JP2002158702A - Packet dividing method, gateway device and router device for executing the method - Google Patents

Abstract

(57) [Problem] To improve the throughput of non-real-time communication while reducing the delay time of real-time packets in a system for performing real-time communication using an IP communication network. SOLUTION: In a portion where a real-time packet and a non-real-time packet are multiplexed, the real-time packet is stored in a high-priority communication packet buffer unit 202, and the non-real-time packet is stored in a low-priority communication packet buffer unit 2.
03, and the packets stored in the high-priority communication packet buffer 202 are preferentially transmitted to the output line via the IP packet transmitting unit 204, and the connection monitoring unit 605
Manages the call state of the real-time packet communication, and determines whether or not the call of the real-time packet communication is set by the call determination unit 606. The packet division is performed only when the real-time packet call is set. The unit 607 performs packet division.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet division method for voice, image and data communication in a packet communication network, and more particularly to a case where voice signals are communicated according to a VoIP (Voice over IP) system in an IP (Internet Protocol) communication network. And a gateway device and a router device that execute the method.

[0002]

2. Description of the Related Art In recent years, real-time data having real-time characteristics represented by voice signals of telephones and non-real-time data having no real-time characteristics represented by file data at the time of file transfer have been packetized. A technique for transmitting a real-time packet and a non-real-time packet via an IP communication network has attracted attention, and in particular, a VoIP technique for transmitting a voice signal over an IP network has attracted attention.

Generally, in the VoIP system, in order to improve sound quality, it is important to reduce a delay time from when a voice signal is transmitted from a transmitting terminal to when it is received by a receiving terminal (for example, Nikkei). BP, "Nikkei Communication 2000.6.5," p70, July 2000.). To this end, a method has been proposed in which real-time data is transmitted with priority over non-real-time data, and packet division is performed to divide the non-real-time data into a predetermined size.

The prior art is disclosed in Japanese Patent Application Laid-Open No. 2000-1839.
A VoIP gateway device using the priority control and packet division method disclosed in Japanese Patent Publication No. 61 will be described. FIG. 1 is a block diagram showing an example of a network configuration using a conventional VoIP gateway device. In the figure, telephone and PB
The connection between X and the connection between the PBX and the VoIP gateway device are respectively connected by a telephone line network. In addition, between the computer terminal and the VoIP gateway device, each VoIP gateway device
The IP gateway devices are connected by an IP communication network.

A voice signal output from a telephone is input to a PBX via a telephone line, and further input from the PBX to a VoIP gateway device via a telephone line. Further, packetized file data output from the computer terminal is input to the VoIP gateway device via the IP communication network.

The VoIP gateway device further outputs the input voice signal and packetized file data via an IP communication network. At this time, the audio signal is packetized and output. The packetized voice signal and the packetized file data output via the IP communication network are input to another VoIP gateway device via the IP communication network, and are transmitted from the VoIP gateway device to each computer terminal, PBX. Output to That is, various data are exchanged via the VoIP gateway device on the IP communication network.

Next, the VoIP gateway device will be described. FIG. 2 is a basic configuration diagram of a conventional VoIP gateway device, and arrows indicate data flows. The VoIP gateway device includes IP packet input interface units 10 to 14, IP packet output interface units 20 to 24, voice input interface units 30 to 34, and a routing unit 40. However, a configuration in which the number of each interface unit is different is also conceivable.

[0008] IP packet input interface unit 10
Numerals 14 are parts to which non-real-time IP packets (non-real-time packets) are input from the IP communication network, and receive IP packets input from the computer terminal. The voice input interface units 30 to 34 receive a voice signal input from the PBX via a telephone line and a call control signal for setting up a call when talking between telephones, and receive an IP packet from the voice signal. (Real-time packet) and outputs it to the routing unit 40.

FIG. 3 shows the voice input interface 3
FIG. In the figure, arrows indicate flows of a voice signal and a call control signal. Voice input interface unit 30
Is an audio signal receiving unit 301 and a digital encoding unit 302
, A voice IP packet generation unit 303, and a connection setting unit 304. The voice input interface units 31 to 34 have the same configuration.

[0010] The audio signal receiving unit 301 is connected to the PBX via a telephone line. The audio signal receiving unit 301 receives an analog audio signal from a telephone line and outputs the analog audio signal to the digital encoding unit 302. The digital encoding unit 302
Digital encoding is performed on the received analog audio signal, and the digital audio signal is converted into an audio IP packet generation unit 30.
3 is output. Voice IP packet generator 303
Generates an IP packet from the received digital voice signal and outputs the IP packet to the routing unit 40. Hereinafter, the IP packet generated by the voice IP packet generation unit 303 will be referred to as a voice IP packet.

[0011] The connection setting unit 304 is connected to a telephone line, and receives a call control signal from the telephone line.
Then, a call control signal is exchanged with the VoIP gateway device connected via the IP communication network, and a call (connection) is set up and released between the two telephones specified by the call control signal. In the VoIP system, when a voice call is made, H.323 communication is performed between VoIP gateways. Call setting information such as a telephone number is exchanged using the H.323 protocol.

Next, the routing unit 40 transmits the IP packet received from the IP packet input interface units 10 to 14 or the voice input interface units 30 to 34 to the corresponding IP packet output interface unit according to the header information.

FIG. 4 is a configuration diagram of the IP packet output interface unit 20. In the figure, arrows indicate flows of IP packets and control signals. The IP packet output interface unit 20 includes a transmission timing determination unit 20
1, a high-priority communication packet buffer unit 202, a low-priority communication packet buffer unit 203, an IP packet transmission unit 204, a communication priority determination unit 205, and a packet division unit 2.
06. The IP packet output interface units 21 to 24 have the same configuration.

The communication priority determining unit 205 receives the IP packet from the routing unit 40, and receives the packet information (I
P address, port number, TOS field value, etc.)
To determine whether the packet is a voice IP packet. Then, in the case of a voice IP packet, it is determined that the communication priority is high, and the packet is transmitted to the high-priority communication packet buffer unit 202. On the other hand, if the packet is other than the voice IP packet, it is determined that the communication priority is low, and the packet is transmitted to the packet division unit 206. The packet division unit 206 divides the IP packet into a predetermined size and transmits the IP packet to the low-priority communication packet buffer unit 203.

The high priority communication packet buffer unit 20
When the IP packet is received, the 2nd and low priority communication packet buffer unit 203 refers to the contents of the line idle flag managed by the transmission timing determining unit 201, and if the line idle flag is 1, sets the line idle flag to 0. , And transmits the IP packet to the IP packet transmitting unit 204.

On the other hand, if the line idle flag is 0, the IP
The packet is held for a predetermined period. When a transmission command is received from the transmission timing determining unit 201, the line vacancy flag managed by the transmission timing determining unit 201 is set to 0, and the first IP packet held among the held IP packets is transmitted. To the unit 204. The transmission timing determining unit 201 holds a line idle flag. The line idle flag is set to 0 at the start of system operation.

FIG. 5 shows that the IP packet transmitting section 204
FIG. 9 is a flowchart illustrating a transmission timing determination procedure when transmitting a P packet.

(S00) A transmission end signal is received from the IP packet transmission unit 204, and the process proceeds to S01.

(S01) It is determined whether or not an IP packet is held in the high-priority communication packet buffer unit 202. If the high priority communication packet buffer 202
If the packet is held, go to S02. On the other hand, if the IP packet is not held in the high-priority communication packet buffer unit 202, the process proceeds to S03.

(S02) A transmission command is output to the high-priority communication packet buffer unit 202, and the process ends.

(S03) It is determined whether or not an IP packet is held in the low-priority communication packet buffer unit 203. If the low-priority communication packet buffer 203
If the packet is held, go to S04. On the other hand, if no IP packet is held in the low-priority communication packet buffer unit 203, the process proceeds to S05.

(S04) A transmission command is output to the low-priority communication packet buffer unit 203, and the process ends.

(S05) The line vacancy flag is set to 1 and the process ends.

When receiving the IP packet from the high-priority communication packet buffer unit 202 or the low-priority communication packet buffer unit 203, the IP packet transmitting unit 204 transmits it to the output line. Then, when the transmission is completed, a transmission end signal is output to transmission timing determining section 201. IP
The time from the start of transmission of an IP packet to the output line from the packet transmission unit 204 to the end thereof is herein referred to as a transmission time.

As described above, in the prior art, a voice IP packet, which is a high-priority communication packet, is preferentially transmitted to an output line, and at the same time, a low-priority communication packet is divided into a predetermined size and transmitted. By reducing the transmission time of the low-priority communication data, the delay time from when the voice IP packet arrives until transmission is reduced.
That is, in the prior art, the real-time packet is transmitted to the output line preferentially, and at the same time, the non-real-time packet is divided into a predetermined size and transmitted to reduce the transmission time of the non-real-time data. The delay time from arrival to transmission is reduced.

[0026]

By the way, when the audio signal is encoded at a speed of 8 kbps, and the audio signal is converted into IP packets for each 20-byte audio signal, it is desirable to set the delay target value to 20 milliseconds. (Nikkei BP
Company, “Nikkei Communication 2000.6.5”, p75, Augu
st 2000.). In this case, for example, the packet size of the non-real-time communication divided on a line of 64 kbit / sec is desirably 160 bytes, and if the IP header is 20 bytes, the overhead due to the header becomes about 13%.
Similarly, overhead on a 128 kbit / s line is 6%, and on a 256 kbit / s line it is 3%.

As described above, the prior art has a problem that the non-real-time communication throughput is reduced due to a large overhead caused by packet division. In particular, the throughput was significantly reduced in low-speed lines.

[0028]

According to a packet division method of the present invention, at least two types of packets, a high-priority communication packet and a low-priority communication packet, are input based on a predetermined communication priority, and the high-priority communication packet is input. A packet division method for multiplexing a communication packet and said low-priority communication packet and dividing said low-priority communication packet prior to said multiplexing when transmitting through a single packet communication network, comprising: It is characterized in that a switch is made as to whether or not to divide the low communication priority packet into a predetermined size based on a condition.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) A network configuration using a gateway device according to Embodiment 1 of the present invention is the same as that of the prior art and will not be described. FIG. 6 is a configuration diagram of the gateway device according to Embodiment 1 of the present invention. The same components as those in the related art are given the same numbers, and perform the same operations as those described in the related art, and thus description thereof will be omitted. As Embodiment 1 of the present invention,
The configuration of the IP packet output interface units 600 to 604 is different. In the figure, the number of the IP packet output interface units is five, but in the present invention, a configuration in which the number of each interface unit is different is also possible.

In the first embodiment, a voice IP packet obtained by packetizing a voice signal having real-time communication is used as a high-priority communication packet, and a file data or the like having no real-time communication is used as a low-priority communication packet. This will be described in detail with respect to an IP packet obtained by packetizing a packet.

The gateway device shown in FIG. 6 comprises IP packet input interface units 10 to 14, IP packet output interface units 600 to 604, voice input interface units 30 to 34, and a routing unit 40. However, a configuration in which the number of each interface unit is different is also conceivable. Arrows indicate flows of data and control signals.

IP packet input interface unit 10
Reference numerals 14 to 14 are portions to which IP packets of non-real-time data are input from the IP communication network. An IP packet input from a computer terminal is received.

The voice input interface units 30 to 34 are units for receiving voice signals, generating IP packets of real-time data from the voice signals, and outputting them to the routing unit 40. The voice input interface unit 30 includes a voice signal receiving unit 301, a digital encoding unit 302, a voice IP packet generation unit 303, and a connection setting unit 30.
And 4. Voice input interface unit 3
1 to 34 have the same configuration.

The audio signal receiving unit 301 is connected to a telephone line, receives an analog audio signal from the telephone line, and outputs the analog audio signal to the digital encoding unit 302. Digital encoding section 302 performs digital encoding on the received analog audio signal, and outputs a digital audio signal to audio IP packet generation section 303. The audio IP packet generation unit 303 generates an IP packet from the received digital audio signal and outputs it to the routing unit 40.

The connection setting unit 304 is connected to a telephone line, and receives a call control signal from the telephone line. Then, a call control signal is exchanged with a gateway device connected via the IP communication network, and a call (connection) is set up and released between the two telephones specified by the call control signal. Further, when a call is set and released, the connection setting unit 304 outputs call setting information to the connection management unit of the corresponding IP packet output interface unit. In addition, in the case of performing a voice call in the VoIP, the H.323 communication is performed between the VoIP gateways. Call setting information such as a telephone number is exchanged using the H.323 protocol.

The connection monitoring unit 605 monitors the state of the call setting for the input voice signal by the connection setting unit 304. The call determination unit 606 determines whether or not a call of a voice signal, that is, a voice IP packet is set based on the call setting state by the connection monitoring unit 605, and executes the packet division unit 607 only when the call is set. I do. When the call of the voice IP packet is not set, the packet dividing unit 607 is not executed.
That is, the IP packet input to the IP packet input interface unit is output to the routing unit 40 as it is. Packet division unit 607
Divides the IP packet input to the IP packet input interface unit into a predetermined size and outputs it to the routing unit 40.

The routing unit 40 receives the IP packet input from the IP packet input interface units 10 to 14, the IP packet divided by the packet division unit 607, or the voice IP packet output from the voice input interface units 30 to 34. Is transmitted to the corresponding IP packet output interface unit according to the header information. IP packet output interface unit 600-60
4 includes a transmission timing determination unit 201, a high-priority communication packet buffer unit 202, a low-priority communication packet buffer unit 203, an IP packet transmission unit 204, and a communication priority determination unit 205.

The communication priority determining unit 205 receives the IP packet from the routing unit 40, and receives the header information (I
P address, port number, TOS field value, etc.)
To determine whether the packet is a voice IP packet. Then, in the case of a voice IP packet, it is determined that the communication priority is high, and the packet is transmitted to the high-priority communication packet buffer unit 202. on the other hand,
If the packet is not a voice IP packet, it is determined that the communication priority is low, and the packet is transmitted to the low-priority communication packet buffer unit 203.

When the high-priority communication packet buffer unit 202 and the low-priority communication packet buffer unit 203 receive the IP packet, they refer to the contents of the line vacancy flag managed by the transmission timing decision unit 201 and determine whether the line vacancy flag is 1. For example, after setting the line vacancy flag to 0, the IP packet is transmitted to the IP packet transmission unit 204. On the other hand, if the line vacancy flag is 0, the IP packet is held for a certain period. When a transmission command is received from the transmission timing determination unit 201, the line vacancy flag managed by the transmission timing determination unit is set to 0, and the first of the held IP packets arrives at the IP packet transmission unit. 2
04. The transmission timing determining unit 201 holds a line idle flag. The line idle flag is set to 0 at the start of system operation.

When receiving the IP packet from the high-priority communication packet buffer unit 202 or the low-priority communication packet buffer unit 203, the IP packet transmitting unit 204 transmits the IP packet to the output line. Then, when the transmission is completed, a transmission end signal is output to transmission timing determining section 201. Before transmitting the IP packet, the IP packet transmitting section 204 transmits an audio IP packet and an I / O packet other than the audio IP packet.
The P packet may be multiplexed and transmitted.

FIG. 7 is a processing flowchart of the packet division method executed in the gateway device according to the first embodiment.

(S701) The call setting information of the voice IP packet managed by the connection monitoring unit 605 is input.

(S702) The call determination unit 606 determines whether or not a call of a voice IP packet is set based on the input call setting information. If a call has been set up, go to S703. If no call has been set up, S
To 704.

(S703) The packet division unit 607 determines that the I
IP packets input to the P packet input interfaces 10 to 14 are divided into predetermined sizes, and the divided IP
Outputs the packet to the routing unit 40, and ends.

(S704) The IP packet input to the IP packet input interfaces 10 to 14 is output to the routing unit 40 as it is, and the processing is terminated.

In the gateway device of the present invention described above, the connection monitoring unit 605, the call determination unit 606, and the packet division unit 60 are assigned before the routing unit 40 assigns the IP packet output interface unit.
Although the description has been given of the case where the low-priority communication packet is divided by the packet No. 7, the packet dividing process may be performed after the routing process in the routing unit 40 is performed by the configuration shown in FIG. 8. In this case, the communication priority determination unit 205 determines that the I
A P packet, that is, an IP packet input in the IP packet input interface units 10 to 14 is a packet to be divided by the packet division unit 607. Note that the operations of the connection monitoring unit 605, the call determination unit 606, and the packet division unit 607 are the same as those described above.

In the gateway device according to the first embodiment of the present invention, the voice input interface units 30 to 3
4 describes a case where an analog voice signal is received from a telephone line. However, as shown in FIG.
Voice IP packet input interface units 900 to 904 for inputting packets may be provided.

The voice packet and the non-voice packet are as follows.
Although input is performed by physically different input systems, the input may be performed by the IP packet interface units 1000 to 1004 which are the same input system as shown in FIG. In that case, the IP packet interface units 1000 to 10
As described with reference to FIG. 9, the information input to 04 is a voice IP packet in which a voice signal or the like is packetized. After inputting the IP packet, the communication priority determining unit 1
In step 010, by referring to the header content of the input IP packet, the communication priority of the IP packet is determined, and the IP packet with the higher communication priority is output to the routing unit 40 as it is. Determines whether or not a call of an IP packet having a high communication priority is set, and divides the packet only when a call is set, as in the operation described above.
Will be output to This packet division processing may be performed after the routing processing as described above.

In the present embodiment, an IP communication network that communicates with IP packets conforming to the Internet protocol is used, but a packet network conforming to another protocol may be used. In this embodiment, the audio input interface unit is provided, and the communication of the real-time data is the communication of the audio signal. However, the present invention is not limited to the audio.

(Embodiment 2) FIG. 11 is a configuration diagram of a gateway device according to Embodiment 2 of the present invention. The same components as those in the prior art and the first embodiment are denoted by the same reference numerals, and perform the same operations as those described in the prior art and the first embodiment, and thus description thereof will be omitted. In the second embodiment of the present invention, a packet size monitoring unit 1111, an output speed monitoring unit 1112, a division determination unit 1113, and a communication state determination unit 1114 are newly added to the configuration of the first embodiment.

Also in the second embodiment, an audio IP packet obtained by packetizing an audio signal having real-time communication is used as a high-priority communication packet, and a file having no real-time communication is used as a low-priority communication packet. A detailed description will be given of an IP packet obtained by packetizing data and the like.

The packet size monitoring unit 1111 monitors the packet size of the IP packet input to the IP packet output interface units 1100 to 1104, and notifies the division determination unit 1113 of the packet size (P). The output speed monitoring unit 1112 monitors the output speed of the IP packets output from the IP packet output interface units 1100 to 1104, and
To notify the output speed (R). Here, the output speed (R) may be a fixed output line speed (L), or when the communication line connected to the IP packet output interface unit is shared by a plurality of communication elements,
It may be a value obtained by actually measuring the speed at which a packet is transmitted from the IP packet output interface unit.

The division determining unit 1113 calculates the packet size (P) notified from the packet size monitoring unit 1111
The output speed (R) is received from the output speed monitoring unit 1112, and the packet division unit 607 determines whether to perform packet division. Communication state determination unit 1114
Is based on the communication state, based on the packet division processing (the packet division processing means the determination by the call determination unit 606, the determination by the division determination unit 1113, and the packet division by the packet division unit 607 based on the determination result). This refers to a series of processing.) It is determined whether or not it is necessary to perform the above. This determination is performed as follows.

First, in the IP packet output interface units 1100 to 1104, an output line speed (L) which is a speed at which an IP packet is transmitted to an output line, a delay target value (D) of the audio information IP packet, and I input from the packet input interface units 10 to 14
MTU (M), which is the maximum transfer unit of the P packet, is set in advance. Then, if L <M ÷ D, packet division processing is performed. On the other hand, when L ≧ M ÷ D, the low-priority communication packet is output to the low-priority communication packet buffer unit 203 without performing the packet division processing. This is because when the output line speed (L) is high, even if the packet size of the non-real-time communication is MTU, the time for which the packet of the real-time communication waits in the buffer is the delay target value (D).
This is because it is smaller than the above and there is no need to perform packet division.

For example, D is determined as follows. Generally, it is desirable that a voice signal be transmitted between terminals with a delay time of 200 milliseconds or less. The delay time in the codec performing digital encoding and decoding is 40
Milliseconds, the delay time in other communication elements is 40 milliseconds, and the delay time caused by fluctuation absorption in the receiving terminal is 80 milliseconds, the delay target value in the IP packet output interface unit is 200- 40-
It is calculated as 40-80 = 40 ms. For example, R is I
When the output line connected to the P packet output interface unit is a line of the INS (registered trademark) 64 service provided by NTT, L is set to 64 kbps. For example, if all input lines connected to the IP packet input interface unit are Ethernet, M = M
Set to 1500 bytes.

In the case of the above example, M ÷ D = 1500 × 8
(Bit) / 80 (millisecond) = 150 kbps, L = 6
Since 4 kbps and L <M ÷ D, the communication state determining unit 1114 determines to perform the packet division processing. As another example, it is said that it is desirable to set D = 20 milliseconds when an audio signal is encoded at a speed of 8 kbps and is converted into IP packets for each 20-byte audio signal (Nikkei BP) , “Nikkei Communication 6/5 20
00 ”, p75, August 2000.)

Next, a packet division method according to the second embodiment of the present invention will be described. FIG. 12 is a processing flowchart of packet division.

(S1200) Upon receiving the IP packet and the packet size P from the packet size monitoring unit 1111, the division determination unit 1113 starts the following procedure.

(S1201) The call judging unit 606 refers to the VoIP connection information by the connection monitoring unit 605.

(S1202) The call determining unit 606 determines that the VoI
Based on the P connection information, it is determined whether or not a call of a high priority communication packet has been set, and if a call has been set, the process proceeds to S1203. If the call has not been set, the process proceeds to S1207.

(S 1203) The division judging unit 1113 sends the packet size (P) from the packet size monitoring unit 1111.
And the output speed (R) from the output speed monitoring unit 1112, respectively.

(S1204) The size of P and D × R are compared, and if P> D × R is satisfied, the flow advances to S1205. If not, go to S1207.

(S1205) The packet dividing unit 607
The received low-priority communication IP packet is divided into a plurality of packets so that the size is equal to or smaller than D × R.

(S1206) The divided packets are transmitted to the low-priority communication packet buffer unit 203, respectively, and the processing ends.

(S1207) The received low-priority communication IP packet is transmitted to the low-priority packet buffer unit 203 without changing its size, and the process ends.

According to the present embodiment, when a call for real-time packet communication is set, the delay target value (D) of the real-time packet is set, and the size of the non-real-time communication packet is set to D. By performing packet division so as to be equal to or less than the value determined by the output speed (R), the delay time of the real-time packet can be suppressed to D or less. At the same time, when the call for the communication of the real-time packet is not set, the packet division is stopped, thereby improving the line use efficiency (throughput) in the non-real-time communication.

For example, D = 20 ms, R = 64 kbp
s, IP header length = 20 bytes, packet size of non-real-time packet = 1500 bytes,
In order to satisfy the delay target value, it is necessary to divide the non-real-time packet into a packet of D × R ≒ 160 bytes, the overhead of the IP header is about 13%, and the line utilization efficiency (throughput) for the payload. Is 87%. On the other hand, in the present embodiment, when a call for real-time packet communication is not set, the packet division is stopped and the non-real-time packet is transmitted with a size of 1500 bytes. This is about 1%, and the line utilization efficiency (throughput) for the payload is 99%. As a result, the line use efficiency (throughput) is improved by 12% as compared with the conventional method of always performing packet division.

In this embodiment, the size of the MTU (M) of the IP packet input interface unit is detected, and the output line speed (L) is compared with M ÷ D. When it is determined that packet division is not necessary to satisfy the target value, the packet division processing in the IP packet output interface unit is omitted. As a result, in the high-speed output interface, the delay target value is satisfied, high line utilization efficiency is maintained,
At the same time, the configuration of the IP packet output interface can be simplified.

In the gateway device of the present embodiment described above, the voice input interface unit 30
34 to 34 have been described for the case of receiving an analog voice signal from a telephone line. However, as described in Embodiment 1, the voice IP packet for inputting a voice IP packet which is a digitized analog packet and further packetized An input interface unit may be provided. Although packets for voice and non-voice packets are input through physically different input systems, they may be input through the same input system IP packet interface unit as described in the first embodiment.

In the present embodiment, an IP communication network that communicates with IP packets conforming to the Internet protocol is used, but a packet network conforming to another protocol may be used. In the present embodiment, a voice input interface unit is provided, and voice is used as real-time communication. However, the present invention is not limited to voice.

(Embodiment 3) A router according to Embodiment 3 of the present invention will be described below. FIG. 13 is a system configuration diagram showing an example of a network configuration using a router device and a VoIP gateway device according to Embodiment 3 of the present invention. The router device has a plurality of computer terminals and V
The figure shows a form in which an oIP gateway device is connected and connected to another router device via an IP communication network.

FIG. 14 is a basic configuration diagram of each of the router device and the VoIP gateway device according to the third embodiment of the present invention. In the figure, arrows indicate the flow of data. The router device R00 shown in FIG. 14 includes IP packet input interface units RI00 to RI04, IP packet output interface units RO01 to RO04, and a routing unit 40. The VoIP gateway device G00 shown in FIG. 14 includes a voice input interface unit GI00 and an IP packet output interface unit GO00. However, a configuration in which the number of each interface unit is different is also conceivable.

FIG. 15 is a configuration diagram of the voice input interface unit GI00 of the VoIP gateway device according to the third embodiment of the present invention. Components that are the same as those in Embodiment 1 or 2 and that perform the same operations are given the same numbers, and descriptions thereof are omitted. In the figure, arrows indicate flows of data and call control signals. The voice input interface unit GI00 of the VoIP gateway device includes a voice signal receiving unit 301, a digital encoding unit 302, a voice IP packet generation unit 303, and a marking unit 1501.
And a connection setting unit 304.

The marking section 1501 is provided with an IETF (Inte
Di standardized by the rnet Engineering Task Force)
IP according to ffServ (Differentiated Service)
v4 (Internet Protocol Version 4), the DOS (Division of EF PHB) is added to the TOS field of the IP header.
fferentiated services code point). Here, DiffServ is RFC2 of IETF.
474, RFC2475, RFC2597, RFC25
98, RFC 2836.
The marked voice IP packet is output to the routing unit 40 via the IP packet output interface unit GO00. By this marking process, the router device can easily distinguish between real-time packets such as voice and other non-real-time packets. The operation of the other components is the same as the operation described in the first or second embodiment.

The IP packet output interface unit GO00 of the VoIP gateway device is a unit for transmitting the voice IP packet generated by the voice input interface unit GI00 to the router device. If the non-real-time communication packet does not arrive at the VoIP gateway apparatus, the priority control as in the first embodiment can be omitted. The IP packet input interface units RI00 to RI04 of the router device are connected to a computer terminal or Vo.
This is a portion to which an IP packet is input from an IP gateway device or the like.

The voice input interface section GI00 of the VoIP gateway device is a portion to which an analog voice signal is input and outputs an IP packet generated from voice information. The IP packet output interface unit RO00 of the router device is a part that controls a real-time packet with priority over a non-real-time packet and transmits the packet to an output line.

FIG. 16 is a configuration diagram of an IP packet output interface unit of the router device according to the third embodiment of the present invention. In the figure, arrows indicate flows of data and control signals. The same components as those in the first or second embodiment and those performing the same operations are denoted by the same reference numerals, and description thereof is omitted. IP packet output interface RO0
1 to RO04 include a transmission timing determination unit 201, a high-priority communication packet buffer unit 202, a low-priority communication packet buffer unit 203, an IP packet transmission unit 204,
Communication priority determination section 1601, call determination section 1603, packet division section 607, high priority communication packet monitoring section 1
602, a packet size monitoring unit 1111, an output speed monitoring unit 1112, a division determination unit 1113, and a communication status determination unit 1114.

The communication priority determining unit 1001 receives the IP packet from the routing unit 40, and
P determines whether the packet should be stored in the high-priority communication packet buffer unit 202 for real-time data communication or the packet to be stored in the low-priority communication packet buffer unit 203 for non-real-time data communication. In the present embodiment, if the value of EF PHB is included in DSCP, it is determined that the packet is a voice IP packet, and the packet is transmitted to the high-priority communication packet buffer unit 202. On the other hand, DS
If the value of CP is other than that, it is determined that the communication priority is low. The operation of the other components is the same as the operation described in the first or second embodiment.

The high priority communication packet monitoring unit 1602
Holds an oIP connection flag and a call setting timer. The VoIP connection flag is set to OFF at the start of system operation, and the call setting timer is also reset. The high-priority communication packet buffer unit 202 is monitored, and when a new high-priority communication packet arrives, the call setting timer is reset once, measurement by the timer is started, the VoIP connection flag is set to ON, and the call determination unit is set. 1603 is notified.

When the call setting timer elapses a predetermined time, the VoIP connection flag is set to OFF and the call determination unit 1603 is notified. The provision of the high-priority communication packet monitoring unit 1602 enables the router device to obtain VoIP call setting information. It is not necessary to perform the H.323 protocol packet analysis, and the device configuration can be simplified. The call determination unit 1603 determines whether a call has been set based on the VoIP connection flag notified from the high priority communication packet monitoring unit 1602.

According to the present embodiment, when a call for real-time packet communication is set, the delay target value (D) of the real-time packet is set, and the size of the non-real-time packet is output as D. By performing packet division so as to be equal to or less than the value determined by the speed (R), the delay time of the real-time packet can be suppressed to D or less. At the same time, when the call for the communication of the real-time packet is not set, the packet division is stopped, thereby improving the line use efficiency (throughput) in the communication of the non-real-time packet.

For example, D = 20 ms, R = 64 kbp
s, IP header length = 20 bytes, packet size of non-real-time packet = 1500 bytes,
In order to satisfy the delay target value, it is necessary to divide a packet for non-real-time communication into a packet having a size of D × R ≒ 160 bytes.
This is 3%, and the line utilization efficiency (throughput) for the payload is 87%.

On the other hand, in this embodiment, when a call for real-time packet communication is not set, packet division is stopped and non-real-time packets
Since the data is transmitted in a size of 0 bytes, the overhead of the IP header is about 1%, and the line use efficiency (throughput) for the payload is 99%. As a result, the line use efficiency (throughput) is improved by 12% as compared with the conventional method of always performing packet division.

In the present embodiment, the size of the MTU (M) of the IP packet input interface is detected, and the output line speed (L) is compared with M ÷ D, so that L is sufficiently fast and the delay is large. When it is determined that packet division is not necessary to satisfy the target value, the packet division processing in the IP packet output interface unit is omitted. As a result, in the high-speed output interface, the delay target value can be satisfied, a high line usage rate can be maintained, and the configuration of the IP packet output interface can be simplified.

In the present embodiment, when there is a high-priority communication packet to be output, it is assumed that a telephone call has been established and the buffering information is turned on to perform packet division. H. A method of analyzing a H.323 signaling packet and detecting a telephone call is also possible.

In the present embodiment, an IP communication network for communicating with IP packets conforming to the Internet protocol is used. However, a packet network conforming to another protocol may be used. In the present embodiment, the VoIP gateway device is provided with the voice input interface unit, and voice is used as real-time communication. However, the present invention is not limited to voice.

Hereinafter, the effect of improving the line use efficiency (throughput) of real-time communication according to the present invention will be specifically described. The delay target value in the gateway device is 20 milliseconds, the output line speed is 64 kbps, and the IP header length is 20
If the size of the non-real-time packet is 1500 bytes, in order to satisfy the delay target value,
The non-real-time packet needs to be divided into 160-byte packets, the overhead of the IP header is about 13%, and the line utilization efficiency (throughput) for the payload is 87%.

On the other hand, in the embodiment using the gateway device of the present invention, when a call for real-time packet communication is not set, the packet division is stopped and the non-real-time packet is transmitted in a size of 1500 bytes. Therefore, the overhead of the IP header is about 1%,
Line utilization efficiency (throughput) for payload is 9
9%. As a result, the line use efficiency (throughput) is improved by 12% as compared with the conventional method of always performing packet division.

As described in the third embodiment, when packet division is performed not only in the gateway device but also in the router device, the delay time of real-time packet communication can be reduced. As a result, the delay time between terminals for real-time packet communication can be further reduced. For example, the delay time for real-time packet communication such as sound quality in VoIP can be reduced, and the line utilization efficiency (throughput) for non-real-time packet communication can be reduced.
Can be improved.

[0091]

As described above, according to the present invention, only when a call for real-time packet communication is set,
By performing packet division on non-real-time packets, line utilization efficiency (throughput) can be improved. In particular, assuming that the delay target value of the real-time packet is D and the communication speed of the output line is R, the delay time of the real-time packet is reduced by dividing the packet so that the size of the non-real-time packet becomes D × R or less. It can be:

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a network configuration using a conventional VoIP gateway device.

FIG. 2 is a basic configuration diagram of a conventional VoIP gateway device.

FIG. 3 is a configuration diagram of a voice input interface unit of a conventional VoIP gateway device.

FIG. 4 is a configuration diagram of an IP packet output interface unit of a conventional VoIP gateway device.

FIG. 5 is a processing flowchart of a transmission timing determination procedure in an IP packet output interface unit of a conventional VoIP gateway device.

FIG. 6 is a configuration diagram of a VoIP gateway device according to the first embodiment of the present invention.

FIG. 7 is a processing flow diagram of a packet division method executed in the gateway device according to the first embodiment of the present invention.

FIG. 8 is a configuration diagram of a gateway device according to the first embodiment of the present invention.

FIG. 9 is a configuration diagram of a gateway device according to the first embodiment of the present invention.

FIG. 10 is a configuration diagram of a gateway device according to the first embodiment of the present invention.

FIG. 11 is a configuration diagram of a gateway device according to the second embodiment of the present invention.

FIG. 12 is a processing flowchart of a packet division method executed in the gateway device according to the second embodiment of the present invention.

FIG. 13 is a system configuration diagram showing an example of a network configuration using a router device and a gateway device according to the third embodiment of the present invention.

FIG. 14 is a basic configuration diagram of a router device and a gateway device according to the third embodiment of the present invention.

FIG. 15 is a configuration diagram of an IP packet input interface unit of the gateway device according to the third embodiment of the present invention.

FIG. 16 is a configuration diagram of an IP packet output interface unit of the router device according to the third embodiment of the present invention.

[Explanation of symbols]

10-14, RI00-RI04, 1000-1004
IP packet input interface unit 30-34, 900-904, GI00 Voice input interface unit 40 Routing unit 201 Transmission timing determination unit 202 High priority communication packet buffer unit 203 Low priority communication packet buffer unit 204 IP packet transmission unit 205, 1601 Communication priority Degree determining unit 301 Audio signal receiving unit 302 Digital encoding unit 303 Audio IP packet generating unit 304 Connection setting unit 20 to 24, 600 to 604, 800 to 804, 110
0-1104, RO00-RO04, GO00 IP packet output interface unit 605 Connection monitoring unit 606, 1603 Call determination unit 607 Packet division unit 1010 Communication priority determination unit 1111 Packet size monitoring unit 1112 Output speed monitoring unit 1113 Division determination unit 1114 Communication State determination unit 1501 Marking unit 1602 High priority communication packet monitoring unit R00 Router device G00, G01 VoIP gateway device GC0 to GC2 Computer terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K030 HA08 HB01 HB28 HD03 JA01 JA05 KX29 LB05 LB19 LC01 5K033 BA14 CB06 CB17 CC01 DA06 DB18 5K034 CC05 EE11 MM14 MM22 MM25 MM31

Claims (14)

[Claims] At least two types of packets, a high-priority communication packet and a low-priority communication packet, are input based on a predetermined communication priority, and multiplexing of the high-priority communication packet and the low-priority communication packet is performed. A packet division method for dividing said low-priority communication packet before said multiplexing when transmitting said packet via a single packet communication network, wherein said low-priority communication packet is divided into predetermined division switching conditions based on a predetermined division switching condition. A packet division method characterized by switching whether or not to divide into packets. 2. The high-priority communication packet is a packet having real-time communication, and the low-priority communication packet is a packet having no real-time communication. 2. The packet dividing method according to claim 1, wherein the low-priority communication packet is divided into a predetermined size only when a call is set up. 3. The packet communication network is an Internet Protocol (IP).
3. The packet division method according to claim 1, wherein the packet division method is a communication network. 4. The communication of the high-priority communication packet is performed by Vo
4. The packet division method according to claim 3, wherein the communication is a voice signal according to an IP (Voice over IP) system. 5. A voice signal obtained by inputting a voice signal and an IP packet in accordance with a voice signal communication method of VoIP (Voice over IP) performed through an IP (Internet Protocol) communication network, and packetizing the voice signal. A gateway device that generates a packet and outputs the IP packet and a voice IP packet, wherein: a voice input interface unit that inputs the voice signal; an IP packet input interface unit that inputs the IP packet; A voice IP packet generation unit that generates a voice IP packet obtained by packetizing a VoIP call; a connection monitoring unit that monitors the state of the VoIP call;
A call judging unit for judging whether an IP call is set; and dividing the IP packet into a predetermined size only when the call judging unit judges that the VoIP call is set. A packet dividing unit that performs the voice IP packet and the IP packet output from the packet dividing unit when the call determining unit determines that the VoIP call is set. And the call determination unit outputs the Vo
If it is determined that the IP call is not set, the IP packet output interface unit that outputs the voice IP packet and the IP packet input to the IP packet input interface unit to the IP communication network A gateway device, comprising: 6. The gateway device further includes an output speed monitoring unit that monitors an output speed (R) between the voice IP packet output from the IP packet output interface unit and the IP packet, and the packet division unit. Is the Vo in the call determination unit.
Only when it is determined that an IP call is set up and the output speed (R) is smaller than a predetermined threshold (T),
6. The gateway device according to claim 5, wherein the IP packet is divided into a predetermined size. 7. The threshold value (T) is defined by a relational expression T = M ÷ D based on a delay target value (D) of the voice IP packet and MTU (M) which is a maximum transfer unit of the IP packet. The gateway device according to claim 6, wherein 8. The gateway device further comprises: an output speed monitoring unit that monitors an output speed (R) of the voice IP packet and the IP packet output from the IP packet output interface unit; and the IP packet input interface. A packet size monitoring unit that monitors a packet size (P) of the IP packet input to the unit, wherein the packet division unit uses the VoI by the call determination unit.
P is determined to be set up, and a relational expression P> D × based on the output speed (R), the packet size (P), and the delay target value (D) of the voice IP packet.
The gateway device according to claim 5, wherein the IP packet is divided into a predetermined size only when R is satisfied. 9. Inputting one or more IP packets via an IP (Internet Protocol) communication network, performing routing processing based on the header content of each of the one or more IP packets, and transmitting the IP packets A router device, wherein the router device includes one or more IP packet input interface units, a connection monitoring unit, a call determination unit,
A packet division unit, a routing unit, and one or more IPs
A packet output interface unit, wherein the IP packet input interface unit comprises:
A real-time IP packet having real-time communication and a non-real-time IP packet having no real-time communication are input as the IP packet input via a communication network. The call determination unit monitors a state of a communication call, and the call determination unit determines whether a communication call of the real-time IP packet is set based on a monitoring result of the connection monitoring unit. Only when it is determined by the call determination unit that a call for communication of the real-time IP packet is set, the non-real-time IP packet is divided into a predetermined size. A predetermined IP packet output interface based on the header content of each IP packet The IP packet output interface unit determines that a call for communication of the real-time IP packet has been set by the call determination unit as the IP packet assigned by the routing unit. If the call determination unit determines that a call for communication of the real-time IP packet or the non-real-time IP packet output from the packet division unit and the real-time IP packet has not been set, , The non-real-time IP input to the real-time IP packet or the IP packet input interface.
And receiving the packet and outputting the packet to the IP communication network. 10. One or more IP packets are input via an IP (Internet Protocol) communication network, routing processing is performed based on the header content of each of the one or more IP packets, and the IP packets are transmitted. The router device includes one or more IP packet input interface units, a packet division unit, a call determination unit, a routing unit, and one or more IP packet IP packet output interface units. The IP packet input interface unit comprises:
A real-time IP packet having a real-time communication and a non-real-time IP packet having no real-time communication are input via a communication network, and the router further checks a call state of the communication of the real-time IP packet. The call determination unit is connected to a call management device for monitoring, and the call determination unit sets the call for communication of the real-time IP packet based on a signal indicating the call status of the communication of the real-time IP packet output from the call management device. The packet division unit determines whether the non-real-time IP packet has a predetermined size only when it is determined that the call for communication of the real-time IP packet is set by the call determination unit. And the routing unit is configured based on a header content of each of the one or more IP packets. Performing a routing process to allocate to each of the predetermined IP packet output interface units, wherein the IP packet output interface unit determines that the call of the real-time IP packet communication is performed by the call determination unit as the IP packet allocated by the routing unit. If it is determined that the communication is set, the real-time IP packet or the non-real-time IP packet output from the packet division unit and the call of the real-time IP packet are not set by the call determination unit. Is determined, the non-real-time IP input to the real-time IP packet or the IP packet input interface.
And receiving the packet and outputting the packet to the IP communication network. 11. The router device according to claim 9, wherein the communication of the real-time IP packet is communication of a voice signal according to a VoIP (VoiceOver IP) method. 12. The router device, further comprising: the real-time IP packet output from the IP packet output interface unit and the non-real-time IP packet.
An output speed monitoring unit that monitors an output speed (R) with a P packet; wherein the packet division unit determines that a call for communication of the real-time IP packet is set by the call determination unit; The non-real-time IP packet is divided into a predetermined size only when the output speed (R) is smaller than a predetermined threshold (T).
12. The router device according to any one of items 11 to 11. 13. The threshold value (T) is a relational expression T = M ÷ D based on a delay target value (D) of the real-time IP packet and MTU (M) which is a maximum transfer unit of the non-real-time IP packet. 13. The router device according to claim 12, wherein: 14. The router device, further comprising: the real-time IP packet output from the IP packet output interface unit and the non-real-time IP packet.
An output speed monitoring unit that monitors an output speed (R) with a P packet; and a packet size monitoring unit that monitors a packet size (P) of the non-real-time IP packet. It is determined that a call for communication of the real-time IP packet has been set, and based on the output speed (R), the packet size (P), and the delay target value (D) of the non-real-time IP packet. The router device according to claim 9, wherein the non-real-time IP packet is divided into a predetermined size only when a relational expression P> D × R is satisfied.