JP2013175938A - Communication apparatus, communication method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide communication service without allowing a user to feel influence by an obstacle even if there is the obstacle in communication by a prescribed IP protocol stack in a communication environment that can use the plurality of IP protocol stacks.SOLUTION: A communication apparatus for relaying communication between a user terminal and a server device includes: connection request transmission means for transmitting a connection request to the server device by using a plurality of types of IP protocol stacks when a service request to the server device is received from the user terminal; session establishment means for establishing a session with the server device by using the IP protocol stack used for a response received from the server device as a response to the connection request; and relay means for transmitting the service request to the server device by using the session, receiving the response to the service request from the server device and transmitting the response to the user terminal.

Description

  The present invention relates to a communication technology in a communication environment in which a plurality of IP protocol stacks such as IPv4 and IPv6 can be used.

  In a dual stack environment of IPv4 and IPv6, a method has been generally used in which IPv6 is prioritized and session establishment is attempted, and when there is a problem such as a timeout, it is retried with IPv4. However, when there is a problem with IPv6, there is a problem that it takes time to establish a session and the convenience of the user is impaired. In order to solve this problem, a method is known in which IPv4 and IPv6 communication establishment is attempted at the same time, and a session is established using a protocol stack that has previously responded (see Non-Patent Document 1).

Happy Eyeballs, http://tools.ietf.org/html/draft-wing-v6ops-happy-eyeballs-ipv6-01 (searched on February 17, 2012)

  However, the above-mentioned Happy Eyeballs are premised on implementation on end terminals, and in the case of terminals and applications that are not installed, there is a problem that user convenience is still bad because it switches to IPv4 after IPv6 timeout. is there.

  The present invention has been made in view of the above points, and in a communication environment in which a plurality of IP protocol stacks such as IPv4 and IPv6 can be used, even if there is a problem in communication with a certain IP protocol stack, The purpose is to realize a technology for providing a communication service without making the user feel the influence.

In order to solve the above problem, the present invention is a communication device that relays communication between a user terminal and a server device,
A connection request transmitting means for transmitting a connection request for the server device using each of a plurality of types of IP protocol stacks when a service request for the server device is received from the user terminal;
Session establishment means for establishing a session with the server device using the IP protocol stack used for the response received from the server device as a response to the connection request;
Relay means for transmitting the service request to the server device using the session, receiving a response to the service request from the server device, and transmitting the response to the user terminal. Configured as a device.

  The present invention can also be configured as a program for causing a communication method executed by the communication device and a computer having a communication function to function as each unit of the communication device.

  According to the present invention, even in a communication environment in which a plurality of IP protocol stacks such as IPv4 and IPv6 can be used, even if communication by a certain IP protocol stack is hindered, communication can be performed without making the user feel the influence of the trouble Technology for providing services is realized.

It is a system configuration figure concerning an embodiment of the invention. 2 is a functional configuration diagram of a proxy device 10. FIG. FIG. 6 is a sequence diagram for explaining an operation example 1; FIG. 10 is a sequence diagram for explaining an operation example 2; FIG. 10 is a sequence diagram for explaining an operation example 3;

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. For example, in this embodiment, an example is shown in which IPv4 and IPv6 are used as the protocol stack, but the present invention can be applied even when the protocol stack is other than IPv4 and IPv6. Although the case of using TCP in communication is shown, this is only an example, and the present invention can be applied to communication using a protocol other than TCP.

(System configuration)
FIG. 1 shows a system configuration diagram according to an embodiment of the present invention. As shown in FIG. 1, the system according to the present embodiment has a configuration in which a proxy device 10, a server device 20, and a user terminal 30 are connected via a network as illustrated. In the present embodiment, the proxy device 10 and the server device 20 are connected via the Internet.

  In the present embodiment, the user terminal 30 is a general terminal such as a PC or a smartphone provided with a browser. The server device 20 has a Web server function and a function of providing requested data in response to a service request (data request in this example). In the present embodiment, a Web service is assumed as a service provided by the server device 20, but this is only an example, and the service provided by the server device 20 is a specific service when the present invention is applied. It is not limited.

  The proxy device 10 includes a relay function that transmits a data request from the user terminal 30 to the requesting server device 20 as a proxy of the user terminal 30 and transmits the data received from the server device 20 to the user terminal 10. Device. In addition, the proxy device 10 according to the present embodiment is connected to the session according to the protocol stack used for transmitting the data request from the user terminal 30 or the protocol stack used for communication of the response from the server device 20. A function of determining a protocol stack to be used for the session and performing session connection using the protocol stack is also provided.

  FIG. 2 shows a functional configuration diagram of the proxy apparatus 10 according to the present embodiment. As shown in FIG. 2, the proxy device 10 according to the present embodiment includes a communication processing unit 11, a session management unit 12, and a protocol stack determination unit 13. The configuration shown in FIG. 2 mainly shows functional units related to the present embodiment, and it goes without saying that it includes an existing function (not shown) for performing processing as a proxy.

  The communication processing unit 11 is a functional unit for performing respective communication (IP packet communication in the present embodiment) with the user terminal 30 and with the server device 20. The communication processing unit 11 includes both the IPv6 function unit 111 and the IPv4 function unit 112, and can perform IPv6 and IPv4 communication both with the user terminal 30 and with the server device 20. It is. In the present embodiment, connection with the user terminal 30 is performed using the protocol stack used in the connection request (TCP syn) from the user terminal 30, and the protocol stack determining unit is connected with the server device 20. The connection is made with the protocol stack determined by 13.

  The session management unit 12 is a functional unit that manages a TCP session between the proxy device 10 and the user terminal 30 (hereinafter simply referred to as “session”) and a session between the proxy device 10 and the server device 20. . The session management unit 12 performs, for example, session generation and extinction management (storage), associating a session between the proxy device 10 and the user terminal 30, and a session between the proxy device 10 and the server device 20, and the like.

  The protocol stack determination unit 13 obtains information on the used protocol stack obtained from the packet received from the user terminal 30 or the packet received from the server device 20 from the communication processing unit 11, and based on a predetermined condition, the server device 20 has a function of determining a protocol stack to be used for connection between the proxy device 10 and the proxy device 10 and notifying the communication processing unit 11 of the determined protocol stack. The predetermined condition is stored in advance in a storage unit such as a memory of the proxy device 10, for example. A specific protocol stack determination method will be described later in the operation example.

  The proxy device 10 is a communication device that can realize the operation described later, and the communication device can also be configured as follows.

The communication device is a communication device that relays communication between a user terminal and a server device,
When a service request for the server device is received from the user terminal, a connection request transmission means for transmitting a connection request for the server device using each of a plurality of types of IP protocol stacks, and as a response to the connection request, Session establishment means for establishing a session with the server device using the IP protocol stack used for the response received from the server device, and sending the service request to the server device using the session, Relay means for receiving a response to the service request from the server device and transmitting the response to the user terminal.

  The connection request transmission unit and the session establishment unit mainly correspond to the above-described protocol stack determination unit 13 and the communication processing unit 11, and the relay unit mainly corresponds to the communication processing unit 11 and the session management unit 12.

  The connection request transmitting means determines the type of IP protocol stack used for transmitting the service request received from the user terminal, and transmits the connection a plurality of times using the plurality of types of IP protocol stacks according to the type. A request transmission order is determined, and the connection requests are sequentially transmitted to the server apparatus by each IP protocol stack in the determined transmission order.

  Further, for example, the connection request transmitting means transmits an initial connection request to the server device using the same IP protocol stack as that used for transmitting the service request received from the user terminal. Further, for example, the session establishing means establishes a session with the server device using the IP protocol stack used for the response received first from the server device.

  The session establishing means receives the response when the response to the connection request is first received from the server device by an IP protocol stack different from the IP protocol stack used for transmitting the service request received from the user terminal. Thereafter, when a response by the same IP protocol stack as the IP protocol stack used for transmission of the service request received from the user terminal is received within a predetermined time, the server apparatus May be configured to establish a session between.

  Further, the connection request transmitting means transmits the connection request to the server apparatus by a second IP protocol stack when a predetermined time has elapsed after transmitting the connection request to the server apparatus by the first IP protocol stack. You may comprise.

  The proxy device 10 according to the present embodiment is used in a computer having a communication function (such as a server) or a communication device including a computer function (such as a router, which is a kind of computer having a communication function). This can be realized by executing a program corresponding to the processing to be described. The program may be stored in a storage medium such as a portable memory, distributed, installed in the device, or downloaded from a server on the network and installed in the device. Further, the processing described in the present embodiment may be realized as a hardware circuit, and the proxy device 10 may be realized as a device including the hardware circuit.

(System operation)
Hereinafter, an operation example of the system according to the present embodiment will be described with reference to the sequence diagrams of FIGS. In each of the following operation examples, it is assumed that proxy settings are made in the browser of the user terminal 30 so as to connect to the proxy device 10 when connecting to the Internet.

<Operation example 1>
First, the operation example 1 will be described with reference to the sequence diagram of FIG. In the operation example 1, the proxy device 10 receives an IPv6 connection request from the user terminal 30, establishes an IPv6 session with the user terminal 30, and sends the request to the server device 20 in both IPv6 and IPv4 according to the service request. In this example, a connection request is sent to the server device 20, but an IPv6 response is received first from the server device 20.

  In this example, a condition for sending a TCP syn packet to the server apparatus 20 using both the IPv6 and IPv4 protocol stacks and establishing a session with the server apparatus 20 using the protocol stack of the response received in advance is determined and stored. The protocol stack determination unit 13 determines the protocol stack to be used by referring to this condition.

  Step 11) When the user performs an operation of accessing the Internet with a Web browser, the user terminal 30 transmits a TCP syn packet to the proxy device 10 using IPv6, and a response of the TCP syn + ack packet from the proxy device 10 is displayed. Through transmission of a TCP ack packet from the terminal 30, a session is established between the user terminal 30 and the proxy device 10 by 3 hand shake using IPv6.

  Step 12) Thereafter, a get request packet for requesting data of the server device 20 is transmitted from the user terminal 30 to the proxy device 10.

  Step 13) Upon receiving the get request packet (service request) from the user terminal 30, the proxy device 10 establishes a session with the server device 20 using a TCP syn packet using IPv6 and a TCP syn using IPv4. Both of the packets are transmitted to the server device 20. At this time, the IPv4 address and IPv6 address of the destination of the get request are inquired of the DNS server, and the TCP syn packet is transmitted using the IPv4 address and IPv6 address acquired from the DNS server. In another example of the present embodiment, the IP address to be used is acquired from the DNS server in the same manner. The operation of acquiring the IP address from the DNS server is a general operation, and the description of this operation is omitted in the following description.

  In step 13, the TCP syn packet using IPv6 and the TCP syn packet using IPv4 are transmitted almost simultaneously, but in actuality, one is first and the other is later. Therefore, for example, a TCP syn packet using IPv6 which is the same protocol stack as that used for establishing a session with the user terminal 30 is transmitted first, and then (after a very short time), IPv4 is transmitted. TCP syn packets may be sent, and both IPv6 and IPv4 TCP syn packets will be sent in a predetermined order regardless of the protocol stack used to establish a session with the user terminal 30. You may make it do.

  Step 14) Upon receiving the TCP syn packet in both IPv6 and IPv4, the server device 20 transmits a TCP syn + ack packet to the proxy device 10 using a protocol stack that can respond. In this example, since the server device 20 has both IPv6 and IPv4 functions, the server device 20 transmits a TCP syn + ack packet to the proxy device 10 in both IPv6 and IPv4. In this example, the TCP syn + ack packet using IPv6 reaches the proxy device 10 first, and the TCP syn + ack packet using IPv4 reaches the proxy device 10 after the TCP syn + ack packet of IPv6. Shall.

  Step 15) The proxy device 10 that has received the TCP syn + ack packet in both IPv6 and IPv4 returns the TCP ack packet to the server device 20 using IPv6 which is the protocol stack received earlier. As a result, an IPv6 session is established between the proxy device 10 and the server device 20. Thereafter, the proxy device 10 transmits a get request packet to the server device 20 using IPv6.

  If a TCP syn + ack packet for only one protocol stack is received, the TCP ack packet is returned to the server device 20 using the protocol stack used for the received packet, A session is established.

  Step 16) The server device 20 transmits data as a response to the get request to the proxy device 10, and the proxy device 10 transfers the data received from the server device 20 to the user terminal 30. Thereafter, communication by IPv6 is performed both between the server device 20 and the proxy device 10 and between the proxy device 10 and the user terminal 30.

  The above example is an example in which the proxy device 10 receives the TCP syn + ack packet based on IPv6 first from the server device 20, but the proxy device 10 receives the TCP syn + ack packet based on IPv4 first from the server device 20. In this case, an IPv4 session is established between the proxy device 10 and the server device 20, and data communication by IPv4 is performed between the proxy device 10 and the server device 20.

<Operation example 2>
Next, an operation example 2 will be described with reference to FIG. The operation example 2 is an example in which the transmission order of the protocol stacks to be sent to the server device 20 is determined according to the protocol stack used for the connection request received by the proxy device 10 from the user terminal 30. In this example (the same applies to the operation example 3), which protocol stack receives a data request (or connection request) from the user terminal 30, which protocol stack sends a connection request to the server device 20, or the server device 20 When a response is received from which protocol stack, conditions such as which protocol stack to connect to and a predetermined time for waiting for transmission are determined in advance and stored in the storage means. Has realized the following operations by referring to this condition. The operation may be realized by executing a program including a condition. Further, the protocol stack determination unit 13 has a timer function for waiting for a predetermined time.

  Step 21) When the user performs an operation of accessing the Internet with a Web browser, the user terminal 30 transmits a TCP syn packet to the proxy device 10 using IPv6, and a response of the TCP syn + ack packet from the proxy device 10 is displayed. Through transmission of a TCP ack packet from the terminal 30, a session is established between the user terminal 30 and the proxy device 10 by 3 hand shake using IPv6.

  Step 22) Thereafter, a get request packet for requesting data of the server device 20 is transmitted from the user terminal 30 to the proxy device 10.

  Step 23) Upon receiving the get request packet from the user terminal 30, the proxy device 10 determines in the protocol stack determination unit 13 that the protocol stack of the data request received from the user terminal 30 is IPv6, and satisfies the predetermined condition. First, a TCP syn packet is transmitted to the server device 20 using IPv6.

  The above conditions in this operation example are as follows. First, a TCP syn packet is transmitted to the server device 20 using the same protocol stack as that of the data request received from the user terminal 30, and a predetermined time elapses after transmitting the TCP syn packet. At this time (for example, after 250 msec), a TCP syn packet is transmitted to the server device 20 by another protocol stack. Therefore, in this example, since the protocol stack of the data request received from the user terminal 30 is IPv6, first, a TCP syn packet is transmitted to the server device 20 using IPv6.

  Step 24) Subsequently, the proxy apparatus 10 transmits the TCP syn packet to the server apparatus 20 by IPv4 250 msec after transmitting the TCP syn packet by IPv6. Although 250msec is only an example, if the first IPv6 response sent does not come after waiting for about 250msec, there is a high possibility of failure, so the interval should be about 250msec. Even if there is a failure in IPv6, it takes less time to establish an IPv4 session than in the past, and communication can be started quickly without causing the user to feel stressed.

  Step 25) Upon receiving the TCP syn packet, the server device 20 transmits a TCP syn + ack packet to the proxy device 10 using a protocol stack that can respond. In this example, since the server device 20 has both IPv6 and IPv4 functions, the server device 20 transmits a TCP syn + ack packet to the proxy device 10 in both IPv6 and IPv4. In this example, the TCP syn + ack packet using IPv6 reaches the proxy device 10 first, and the TCP syn + ack packet using IPv4 reaches the proxy device 10 after the TCP syn + ack packet of IPv6. .

  Step 26) The proxy device that has received the TCP syn + ack packet in both IPv6 and IPv4 uses the previously received protocol stack (IPv6 in this example) to send the TCP ack packet to the server device 20 based on a predetermined condition. Return to. As a result, an IPv6 session is established between the proxy device 10 and the server device 20, and the proxy device 10 transmits a get request packet to the server device 20 using IPv6.

  If a TCP syn + ack packet for only one protocol stack is received, the TCP ack packet is returned to the server device 20 using the protocol stack used for the received packet, A TCP session will be established.

  Also, when a TCP syn + ack packet in one protocol stack is received first, the TCP ack is received in the protocol stack that received first without waiting for the reception of the TCP syn + ack packet in the other protocol stack. A packet may be transmitted. For example, when a TCP syn + ack packet in IPv6 is received first, a TCP ack packet in IPv6 may be transmitted regardless of whether the TCP syn + ack packet in IPv4 is received. Also, for example, if a TCP syn + ack packet in IPv6 is received before the TCP syn packet transmission timing arrives in IPv4, the TCP syn packet transmission in IPv4 is canceled and TCP in IPv6 An ack packet may be transmitted.

  Step 27) The server device 20 transmits data as a response to the get request to the proxy device 10, and the proxy device 10 transfers the data received from the server device 20 to the user terminal 30. Thereafter, communication by IPv6 is performed both between the server device 20 and the proxy device 10 and between the proxy device 10 and the user terminal 30.

  The above two examples are examples in the case where a connection request in IPv6 is transmitted from the user terminal 30, but when a connection request in IPv4 is transmitted from the user terminal 30, the proxy device 10 can only use IPv4. A connection request may be transmitted to the server device 20, or a connection request may be transmitted by both IPv4 and IPv6. When sending a connection request in both IPv4 and IPv6, the connection request in IPv4 may be sent first. Alternatively, regardless of the protocol suite with the user terminal 30, an IPv6 connection request may be transmitted to the server device 20 first, and an IPv4 connection request may be transmitted to the server device 20 after a predetermined time.

<Operation example 3>
In the above two examples, the proxy device 10 establishes a session between the server device 20 and the proxy device 10 using the protocol stack of the TCP syn + ack packet received from the server device 20 first. In order to prioritize the session establishment in the stack, even if the TCP syn + ack packet by one protocol stack is received from the server device 20 first, the other waits for a predetermined time (eg, 250 msec), and within the predetermined time When a TCP syn + ack packet by the other protocol stack is received, a TCP ack packet by this protocol stack is transmitted, and a TCP syn + ack packet by the other protocol stack is not received within a predetermined time. TCP ack packet with the same protocol stack as the first received TCP syn + ack packet May be transmitted.

  For example, when the protocol stack between the proxy device 10 and the user terminal 30 is IPv6, priority is given to IPv6, and even if an IPv4 TCP syn + ack packet is received first from the server device 20, it is predetermined after reception. Wait for IPv6 TCP syn + ack packet for a time (example: 250msec), and if the IPv6 TCP syn + ack packet is received within 250msec, the session between proxy device 10 and server device 20 will use IPv6. To establish it. Thereby, the protocol stacks between the user terminal 30 and the proxy device 10 and between the proxy device 10 and the server device 20 can be aligned, so that an unexpected error or the like can be prevented.

  FIG. 5 is a diagram illustrating an operation between the proxy device 10 and the server device 20 when priority is given to IPv6.

  Step 31) The proxy device 10 transmits a TCP ack packet to both the IPv6 and IPv4 to the server device 20 in the same manner as in the operation examples 1 and 2.

  Step 32) The proxy device 10 receives the TCP syn + ack packet in IPv4 first, but does not return the TCP ack packet in IPv4 immediately, but the TCP syn + ack packet in IPv6 passes for a predetermined time. Wait until.

  Step 33) The proxy device 10 receives the TCP syn + ack packet in IPv6 within a predetermined time after receiving the TCP syn + ack packet in IPv4.

  Step 34) Since the proxy device 10 receives the TCP syn + ack packet in IPv6 within a predetermined time, the proxy device 10 transmits the TCP ack packet in IPv6 to the server device 20 and transmits a get request.

  Step 35) The server device 20 transmits the requested data to the proxy device 10 using IPv6.

(Other examples)
In the example described so far, once a session is established with a certain protocol stack between the proxy device 10 and the server device 20, communication is performed using the session. After the establishment, the session may be switched to another protocol stack. For example, even if a session is established with IPv4 between the proxy device 10 and the server device 20 first, if the proxy device 10 subsequently receives a response (TCP syn + ack) with IPv6, the user terminal 30 The session between the proxy device 10 and the server device 20 may be switched to a session using IPv6 at a timing that does not hinder data communication between the server devices 20.

  In the examples described so far, basically, the session between the proxy device 10 and the server device 20 is established with the same protocol stack as the protocol stack between the user terminal 30 and the proxy device 10. Regardless of the protocol stack between the user terminal 30 and the proxy device 10, one of the protocol stacks may be preferentially used to establish a session between the proxy device 10 and the server device 20.

  In addition, although the present embodiment describes an example in which the user terminal 30 performs Web access via the proxy device 10, the proxy device 10 of the present invention is a SIP proxy server, DNS resolver, or other relay system application. It is also possible to apply to. Further, the function of the proxy device 10 may be implemented in a CPE (broadband router or the like).

(Effect of embodiment)
As described above, according to the technology described in the present embodiment, the proxy device 10 controls switching between IPv6 and IPv4, so that the protocol stack used in the user terminal 30 or the protocol stack used on the service providing side can be changed. It is possible to provide a user-free communication environment.

  The present invention is not limited to the above-described embodiments, and various modifications and applications are possible within the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Proxy apparatus 11 Communication processing part 111 IPv6 function part 112 IPv4 function part 12 Session management part 13 Protocol stack determination part 20 Server apparatus 30 User terminal

Claims (9)

A communication device that relays communication between a user terminal and a server device,
A connection request transmitting means for transmitting a connection request for the server device using each of a plurality of types of IP protocol stacks when a service request for the server device is received from the user terminal;
Session establishment means for establishing a session with the server device using the IP protocol stack used for the response received from the server device as a response to the connection request;
Relay means for transmitting the service request to the server device using the session, receiving a response to the service request from the server device, and transmitting the response to the user terminal. apparatus. The connection request transmitting means determines the type of IP protocol stack used for transmitting the service request received from the user terminal, and transmits the connection a plurality of times using the plurality of types of IP protocol stacks according to the type. The communication apparatus according to claim 1, wherein a transmission order of requests is determined, and the connection requests are sequentially transmitted to the server apparatus by each IP protocol stack in the determined transmission order. The connection request transmitting means transmits an initial connection request to the server device using the same IP protocol stack used for transmitting a service request received from the user terminal. 2. The communication device according to 2. The session establishment means establishes a session with the server device using an IP protocol stack used for a response received first from the server device. The communication apparatus according to claim 1. The session establishing means receives the response when the response to the connection request is first received from the server device by an IP protocol stack different from the IP protocol stack used for transmitting the service request received from the user terminal. Thereafter, when a response by the same IP protocol stack as the IP protocol stack used for transmission of the service request received from the user terminal is received within a predetermined time, the server apparatus The communication device according to claim 1, wherein a session between the communication devices is established. The plurality of types of IP protocol stacks include a first IP protocol stack and a second IP protocol stack,
The connection request transmitting means transmits the connection request to the server apparatus by the second IP protocol stack when a predetermined time has elapsed after transmitting the connection request to the server apparatus by the first IP protocol stack. The communication device according to claim 1, wherein: The communication device according to any one of claims 1 to 6, wherein the plurality of types of IP protocol stacks include two types of IP protocol stacks of IPv4 and IPv6. A communication method executed by a communication device that relays communication between a user terminal and a server device,
A connection request transmission step of transmitting a connection request for the server device using each of a plurality of types of IP protocol stacks when a service request for the server device is received from the user terminal;
A session establishment step of establishing a session with the server device using an IP protocol stack used for a response received from the server device as a response to the connection request;
A relay step of transmitting the service request to the server device using the session, receiving a response to the service request from the server device, and transmitting the response to the user terminal. Method.   The program for functioning a computer provided with a communication function as each means of the communication apparatus of any one of Claims 1 thru | or 7.

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