JP2010178212A - Intercom system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intercom system capable of performing speech communication between intercoms connected to a plurality of networks with different communication capacities, while maintaining the high quality of speech communication or videos. <P>SOLUTION: Intercom systems A and B include a plurality of sets of communication terminals 1 and a controller 2, to which the plurality of sets of communications terminals 1 are connected through a transmission line L1 composed of a pair of balanced twisted pair lines. The controllers 2 and 2 of both intercom systems A and B are connected by a LAN (local area network). The controller 2 includes a bridge 21 for protocol conversion between a first network and a second network, wherein the first network is configured by connecting the communication terminals 1 and the controller 2 by the transmission line L1, and the second network is the LAN. Among the first network and the second network, the controller 2 restricts communication traffic flowing from a network with a relatively large communication capacity into a network with a relatively small communication capacity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an intercom system.

  Conventionally, an intercom system for collective housing as described in Patent Document 1 has been provided.

  The intercom system described in Patent Document 1 is a digital multiple packet transmission of audio data and video data by IP protocol over a LAN using 10/100 Mbps Ethernet (registered trademark), and is installed in each dwelling unit of an apartment house. Communication terminals, such as dwelling unit intercoms, lobby intercoms installed at the common entrance of apartment buildings, and telephone terminals for management rooms installed in the management rooms of apartment buildings, transmit to control devices that control communication between communication terminals. Connected through a line.

  Conventionally, an intercom system that transmits and receives data signals such as audio, video, and control data by digital carrier wave transmission between communication terminals and control devices has also been proposed.

Japanese Patent No. 3900062

  By the way, there are intercom systems that perform data transmission by carrier wave digital transmission as intercom systems, and intercom systems that are configured with LANs such as Ethernet (registered trademark). When a bridge is used, a bridge that converts the communication method between the two intercom systems is used, and the bridge converts the communication method to enable communication between the two systems.

  In addition, in an intercom system with a large number of intercom units, such as when one housing complex is composed of multiple dwelling units, a network is constructed by connecting dwelling unit intercoms to control devices via transmission lines for each unit. In addition, communication can be performed between communication terminals connected to different networks by connecting a plurality of networks with a LAN such as Ethernet (registered trademark).

  As described above, when two interphone systems having different communication methods are connected by a bridge, or a plurality of networks are connected by a LAN, the interphone system and the LAN may be connected by a bridge. However, there are cases where the communication capacity differs between a LAN and a LAN that perform data transmission by carrier wave digital transmission. In this case, when a plurality of networks having different communication capacities are connected via a bridge and communication traffic on the network side having a relatively small communication capacity is overloaded, a network having a relatively large communication capacity is There has been a problem that voice data and video data flowing into a network having a relatively small communication capacity are discarded, and the quality of the voice and video is deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an interphone system capable of data transmission between a plurality of networks having different communication capacities while maintaining high communication quality. There is to do.

  In order to achieve the above object, the invention of claim 1 is a transmission in which a plurality of communication terminals having at least voice communication means and a control device for controlling communication between the communication terminals are composed of a pair of balanced pair lines. In an interphone system in which a communication terminal and a control device transmit and receive data signals by carrier wave digital transmission, the first network is connected to the first network and performs communication by carrier wave digital transmission. A transmission unit including a second transmission unit connected to a second network having a communication method different from that of the first network, and a bridge unit configured to convert the communication method between the first and second networks. The control device has a communication capacity relative to a network having a relatively large communication capacity among the first and second networks. Intercom system, characterized in that to limit the communication traffic volume flowing into the small network.

  According to a second aspect of the present invention, in the first aspect of the present invention, the bridge unit prioritizes the transfer data buffer for temporarily storing the communication data and the communication data flowing from one of the first and second transmission units. A communication processing unit that temporarily stores the data in the transfer data buffer and outputs the communication data read from the transfer data buffer to the other transmission unit, and the amount of communication data flowing in from a network having a relatively large communication capacity However, when the communication capacity exceeds the communication capacity of the relatively small network, the communication data stored in the transfer data buffer flows from the network having a relatively large communication capacity, and the priority is relatively It is characterized by discarding low communication data.

  According to a third aspect of the present invention, in the second aspect of the present invention, the transfer data buffer includes a first transfer data buffer for temporarily storing communication data flowing in from the first network in an area corresponding to the priority, and a second network. Capacity setting for setting the capacity of the storage area according to the priority for each of the first and second transfer data buffers, the second transfer data buffer temporarily storing the communication data flowing in from the area according to the priority And storing the communication data flowing in from the first and second networks in the first and second transfer data buffers in the first and second transfer data buffers in an area according to the priority. In addition, the communication data is discarded if there is no space in the corresponding area.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the limit value of the communication traffic volume is managed according to the communication capacity of the network having the smaller communication capacity of the first and second networks to which the bridge unit is connected. A call control / communication capacity management unit is provided in the control device. When there is a communication start request from a communication terminal of any network, the call control / communication capacity management unit is connected to the communication terminal that has output the communication start request. And the bridge unit connected to the network of the communication partner communicate with the communication terminal that has output the communication start request when it is determined that both do not exceed the communication traffic volume limit value assigned to each. The start is permitted.

  According to a fifth aspect of the present invention, in the first aspect of the present invention, the control device includes a call control / communication capacity management unit that performs call control between the first and second networks connected to the bridge unit. / The communication capacity management unit manages a multicast address used to collectively control a plurality of communication terminals for each of the networks connected to the bridge unit, and the communication terminals have a relatively small communication capacity. When it is desired to collectively transmit communication data to a plurality of communication terminals connected to the network, the communication data is transmitted to a multicast address in which a plurality of communication terminals to be transmitted are grouped, and the call control / communication capacity management unit When a communication request addressed to a multicast address is received from one of the communication terminals, the bridge unit to which the communication partner network is connected is malformed. And permits the passage of the cast address data.

  A sixth aspect of the invention is characterized in that, in any one of the first to fifth aspects of the invention, a plurality of connection means for detachably attaching the bridge portion are provided in the control device.

  According to the first aspect of the present invention, the amount of communication traffic from a network having a relatively large communication capacity to a relatively small network among the first and second networks connected via the bridge unit is limited. Therefore, it is possible to prevent the communication traffic of the network having a relatively small communication capacity from being overloaded, and the communication quality can be kept high. Therefore, interphone systems that transmit and receive data signals by carrier wave digital transmission and interphone systems that have different communication capacities such as an interphone system that is configured with a LAN such as Ethernet (registered trademark) can be mixed. A high-quality communication is established between communication terminals connected to a plurality of networks by connecting a plurality of networks in which a dwelling unit intercom is connected via a transmission line in each building with a LAN such as Ethernet (registered trademark). It can be carried out.

  According to the second aspect of the present invention, since communication data with a relatively low priority is discarded, communication data with a high priority can be transferred with priority over other data. For example, when various types of information data are transmitted as communication data together with audio data and video data, the audio data and video data can be set by setting the priority of the audio data and video data higher than other data. Is preferentially transferred, the call quality can be kept high.

  According to the invention of claim 3, the capacity setting unit sets the capacity of the storage area corresponding to the priority for each of the first and second transfer data buffers, so that communication data with a low priority is received. It is possible to prevent them from being discarded uniformly, and to transfer the communication data of each priority to the other network according to a certain ratio.

  According to the invention of claim 4, the call control / communication capacity management unit includes both a bridge unit connected to the communication terminal that has output the communication start request and a bridge unit connected to the network of the communication partner. Since the start of communication is permitted only when it is determined that both of the traffic traffic limit values assigned to the bridge part do not exceed, the communication traffic will not be overloaded in any network, and the communication quality will be high. Can keep. In addition, the call control / communication capacity management unit collectively manages the usable communication capacity of all the bridge units, and the limit value of the communication traffic amount of each network can be set centrally. It is not necessary to determine whether to discard communication data on the part side, the configuration of the bridge part can be simplified, and the transfer speed of the bridge part can be increased.

  By the way, when broadcast data is input to the control device, the broadcast data is transmitted to the networks connected to all the bridge units, and communication traffic increases in all the networks. According to this, when it is desired to transmit communication data to a plurality of communication terminals connected to a network having a relatively small communication capacity, the communication data is transmitted to a multicast address in which a plurality of communication terminals to be communicated are grouped. In addition, since the call control / communication capacity management unit sets whether or not the multicast address can be passed to the bridge unit, there is an advantage that communication traffic on the network unrelated to the multicast address does not increase.

  According to the sixth aspect of the present invention, since the bridge portion is detachable with respect to the plurality of connecting means, the number of bridge portions can be easily increased or decreased according to the system configuration.

1 is a system configuration diagram of Embodiment 1. FIG. It is a schematic block diagram of a communication terminal same as the above. It is a schematic block diagram of a bridge part same as the above. It is a schematic block diagram of the bridge part of Embodiment 2. FIG.

  Hereinafter, an embodiment in which the technical idea of the present invention is applied to an intercom system for an apartment house installed in an apartment house will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a system configuration diagram of Embodiment 1, and two interphone systems A and B are connected via a LAN such as Ethernet (registered trademark).

  Each of the interphone systems A and B includes a plurality of communication terminals 1 having at least voice communication means and a control device 2 that controls a call between the communication terminals, as a transmission line L1 composed of a pair of balanced pair lines. The first network is configured by a plurality of communication terminals 1, a control device 2, and a transmission line L 1 that connects between the communication terminal 1 and the control device 2. The control devices 2 and 2 of the interphone systems A and B are connected via a LAN switching switching unit (Hub) 3 such as Ethernet (registered trademark), and between the communication terminals 1 of both interphone systems A and B. You can now make calls. In addition, as the communication terminal 1 of each intercom system A and B, the intercom for a dwelling unit installed in each dwelling unit of a housing complex, the lobby intercom installed in the common entrance (lobby) of a housing complex, the management office of a housing complex There are administrative office machines installed in the rooms.

  As shown in FIG. 2, each communication terminal 1 displays a voice processing circuit 11 that performs voice call processing using a microphone MC and a speaker SP, a video display unit 12 that displays video, and a display on the video display unit 12. A video processing circuit 13 to be controlled, a digital transmission circuit 15 connected to the transmission line L1 through the line coupling circuit 14, and a digital communication circuit 16 that transmits and receives transmission signals through the digital transmission circuit 15 are provided.

  The audio processing circuit 11 outputs audio data encoded by a predetermined encoding method such as PCM to the digital communication circuit 16 after A / D conversion of the audio collected by the microphone MC, and input from the digital communication circuit 16 After the audio data to be decoded is decoded, the speaker SP is driven by an analog audio signal that has been D / A converted, and the audio is sounded. Here, a voice call means is constituted by the microphone MC, the speaker SP, the voice processing circuit 11, and the like.

  The video processing circuit 13 includes a drive circuit that drives the video display unit 12 including a display device such as a liquid crystal display, and the video display unit 12 is driven by video data input from the digital communication circuit 16, whereby the video display unit 12 displays a video (for example, a moving image captured by a camera of a lobby intercom).

  The digital transmission circuit 15 includes a transmission amplifier A1 and a reception amplifier A2 connected to the transmission line L1 via the line coupling circuit 14. The transmission signal that is digitally modulated by the transmission processing unit 17 of the digital communication circuit 16 is input to the transmission amplifier A1, and the transmission signal is amplified and transmitted to the transmission line L1 via the line coupling circuit. The reception amplifier A2 receives a transmission signal from the transmission line L1 through the line coupling circuit 14, amplifies the transmission signal, and outputs the amplified transmission signal to the reception unit 18 of the digital communication circuit 16.

  The digital communication circuit 16 digitally modulates the audio data input from the audio processing circuit 11 and outputs it to the transmission amplifier A1 of the digital transmission circuit 15, and outputs a transmission permission signal to the transmission amplifier A1 to start transmission. A processing unit 17 and a receiving unit 18 that digitally demodulates a transmission signal received by the reception amplifier A2 of the digital transmission circuit 15 and outputs audio data to the audio processing circuit 11 and video data to the video processing circuit 13 are provided. Yes. Further, the digital communication circuit 16 may include a communication control unit that controls transmission / reception timing and extracts a necessary data part from the packet.

  The communication terminal 1 is connected to the control device 2 via a transmission line L1 composed of a pair of balanced pair lines, and transmits data signals such as voice, video, control command, and information data by a carrier wave digital transmission system. Yes.

  On the other hand, as shown in FIG. 1, the control device 2 performs call control / call control for performing call control between a plurality of bridge units 21 to which communication terminals 1 of different systems are connected via a transmission line L1. The communication capacity management unit 22, a plurality of bridge units 21, and the call control / communication capacity management unit 22 are connected, and an external switching switching unit 3 is connected to relay transmission data. 23. The switching exchange unit 23 includes a plurality of connection ports (not shown) to which RJ45 modular plugs are detachably connected, and connection means (see FIG. 5) composed of RJ45 modular plugs connected to a cable from the bridge unit 21. (Not shown) is connected to the connection port of the switching exchange unit 23, so that the bridge unit 21 is detachably connected to the switching exchange unit 23. The number of bridge units 21 is adjusted according to the system configuration. It can be easily increased or decreased.

  3 is a block diagram of the bridge unit 21, and the bridge unit 21 includes a transmission amplifier A3 and a reception amplifier A4 connected to the transmission line L1, and a communication unit 30. The communication unit 30 has a communication method different from that of the network 1 side transmission unit (first transmission unit) 31 connected to the first network via the transmission amplifier A3 and the reception amplifier A4, and the first network. Network 2 side transmission unit (second transmission unit) 32 connected to two networks (LAN in this embodiment such as Ethernet (registered trademark)), a memory unit 33 for temporarily storing transfer data, The communication processing unit 36 that performs the transfer process of the data signal that has flowed in from the second network, the priority of the data input from the network 1 side transmission unit 31 and the network 2 side transmission unit 32, respectively, are determined and input A priority determination unit 37 for giving priority to data, and a communication traffic for determining the communication traffic amount of the first network and the second network. Transfer data buffer capacity setting section (capacity setting section) for setting the buffer capacity of the network 1 side transfer data buffer 34 and the network 2 side transfer data buffer 35 based on the determination results of the traffic determination section 38 and the communication traffic determination section 38 39). The communication data output from the network 1 side transmission unit 31 is amplified by the transmission amplifier A3 and output to the transmission line L1, and the communication data input from the transmission line L1 is amplified by the reception amplifier A4, and then the network 1 Input to the side transmission unit 31.

  The memory unit 33 includes a network 1 side transfer data buffer (first transfer data buffer) 34 for temporarily storing data flowing in from the network 1 side transmission unit 31 (first network side), and a network 2 side transmission unit 32 ( A network 2 side transfer data buffer (second transfer data buffer) 35 for temporarily storing data flowing in from the second network side) is provided.

  The communication processing unit 36 assigns the priority determined by the priority determination unit 37 to the communication data flowing from the network 1 side transmission unit 31 and temporarily stores it in the network 1 side transfer data buffer 34. The communication method of the communication data read from the 1-side transfer data buffer 34 is converted and output to the network 2 side transmission unit 32, and the communication data flowing in from the network 2 side transmission unit 32 is determined by the priority determination unit 37. The assigned priority is temporarily stored in the network 2 side transfer data buffer 35, and the communication method of the communication data read from the network 2 side transfer data buffer 35 is converted and output to the network 1 side transmission unit 31. .

  In this way, the bridge unit 21 communicates between a first network that digitally transmits a data signal to and from the communication terminal 1 and a second network that includes a LAN such as Ethernet (registered trademark). In this embodiment, since the communication capacity of the first network is smaller than the communication capacity of the second network, communication data flowing from the second network is converted into the first network. When the data is transferred without limit, the communication traffic of the first network having a relatively small communication capacity is overloaded. At this time, there has been a problem that data quality such as voice and video flowing into the first network from the second network having a relatively large communication capacity is discarded, and the communication quality is deteriorated.

  Therefore, in the control device 2 of the present embodiment, the communication capacity is relatively higher than the network having the relatively large communication capacity (the second network on the LAN side in the present embodiment) among the first and second networks. Limiting the amount of communication traffic flowing into a small network (the first network to which the communication terminal 1 is connected via the transmission line L1) prevents communication data exceeding the communication capacity from flowing into the first network. Since the communication traffic amount of the first network does not exceed the communication capacity, it is possible to prevent the data signal from being discarded due to overloading of the first network. In other words, the control device 2 converts the communication method of the data signal flowing in from the second network within a range not exceeding the communication capacity of the first network and transmits it to the first network, thereby improving the communication quality. While maintaining the quality, data communication can be performed between two networks having different communication methods.

  Here, a process in which the control device 2 limits the amount of data flowing into the first network will be described in detail below. In the present embodiment, the bridge unit 21 of the control device 2 performs processing for limiting the amount of communication traffic. First, the communication traffic determination unit 38 of the bridge unit 21 determines the size of communication traffic in the first and second networks. judge. For example, the communication traffic determination unit 38 compares the amount of data per unit time flowing into the network 1 side transmission unit 31 and the network 2 side transmission unit 32, or the inflow frequency of the data signal, to determine which network communication. Judging whether the traffic is large. Note that the user may determine the magnitude of the communication traffic of the first and second networks by setting determination information from the outside to the communication traffic determination unit 38.

  When the communication traffic determining unit 38 determines that the communication traffic is larger in the second network, the transfer data buffer capacity setting unit 39 sets the capacity of the network 2 side transfer data buffer 35 to the memory unit 33. Is set to a capacity that is smaller than the capacity of the network 1 side transfer data buffer 34 and has a smaller communication capacity, and the network 1 side transfer is performed in accordance with this setting instruction. The capacities of the data buffer 34 and the network 2 side transfer data buffer 35 are set.

  Here, when a packet is input from the second network to the network 2 side transmission unit 32, the network 2 side transmission unit 32 removes the header of the packet including the physical layer / MAC layer, and replaces the data unit with the communication processing unit. To 36. When the data unit is input from the network 2 side transmission unit 32, the communication processing unit 36 temporarily stores this data unit in the network 2 side transfer data buffer 35 of the memory unit 33. The communication processing unit 36 monitors the operation state of the network 1 side transmission unit 31 and, when the network 1 side transmission unit 31 becomes communicable, reads the data unit temporarily stored from the network 2 side transmission unit, The communication method is converted and output to the network 1 side transmission unit 31. The network 1 side transmission unit 31 amplifies the data input from the communication processing unit 36 by the transmission amplifier A3 and then outputs the data to the first network, and transmits the data to the communication partner communication terminal 1 by carrier wave digital transmission. A data signal can be output.

  In this way, the bridge unit 21 changes the communication method of the data flowing in from the second network and sends it to the first network, but the network 2 side transfer temporarily stores the data flowing in from the second network. The capacity of the data buffer 35 is smaller than that of the network 1-side transfer data buffer 34 and is set to a capacity that matches the communication capacity of the first network. When the amount of communication data flowing in from the network 2 side transmission unit 32 exceeds the capacity of the network 2 side transfer data buffer 35, the communication data exceeding the capacity is discarded. Among communication data stored in the data buffer, communication data having a relatively low priority is discarded, and communication data having a higher priority is stored in the network-side transfer data buffer 35. Here, of the data signal, for example, if the priority of audio data or video data is set higher than the priority of other data, the audio data or video stored in the network 2 side transfer data buffer 35 is set. The data can be prevented from being discarded, and the audio / video data is transmitted to the first network in preference to the other data, so that the video / audio quality of the interphone can be kept high. Since the communication capacity of the second network is larger than the communication capacity of the first network, the data flowing in from the first network and stored in the network 1 side transfer data buffer 34 is transferred to the network 2 side transmission unit. Even if it is sent from 32 to the second network, the communication traffic of the second network will not be overloaded.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the communication data flowing into the bridge unit 21 from the first and second networks is given priority of three levels of high, medium, and low, and the data flowing from the first network side is temporarily stored. An area 34A for storing communication data with high priority, an area 34B for storing communication data with medium priority, and an area 34C for storing communication data with low priority in the network 1 side transfer data buffer 34 And the network 2 side transfer data buffer 35 for temporarily storing the data flowing in from the second network side, the area 35A for storing communication data with high priority, and the communication data with medium priority are stored. An area 35B and an area 35C for storing communication data with low priority are provided. The transfer data buffer capacity setting unit 39 is configured to individually set the capacities of the areas 34A to 34C and 35A to 35C for the respective transfer data buffers 34 and 35 based on the determination result of the communication traffic determination unit 38. The command is output to the memory unit 33. Based on this setting command, the memory unit 33 stores the storage areas 34A to 34C of the network 1 side transfer data buffer 34 and the storage areas 35A to 35C of the network 2 side transfer data buffer 35. 35C is set. Since the configuration other than the network 1 side transfer data buffer 34 and the network 2 side transfer data buffer 35 is the same as that of the intercom system described in the first embodiment, common components are denoted by the same reference numerals, Description is omitted.

  In the present embodiment, the network 1 side transfer data buffer 34 and the network 2 side transfer data buffer 35 are provided with storage areas 34A to 34C and 35A to 35C for storing high, medium and low priority communication data, respectively. The capacity is set for each of the areas 34A to 34C and 35A to 35C. When the communication processing unit 36 temporarily stores the communication data input from the network 1 side transmission unit 31 and the network 2 side transmission unit 32 in the network 1 side transfer data buffer 34 and the network 2 side transfer data buffer 35, respectively. Is stored in an area corresponding to the priority assigned to the communication data by the priority determination unit 37. If there is no free area in the storage area, the input communication data is discarded. Here, since the communication capacity of the first network is smaller than the communication capacity of the second network, the capacity of the transfer data buffer 35 on the network 2 side is set to a capacity that matches the communication capacity of the first network. Yes. Therefore, when the communication processing unit 36 stores the communication data input from the network 2 side transmission unit 32 in the storage areas 35A to 35C of the transfer data buffer 35 according to the priority, there is an empty area in the area. In this case, the communication data input from the network 2 side transmission unit 32 is discarded, but the capacities of the storage areas 34A to 34C and 35A to 35C corresponding to the priorities are set separately. Therefore, communication data with low priority can be prevented from being uniformly discarded as in the intercom system described in the first embodiment, and communication data with each priority can be transferred to the other network according to a certain ratio. Can do.

(Embodiment 3)
Embodiment 3 of the present invention will be described below. Since the configuration of the intercom system is the same as that of the first embodiment, common components are denoted by the same reference numerals, and illustration and description thereof are omitted.

  In the first and second embodiments described above, the bridge unit 21 restricts the amount of communication traffic flowing from the second network having a relatively large communication capacity into the first network having a relatively small communication capacity. On the other hand, in the present embodiment, the call control / communication capacity management unit 22 of the control device 2 limits the amount of communication traffic flowing into the first network having a relatively small communication capacity.

  That is, the call control / communication capacity management unit 22 manages the limit value of the communication traffic amount according to the communication capacity of the network having the smaller communication capacity of the first and second networks connected to the bridge unit 21. In this embodiment, since the first network has a smaller communication capacity than the second network, the limit value of the communication traffic amount is determined in accordance with the communication capacity of the first network. Then, when there is a communication start request from the communication terminal 1 connected to any one of the bridge units 21, the call control / communication capacity management unit 22 and the communication partner 1 are connected to the bridge unit 21 to which the communication terminal 1 is connected. When the bridge unit 21 connected to the other network determines that it does not exceed the limit value of the amount of communication traffic assigned to each of them, the communication terminal that has output the communication start request is permitted to start communication. Therefore, communication traffic is not overloaded on both the network to which the communication terminal 1 that has issued the communication start request is connected and the network to which the communication terminal 1 of the communication partner is connected, and audio data, video data, etc. Therefore, the communication quality can be kept high. Further, the call control / communication capacity management unit 22 collectively manages the usable communication capacity of all the bridge units 21, and centralizes the limit value of the communication traffic amount of each network to which the bridge unit 21 is connected. Since it is not necessary to determine whether or not to discard communication data on the bridge unit 21 side, the configuration of the bridge unit 21 can be simplified and the transfer speed of the bridge unit 21 can be increased. There is also an advantage.

(Embodiment 4)
Embodiment 4 of the present invention will be described below. Since the configuration of the intercom system is the same as that of the first embodiment, common components are denoted by the same reference numerals, and illustration and description thereof are omitted.

  In the first and second embodiments described above, the bridge unit 21 restricts the amount of communication traffic flowing from the second network having a relatively large communication capacity into the first network having a relatively small communication capacity. On the other hand, in the present embodiment, the call control / communication capacity management unit 22 that performs call control between the first and second networks connected to the bridge unit 21 has the first communication capacity relatively small. The amount of communication traffic flowing into the network is limited.

  That is, the call control / communication capacity management unit 22 manages a multicast address used to collectively control a plurality of communication terminals 1 for each of the networks connected to the bridge unit 21, and any network When the communication terminal 1 connected to the communication terminal 1 wants to collectively transmit communication data to a plurality of communication terminals 1 connected to a network having a relatively small communication capacity, a multicast in which a plurality of communication terminals 1 to be transmitted are grouped. When the communication data is transmitted to the address and the call control / communication capacity management unit 22 receives the communication request addressed to the multicast address from any of the communication terminals 1, the call control / communication capacity management unit 22 sends the communication data to the bridge unit 21 to which the communication partner network is connected. Multicast address data is allowed to pass through. At this time, the bridge unit 21 that has received the multicast address data collectively transmits the multicast address data to all the communication terminals 1 connected to the bridge unit 21. Can be controlled.

  Here, when broadcast data is input to the switching exchange unit 23 of the LAN, the broadcast data is transmitted to all connection ports included in the switching exchange unit 23, and as a result, all of the connection data connected to the switching exchange unit 23 is transmitted. Since broadcast data is sent to the bridge unit 21, there is a problem that communication traffic of the networks connected to all the bridge units 21 increases.

  On the other hand, in the present embodiment, when it is desired to send data collectively to a plurality of communication terminals 1 belonging to a network (for example, the first network) having a relatively small communication capacity connected to the bridge unit 21, broadcast communication is performed. Instead, data communication is performed to a multicast address in which a plurality of communication terminals 1 to be transmitted are grouped, and the call control / communication capacity management unit 22 sets whether or not the multicast address can be passed to the bridge unit 21. Therefore, it is possible to prevent an increase in communication traffic of a network that does not belong to a multicast address that is not related to transmission.

A, B Intercom system 1 Communication terminal 2 Control device 3 Switching switching unit 21 Bridge unit 22 Call control / communication capacity management unit 23 Switching switching unit 30 Communication unit 31 Network 1 side transmission unit (first transmission unit)
32 Network 2 side transmission unit (second transmission unit)
33 Memory 34 Network 1 side transfer data buffer (first transfer data buffer)
35 Network 2 side transfer data buffer (second transfer data buffer)
36 Communication processing part L1 Transmission line

Claims (6)

A plurality of communication terminals provided with at least voice communication means and a control device for controlling communication between the communication terminals are connected via a transmission line composed of a pair of balanced pair lines to form a first network, In an intercom system in which a communication terminal and a control device transmit and receive data signals by carrier wave digital transmission,
A first transmission unit connected to the first network and performing communication by carrier wave digital transmission; and a second transmission unit connected to a second network having a communication method different from that of the first network. The control device includes a bridge unit that converts a communication method between the second network and the second network, and the control device has a communication capacity relative to a network having a relatively large communication capacity among the first and second networks. An intercom system characterized by limiting the amount of communication traffic flowing into a small network.   The bridge unit temporarily transfers the communication data stored in the transfer data buffer by giving priority to the transfer data buffer that temporarily stores the communication data, and the communication data that has flowed in from one of the first and second transmission units. A communication processing unit that converts a communication method of communication data read from the data buffer and outputs the communication method to the other transmission unit, and the communication data amount flowing from a network having a relatively large communication capacity is relatively high in communication capacity. When the communication capacity of a small network is exceeded, communication data stored in the transfer data buffer that flows from a network with a relatively large communication capacity and discards communication data with a relatively low priority. The intercom system according to claim 1.   The transfer data buffer temporarily stores communication data flowing in from the first network in an area corresponding to the priority, and temporarily transfers communication data flowing in from the second network in the area corresponding to the priority. A second transfer data buffer for storing, and a capacity setting unit for setting the storage area capacity according to the priority for each of the first and second transfer data buffers, and flowing from the first and second networks When storing communication data in the first and second transfer data buffers, the first and second transfer data buffers are temporarily stored in areas corresponding to the priorities, and if there is no space in the corresponding areas, the communication data is discarded. The intercom system according to claim 2, wherein:   The control device is provided with a call control / communication capacity management unit that manages the limit value of the communication traffic amount according to the communication capacity of the network having the smaller communication capacity of the first and second networks to which the bridge unit is connected When there is a communication start request from a communication terminal of any network, the call control / communication capacity management unit is connected to the bridge unit to which the communication terminal that has output the communication start request is connected and the communication partner network. 2. The communication terminal that outputs a communication start request is permitted to start communication when it is determined that the limit value of the communication traffic amount allocated to each of the bridge units does not exceed both. Intercom system.   The control device includes a call control / communication capacity management unit that performs call control between the first and second networks connected to the bridge unit, and the call control / communication capacity management unit is a network connected to the bridge unit. For each of the above, a multicast address used to collectively control a plurality of communication terminals is managed, and the communication terminals collectively communicate with a plurality of communication terminals connected to a network having a relatively small communication capacity. When data is to be transmitted, the communication data is transmitted to a multicast address in which a plurality of communication terminals to be transmitted are grouped, and the call control / communication capacity management unit sends a communication request addressed to the multicast address from any communication terminal. When it is received, the multicast address data is allowed to pass through to the bridge unit to which the communication partner network is connected. Intercom system of claim 1, wherein.   6. The intercom system according to claim 1, wherein a plurality of connection means for detachably attaching the bridge portion are provided in the control device.

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