JP2001024703A - Voice repeater and multiplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain equipment provided with a transmission means reducing the overhead of transmission by connecting and multiplexing voice data to reduce the ratio of the size of a header to the size of data to transmit actually. SOLUTION: A voice repeater and multiplexer 201 repeats and multiplexes voice between a telephone network 102 and an IP network 103. A voice terminal 101 is connected to a telephone network 102. Then, this communication system converts a voice signal exchanged between two voice terminals 101, connected to the network 102 to a voice packet and multiplexes it to generate a connection packet 104. Then, the repeater and multiplexer 201, connected to the network 102 and the network 103, repeats the connection packet from the network 102 to the network 103 by IP multicast communication or IP broadcast communication and exchanges the repeated connection packet 104 to a voice signal by the repeater and multiplexer 201 to repeat to the network 201.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice communication between voice terminals connected to a telephone network. And a relay and multiplexing device for relaying using multicast communication or broadcast communication.

[0002]

2. Description of the Related Art Conventionally, TCP / IP or UDP /
One session is established for each voice communication by unicast communication using IP, and one session is established between two relay devices.
One-to-one communication is being performed. Also, in order to reduce the overhead of communication between relay devices, there is known a method of multiplexing several voice packets of the same destination into one packet.

[0003] In contrast to one-to-one communication of unicast communication, multicast communication for performing one-to-many communication to a specific group using a special group address (reference:
IETF RFC 1112) and one address to all devices on the network using a broadcast address.
There is broadcast communication for performing many-to-many communication.

[0004]

In an IP telephone comprising a telephone network, a voice terminal connected to the telephone network, an IP network, and a relay device connected to the telephone network and the IP network, an analog telephone is used. In order to mutually convert an audio signal and a digital audio signal, the conventional PCM method requires a data amount of 64 kbps. However, in the recent high-compression conversion method, it is 6 to 8 kbps, which is as small as about 1/10,
ITU-TG G., which is currently the mainstream in IP telephony. 72
In the 3.1 system, the size of one voice packet is only 24 bytes. On the other hand, for IP phones, RTP / UDP
A voice packet is transmitted using / IP, but a header is added when actually transmitting the packet, and the size of the header is 40 (= 12 + 8 + 20) bytes (reference document: IETF RFC1889). Then, when the above-mentioned high compression conversion method is used, the size of the header becomes larger than the amount of data to be actually transmitted, which causes a problem of transmission overhead.

Conventionally, TCP / IP or UD
Using P / IP, one session was established for each voice communication by unicast communication, and one-to-one communication was performed between two relay devices. In this method, when a plurality of sessions are established between two relay devices, the number of voice packets increases, so that the packet relay process in the router device and the voice packet transmission / reception process in the IP phone relay device are performed. There is a problem that the load increases. To solve this problem, a method of multiplexing voice packets and reducing the number of voice packets is considered. However, since conventional IP telephones use unicast communication, in the case of multiplexing, multiplexing must be performed for each same destination and sent to the destination by unicast communication. In this method, multiplexing buffers must be prepared for the number of destinations, a multiplexing buffer must be reserved when communication with a new destination occurs, and the multiplexing buffer must be released when communication with a certain destination disappears. . Such multiplexing buffer management is as follows.
There is a problem that the processing load of the voice relay and multiplexing device is caused.

In an IP network, MTU (Max Tra) is used.
nsfer Unit), the transmittable packet size is limited. In addition, a packet having a long packet length causes a delay in relaying at the router. Therefore, if the packet length is increased for multiplexing, there is a problem that transmission is impossible or transmission delay is increased.

Also, by multiplexing many voice packets, transmission overhead is reduced, but conversely, processing time for multiplexing is increased, and end-to-end delay time is increased. There is a problem.

A first object of the present invention is to provide a transmitting means for reducing the ratio of the size of a header to the size of data to be actually transmitted by concatenating and multiplexing voice data, thereby reducing transmission overhead. It is an object of the present invention to provide a voice relay and multiplexing device provided with such a device.

A second object of the present invention is to multiplex data independently of the destination and use multicast communication to address a specific group of relay and multiplexing devices or all voice relay using broadcast communication. An object of the present invention is to provide a voice relay / multiplexing apparatus including a transmitting unit that eliminates a processing load for preparing and managing a multiplexing buffer for each destination by transmitting to a multiplexing apparatus.

A third object of the present invention is to limit the packet length to less than a specified length, thereby avoiding transmission restrictions by the MTU and suppressing an increase in communication delay by a router. It is to provide a chemical conversion device.

A fourth object of the present invention is to provide a voice relay and multiplexing apparatus having means for suppressing an increase in communication delay due to multiplexing processing by limiting a multiplexing interval of voice packets. is there.

[0012]

According to the present invention, there is provided a telephone network, a voice terminal connected to the telephone network, an IP network, and a telephone network connected to the telephone network and the IP network. A voice signal exchanged between two voice terminals connected to the telephone network in a communication system including a plurality of relay and multiplexing devices is relayed from the telephone network to the IP network, and the relayed voice signal is transmitted. Is a relay and multiplexing device that relays an audio signal input from a telephone line accommodated by the device into audio data of an arbitrary size,
Voice packet generating means for generating voice packets by adding telephone destination information to the voice data; connecting packet generating means for connecting any number of voice packets to generate one connected packet; Transmitting means for transmitting the connection packet to the IP network, receiving means for receiving the connection packet from the IP network, connection packet dividing means for dividing the connection packet into voice packets constituting the connection packet, and transmitting the voice packet to telephone destination information and voice data. Means for outputting an audio signal to an arbitrary telephone line accommodated in the device using the destination information by using the destination information. Accordingly, by multiplexing the voice packets by concatenating them into a concatenated packet, the ratio of the RTP / UDP / IP header size to the size of the concatenated packet is smaller than the ratio of the RTP / UDP / IP header size to the voice packet size.
/ IP header size ratio can be reduced, and transmission overhead can be reduced.

In the transmission means, instead of transmitting by unicast communication, the transmission means is addressed to a specific group of relay / multiplex apparatuses using multicast communication, or to all relay / multiplex apparatuses using broadcast communication. By transmitting, the voice packet is multiplexed independently of the destination and transmitted to the relay and multiplexing device, so that a multiplexing buffer is prepared for each destination, and the buffer is linked with the generation and disappearance of the connection. It is possible to eliminate the processing load that has to be managed.

[0014] Further, by providing a packet length limiting means for suppressing the packet length to less than a predetermined length, the packet length is limited to less than a designated length, and the MTU in the IP network is reduced.
, It is possible to avoid transmission restrictions and suppress an increase in transmission delay due to the router.

Further, by providing a packet generation interval control means for suppressing the multiplexing interval to a predetermined time interval or less, it is possible to suppress an increase in communication delay due to the multiplexing process.

The hardware configuration includes a telephone network, a voice terminal connected to the telephone network, an IP network, and a plurality of voice relay and multiplexing devices connected to the telephone network and the IP network. A voice signal exchanged between two voice voice terminals connected to the telephone network in the communication system configured is relayed from the telephone network to the IP network, and the relayed voice signal is transmitted from the IP network to the telephone network. A voice relay and multiplexing device for relaying, comprising: a telephone network interface for connection to the telephone network; an IP network interface for connection to the IP network; a memory for storing data and programs; and a secondary storage. Device and CPU for executing the program
And a control console for controlling these, wherein the telephone network interface receives a voice signal from the telephone network and outputs a voice signal to the telephone network, and the IP network interface comprises the IP network interface. Receiving the concatenated packet from the network and transmitting the concatenated packet to the IP network, wherein the memory and the secondary storage device are input at the telephone network interface and receive voice packets for transmission over the IP network interface; Storing the converted audio data,
Processing for storing voice data received by the IP network interface and converted into a voice signal for output on the telephone network interface, and generating a connection packet from the input voice signal; A program for realizing a process of reproducing an audio signal from the concatenated packet is stored.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a configuration diagram of a communication system according to the present embodiment. Reference numeral 102 denotes a telephone network, and 103, an IP network. The voice relay and multiplexing device 201 relays and multiplexes voice between the telephone network 102 and the IP network 103. The voice terminal 101 is a voice terminal connected to the telephone network 102. In the present embodiment, a voice signal exchanged between two voice terminals connected to the telephone network is converted into a voice packet, further multiplexed, and
Is generated, and the voice relay and multiplexing device 201 connected to the telephone network and the IP network relays the IP packet from the telephone network to the IP network by IP multicast communication or IP broadcast communication. The signal is converted into a voice signal by a multiplexer and relayed to a telephone network.

FIG. 2 shows a hardware configuration of the voice relay / multiplexer. In FIG. 2, in a communication system including a telephone network, a voice terminal connected to the telephone network, an IP network, and a plurality of relay and multiplexing devices connected to the telephone network and the IP network. Voice relay and multiplexing device 201 for relaying voice signals exchanged between two voice terminals connected to the telephone network from the telephone network to the IP network, and relaying the relayed voice signals from the IP network to the telephone network. Are a telephone network interface 205 for connection to a telephone network, an IP network interface 206 for connection to an IP network, and memories 203 and 2 for storing data and programs for voice relay and multiplexing processing 301. Secondary storage device 204
And a central processing unit 202 for executing the processing.

The telephone network interface 205 is a telephone network 1
02, and outputs a voice signal to the telephone network. The IP network interface 206 receives the connection packet from the IP network 103, transmits the connection packet to the IP network, and And the secondary storage device 204 is input at the telephone network interface 205,
The voice data converted from the voice signal for transmission by the IP network interface 206 is stored, and the voice data received by the IP network interface 206 is stored in the telephone network interface 2.
At step 05, audio data to be converted into an audio signal for output is stored, and a program for realizing the audio relay and multiplexing processing 301 is stored. The processing in the voice relay and multiplexing apparatus can be processed by the central processing unit 202.

FIG. 3 shows the software configuration of the voice relay and multiplexing process 301. In FIG. 3, a voice relay / multiplexing process 301 includes a telephone network interface control unit 310 for controlling the telephone network interface 205, an IP network interface control unit 311 for controlling the IP network interface 206, and voice from the telephone network to the IP network. , A packet reception processor 307 for relaying voice from the IP network to the telephone network, and a telephone destination processor 305.
And a group destination processing unit 306.

The packet transmission processing unit 302 has a function of generating a voice packet based on the voice signal input from the telephone network interface control unit 310 and the telephone destination information obtained from the telephone destination processing unit 305. 3
03 and two or more voice packets obtained by the voice packet generation unit 303 are connected to generate a connection packet, and the I packet is transmitted to the group address obtained by the group destination processing unit 306.
A connection packet generation unit 309 having a function of performing transmission processing on the P network interface control unit 311.

The packet reception processing unit 307 is obtained by the connection packet separation unit 309 for decomposing the connection packet received by the IP network interface control unit 311 into voice packets constituting the connection packet, and the connection packet separation unit 309. Voice packet analysis unit 308 extracts voice data and telephone destination information from the voice packet, passes the telephone destination information to telephone destination processing unit 305, and outputs a voice signal corresponding to the telephone destination information to telephone network interface control unit 310. It is composed of

The telephone destination processing unit 305 exchanges telephone destination information with the telephone network interface control unit 310, and manages a caller telephone number and a destination telephone number in correspondence with each other.

The group address processing unit 306 exchanges telephone destination information with the telephone destination processing unit 305, and associates the telephone destination information with group address information for IP multicast communication or broadcast address information for IP broadcast communication. And exchanges group address information or broadcast address information with the IP network interface control unit 311.

FIG. 4 shows a packet structure of a voice packet generated by the voice packet generation unit 306. The voice packet is obtained by converting a voice signal obtained from the telephone network interface control unit 310 into a predetermined data length (for example, 20 bytes).
Voice data 403 and a telephone destination processing unit 305
And the telephone destination information obtained in step (1). The telephone destination information includes a caller telephone number 401 and a callee telephone number 402.

FIG. 5 shows the packet structure of the concatenated packet generated by the concatenated packet generator 309. The connection packet includes a sequence of one or more voice packets 502 generated by the voice packet generation unit 306, and a connection number storage unit 501 that stores the total number of voice packets connected to the connection packet.

FIG. 6 shows a flowchart of the processing operation of the packet transmission processing unit 302. In FIG. 6, the packet transmission processing unit 302 first initializes a connected packet generation buffer (step 602). Next, it is determined whether or not the connection processing of the voice packets has been completed, for example, based on whether or not all of the voice packets generated from the telephone network interface in use have been completely connected (step 60).
3) If not completed, the voice packet generator 3
At step 06, an audio packet is generated (step 701) and added to the last part of the connection packet generation buffer (step 604). If the connection has been completed, the total number of connected voice packets is stored in the connected number storage unit 5 of the connected packets.
01 (step 605), and transmits the connected packet to the group address obtained by the group address processing unit 306 (step 606).

FIG. 7 shows a flowchart of the processing operation of the voice packet generation processing 701. In FIG. 7, a voice packet generation unit 303 divides a voice signal obtained from a telephone network interface into a predetermined data length (for example, 20 bytes) to generate voice data (step 702), and a telephone destination processing unit. The telephone destination information including at least the caller telephone number and the destination telephone number obtained in 305 is added (step 703).

FIG. 8 shows a flowchart of the processing operation of the packet reception processing unit 307. In FIG. 8, the packet reception processing unit 307 determines whether all voice packets have been extracted from the concatenated packet (step 802). If there are still unextracted voice packets, 1
The voice packets are extracted by the voice packet analysis unit (step 803), and the voice signal is reproduced from the telephone line interface (step 901). If all voice packets have been extracted, the process ends (step 804).

FIG. 9 shows a flowchart of the processing operation of the voice packet analysis processing 901. In FIG. 9, the voice packet analysis unit 306 extracts the telephone destination information from the voice packet (step 902), and determines whether the voice packet to be processed by the own voice relay device is based on the destination telephone number included in the telephone destination information. Is determined (step 90
3) If the packet is a voice packet to be processed, the voice data is passed to the telephone network interface control unit 310 (step 9).
04).

According to this embodiment, by multiplexing voice packets by concatenating them into concatenated packets, the ratio of the size of the RTP / UDP / IP header to the size of the voice packets is smaller than that of the RTP / UDP / IP header. The ratio of the size of the RTP / UDP / IP header to the size can be reduced, and the transmission overhead can be reduced.

In the packet transmission processing unit 202, instead of transmitting by IP unicast communication, transmission is performed by using IP multicast communication or IP broadcast communication, so that voice packets of all destinations are multiplexed to perform voice relay. By transmitting the data to the multiplexing device 301, a multiplexing buffer is prepared for each destination, and it becomes possible to reduce the processing load required to manage the buffer in conjunction with the generation and disappearance of the connection.

FIG. 10 shows a voice relay and multiplexing process 1001 including a packet transmission processing unit 1002 with a packet length restriction unit further provided with a unit for restricting a concatenated packet to a predetermined packet length or less in the packet transmission processing unit 302. 1 shows the software configuration. In FIG. 10, the voice relay and multiplexing process 1001 including the packet transmission processing unit 1002 with
05, a telephone network interface control unit 310 for controlling
An IP network interface control unit 311 for controlling the IP network interface 206, and a packet transmission processing unit 100 with packet length limiting means for relaying voice from the telephone network to the IP network
2, a packet reception processing unit 307 for relaying voice from the IP network to the telephone network, a telephone destination processing unit 305, and a group destination processing unit 306.

The packet transmission processing unit 1002 with packet length restriction means has a function of generating a voice packet based on the voice signal input from the telephone network interface control unit 310 and the telephone destination information obtained from the telephone destination processing unit 305. A voice packet generation unit 303 provided, and a connected packet generated by concatenating one or more voice packets obtained by the voice packet generation unit 303, and an IP network interface control unit to a group address obtained by the group destination processing unit 306. 3
11, a connection packet generation unit 309 having a function of performing a transmission process on the packet 11 and a packet length restriction unit 1 for restricting the packet length of the connection packet to a predetermined packet length or less.
003.

FIG. 11 shows a flowchart of the processing operation of the packet transmission processing unit 1002 with packet length limiting means. In FIG. 11, the packet transmission processing unit 1002 with the packet length limiting unit first initializes a connected packet generation buffer (step 1102). Next, it is determined whether or not the connection processing of the voice packets has been completed, for example, based on whether or not all the voice packets generated from the telephone network interface in use have been all connected (step 1).
103) If not completed, it is determined whether the packet length of the concatenated packet exceeds the packet length specified in advance (for example, 500 bytes) by concatenating the voice packets (step 1104). If the packet length does not exceed, the voice packet generation unit 306
Generates a voice packet (step 701) and adds it to the last part of the connection packet generation buffer (step 110).
5) Return to step 1103. In step 1104, if the packet length exceeds, the total number of concatenated voice packets is stored in the concatenated packet concatenated number storage unit 501 (step 1106), and the concatenated packet is stored in the group address (Step 1107) and return to step 1102. If the connection process is completed in step 1103, the total number of connected voice packets is stored in the connection number storage unit 501 of the connected packets (step 110).
8), the concatenated packet is transferred to the group address processing unit 306.
To the group address obtained in (1)
109).

According to the present embodiment, in addition to the effect of the packet transmission processing unit 302, the packet length of a concatenated packet generated by concatenating voice packets can be limited to less than a predetermined length. Therefore, it is possible to limit the length of packets that can be transmitted by the MTU of the IP network, and to suppress the influence of a relay delay of a packet having a long packet length in a router.

Further, the processing method of the packet transmission processing unit 1002 with the packet length limiting means is effective not only for voice relay by IP multicast communication and IP broadcast communication but also for voice relay by IP unicast communication.

FIG. 12 shows a packet transmission processing unit 12 having a generation interval adjusting unit further comprising a unit for generating a connected packet at a predetermined time interval in the packet transmission processing unit 302.
2 shows a software configuration of the voice relay and multiplexing process 1201 provided with the H.02. In FIG. 12, a voice relay and multiplexing process 1201 including a packet transmission processing unit 1202 with a generation interval adjusting unit includes a telephone network interface control unit 310 for controlling a telephone network interface 205 and an IP network for controlling an IP network interface 206. An interface control unit 311; a packet transmission processing unit 1202 with generation interval adjusting means for relaying voice from the telephone network to the IP network; and a packet reception processing unit 307 for relaying voice from the IP network to the telephone network.
, Telephone destination processing unit 305, group destination processing unit 30
And 6.

The packet transmission processing unit with generation interval adjusting unit 1202 has a function of generating a voice packet based on the voice signal input from the telephone network interface control unit 310 and the telephone destination information obtained from the telephone destination processing unit 305. Voice packet generation unit 303 provided and voice packet generation unit 3
03, a concatenated packet is generated by concatenating one or more voice packets obtained in step 03, and the IP network interface control unit 31 is sent to the group address obtained in the group destination processing unit 306.
A connection packet generation unit 309 having a function of performing a transmission process on the transmission packet 1 and a generation interval control unit 1203 that limits the generation interval of the connection packet to a predetermined time interval or less.

FIG. 13 shows a flowchart of the processing operation of the packet transmission processing unit 1202 with generation interval adjusting means. In FIG. 13, the packet transmission processing unit with generation interval adjusting unit 1202 first initializes a connected packet generation buffer (step 1302). Next, it is determined whether or not the connection processing of the voice packets has been completed, for example, based on whether or not all the voice packets generated from the telephone network interface in use have been connected (step 13).
03), if it is not completed, a predetermined time (for example, 30
(Milliseconds) or more (step 1)
304). If the time has elapsed, the voice packet generator 306 generates a voice packet (step 70).
1), add it to the end of the connection packet generation buffer (step 1305), and return to step 1303. In step 1304, if the time has elapsed, the total number of connected voice packets is stored in the connection number storage unit 501 of the connection packet (step 1306), and the connection packet is obtained by the group address processing unit 306. It transmits to the group address (step 1307), and returns to step 1302. If in step 1303,
When the connection processing is completed, the total number of connected voice packets is stored in the connection number storage unit 501 of the connection packet (step 1308), and the connection packet is transmitted to the group address obtained by the group address processing unit 306. (Step 1309).

According to the present embodiment, in addition to the effect of the packet transmission processing unit 302, by further limiting the generation interval of a concatenated packet for multiplexing voice packets,
It is possible to suppress an increase in communication delay due to the multiplexing process.

Further, the processing method of the packet transmission processing unit 1202 with the generation interval adjusting means is effective not only for voice relay by IP multicast communication and IP broadcast communication but also for voice relay by IP unicast communication.

FIG. 14 shows a packet transmission processing unit 1402 with a packet length restriction unit and a generation interval adjustment unit further provided with a unit for generating a connected packet at a predetermined time interval in the packet transmission processing unit 1002 with the packet length restriction unit.
7 shows a software configuration of the voice relay and multiplexing processing 1401 provided with. In FIG. 14, a voice relay and multiplexing process 1401 provided with a packet transmission processing unit 1402 having a packet length limiting unit and a generation interval adjusting unit is a telephone network interface control unit 3 for controlling the telephone network interface 205.
10, an IP network interface control unit 311 for controlling the IP network interface 206, a packet transmission processing unit 1402 with a packet length limiting unit and a generation interval adjusting unit for relaying voice from the telephone network to the IP network, A packet reception processing unit 307 for relaying voice to the telephone, a telephone destination processing unit 305, and a group destination processing unit 306 are provided.

The packet transmission processing unit 1402 with the packet length limiting unit and the generation interval adjusting unit is configured to transmit a voice packet based on the voice signal input from the telephone network interface control unit 310 and the telephone destination information obtained from the telephone destination processing unit 305. Voice packet generator 303 having a function of generating
And a concatenated packet generated by concatenating one or more voice packets obtained by the voice packet generation unit 303 and transmitting the packet to the IP network interface control unit 311 to the group address obtained by the group destination processing unit 306. Packet generation unit 309 having a function of performing the above operation, a packet length restriction unit 1003 for restricting the packet length of the connection packet to a predetermined packet length or less, and restricting the generation interval of the connection packet to a predetermined time interval or less And a generation interval control unit 1203.

FIG. 15 shows a flowchart of the processing operation of the packet transmission processing unit 1402 with packet length limiting means and generation interval adjusting means. In FIG. 15, the packet transmission processing unit 1402 with the packet length limiting unit and the generation interval adjusting unit first initializes a connected packet generation buffer (step 1502). Next, it is determined whether or not the connection processing of the voice packets has been completed, for example, based on whether or not all the voice packets generated from the telephone network interface in use have been connected (step 1503).
If not, it is determined whether the packet length of the concatenated packet exceeds the packet length specified in advance (for example, 500 bytes) by concatenating the voice packets (step 1504). If the packet length does not exceed, it is determined whether or not a predetermined time (for example, 30 milliseconds) has elapsed since the last transmission of the connected packet (step 1505). if,
If the time has not elapsed, the voice packet generator 30
6, a voice packet is generated (step 701) and added to the last part of the connection packet generation buffer (step 15).
06), returning to step 1503; In step 1504, if the packet length exceeds, or if the time has elapsed in step 1505, the total number of connected voice packets is stored in the connected number storage 501 of the connected packets (step 1507). The connection packet is transmitted to the group address obtained by the group address processing unit 306 (step 1508), and the process returns to step 1502. If the connection processing is completed in step 1503, the total number of connected voice packets is stored in the connection number storage unit 501 of the connection packet (step 1509), and the connection packet is obtained by the group address processing unit 306. The address is transmitted to the group address (step 1510).

According to this embodiment, in addition to the effect of the packet transmission processing unit 1002 with the packet length limiting means, the communication interval due to the multiplexing process is further reduced by limiting the generation interval of the connection packet for multiplexing the voice packets. Can be suppressed from increasing.

Further, the processing method of the packet transmission processing unit 1402 with the packet length limiting means and the generation interval adjusting means is effective not only for voice relay by IP multicast communication and IP broadcast communication but also for voice relay by IP unicast communication. is there.

[0049]

According to the present invention, the ratio of the size of the RTP / UDP / IP header to the size of the data to be actually transmitted is reduced by concatenating and multiplexing the voice data, thereby reducing the transmission overhead. It becomes possible.

Further, by multiplexing the data of all the destinations and transmitting the data using broadcast communication (IP multicast communication or IP broadcast communication), a processing load for preparing and managing a multiplexing buffer for each destination is reduced. It can be eliminated.

Further, by limiting the packet length to less than the specified length, it is possible to avoid the transmission restriction by the MTU and to suppress an increase in transmission delay by the router. This is effective not only in voice relay by IP multicast communication and IP broadcast communication but also in voice relay by IP unicast communication.

By limiting the multiplexing interval of voice packets, it is possible to suppress an increase in communication delay due to multiplexing processing. This is effective not only in voice relay by IP multicast communication and IP broadcast communication but also in voice relay by IP unicast communication.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a communication system.

FIG. 2 is a configuration diagram of a voice relay and multiplexing device.

FIG. 3 is a block diagram of a voice relay and multiplexing process.

FIG. 4 is an explanatory diagram of a packet structure of a voice packet.

FIG. 5 is an explanatory diagram of a packet structure of a concatenated packet.

FIG. 6 is a flowchart of a processing operation of a packet transmission processing unit.

FIG. 7 is a flowchart of a processing operation of a voice packet generation unit.

FIG. 8 is a flowchart of a processing operation of a packet reception processing unit.

FIG. 9 is a flowchart of a processing operation of a voice packet analysis unit.

FIG. 10 is a functional block diagram of a voice relay and multiplexing apparatus including a packet transmission processing unit with a packet length limiting unit.

FIG. 11 is a flowchart of a processing operation of a packet transmission processing unit with a packet length limiting unit.

FIG. 12 is a functional block diagram of a voice relay and multiplexing apparatus including a packet transmission processing unit with a generation interval adjusting unit.

FIG. 13 is a flowchart of a processing operation of a packet transmission processing unit with a generation interval adjusting unit.

FIG. 14 is a functional block diagram of a voice relay and multiplexing apparatus including a packet transmission processing unit with a packet length limiting unit and a generation interval adjusting unit.

FIG. 15 is a flowchart of a processing operation of a packet transmission processing unit with a packet length limiting unit and a generation interval adjusting unit.

[Explanation of symbols]

101: voice terminal, 102: telephone network, 103: IP network,
201: voice relay and multiplexing device.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toru Hoshi 1099 Ozenji Temple, Aso-ku, Kawasaki City, Kanagawa Prefecture F-term in the Hitachi, Ltd. System Development Laboratory 5K028 DD04 KK32 5K030 HB01 HC02 HD01 HD05 JA01 JA05 JT01 KA02 KX28 5K051 AA05 BB01 JJ13 5K101 LL01 RR05 SS08

Claims (5)

[Claims] 1. A communication system comprising a telephone network, a voice terminal connected to the telephone network, an IP network, and a plurality of voice relay and multiplexing devices connected to the telephone network and the IP network. Voice relay and multiplexing for relaying voice signals exchanged between two voice terminals connected to the telephone network from the telephone network to the IP network, and relaying the relayed voice signals from the IP network to the telephone network; An audio packet generating means for dividing an audio signal input from a telephone line accommodated in the device into audio data of an arbitrary size, and adding destination information to the audio data to generate an audio packet; Concatenated packet generating means for concatenating an arbitrary number of voice packets to generate one concatenated packet; and packet transmission for broadcasting the concatenated packet to one or more voice relay and multiplexing devices connected to the IP network. means Packet receiving means for receiving the concatenated packet from the IP network; concatenated packet dividing means for dividing the concatenated packet into voice packets constituting the concatenated packet; separating the voice packet into destination information and voice data; Voice relaying means for extracting voice data addressed to a telephone line accommodated by the apparatus using the information and outputting a voice signal to the destination telephone line with the voice data. A multiplexing device. 2. The voice relay and multiplexing apparatus according to claim 1, further comprising a packet length limiting means for limiting a connected packet to a predetermined packet length or less. 3. The voice relay and multiplexing apparatus according to claim 1, further comprising means for generating a connection packet at a predetermined time interval. 4. The voice relay and multiplexing apparatus according to claim 2, further comprising means for generating connected packets at predetermined time intervals. 5. A communication system comprising a telephone network, a voice terminal connected to the telephone network, an IP network, and a plurality of voice relay and multiplexing devices connected to the telephone network and the IP network. Relaying voice signals exchanged between two voice voice terminals connected to the telephone network from the telephone network to the IP network,
A voice relay and multiplexing device for relaying the relayed voice signal from an IP network to a telephone network, comprising: a telephone network interface for connecting to the telephone network; and an IP network for connecting to the IP network. An interface, a memory for storing data and a program, a secondary storage device, and a central processing unit for executing the program. The telephone network interface receives a voice signal from the telephone network, and the telephone network The IP network interface receives the connection packet from the IP network and broadcasts the connection packet to the IP network; and the memory and the secondary storage device are connected to the telephone network. Storing voice data input at the interface and converted from voice signals for transmission over the IP network interface;
A process of storing voice data received by the IP network interface and converted to a voice signal for output by the telephone network interface; and generating a connection packet from the input voice signal; and A voice relay and multiplexing device storing a program for realizing a process of reproducing a voice signal from the received connection packet.