JP2006019777A - Packet transfer system, gateway device and packet transfer method used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packet transfer system capable of realizing smooth communication without generating a loss in a packet even if a device having low packet processing capability is provided in a network. <P>SOLUTION: A gateway device 2 is installed between a network 101 having packet processing capability of Xpps and a network 102 having packet processing capability of Ypps (Y=nX), and absorbs the difference in packet processing capability between the networks 101 and 102. The gateway device 2 decomposes a packet received from the network 102 into n packets, and sends the decomposed packets to the network 101. Also, the gateway device 2 combines the n packets received from the network 101, and sends the combined packets to the network 102. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a packet transfer system, a gateway apparatus, and a packet transfer method used therefor, and more particularly to a packet transfer method between networks having different packet transfer rates.

  In recent years, with the spread of the Internet network, a system for connecting networks using the Internet network has been spread. There is also a system for connecting networks via a network device such as a gateway device.

  For systems that connect networks using an Internet network, devices and methods for avoiding transmission delays and transmission fluctuations during packet transfer periods have been proposed (see, for example, Patent Documents 1 and 2).

JP 2001-136207 A JP 2001-168914 A

  In the above-described conventional system for connecting between networks, an application in a network device is not generally operated assuming a network with a low packet processing capability.

  Therefore, if there is a network with low packet processing capability in the network through which the packet passes, it may not be possible to process the packet transmitted from the terminal, so when interconnecting networks with different packet processing capabilities, Even if a network with a low packet processing capability exists, a method that can realize smooth communication without packet loss is being sought.

  Therefore, an object of the present invention is to solve the above-described problems, and a packet transfer system capable of realizing smooth communication without causing a packet loss even when a device having a low packet processing capacity exists in the network. Another object of the present invention is to provide a gateway device and a packet transfer method used therefor.

  The packet transfer system according to the present invention is a packet transfer system in which a plurality of networks each having a different packet processing capability are connected by a gateway device, and when performing packet transfer between the networks, the network according to the packet processing capability of each network. The gateway device is provided with combining / disassembling means for combining or disassembling packets.

  The gateway device according to the present invention is a gateway device for connecting a plurality of networks each having a different packet processing capability, and when performing packet transfer between the networks, the combination of packets according to the packet processing capability of each of those networks A combined decomposition means for performing any of the decomposition is provided.

  The packet transfer method according to the present invention is a packet transfer method used in a packet transfer system in which a plurality of networks each having different packet processing capabilities are connected by a gateway device, and performs packet transfer between the networks on the gateway device side. In this case, a process for combining or decomposing packets is provided according to the packet processing capability of each network.

  That is, the packet transfer system of the present invention is characterized in that communication traffic having a large PPS (Packet Per Second) value is passed even when a device having a low packet processing capability is included in the network.

  In general, the performance of network devices is often affected by PPS rather than the packet size. Therefore, when there is a device with a low packet processing capability in the network, the number of packets is reduced by combining a plurality of packets before passing through the network, and the PPS is kept low. As a result, in the packet transfer system of the present invention, it is possible to reduce the load on the network device and to prevent packet overflow.

  For example, let us consider communication across networks with different packet processing capabilities. Here, the packet processing capability in the first network is as large as Ypps, but the packet processing capability of the second network 3 is as small as Xpps. .

  When the first terminal connected to the first network and the second terminal connected to the second network communicate with each other, the second network has poor packet processing capability. If the packet is allowed to flow through the second network as it is, a packet overflow occurs.

  Therefore, in the packet transfer system of the present invention, the number of packets is reduced by combining the packets flowing in from the second network by the gateway device, and then sent to the first network. As a result, only a few packets flow in the first network.

  At the same time, in the packet transfer system of the present invention, a packet flowing in from the first network is decomposed by the gateway device so as to correspond to the second network and then sent to the second network. As a result, packet overflow can be prevented in the second network, and smooth communication can be realized.

  The operation of the gateway device here is to divide and combine packets according to the processing capability of each network. Further, by adjusting the number of packets to be divided / combined, it becomes possible to cope with any interconnection of networks having any packet processing capability.

  By adopting the configuration and operation as described below, the present invention can realize smooth communication without causing packet loss even if a device with low packet processing capacity exists in the network. An effect is obtained.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a packet transfer system according to an embodiment of the present invention. In FIG. 1, a terminal (# 1) 1, a network 101, a gateway device 2, a network 102, and a terminal (# 2) 3 are configured.

  The networks 101 and 102 have different packet processing capabilities and are interconnected by gateway devices. The terminal (# 1) 1 is connected to the network 101, and the terminal (# 2) 3 is connected to the network 102.

  The network 101 is a network having a packet processing capability of Xpps (packet per second) (packet processing capability is low), and the network 102 is a network having a packet processing capability of Ypps (high packet processing capability).

  The gateway device 2 is installed between the network 101 and the network 102, and combines and disassembles packets to ensure consistency in packet transfer rates between the network 101 and the network 102.

  FIG. 2 is a block diagram showing a configuration of the gateway device 2 of FIG. In FIG. 2, the gateway device 2 controls the packet combining / disassembling circuit 21 for combining and disassembling the packets, and packet transfer for controlling the packet combining speed of the network 101 and the network 102 by controlling the packet combining / disassembling circuit 21. And a speed matching circuit 22.

  FIG. 3 is a sequence chart showing the operation of the packet transfer system according to the embodiment of the present invention. The operation of the packet transfer system according to one embodiment of the present invention will be described with reference to FIGS.

  Considering the case where the terminal (# 1) 1 and the terminal (# 2) 3 communicate with each other, when the terminal (# 1) 1 and the terminal (# 2) 3 communicate with each other, the network 101 and the network 102 Is used.

  However, the packet processing capability of the network 101 is Xpps, the packet processing capability of the network 102 is Ypps, and there is a difference between the packet processing capabilities of the networks 101 and 102 (here, it is assumed that there is a relationship of Y = nX). n is an integer). Therefore, the gateway device 2 is installed between the network 101 and the network 102, and the gateway device 2 absorbs the difference in packet processing capability between the networks 101 and 102.

  Specifically, the gateway device 2 breaks down the packet that has entered from the network 102 into n pieces (a1, a2 in FIG. 3), and sends the broken down packet to the network 101 (a3 in FIG. 3).

  Conversely, n packets that have entered from the network 101 are combined in the gateway device 2 (a11, a12 in FIG. 3), and the combined packets are sent to the network 102 (a13 in FIG. 3).

  In the above example, the connection between the network 101 having the packet processing capability of Xpps and the network 102 having the packet processing capability of Ypps has been described. However, other networks having a packet processing capability can be used. In that case, it is possible to respond flexibly by changing the number of connections and divisions (corresponding to n above) in the gateway device 2.

  FIG. 4 is a block diagram showing the configuration of a packet transfer system according to another embodiment of the present invention. FIG. 4 shows an example in which VoIP (Voice over Internet Protocol) packet data is passed through a network having a low packet processing capability to enable IP (Internet Protocol) telephone calls. In FIG. 4, the configuration of the gateway device 15 is the same as the configuration of the gateway device 2 shown in FIG.

  The telephone terminal (# 1) 11 is connected to the business operator network 201 through an MGW (Media Gateway) (# 1) 13. The MGW (# 1) 13 is a device that digitizes analog voice data and transmits it as a packet. The MGW (# 1) 13 exists in the operator network 201 and accommodates a line to the telephone terminal (# 1) 11.

  The MGW (# 1) 13 packetizes the voice data from the telephone terminal (# 1) 11 at a speed of Xpps and transmits it to the carrier network 201. The carrier network 201 is a network of a telecommunications carrier with which the telephone terminal (# 1) 11 is contracted. The carrier network 201 has a low packet processing capability (Xpps).

  The IP network 202 constructs an IP telephone network and includes the IP telephone terminal 16. The IP network 202 has a high packet processing capability (Ypps) (Y = nX). The gateway device 15 is a device that absorbs the difference in packet transfer rate between the carrier network 201 and the IP network 202. The IP telephone terminal 16 is connected to the IP network 202.

  The MGW (# 2) 14 converts packet data from the IP network 202 into digital data of TDM (Time Division Multiplexing), and transmits the digital data to a PSTN (Public Switched Telephony Network) 203. Similarly, the MGW (# 2) 14 converts the TDM digital data from the PSTN 203 into Ypps packet data, and transmits the packet data to the IP network 202. The PSTN 203 is a public telephone network to which a telephone terminal (# 2) 12 is connected.

  5 and 6 are sequence charts showing the operation of the packet transfer system according to another embodiment of the present invention. The operation of the packet transfer system according to another embodiment of the present invention will be described with reference to FIG. 2 and FIGS. First, the operation when the telephone terminal (# 1) 11 makes a call with the IP telephone terminal 16 will be described with reference to FIG.

  When voice data is transmitted as an analog signal from the telephone terminal (# 1) 11 to the MGW (# 1) 13 (b1 in FIG. 5), the MGW (# 1) 13 digitizes the analog voice data and the packet rate becomes Xpps. (B2 in FIG. 5), and the packet is sent to the operator network 201.

  The voice packet data is transferred through the carrier network 201 at the packet rate Xpps and reaches the gateway device 15 (b3 in FIG. 5). In order to adapt to the packet transfer rate of the IP network 202, the gateway device 15 combines n received packets and transmits to the IP network 202 at a packet rate Ypps (Y = nX) (b4 in FIG. 5).

  The combined voice packet data reaches the IP telephone terminal 16 via the IP network 202 (b5 in FIG. 5). The IP telephone terminal 16 synthesizes and decodes the packet received at the packet rate Ypps, and asks the user to hear the decoded voice (b6 in FIG. 5).

  When the IP telephone terminal 16 transmits voice packet data at the packet rate Ypps, the voice packet data reaches the gateway device 15 via the IP network 202 (b11 in FIG. 5). In order to adapt to the packet transfer rate of the carrier network 201, the gateway device 15 breaks down the packet received from the IP network 202 into n pieces (b12 in FIG. 5) and transmits the packet to the carrier network 201 at the packet rate Xpps. (B13 in FIG. 5).

  The MGW (# 1) 13 analogizes the digital voice data transferred at the packet rate Xpps in the carrier network 201 (b14 in FIG. 5), and sends the voice data of the analog signal to the telephone terminal (# 1) 11 Transmit (b15 in FIG. 5).

  Next, the operation when the telephone terminal (# 1) 11 and the telephone terminal (# 1) 12 connected to the PSTN 203 make a call will be described with reference to FIG.

  When voice data is transmitted as an analog signal from the telephone terminal (# 1) 11 to the MGW (# 1) 13 (c1 in FIG. 6), the MGW (# 1) 13 digitizes the analog voice data and the packet rate becomes Xpps. (C2 in FIG. 6), and the packet is sent to the operator network 201.

  The voice packet data is transferred through the carrier network 201 at the packet rate Xpps and reaches the gateway device 15 (c3 in FIG. 6). In order to adapt to the packet transfer rate of the IP network 202, the gateway device 15 combines n received packets and transmits them to the IP network 202 at a packet rate Ypps (Y = nX) (c4 in FIG. 6).

  Since the packet transmitted to the IP network 202 reaches the MGW (# 1) 14 (c5 in FIG. 6), the MGW (# 1) 14 converts the packet data from the IP network 202 into a format suitable for the PSTN 203 (TDM data). (C6 in FIG. 6), and reaches the telephone terminal (# 2) 12 through the PSTN 203 as voice data.

  Note that a call from the telephone terminal (# 2) 12 to the telephone terminal (# 1) 11 reaches the telephone terminal (# 1) 11 in the reverse order of the above sequence.

  The gateway device 15 combines n packet data from the carrier network 201 to convert the packet transmission rate from Xpps to Ypps (Y = nX: n is an integer) that is the packet transfer rate of the IP network 202.

  Similarly, the gateway device 15 converts the packet rate from Ypps to Xpps which is the packet transmission rate of the carrier network 201 by breaking the packet data from the IP network 202 into n pieces. Thus, in this embodiment, packet overflow due to insufficient processing capacity in the operator network 201 can be prevented.

  FIG. 7 is a flowchart showing variable determination processing by the gateway device 15 of FIG. The variable determination process by the gateway device 15 will be described with reference to FIGS. 2, 4, and 7. This variable determination process is performed by the packet transfer rate matching circuit 22 of the gateway device 15.

  When the gateway device 15 sets X and Y, which are variables indicating the packet transfer rate (pps), and the packet combination / decomposition value n, the gateway device 15 first sets the variable according to the packetization cycle (= sampling cycle) adopted by the IP telephone terminal 16. Y is determined (step S1 in FIG. 7). For example, if the packetization period is 50 ms, 20 packets are generated in 1 s, so the packet transfer rate is 20 pps, and the value of the variable Y in this case is 20.

  Next, the gateway device 15 determines the variable X based on the packet processing capability of the network device having the lowest packet processing capability in the carrier network 201 (step S2 in FIG. 7). For example, if the packet processing capability of the network device in the operator network 201 is 5 packets per second, X = 5.

  Finally, the gateway device 15 determines a variable n from the variables X and Y determined as described above (step S2 in FIG. 7). This variable n is the number of packets that the gateway device 15 disassembles or combines the packets. Here, since 20 pps packet is converted to 5 pps, n = 4.

  Note that the telephone terminal (# 1) 11 and the MGW (# 1) 13 may be integrated into a user terminal. Specifically, a case where a user makes a call by connecting a headset (an integrated device of headphones and a microphone) to a PDA (Personal Digital Assistant) or a personal computer can be considered. In this case, since the voice data is packetized into Xpps inside the PDA or personal computer, the MGW (# 1) 13 becomes unnecessary.

  Further, in this embodiment, an example is shown in which two networks (the operator network 201 and the IP network 202) are interconnected by the gateway device 15. However, it is possible to interconnect three or more networks.

  As described above, according to the present invention, even when a network device having a low packet processing capability exists in the network, smooth communication can be realized without causing packet loss.

  In the present invention, networks having different packet processing capabilities can be interconnected. Furthermore, in the present invention, it is possible to connect not only two networks but also three or more networks.

  Furthermore, according to the present invention, the number of packets to be combined and disassembled can be varied to flexibly cope with any interconnection of networks having different packet processing capabilities.

It is a block diagram which shows the structure of the packet transfer system by one Example of this invention. It is a block diagram which shows the structure of the gateway apparatus of FIG. It is a sequence chart which shows operation | movement of the packet transmission system by one Example of this invention. It is a block diagram which shows the structure of the packet transfer system by the other Example of this invention. It is a sequence chart which shows the operation | movement of the packet transfer system by the other Example of this invention. It is a sequence chart which shows the operation | movement of the packet transfer system by the other Example of this invention. It is a flowchart which shows the variable determination process by the gateway apparatus of FIG.

Explanation of symbols

1 terminal (# 1)
2,15 Gateway device
3 Terminal (# 2)
11 Telephone terminal (# 1)
12 Telephone terminal (# 2)
13 MGW (# 1)
14 MGW (# 2)
16 IP phone terminal
21 Packet coupling and decomposition circuit
22 packet transfer rate matching circuit 101,102 network
201 operator network
202 IP network
203 PSTN

Claims (12)

  A packet transfer system in which a plurality of networks each having different packet processing capabilities are connected by a gateway device, and when packet transfer is performed between the networks, either of combining or disassembling packets according to the packet processing capability of each of those networks A packet transfer system characterized in that the gateway device has combining / disassembling means for performing the above.   The packet transfer system according to claim 1, wherein the gateway device interconnects two or more networks.   The gateway apparatus includes a matching unit configured to perform matching so that the packets are transferred at a speed adapted to the packet processing capability of each network when the networks having different packet processing capabilities are interconnected. The packet transfer system according to claim 1 or 2.   4. The packet transfer system according to claim 3, wherein the matching unit varies the number of coupling and decomposing of the packets by the combining / decomposing unit according to the difference in the packet processing capability.   A gateway device for connecting a plurality of networks each having a different packet processing capacity, and performing packet combining or disassembly according to the packet processing capacity of each of the networks when transferring packets between the networks. A gateway device comprising disassembling means.   6. The gateway apparatus according to claim 5, wherein two or more networks are interconnected.   6. The matching device according to claim 5, further comprising matching means for performing matching so that the packets are transferred at a speed adapted to the packet processing capability of each network when the networks having different packet processing capabilities are interconnected. 6. The gateway device according to 6.   8. The gateway apparatus according to claim 7, wherein the matching unit varies the number of packets combined and decomposed by the combining / disassembling unit according to the difference in the packet processing capability.   A packet transfer method for use in a packet transfer system in which a plurality of networks each having a different packet processing capability are connected by a gateway device, wherein the packet processing of each of the networks is performed when performing packet transfer between the networks on the gateway device side. A packet transfer method comprising processing for combining or disassembling packets according to capability.   The packet transfer method according to claim 9, wherein the gateway device interconnects two or more networks.   The gateway apparatus includes a process of performing matching so that when the networks having different packet processing capacities are interconnected, the packet transfer is performed at a speed adapted to the packet processing capacities of the respective networks. The packet transfer method according to claim 9 or 10. 12. The packet transfer method according to claim 11, wherein in the matching processing, the number of combining and disassembling of the packet is varied according to the difference in the packet processing capability.

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