JP2004336144A - Multimedia information communication system and private branch exchange thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize a delay in the arrival timing of voice packets and a packet loss in the case of utilizing an external communication network for packet transmission to make voice communication. <P>SOLUTION: A gateway section 191 and a router section 192 are incorporated in a line interface section 19 having been already equipped on a master apparatus 1B, and the line interface section 19 is provided with only an interface function with a LAN 3 and an interface function with an IP network IPN so as to eliminate the need for the LAN 3 interconnecting between the gateway section 191 and the router section 192. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a system for performing multimedia information communication via a LAN (Local Area Network), and more particularly, to a multimedia information communication system having an enhanced voice communication service function and a private branch exchange thereof.
[0002]
[Prior art]
In a conventional private network system, for example, a voice communication terminal such as a telephone is accommodated as an extension terminal in a telephone exchange device such as a PBX (Private Branch Exchange) or a key telephone main unit, and a communication between the extension terminal and an external communication network such as a public network. A telephone exchange device is used to exchange connection between the terminals and between extension terminals to enable a telephone conversation. Further, a data terminal such as a personal computer is connected to a LAN, and electronic mail and data are transmitted between the data terminals via the LAN. Further, a system has been proposed in which a voice communication system using a telephone exchange device and a data communication system using a LAN are linked by using a gateway.
[0003]
This type of system can connect a LAN to an IP network. In this case, the LAN and the IP network are connected via a router. The router is provided with a protocol conversion function, a data format conversion function, and the like, whereby a router is connected between the extension terminal accommodated in the telephone exchange and the IP network or between a data terminal connected to the LAN and the IP network. Enables multimedia information communication (for example, Patent Document 1).
[0004]
By the way, in the above-mentioned system, securing QoS (Quality of service) of voice in an IP network is an important issue, and accordingly, various schemes for securing QoS are being considered.
[0005]
[Patent Document 1]
Japanese Patent Application No. 9-161722.
[0006]
[Problems to be solved by the invention]
However, in the above system, when voice communication is performed between the extension terminal and the IP network, a transmission voice signal generated from the extension terminal and a reception voice signal to the extension terminal are packetized and transmitted on the LAN. Therefore, packet arrival timing delay and packet loss may occur due to traffic on the LAN.
[0007]
In addition, when the IP network has a low data rate, the voice delay due to long packets becomes extremely large, and thus the probability of occurrence of packet loss becomes extremely high.
[0008]
In order to solve these problems, the router gives priority to UDP (User Datagram Protocol) or fragments data packets, but in any case, a delay in software processing occurs until voice is recognized on the packet. It is inevitable.
[0009]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a multimedia information communication system capable of minimizing delay of packet arrival timing and packet loss when performing voice communication using an external communication network for performing packet transmission. A private branch exchange device is provided.
[0010]
[Means for Solving the Problems]
The present invention is configured as follows to achieve the above object.
[0011]
(1) A private branch exchange that connects a local area network for transmitting a packet, a plurality of extension terminals including telephone terminals, and performs a predetermined switching process on these extension terminals, a private branch exchange and the local area network And a gateway unit which converts a signal arriving from the private branch exchange into a packet and transmits it to the local area network, and converts a packet arriving from the local area network into a signal and transmits the signal to the private branch exchange. And a connection between the local area network and an external communication network for transmitting packets based on the control of the private branch exchange, and converts packets arriving from the local area network into packets for transmission to the external communication network for external communication. To the external network. A router unit for converting a packet arriving from a work into the packet for transmission on the local area network and transmitting the packet to the local area network, wherein the gateway unit and the router unit are private branch exchange devices. It is built in.
[0012]
That is, the invention of (1) includes a gateway unit for connecting a local area network in a private branch exchange, a router unit for connecting a local area network and an external communication network, and a local unit in the gateway unit. Only the interface function with the area network is provided, and only the interface function with the local area network and the interface function with the external communication network are provided in the router unit.
[0013]
Therefore, according to the invention of (1), it is not necessary to install a dedicated gateway and a dedicated router separately from the private branch exchange, and not only the gateway and the router are built in the private branch exchange but also the gateway and the private branch. This eliminates the need for a communication line and a dedicated interface unit between the switching unit and the communication line and a dedicated interface unit between the router unit and the private branch exchange unit. In the meantime, the number of lines connecting the private branch exchange and the router unit can be reduced to simplify the system wiring structure, thereby minimizing the delay in voice packet arrival timing and the occurrence of packet loss. it can.
[0014]
(2) The private branch exchange comprises a plurality of line interface units capable of connecting a communication line including an extension to which an extension terminal is connected, and an exchange for selectively connecting the plurality of line interface units in response to a call setting request. And a control unit, wherein at least a part of the line interface unit is set as a first line interface unit, and a gateway unit and a router unit are built in the first line interface unit to provide a local area network and an external communication unit. A network is connected, a line interface different from the first line interface is set as a second line interface, and a communication line other than the local area network and the external communication network is connected to the second line interface. It is characterized in that it is connected.
[0015]
That is, the invention of (2) provides a private branch exchange in which a gateway unit and a router unit are built in the line interface unit already provided, and the line interface unit has an interface function with a local area network and an external function. Only an interface function with a communication network is provided.
[0016]
Therefore, according to the invention of (2), since the router unit and the gateway unit are provided integrally in one line interface unit, it is not necessary to separately prepare the router unit and the gateway unit, and furthermore, the local area and the gateway area of the gateway unit are not required. Since the network interface function and the local area network interface function of the router unit are shared, a local area network connecting between the gateway unit and the router unit can be dispensed with. In this case, the wiring structure of the system can be further simplified as compared with that of the first embodiment, and a structure that is not affected by collision due to congestion on the local area network and throughput when performing communication with an external communication network can be achieved. Therefore, the delay of the arrival timing of the packet to the external communication network and the packet loss can be significantly reduced.
[0017]
(3) The first line interface unit determines an audio packet among packets to be transmitted to the external communication network in the router unit, and transmits the audio packet to the external communication network with the highest priority. And
[0018]
According to the invention of (3), when the voice signal from the telephone terminal is packetized, the router unit can recognize that the packet is voice, and gives priority to this voice packet over other packets for external communication. Can be sent to the network. Thus, optimal voice communication can be performed between the telephone terminal and the external communication network. Further, the voice packet can be determined without setting the protocol and the packet.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, some embodiments of the present invention will be described in detail with reference to the drawings.
[0020]
FIG. 1 is a schematic configuration diagram showing a multimedia information communication system according to the present invention.
[0021]
This system has a main device 1 and a LAN 3. The main device 1 arbitrarily connects a plurality of extension terminals (2-1 to 2-i) 2 including a telephone and the like. The LAN 3 connects data terminals PC1 to PCj such as personal computers.
[0022]
Further, a gateway GW is connected between the main device 1 and the LAN 3. The gateway GW connects between the main device 1 and the LAN 3 and has a function of converting a communication protocol and a signal format between the main device 1 and the LAN 3.
[0023]
Further, a router RT is connected to the LAN 3. The router RT connects between the LAN 3 and the IP network IPN for packet transmission based on a control packet directly arriving from the main unit 1, and converts a communication protocol and a signal format between the LAN 3 and the IP network IPN. Has functions.
[0024]
There is also a multimedia information communication system in which the gateway GW and the router RT are built in the main device 1.
FIG. 2 is a schematic configuration diagram of the multimedia information communication system.
[0025]
The main device 1A includes a time switch 11, a line interface unit 12, a plurality of (i) extension interface units 13 (13-1 to 13-i), and a central control unit 14. The interface unit 12 and the extension interface unit 13 are connected to each other via a PCM highway 15.
[0026]
The office line interface unit 12, the extension interface unit 13, and the central control unit 14 are connected to each other via a data highway 16. Further, the time switch 11 is directly connected to the control unit 14.
[0027]
The time switch 11 exchanges time slots on the PCM highway 15 based on the control of the control unit 14 to arbitrarily switch between the line interface unit 12 and the extension interface unit 13 and between the extension interface units 13. Exchange connection.
[0028]
A station line L such as a public line or a dedicated line is connected to the station line interface unit 12 as needed. The office line interface unit 12 performs an office line interface operation for the connected office line L. The office line interface unit 12 exchanges various control information related to the office line interface operation with the central control unit 14 via the data highway 16.
[0029]
The extension terminal 2 is connected to the extension interface unit 13 as needed. The extension interface unit 13 performs an extension interface operation for the connected extension terminal 2. The extension interface unit 13 exchanges various control information related to the extension interface operation with the central control unit 14 via the data highway 16.
[0030]
The central control unit 14 performs a process based on a predetermined exchange processing program, thereby comprehensively controlling each of the time switch 11, the office line interface unit 12, and the extension interface units (13-1 to 13-i) 13. The operation as the main device 1A is realized.
[0031]
Incidentally, the gateway unit 17 and the router unit 18 are built in the main device 1A. The gateway unit 17 is configured such that the main device interface function is deleted from the general-purpose gateway GW, and only the interface function with the LAN 3 is provided.
[0032]
The router unit 18 has a main unit interface function deleted from the router RT and the general-purpose dial-up router device, and has only an interface function with the LAN 3 and an interface function with the IP network IPN. .
[0033]
The gateway unit 17 has a functional configuration as shown in FIG. That is, the gateway unit 17 includes a LAN interface unit (LAN I / F) 171, a connection control unit 172, a packet processing unit 173, and a data management unit 174.
[0034]
The connection control unit 172 controls connection between the LAN 3 and the PCM highway 15 based on the control from the central control unit 14.
[0035]
The packet processing unit 173 converts the audio signal received from the PCM highway 15 into an audio packet that can be handled by the LAN 3 and sends it out to the LAN 3, and converts the audio packet received from the LAN 3 into an audio signal that can be handled by the PCM highway 15. And transmits the data to the PCM highway 15.
[0036]
The data management unit 174 stores routing information and the like necessary for connection control of the connection control unit 172.
[0037]
The router 18 has a functional configuration as shown in FIG. That is, the router unit 18 includes a LAN interface unit (LAN I / F) 181, an IP network interface unit (IP network I / F) 182, a connection control unit 183, a packet processing unit 184, and a data management unit 185. It has.
[0038]
The connection control unit 183 controls connection between the LAN 3 and the IP network IPN based on the control from the central control unit 14.
[0039]
The packet processing unit 184 converts a packet received from the LAN 3 into a packet that can be handled by the IP network IPN and sends the packet to the IP network IPN, and converts a packet that has arrived from the IP network IPN into a packet that can be handled by the LAN 3. It has the function of transmitting to LAN3. Here, a packet received from the LAN 3 is fragmented, a finely divided packet is generated, and transmitted to the IP network IPN.
[0040]
The data management unit 185 stores routing information and the like necessary for connection control of the connection control unit 183.
[0041]
Next, a voice communication operation by the system configured as described above will be described.
[0042]
As shown in FIG. 5, for example, in order to perform voice communication between the terminal device TT1 connected to the IP network IPN and the extension terminal 2-1 connected to the main device 1A, a calling operation is performed at the terminal device TT1. Suppose it was done. Then, an incoming signal is sent from the IP network IPN to the router unit 18. The router unit 18 that has received the incoming signal identifies the extension terminal 2-1 by referring to the routing information stored in the data management unit 185, and transmits the data highway 16 and the extension to the extension terminal 2-1. The connection request signal is transmitted via the interface unit 13-1.
[0043]
The extension terminal 2-1 that has received the connection request signal emits a sound or displays an incoming call, thereby notifying the user of the occurrence of the incoming call. When the user performs a response operation to the incoming call notification, the extension terminal 2-1 transmits a connection response signal to the router 18 of the request source, and the router 18 having received the connection response signal transmits the connection response signal to the IP network IPN. A response signal is transmitted to the terminal. Thus, a communication path is formed between the source terminal device TT1 and the destination extension terminal 2-1 via the IP network IPN, the router unit 18 and the gateway unit 17, and thereafter, the terminal device TT1 and the extension terminal 2 Voice communication is possible between -1.
[0044]
That is, the voice packet transmitted from the terminal device TT1 is transmitted to the router unit 18 via the IP network IPN. In the router unit 18, the received voice packet is converted into a voice packet for LAN 3 transmission, and the voice packet is transmitted to the gateway unit 17 via the LAN 3. In the gateway unit 17, the received voice packet is converted into a voice signal, and this voice signal is transmitted to the extension terminal 2-1 via the PCM highway 15 and the extension interface unit 13-1. In the extension terminal 2-1, the supplied audio signal is loudspeaked by a speaker or the like.
[0045]
On the other hand, the transmission voice signal input by a microphone or the like is transmitted to the gateway unit 17 via the PCM highway 15 by the extension terminal 2-1. In the gateway unit 17, the voice signal received from the PCM highway 15 is converted into a voice packet, and this voice packet is transmitted to the router unit 18 via the LAN 3.
[0046]
In the router unit 18, the voice packet received from the LAN 3 is fragmented, and the voice packet is transmitted to the terminal device TT1 via the IP network IPN.
[0047]
On the other hand, when a call is transmitted from the extension terminal 2-1 connected to the main apparatus 1 to the terminal apparatus TT1 connected to the IP network IPN, the connection is performed in the reverse procedure.
[0048]
(1st Embodiment)
The first embodiment relates to the main device 1, the gateway GW, and the router RT in FIG.
[0049]
FIG. 6 is a schematic configuration diagram of the multimedia information communication system according to the first embodiment. In FIG. 6, the same portions as those in FIG. 2 are denoted by the same reference numerals, and detailed description will be omitted.
[0050]
That is, in the first embodiment, the line interface unit 19 is newly provided in the main device 1B. The line interface unit 19 includes a gateway unit 191 and a router unit 192. The line interface unit 19 is connected to the LAN 3 and the IP network IPN as needed, and further connected to the PCM highway 15 and the data highway 16.
[0051]
The line interface unit 19 converts a voice signal received from the PCM highway 15 into a voice packet, converts a voice packet received from the LAN 3 or the IP network IPN into a voice signal, and sends the voice signal to the PCM highway 15. After fragmenting the packet received from the LAN 3, the packet is transmitted to the IP network IPN, and the packet received from the IP network IPN is converted into a packet for LAN transmission and transmitted to the LAN 3.
[0052]
Further, the line interface unit 19 has a function of determining a voice packet among the packets when the signal is packetized, and transmitting the voice packet to the IP network IPN with the highest priority.
[0053]
Next, a voice communication operation by the system configured as described above will be described.
[0054]
Now, it is assumed that the extension terminal 2-1 connected to the main device 1B and the terminal device TT1 connected to the IP network IPN are performing voice communication. At the same time, it is assumed that the data terminal PC1 connected to the LAN 3 and the terminal device TT2 connected to the IP network IPN are communicating.
[0055]
The signal transmitted from the extension terminal 2-1 is transmitted to the line interface unit 19 via the extension interface unit 13-1 and the PCM highway 15 as shown in FIG. The line interface unit 19 sequentially converts the received voice signal into voice packets “2”, “4”, “5”,.
[0056]
Further, the long packet transmitted from the data terminal PC1 is transmitted to the line interface unit 19 via the LAN3. The line interface unit 19 sequentially fragments the received long packets into packets “1”, “3”, “6”, “7”,.
[0057]
Note that identification numbers indicating the packet transmission order from the start of communication are inserted into the headers of these packets “1” to “7”. Among them, an identification number is inserted into a voice packet in preference to other data packets. Here, “1” to “5” are voice packets, and “6” and “7” are data packets other than voice.
[0058]
Each of the above packets is transmitted to the terminal devices TT1 and TT2 via the IP network IPN.
[0059]
As described above, in the first embodiment, in the main device 1B, the gateway unit 191 and the router unit 192 are built in the already provided line interface unit 19, and the line interface unit 19 is connected to the LAN3. Only the interface function and the interface function with the IP network IPN are provided, and the LAN 3 is deleted to connect between the gateway unit 191 and the router unit 192.
[0060]
Therefore, by integrally providing the gateway unit 191 and the router unit 192 in one line interface unit 19, it is not necessary to separately prepare a router and a gateway, and the LAN interface function of the gateway unit 191 and the LAN interface of the router unit 192 are not required. Since the interface function is shared, the LAN 3 connecting the gateway unit 191 and the router unit 192 can be eliminated. As a result, the wiring structure of the system can be simplified, and when communicating with the IP network IPN, it is possible to adopt a structure that is not affected by collision due to congestion on the LAN 3 and throughput. Therefore, the delay of the arrival timing of the packet with respect to the IP network IPN and the packet loss can be significantly reduced.
[0061]
Further, according to the line interface unit 19 of the first embodiment, the router unit 192 determines a voice packet among packets to be transmitted to the IP network IPN, and gives priority to the voice packet to the IP network IPN. Therefore, optimal voice communication can be performed between the extension terminal 2-1 and the terminal device TT1 on the IP network IPN. In addition, since the voice packet can be determined without setting the protocol and the settings in the packet, the processing load on the line interface unit 19 can be greatly reduced.
[0062]
Further, the line interface unit 19 converts a voice signal arriving from a certain extension interface unit 13-1 into a voice packet and transmits it to the IP network IPN, while a voice signal arriving from another extension interface unit 13-2 is converted. Is transmitted to the LAN 3 after being converted into a voice packet. The same applies to the reception of a packet from the LAN 3 and the reception of a packet from the IP network IPN.
[0063]
(Other embodiments)
Note that the present invention is not limited to the above embodiments, and does not depart from the gist of the present invention in terms of the type and configuration of the system, the types of extension terminals, the configurations of the gateway and the server, and the means for fragmenting packets. Various modifications can be made within the scope.
[0064]
【The invention's effect】
As described above in detail, according to the present invention, when performing voice communication using an external communication network that performs packet transmission, a multi-path capable of minimizing delay in arrival timing of a voice packet and packet loss can be achieved. A media information communication system and its private branch exchange can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a basic configuration of a multimedia information communication system.
FIG. 2 is a schematic configuration diagram showing another basic configuration of the multimedia information communication system.
FIG. 3 is a block diagram showing a configuration of a gateway unit shown in FIG. 2;
FIG. 4 is a block diagram showing a configuration of a router unit shown in FIG. 2;
FIG. 5 is a view for explaining a voice communication operation in the system shown in FIG. 2;
FIG. 6 is a schematic configuration diagram showing a multimedia information communication system according to the first embodiment of the present invention.
FIG. 7 is a view for explaining a voice communication operation in the system shown in FIG. 6;
[Explanation of symbols]
1, 1A, 1B main device, 2 (2-1 to 2-i) extension terminal, 3 LAN, 11 time switch, 12 office line interface unit, 13 (13-1 to 13-i) Extension interface unit, 14 Central control unit, 15 PCM highway, 16 Data highway, 17,191 Gateway unit, 18, 192 Router unit, 19 Line interface unit, 171, 181 LAN interface unit (LAN I / F), 172, 183 connection control unit, 173, 184 packet processing unit, 174, 185 data management unit, 182 IP network interface unit (IP network I / F), GW gateway, IPN IP network , L: office line, PC1 to PCj: data terminal, RT: router, TT1, TT2: terminal device.

Claims (6)

A local area network for transmitting packets,
A private branch exchange that connects a plurality of extension terminals including a telephone terminal and performs predetermined exchange processing on these extension terminals;
A connection between the private branch exchange and the local area network, a signal arriving from the private branch exchange being converted into a packet and transmitted to the local area network, and a packet arriving from the local area network being signaled. To a private branch exchange device,
A connection is established between the local area network and an external communication network for transmitting packets based on control from the private branch exchange, and a packet arriving from the local area network is converted into a packet for external communication network transmission. A router for transmitting to the external communication network, converting a packet arriving from the external communication network to the local area network transmission packet, and transmitting the packet to the local area network. hand,
A multimedia information communication system, wherein the gateway unit and the router unit are built in the private branch exchange. The private branch exchange apparatus includes a plurality of line interface units capable of connecting a communication line including an extension to which the extension terminal is connected, and an exchange control for selectively connecting the plurality of line interface units in response to a call setting request. And a part,
At least a part of these line interface units is set as a first line interface unit, and the gateway unit and the router unit are incorporated in the first line interface unit to connect the local area network and the external communication network. Then, a line interface different from the first line interface is set as a second line interface, and communication lines other than the local area network and the external communication network are connected to the second line interface. 2. The multimedia information communication system according to claim 1, wherein the communication is performed. The first line interface unit determines an audio packet among packets to be sent to the external communication network in the router unit, and transmits the audio packet to the external communication network with the highest priority. The multimedia information communication system according to claim 2, wherein A local area network for transmitting packets,
A private branch exchange that connects a plurality of extension terminals including a telephone terminal and performs predetermined exchange processing on these extension terminals;
A connection between the private branch exchange and the local area network, a signal arriving from the private branch exchange being converted into a packet and transmitted to the local area network, and a packet arriving from the local area network being signaled. To a private branch exchange device,
A connection is established between the local area network and an external communication network for transmitting packets based on control from the private branch exchange, and a packet arriving from the local area network is converted into a packet for external communication network transmission. A router for transmitting to the external communication network, converting a packet arriving from the external communication network to the local area network transmission packet, and transmitting the packet to the local area network. Private branch exchange device,
A private branch exchange, wherein the gateway unit and the router unit are incorporated in the own device to connect the local area network and the external communication network. A plurality of line interface units capable of connecting a communication line including an extension connected to the extension terminal,
An exchange control unit for selectively connecting a plurality of line interface units in response to a call setting request,
At least a part of these line interface units is set as a first line interface unit, and the gateway unit and the router unit are incorporated in the first line interface unit to connect the local area network and the external communication network. Then, a line interface different from the first line interface is set as a second line interface, and communication lines other than the local area network and the external communication network are connected to the second line interface. The private branch exchange according to claim 4, wherein The first line interface unit determines an audio packet among packets to be sent to the external communication network in the router unit, and transmits the audio packet to the external communication network with the highest priority. The private branch exchange according to claim 5, wherein

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