, ACK is received (S72). After that, the operation is performed according to the correspondence on the IP outside line side and the incoming / outgoing determination table (S73).

  Fig. 5 (b) shows the operation when accepting the media capability of the caller as it is, receiving an INVITE containing the media capability of SP: L4a 2M VGA 30fps from the IP outside line: voice: high sound quality, standard sound quality. (S74), a response 180 Ringing is sent to the effect that the call can be made with the presented media capability (S75), and for voice, the extension media phone has the highest media capability or the extension phone quality selection A 200 OK response with the SDP of the high sound quality selected with the button or the standard sound quality added is transmitted (S76). Then, after receiving ACK (S77), a call is started (S78) with media capability of voice: high sound quality or standard sound quality, video: SP @ L4a 2M VGA 30fps.

  FIG. 6 is a flowchart showing the operation when there is a broadcast incoming call from the IP outside line. Fig. 6 (a) shows the operation when the incoming video call is restricted and the caller's media capability is not accepted. From the IP external line: Voice: High sound quality, Standard sound quality, Video: SP @ L4a 2M VGA 30fps When the INVITE including the media capability is received (S79), a response 488 Warning 304 of a fallback request to only audio due to video incoming restriction is transmitted (S80). Thereafter, ACK is received (S81). After that, it operates according to the correspondence on the IP outside line side and the above-mentioned incoming / outgoing decision table (S82).

  Figure 6 (b) shows the operation when the incoming call media capability is accepted as it is without restricting the incoming video. Voice: High quality, standard quality, video: SP @ L4a 2M VGA 30fps When receiving an INVITE that includes the media capability (S83), a response 180 Ringing is sent to the effect that the call is still possible (S84), and for the voice, the extension phone receiving the media capability is the highest, or A 200 OK response with the SDP of the high sound quality or the standard sound quality selected by the sound quality selection button of the extension telephone is added (S85). Then, after receiving the ACK (S86), a call is started (S87) with a media capability of voice: high sound quality or standard sound quality, video: SP @ L4a 2M VGA 30fps. In this case, high-quality sound or standard sound quality is selected by the received extension telephone, and as described above, a mute image may be transmitted.

  Although the embodiment has been described above, the present invention is not limited to the above embodiment. For example, the media capability of the above-described extension telephone is merely an example and may be other.

It is a functional block diagram which shows one Embodiment of this invention. It is a flowchart which shows the example of a fallback when an extension telephone transmits to an IP outside line. It is a figure which shows the example of the incoming / outgoing possibility determination table according to system data. It is a flowchart which shows operation | movement in case an extension telephone transmits to an IP outside line. It is a flowchart which shows operation | movement when there exists an individual call from an IP outside line. It is a flowchart which shows operation | movement when there exists a broadcast incoming from an IP outside line.

Explanation of symbols

1 ... Main control unit (CCU), 2 ... TDM system main control unit (TCCU), 3 ... Customer edge unit (CEU), 4 ... Voice conversion unit (VCU), 5 ... TDM bus, 6, 8, 9, 10 ... LAN cable, 7 ... switching hub (HUB), 11, 21, 31, 41 ... CPU, 12, 22, 32, 42 ... DDR memory (RAM), 13, 23, 33, 43 ... flash memory, 14, 34 ... dedicated chip, 15 ... compact flash (registered trademark) (CF) memory, 16, 35, 44 ... layer 2 switches (L2SW), 24 ... Phi (PHY), 25 ... Highway switch, 26 ... Dch control signal communication chip, 27,45 ... DSP, 81 ... Fax terminal, 82 ...・ Hotel phone terminal, 83 ... Digital button phone, 84 ... Single phone, 91 ... IP button phone, 92 ... Voice conference device, 93 ... IP cordless phone, 94 ... Computer, 95 ... Maintenance computer, 1 00 ・ ・ ・ IP button telephone device

Claims (6)

In an IP button telephone apparatus that accommodates extension telephones of various media capabilities and enables calls with IP external lines that support voice communication and video communication.
1. An IP button telephone device comprising a main control unit that allows a telephone to select an optimum media capability for an extension telephone and a counterpart device while exchanging media capabilities with the counterpart device via SIP. The main control unit falls back while exchanging media capabilities with each other device by SIP when the extension telephone transmits to the IP outside line, and selects the optimum media capability between the extension telephone and the other device. 2. The IP button telephone apparatus according to claim 1, wherein a telephone call is possible. The main control unit exchanges media capabilities with the other side device by SIP using an incoming call determination table according to the system data set in advance in the IP button telephone device as an algorithm when there is an individual incoming call from the IP outside line to the extension telephone. However, the IP button telephone apparatus according to claim 1, wherein a telephone conversation can be performed with an optimum media capability between the extension telephone and the other party apparatus. The main control unit exchanges the media capability with the counterpart device by SIP using an incoming call determination table according to the system data set in advance in the IP button telephone device as an algorithm when there is a broadcast incoming call from the IP external line to the extension telephone, The incoming call is rejected if the incoming call is not possible, and is called in a ringing state if the incoming call is possible, so that a call can be made from any of the plurality of extension telephones grouped. IP button telephone device. The main control unit receives a call from an IP external line when an internal telephone that does not have video capability receives a call when the broadcast incoming call including video and audio is possible from the IP external line to the internal telephone. 5. The IP button telephone device according to claim 4, wherein the video packet is discarded and the mute image is transmitted as a video packet to the IP outside line. The main control unit is an extension that receives voice and video broadcasts from an IP external line to an extension telephone, has a voice media capability only when a hold operation is performed from a video and voice call state on the IP external line and the extension telephone. 5. The IP button telephone device according to claim 4, wherein when transferred to the telephone, the video packet from the IP external line is discarded and a mute image is transmitted as a video packet to the IP external line.

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