JP2000316021A - Connection device between networks, communication equipment and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To flexibly change a repeating protocol in accordance with a communication protocol and to realize communication without waste and contradiction by repeating a communication packet with the repeating protocol selected by a first repeating protocol selection means. SOLUTION: A protocol judgment part 13 judges whether an inputted packet is a transmission control protocol(TCP) packet or a user datagram protocol(UDP) packet. A judgment signal JS outputted from the protocol judgment part 13 changes over a switch 14 to a contact point 14A of a transmission/ reception interface 16-side according to that the packet is the UDP packet. When the input packet is a TCP packet PC1 and a protocol type PT of an IP header shows the TCP, the judgment signal JS changes over the switch 14 to a contact point 14B of a down line radio link protocol(RLP) processing part 15-side. Thus, a communication packet is repeated by a repeating protocol selected by a first repeating protocol selection means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and can be applied to, for example, a communication system in which a wired network such as the Internet and a wireless network such as a mobile telephone are connected by a gateway device. Things.

[0002] The present invention also relates to a communication device as a component of such a communication system.

Further, the present invention relates to an inter-network connection device (for example, a gateway device) as a component of such a communication system.

[0004]

2. Description of the Related Art Document 1: Evolution of Wireless Data S
ervices: IS-95 to cdma2000, IEEE Communication Ma
gazine, October 1998, pp. 140-149 Conventionally, as a system consisting of this kind of gateway device and communication device,
In p. There were 144 shown in Figure 1.

In the system configuration shown in FIG. 1, an MSC (Mobile Switching Center) having the function of a gateway device is arranged at the center of the system configuration.

[0006] One of the MSCs has an IWF (Inter
Working Function), and a PDN (Public Data Network) is further connected to the IWF.

A mobile telephone base station BS (Base Station) is connected to the other of the MSCs, and the base station BS is connected to a mobile station MS (Mobile Station) via a radio line.
Is connected.

The MSC has an RLP (Radio Link protocol)
l) is implemented, and p. 144 1.
By operating a retransmission protocol (ARQ: Automatic Repeat reQuest) between the MSC and the MS as described in 25 (left column, line 25) to 1.28 (left column, line 28), reliability is improved. We provide a data transmission service with

[0009] The retransmission protocol is a system in which the transmitting side repeatedly transmits the same data until an acknowledgment confirming that the transmitted data has correctly arrived at the destination arrives from the receiving side to the transmitting side. By doing so, it can be expected that accurate data transmission will be eventually performed even on a communication line having many errors such as a wireless line, and high-quality data transmission will be possible.

In addition, p. 145 Figure3
2 shows a hierarchical protocol configuration of a communication device connected to a wireless line. Applications used on the Internet are TCP (Transmission Control P
rotocol) or UDP (User Datagram Protoco)
l) is used as a transport layer protocol.

IP (Internet Protocol) packets use TCP as a transport protocol.
Regardless of whether DP is used, it is transferred as a PPP packet using the function of the 0SI layer2.

[0012] 0SI layer 2 is described in p. 1
46 As described in 1.17 to 1.21, the ARQ is operated if the quality of the transmission path is poor, and the ARQ is not operated if the quality of the transmission path is sufficiently high. As described above, in the conventional technique, the same reliable data transmission protocol is applied to the relay of the TCP packet and the relay of the UDP packet.

[0013]

However, in the above system configuration, when the condition of the transmission path is poor, both the TCP packet and the UDP packet receive retransmission in the RLP equally, and a delay due to the retransmission occurs.

According to the retransmission protocol, each part of the exchanged information sequence is transmitted accurately, but a procedure in which an end-to-end user changes the information to be transmitted according to the received information, such as a telephone. It is often the case that the real-time property is more important than the accuracy of each part in the form of communication that is realized by repeating the above. A situation in which retransmission is frequently performed in order to transmit accurate information, communication is often interrupted, and the progress of the procedure is stopped may cause unbearable pain to the user, and may reduce communication reliability. The content of the required reliability usually changes according to the type of application.

An application that uses the UDP as a transport protocol generally requires real-time properties. An Internet telephone that transmits voice signals over the Internet is a typical example.

In particular, when at least one communication terminal of the Internet telephone is connected to a wireless line like the communication device MS, the RLP is also used for the UDP packet.
Retransmission occurs frequently, and communication is often interrupted due to delay caused by retransmission.

In addition, in UDP, retransmission between terminals is not performed. Therefore, if a transmission error occurs in a portion other than the radio line on the communication path, no error is generated in the terminal even if retransmission by RLP is repeated no matter how much. The packet cannot be delivered.

Therefore, depending on whether the transport protocol is, for example, TCP or UDP, the data link protocol can be changed to perform communication without contradiction or waste.

If this problem is grasped more broadly, the data link protocol between the communication terminals and the gateway cannot be changed in accordance with the transport protocol between the communication terminals. The root of the problem is considered to be that the relationship between the transport protocol and the data link protocol is rigid.

The problem is that the data link protocol may perform an operation (for example, the retransmission) contrary to the intended function of the transport protocol due to the rigidity.

[0021]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an inter-network connection device which is installed on a communication path between a plurality of communication devices and relays communication between the plurality of communication devices. A plurality of relay protocols, and first relay protocol selecting means for selecting the relay protocol according to a communication protocol of a communication packet received from a first communication device among the plurality of communication devices,
The communication packet is relayed by the relay protocol selected by the first relay protocol selecting means.

The present invention also relates to an inter-network connection device which is installed on a communication path between a plurality of communication devices and relays communication between the plurality of communication devices. And a second relay protocol selecting unit for selecting the relay protocol based on information described in a communication packet received from the second communication device among the devices, wherein the second relay protocol selecting unit selects the relay protocol. The relay of the communication packet is performed using the relay protocol.

Further, the present invention relates to a communication apparatus having a plurality of communication protocols, wherein a plurality of relay protocols;
Relay protocol connection means for connecting the relay protocol according to the communication protocol.

According to the present invention, there is provided a communication apparatus having an inter-network connecting apparatus for relaying communication on a communication path between a plurality of communication apparatuses, comprising: (1) a plurality of communication protocols for communicating with a communication apparatus of the other party; (2) a plurality of relay protocols, and (3) relay protocol connection means for connecting to the relay protocol according to the communication protocol, and (4) the relay protocol connected by the relay protocol connection means. It is characterized by communicating.

Further, a communication system according to the present invention includes the communication device according to any one of claims 1 to 8 among a plurality of communication devices, and the network connection device according to any one of claims 9 to 15. Is provided on a communication path between the plurality of communication devices.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (A) Embodiment The network connecting apparatus, communication apparatus, and communication system according to the present invention are applied to a communication system using TCP and UDP as a transport layer protocol (communication protocol). The embodiment will be described using the case as an example.

(A-1) Configuration of the Embodiment FIG. 4 shows the overall configuration of the communication system 40 of the present embodiment. In FIG. 4, a wired line 44 is connected to the communication device 41, and a communication device 43 is connected to the gateway device 42 connected to the wired line 44 via a wireless line 45. Specifically, for example, the wired line 44 is the Internet, the communication device 41 is a personal computer (personal computer), the wireless line 45 is a mobile phone line, and the communication device 4
Reference numeral 3 may be a mobile phone or the like.

However, the personal computer 41 is equipped with functions such as an Internet telephone in addition to a file transfer function.
It is assumed that the mobile phone 43 has a file transfer function and the like in addition to the Internet telephone function.

FIG. 1 shows a detailed configuration example of the gateway device 42.

In FIG. 1, the gateway device 42
The input / output terminal 11 on the wired line 44 side, the wired line transmitting / receiving interface 12, the protocol determining unit 13, the switch 14, the downlink RLP processing unit 15, the wireless line transmitting / receiving interface 16, and the wireless line 45 side , And an RLP processing unit 18 on the uplink side.

Regarding the downlink RLP processor 15 and the uplink RLP processor 18, the direction of an information packet flowing from the wired line 44 to the wireless line 45 is changed to the downstream direction D.
D and vice versa are called up direction UD. The same applies to the following.

FIG. 4 shows a detailed configuration example of the portable telephone 43. As shown in FIG.

In FIG. 4, the mobile phone 43 includes an input / output terminal 21 connected to a radio line 45, a transmission / reception interface 22, a downlink RPL processing unit 23, a TCP processing unit 24, a UDP processing unit 25, An application processing unit 26 and an uplink RPL processing unit 27 are provided.

The personal computer 41 has a detailed configuration as shown in FIG.

In FIG. 3, a personal computer 41 includes an input / output terminal 31 connected to a wired line 44, a transmission / reception interface 32, a TCP processing unit 33, and a UDP processing unit 34.
And an application processing unit 35.

The structural correspondence between the portable telephone 43 and the personal computer 41 is as follows.
The application processing unit 26 in the mobile phone 43 and the application processing unit 35 in the personal computer 41 correspond,
For TCP communication, the TCP processing units 24 and 33 support
For P communication, the UDP processing units 25 and 34 correspond,
P corresponds to the downlink RLP processing units 15 and 23, and the uplink RLP corresponds to the uplink RLP processing units 18 and 27, and each protocol processing is terminated in each unit.

Here, RLP is a protocol (relay protocol) of the data link layer, which is a lower layer of the transport protocol.

The data is temporarily stored in or around the downlink RLP processor 15 and the uplink RLP processor 27 in order to perform retransmission by RLP between the gateway device 42 and the communication device 43. It is necessary to provide a retransmission buffer memory (not shown) for accumulating the retransmission buffer memory.

Further, in or around the TCP processing units 33 and 24, a retransmission buffer memory for temporarily storing data for retransmission by TCP between the communication device 41 and the communication device 43 ( (Not shown).

The operation of this embodiment having the above configuration will be described below.

(A-2) Operation of Embodiment First, information transmission using the UDP packet PC2 (see FIG. 6) will be described. This may correspond to, for example, an Internet telephone call using the mobile phone 43.

In the case of the down direction DD, the application data A in the UDP packet PC2 is transmitted from the application processing unit 35 of the personal computer 41 to the application processing unit 26 of the mobile phone 43 through the gateway device 42.
D2 is transmitted.

The application processing unit 3 of the personal computer 41
Reference numeral 5 denotes a packet (application data) depending on the type of application, which is transmitted to the TCP processing unit 33 or the
Output to the processing unit 34.

In other words, when transmitting a packet, the application processing unit 35 determines whether the type of the application is an application data (AD2) if the type of the application is a file transfer application that does not require real-time transmission but requires error-free data transfer. ) To TC
The application data (AD1) is output to the UDP processing unit 34 when the application is output to the P processing unit 33 and the real-time property is important such as the Internet telephone.

The correspondence between the application type and the output destination, that is, the correspondence between the application type and the protocol of the transport layer may be set in advance.

Since the application is a real-time application in which real-time characteristics are important, such as an Internet telephone, the transport protocol is UDP, and the application data AD 2 is output to the UDP processing unit 34.

Therefore, the real-time packet corresponding to the application is assembled by the UDP processing unit 34. The UDP packet PC2 assembled by the UDP processing unit 34 is output to the transmission / reception interface 32,
The data is sent from the input / output terminal 31 to the wired line 44.

The structure of the UDP packet PC2 is shown in FIG.
As shown in (1), an IP header added by IP (Internet Protocol), a UDP header added by UDP (User Datagram Protocol), and application data AD2 generated by an upper layer application (application processing unit 35) are provided.

On the other hand, if the application is an application in which the accuracy of each part of the information sequence is more important than real-time performance, such as a file transfer application, the output packet is assembled by the TCP processing unit 33, TCP packet P shown in FIG.
It has a structure like C1. TCP packet P
The configuration of C1 is different from the UDP packet PC1 of FIG. 6 in that the UDP header is replaced by a TCP header added by TCP (Transmission Control Protocol).

After being transmitted from the input / output terminal 31 of the personal computer 41 and arriving at the gateway 42 via the Internet 44, the UDP packet PC2 is transmitted to the input / output terminal 11 of the gateway 42,
2 and is supplied to the protocol determination unit 13 and the switch 14.

The protocol determining section 13 determines whether the input packet is a TCP packet or a UDP packet. This determination is made by checking the protocol type PT in the IP header of the packet.

In FIG. 7 showing the structure of the IP header,
One line of the IP header consisting of six lines L1 to L6 is composed of 4 bytes (32 bits). At the 10th byte (the 2nd byte of L3) counting from the beginning (the left end of L1) of the IP header, there is a 1-byte field indicating the protocol type PT. In this field, a code indicates whether the upper protocol (transport layer protocol) is TCP or UDP.

Here, since the packet is a UDP packet PC2, the protocol type PT indicates UDP.

Accordingly, the determination signal JS output from the protocol determination unit 13 as a result of the determination switches the switch 14 to the contact 14A on the transmission / reception interface 16 side in response to the packet being a UDP packet.

If the input packet is a TCP packet PC1 and the protocol type PT of the IP header is TCP
Is displayed, as described later, the determination signal JS
Switches the switch 14 to the contact 14B on the side of the downlink RLP processing unit 15.

From the switch 14 (contact 14A), the UD is transmitted via the transmission / reception interface 16 and the input / output terminal 17.
The UDP packet PC2 supplied to the P processing unit 25
In the DP processing unit 25, the application data AD2
Is extracted, and the application data AD2 is supplied to the application processing unit 26. Thus, the user of the mobile phone 43 can read the application data A
D2, it is possible to receive information corresponding to the downlink direction DD.
Is completed.

On the contrary, in the upward UD of the UDP packet PC2, the application data AD2 generated by the application processing unit 26 according to the information input from the user of the mobile phone 43 is supplied to the UDP processing unit 25.

When receiving the application data AD2, the UDP processing unit 25 adds a UDP header to the application data AD2. After this,
The signal is transmitted to the wireless line 45 via the transmission / reception interface 22 and the input / output terminal 21.

Then, the signal is supplied from the wireless line 45 to the Internet 44 via the input / output terminal 17, the transmission / reception interface 16, the transmission / reception interface 12, and the input / output terminal 11 of the gateway device 42. The UDP packet PC2 is supplied from the Internet 44 to the personal computer 41.

In the personal computer 41, the UDP packet PC 2 is sequentially transmitted and processed through the input / output terminal 31 and the transmission / reception interface 32, and reaches the UDP processing unit 34.

The UDP processing unit 34 outputs a UDP packet PC
2 to extract the application data AD2 and supply it to the application processing unit 35. The application processing unit 35 processes the application data AD2 and provides information corresponding to the application data AD2 to the user of the personal computer 41, so that the upstream UD
Is completed.

As described above, the down direction DD and the up direction UD
Also, between the gateway device 42 and the communication device 43 (or 41), the communication device 43 and the communication device 41
In the meantime, during the transmission and processing of UDP, packets are not retransmitted, so that information transmission in each direction is transmitted without interruption as long as the source user continues to send information, suitable for telephones etc. Communication environment to the user.

Next, information transmission of the TCP packet PC1 will be described. This may correspond to, for example, a case where electronic mail is transmitted and received using the mobile phone 43.

In the downstream direction DD, the TCP processing unit 33 operates in place of the UDP processing unit 34 in the personal computer 41 serving as the transmission source, and the TCP data is transmitted to the application data AD1.
The point that the communication by TCP is performed by adding a P header is different from the above-described UDP transmission and processing steps.

In the gateway device 42 receiving the TCP packet PC1 from the Internet 44, the protocol type PT of the IP header of the packet PC1 is set.
However, the determination signal JS of the protocol determination unit 13 that has detected that TCP is displayed
The contact is switched to the contact 14B on the LP processing unit 15 side.

The TCP packet PC1 is transmitted via the contact 14B.
As shown in FIG. 8, the downlink RLP processing unit 15 that has received the TCP packet PC1 divides the TCP packet PC1 into segments SG whose maximum segment length is limited to, for example, 80 bytes, and resequences the segment SG with the sequence number SN. A control bit CB for configuration and a parity bit PB for error detection are added to the packet PC for wireless transmission.
12.

In FIGS. 8A and 8B, one TC
The P packet PC1 is divided into three segments SG1 to SG3.

Then, as shown in FIGS. 8B and 8C, at the head of any one segment (SG3),
A sequence number SN and a control bit CB are added, and a parity bit PB is added at the end.

The sequence number SN is a serial number that differs for each segment SG.
It is used for associating the acknowledgment signal (ACK) from the processing unit 23 with the transmission segment.

In this case, the retransmission by the RLP between the gateway device 42 and the communication device 43 is performed substantially in units of the segment SG.
Since one TCP packet PC1 transmitted to the P processing unit 15 corresponds to a three-segment SG, the retransmission buffer memory needs to have a capacity to store at least the three-segment SG.

While the retransmission is being performed, not only does the information received by the user of the mobile phone 43 of the transmission destination be interrupted, but also depends on the capacity of the retransmission buffer memory. It is also necessary to stop sending information by the 41 users. Otherwise, an overflow may occur in the retransmission buffer memory.

The control bit CB is a bit indicating whether or not one segment SG is the last segment of a TCP packet. For example, the control bit CB is "1" if the last segment is not, and "0" if not the last segment. . The parity bit PB is transmitted to the downlink RLP processor 23 in the mobile phone 43.
Used for error detection in

The wireless transmission packet PC 12 reaches the mobile phone 43 via the transmission / reception interface 16, the input / output terminal 17, and the wireless line 45 where transmission errors are likely to occur, and the mobile phone 43 performs accurate wireless transmission as described later. If this has been done, a acknowledgment ACK is sent back.

Downlink RLP in gateway device 42
If the processing unit 15 does not receive the reception acknowledgment ACK from the mobile phone 43 before the set timer expires, the processing unit 15 receives the reception acknowledgment ACK by a normal ARQ method of retransmitting the segment (packet PC12). Continue resending the segment until

In the transmission / reception interface 16 of the gateway device 42, the UDP directly input from the switch 14
The packet SG and the segment SG (packet PC12) processed in the downlink RLP processor 15 are multiplexed.

In this multiplexing, the portable telephone 43 and a portable information terminal (not shown) which requires another type of retransmission besides the portable telephone are simultaneously connected to the gateway device 42 via a radio line 45 or the like. This is an operation corresponding to the case.

FIG. 9 is an explanatory diagram of multiplexed output signals of the transmission / reception interface 16. Separate logical channel numbers LN are assigned to the output (segment SG) from the downlink RLP processing unit 15 and the direct output (UDP packet PC2) from the switch 14, and a logical channel number LN is added to each output.

Using the logical channel number LN, demultiplexing is performed in the transmission / reception interface 22 in the portable telephone 43. In the illustrated example using 8 bits as the logical channel number LN, a maximum of 25
Six wireless communication terminals can be multiplexed.

The packets multiplexed in this way by the transmission / reception interface 16 are output to the radio line 45 via the input / output terminal 17.

Transmission / reception interface 2 of portable telephone 43 connected to radio line 45 via input / output terminal 21
2 performs a demultiplexing operation corresponding to the multiplexing operation of the transmission / reception interface 16.

Of the outputs after the demultiplexing of the transmission / reception interface 22, the direct output from the switch 14 corresponding to the UDP packet PC2 is supplied to the UDP processing unit 25 as described above, but corresponds to the TCP packet PC1. Output from downlink RLP processor 15 (segment S
G) is supplied to the downlink RLP processing unit 23.

Downlink RL receiving segment SG
The P unit 23 checks the parity bit part PB of the received segment SG to check whether the wireless transmission is correctly performed, that is, whether the segment SG contains an error, as described above.

If the segment SG contains no error, the downlink RLP processing section 23
Send CK. The reception confirmation ACK reaches the downlink RLP processing unit 15 via the transmission / reception interface 22, the input / output terminal 21, the wireless line 45, the input / output terminal 17 of the gateway device 42, and the transmission / reception interface 16.

Further, the downlink RLP processing unit 23 uses the control bit CB of the segment SG correctly received, and performs the TCP reverse operation in the order shown in FIG. 8 (A) → (B) → (C).
Reconfigures the packet PC1 and its TCP packet PC1
Is output to the TCP processing unit 24.

The TCP processing unit 24 transmits the TCP packet PC1
And outputs the application data part AD1 to the application processing part 26 at the same time as the uplink U including the ACK signal defined by the TCP protocol.
D TCP packet PC1 to the uplink RLP processing unit 27
Output to

The uplink RLP processing unit 27 in the mobile phone 43 serving as a transmission source in the uplink UD is connected between the uplink RLP processing unit 18 of the gateway device 42 and the downlink RLP processing unit 15 described above. A retransmission operation based on ARQ similar to the operation performed between the RLP processing units 23 is performed.

The output of the uplink RLP processing section 18 includes the transmission / reception interface 12, the input / output terminal 11,
4. The application processing of the personal computer 41 to which the application data AD1 which is delivered to the TCP processing unit 33 via the input / output terminal 31 of the personal computer 41 and the transmission / reception interface 32 and is generated by the application processing unit 26 of the mobile phone 43 is transmitted. The unit 35 is reached.

After all, in the present embodiment, the gateway device 42 is provided with the protocol determination unit 13 so that the TCP packet P
Retransmission by RLP is performed only for C1, and retransmission is not performed for UDP packet PC2 regardless of the communication quality.

In the case of TCP, the communication devices 43 and 41
During the period, the retransmission by the normal TCP is also performed together with the retransmission by the RLP. For example, in the down direction DD, there may be cases where a normal packet does not exist in the retransmission buffer of the gateway device 42 due to a transmission error of the Internet 44. In such a case, the communication device 43 becomes normal only by retransmission by RLP. Since packets cannot be received, end-to-end retransmission by TCP is necessary.

(A-3) Effects of the Embodiment As described above, according to the communication system of the present embodiment, in the case of a real-time application such as an Internet telephone using UDP as a transport protocol, there are many errors in a wireless line. However, by not retransmitting the packet, the delay is reduced to provide the user with a comfortable use environment. For applications using TCP where each part of the information sequence requires accurate data transmission, error detection and packet retransmission must be performed. Since the reliability of the communication system is increased by executing the operation, a highly flexible operation of the communication system can be realized as a whole.

(B) Other Embodiments In the above embodiment, an AR that repeats retransmission until data is correctly transmitted is used as a relay protocol for a TCP packet between the gateway device and the wireless communication device.
Although the Q protocol is used and a protocol that does not perform retransmission at all as a relay protocol for a UDP packet is used, for example, when a UDP application does not require strict real-time performance, the number of retransmissions is limited as a relay protocol for a UDP packet. The ARQ protocol may be used.

As a result, the packet error rate is improved compared to the above embodiment in which no packet retransmission is performed, and
The accuracy of each part of the information sequence to be transmitted can be improved.

In the above embodiment, the communication device 41 on the wired line 44 is a personal computer, and the communication device 43 on the wireless line 45 is a mobile phone. However, the present invention is not limited to these.

For example, the communication device 41 may be replaced with a multifunctional fixed telephone or the like, and the communication device 43 may be replaced with a wireless communication terminal other than a mobile phone.

In the above embodiment, the wired line 44 is the Internet, and the wireless device 45 connects the gateway device 42 and the communication device 43. However, the present invention is not limited to these. That is, the wired line 44 may be a wired line other than the Internet or a wireless line, and the wireless line 45 may be a wired line.

In the above-described embodiment, retransmission is performed only at both ends of the radio line 45. However, if the retransmission line is a line where the possibility of transmission error is not low, the radio line 45 is used. Not only that, but also at both ends of a wired line (44 etc.).

Further, protocols such as TCP, UDP, and IP are not limited to these.

That is, in general, the TCP can be replaced with a transport layer protocol that retransmits a packet, and the UDP can be replaced with a transport layer protocol that does not retransmit a packet. The IP can be replaced with a network layer protocol.

For example, the TCP is referred to as SPX (Sequence
d Packet Exchange).
P may be replaced with IPX (Internetwork Packet Exchange) or the like.

Therefore, the protocols of the transport layer provided in the communication devices 41 and 43 are TCP and UDP.
Not limited to the type, three or more types may be used.

Further, in the above description, the gateway device 4
Although the second protocol determination unit 13 and the switch 14 are provided only in the down direction DD, they may be provided in the up direction UD.

Further, in the above embodiment, the communication device 41
The communication device 43 is a two-way communication device that transmits and receives information (application data AD1 or AD2), but one or both of them may be a communication device dedicated to reception or transmission.

Further, in the above embodiment, hardware is used, but the present invention can be realized by using software. For example, the application processing unit 26, the TCP processing unit 24, the UDP processing unit 2 in the communication device 43
5. The connection relationship between the downlink RLP processing unit 23 and the uplink RLP processing unit 27, etc., is usually performed by software.

That is, the present invention can be widely applied to an inter-network connection device installed on a communication path between a plurality of communication devices and relaying communication between the plurality of communication devices.

[0105]

As described above, according to the present invention, the relay protocol can be flexibly changed according to the communication protocol, the communication reliability can be improved, and communication without waste and contradiction can be performed. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a gateway device according to an embodiment.

FIG. 2 is a block diagram illustrating a configuration of a wireless communication device according to the embodiment;

FIG. 3 is a block diagram illustrating a configuration of a wired line communication device according to the embodiment;

FIG. 4 is a schematic diagram showing an overall configuration of a communication system according to an embodiment.

FIG. 5 is a schematic diagram showing a configuration of a TCP packet according to the embodiment.

FIG. 6 is a schematic diagram showing a configuration of a UDP packet according to the embodiment.

FIG. 7 is a schematic diagram showing a configuration of an IP header according to the embodiment.

FIG. 8 is a schematic diagram illustrating a procedure for dividing or reconfiguring a TCP packet according to the embodiment;

FIG. 9 is a schematic diagram showing a configuration of a multiplexed packet according to the embodiment.

[Explanation of symbols]

13: Protocol determination unit, 14: Switch, 14A, 1
4B ... contact point, 15, 23 ... downlink RLP processing unit, 1
8, 27: Uplink RLP processing unit, 24, 33: TCP
Processing unit, 25, 34 UDP processing unit, 26, 35 Application processing unit, PC1 TCP packet, PC2
... UDP packet, PT ... protocol type, 40 ... communication system, 41, 43 ... communication device, 42 ... gateway device, 44 ... wired line, 45 ... wireless line, DD ... down direction, UD ... up direction.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 29/06 F term (Reference) 5B089 GA31 GB01 HA10 HA11 HB02 HB19 KA12 KC23 KC52 KD01 KF05 KF06 ME08 5K030 HA08 HB18 HC01 HC09 HD03 JL01 JT09 LA01 5K033 CB02 CB08 DA19 DB18 5K034 EE03 FF11 HH61 JJ24 MM03

Claims (17)

[Claims] 1. An inter-network connection device that is installed on a communication path between a plurality of communication devices and relays communication between the plurality of communication devices, comprising: a plurality of relay protocols; First relay protocol selecting means for selecting the relay protocol in accordance with a communication protocol of a communication packet received from a first communication device, wherein the first relay protocol selecting means selects the relay protocol. An inter-network connection device for relaying a communication packet. 2. The inter-network connection device according to claim 1, wherein the relay protocol is selected based on information described in a communication packet received from a second communication device among the plurality of communication devices. A communication packet received from the first communication device, relayed by a relay protocol selected by the first relay protocol selection device, and a communication packet received from the second communication device. Is an inter-network connection device for relaying according to the relay protocol selected by the second relay protocol selecting means. 3. The inter-network connection device according to claim 1, wherein the first relay protocol selection unit is configured to select the first relay protocol according to a communication protocol of a communication packet received from the first communication device. Is selected between the relay protocol having a property different from the communication protocol of the communication packet and the relay protocol having the same property. 4. The inter-network connection device according to claim 1, wherein the first relay protocol selecting unit is configured to retransmit the communication packet received from the first communication device when the communication packet is retransmitted. An inter-network connection device, wherein the relay protocol is selected based on whether the communication protocol is a first communication protocol or a second communication protocol that does not retransmit the communication packet. 5. The inter-network connection device according to claim 1, wherein the relay protocol performs a first retransmission of a communication packet.
And a second relay protocol that does not perform retransmission of the communication packet or limits the number of retransmissions, wherein the first relay protocol selection unit performs communication received from the first communication device. When the packet is the first communication protocol, the first communication protocol is used as the relay protocol.
Wherein the relay protocol is selected and if the second communication protocol is selected, the second relay protocol is selected as the relay protocol. 6. The inter-network connecting apparatus according to claim 1, wherein a maximum packet size of the first relay protocol is shorter than a maximum packet size of the first communication protocol. Network connection device. 7. The inter-network connection device according to claim 1, wherein at least one of the communication paths among the plurality of communication devices is connected to the inter-network connection device. An inter-network connection device, wherein the communication path is a wireless line. 8. An inter-network connection device installed on a communication path between a plurality of communication devices and relaying communication between the plurality of communication devices, comprising: a plurality of relay protocols; Second relay protocol selecting means for selecting the relay protocol based on information described in a communication packet received from a second communication device, wherein the relay selected by the second relay protocol selecting means is provided. An inter-network connection device, wherein the communication packet is relayed by a protocol. 9. A communication device having a plurality of communication protocols, comprising: a plurality of relay protocols; and relay protocol connection means for connecting the relay protocols in accordance with the communication protocols. 10. A communication device having an inter-network connection device for relaying communication on a communication path between a plurality of communication devices, comprising: a plurality of communication protocols for communicating with a counterpart communication device; And a relay protocol connection means for connecting to the relay protocol according to the communication protocol, wherein communication is performed using the relay protocol connected by the relay protocol connection means. 11. The communication device according to claim 9, wherein the relay protocol connection unit has a property that the relay protocol is different from the communication protocol of the communication packet in accordance with the communication protocol of the communication packet. A communication device connected to the relay protocol or connected to the relay protocol having the same property. 12. The communication device according to claim 9, wherein the communication protocol is a first device for retransmitting a communication packet.
And a second communication protocol that does not perform retransmission of the communication packet. The relay protocol connection means may be a communication packet of the first communication protocol or a communication packet of the second communication protocol. A communication device for connecting a relay protocol based on whether there is any. 13. The communication device according to claim 9, wherein the relay protocol performs a first retransmission of a communication packet.
And a second relay protocol that does not retransmit the communication packet or limits the number of retransmissions, wherein the relay protocol connection means is a communication packet of the first communication protocol. A communication device connected to a first relay protocol as the relay protocol, and connected to a second relay protocol as the relay protocol if the packet is a communication packet of the second communication protocol. 14. The communication device according to claim 9, wherein a maximum packet size of the first relay protocol is shorter than a maximum packet size of the first communication protocol. apparatus. 15. The communication device according to claim 9, wherein the relay protocol includes at least a relay protocol that is the same as the relay protocol of the network connection device. 16. The communication device according to claim 1, wherein the communication device includes a plurality of communication devices.
The communication device according to any one of claims 9 to 15, further comprising:
A communication system, wherein the inter-network connection device according to any one of the above is installed on a communication path between the plurality of communication devices. 17. The communication system according to claim 16, wherein a communication path between at least one of the communication devices and the inter-network connecting device is a wireless line. A communication system, comprising: