JP4572306B2 - COMMUNICATION DEVICE, COMMUNICATION METHOD, AND PROGRAM - Google Patents

Description

The present invention is, for example, TCP (Transmission on the Internet).
More particularly, the present invention relates to a communication apparatus, a communication method, and a program that can communicate with a host computer having a plurality of communication interfaces with a connection combination suitable for each communication interface.

Conventional computers are usually connected to the Internet by a single communication interface (for example, Ethernet). In the near future, the number of computers connected to the Internet by a plurality of communication interfaces (for example, 100 Mbps Ethernet and 54 Mbps wireless LAN) is expected to increase. When transferring files between computers having a plurality of communication interfaces, it is efficient to use a plurality of communication interfaces simultaneously. At this time, it appears that communication is performed with one TCP connection from the application that performs file transfer. However, inside the TCP, a plurality of sub-connections are bundled and shown as one TCP connection to the application. Such TCP is called multilink TCP. Various methods for realizing multilink TCP have been proposed (see, for example, Patent Document 1).
JP 2002-94595 A

  In the above example, communication between computers having Ethernet of 100 Mbps and wireless LAN of 54 Mbps is given. At this time, if a sub-connection is established between two computers and between Ethernet interfaces and between wireless LAN interfaces, a TCP connection with a maximum of 154 (= 100 + 54) Mbps can be used from the application. However, if the Ethernet of one computer is connected to the wireless LAN of the other computer, the maximum TCP connection is 108 (= 54 + 54) Mbps.

  Also, it is not possible to know the reachability of a route created by address pairs and the network congestion status by simply exchanging address information between hosts. For this reason, depending on the interface pair to be connected, communication performance may be degraded or communication may be disabled.

  In view of the above-described problems, an object of the present invention is to provide a communication device, a communication method, and a program that can communicate between hosts having a plurality of communication interfaces with a connection combination suitable for each communication interface.

Communication apparatus of the present invention, a plurality of communication interfaces, the address information obtaining means for obtaining address information of a plurality of communication interfaces established by communication partner communication partners and connection by one of the communication interfaces, of its own transmitting means for transmitting a connection establishment request requesting the establishment of all the one-to-one connection between each communication interface of the plurality of communication interfaces each communication interface with a communication partner of the plurality of communication interfaces, by the transmitting means A pair that can be established simultaneously between the RTT measuring means for measuring the time (RTT) until each confirmation response to the transmitted connection establishment request, and the plurality of communication interfaces of the own device and the plurality of communication interfaces of the communication partner One address pair combination for a connection By calculating the sum of the RTT for each of the address pair Te, characterized in that it comprises an address pair selection means for establishing a multi-link by selecting a combination of address pairs that total RTT is minimized.

  In addition, the address information acquisition means establishes a connection with a communication partner by a maximum speed communication interface in the own device, thereby establishing a connection at high speed by effectively using the communication interface resource of the own device. Can do.

  The address information acquisition means also acquires information related to the type of the communication interface together with the address information of a plurality of communication interfaces of the communication partner, and the address pair selection means is the same type of communication between the communication partner and the own device. Assuming that the interfaces are connected, by selecting the address pair that minimizes the total RTT and establishing a multilink, the connection combinations can be constrained, and there are fewer address pair options and less computation. Can do.

Further, the communication method of the present invention comprises a plurality of communication interfaces, an address information acquisition step of establishing a connection with a communication partner by one of the communication interfaces and acquiring address information of the plurality of communication interfaces of the communication partner; a transmission step of transmitting a connection establishment request requesting the establishment of all the one-to-one connection between the host machine each of the plurality of communication interfaces of a plurality of communication interfaces of each communication interface with the communication partner of the communication interfaces, the Establishing simultaneously between the RTT measurement step for measuring the time (RTT) until each confirmation response to the connection establishment request transmitted by the transmission step, and the plurality of communication interfaces of the own device and the plurality of communication interfaces of the communication partner Possible one-to-one connection By calculating the sum of the RTT of each address pair in combination address pair, characterized in that it comprises an address pair selecting step of establishing a multi-link by selecting a combination of address pairs that total RTT is minimized .

The present invention also provides a computer,
A plurality of communication interfaces, the address information obtaining means for obtaining address information of a plurality of communication interfaces established by communication partner communication partners and connection by one of the communication interfaces, each of the plurality of communication interfaces of its own A transmission means for transmitting a connection establishment request for requesting establishment of all one-to-one connections between the communication interface and each of the communication interfaces of the communication partners, and each of the connection establishment requests transmitted by the transmission means. RTT measuring means for measuring time to confirmation response (RTT);
Calculate the sum of the RTTs of each address pair in a combination of address pairs of a one-to-one connection that can be simultaneously established between the plurality of communication interfaces of the own device and the plurality of communication interfaces of the communication partner. This is a program for functioning as a communication apparatus including an address pair selection unit that selects a combination of address pairs that minimizes RTT and establishes a multilink.

  According to the present invention, the communication partner has a plurality of communication interfaces and the own device has a plurality of communication even if the communication partner does not know the information about the plurality of communication interfaces and the communication is started at any place. Communication can be performed with a connection combination of interfaces and communication interfaces suitable for the communication environment in which they exist. Further, even when the communication environment changes during communication, it is possible to communicate with a connection combination of communication interfaces suitable for the communication environment in which the communication environment is dynamically changed.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram illustrating a configuration of a communication apparatus according to an embodiment of the present invention. In this embodiment, the host 10 has two communication interfaces A and B, and the host 20 has two communication interfaces C and D. The host 10 includes the communication interfaces A and B and a communication control unit 11 that controls the communication interfaces A and B. Similarly, the host 20 includes communication interfaces C and D and a communication control unit 21.

  FIG. 2 is a flowchart illustrating a procedure for establishing communication by the communication apparatus according to the present embodiment. In this embodiment, a procedure for establishing a TCP connection is shown. Here, it is assumed that a TCP connection is established from the host 10 to the host 20. First, the host 10 selects one having a high communication speed from the two communication interfaces A and B of its own device, and establishes a TCP connection with the host 20. This TCP connection is a primary connection. The host 10 and the host 20 use this primary connection to exchange information on communication interfaces held by each other. This information includes the address, type, communication speed, and (in the case of wireless) electric field strength of the communication interface (step S11).

  Next, the host 10 generates possible connection combinations of the plurality of communication interfaces A and B possessed by itself and the plurality of communication interfaces C and D possessed by the host 20, and attempts to establish a sub-connection for each combination. . Specifically, a SYN (connection establishment request) control packet is transmitted (step S12). The host 20 that has received the SYN control packet for the sub-connection returns a SYN + ACK (response and connection establishment request) control packet to the host 10 as a response. In this case, when sending the SYN from each of the communication interfaces A and B, the host 10 can send the SYNs one after another without waiting for the return of the SYN + ACK to the previously sent SYN, which is necessary for establishing the communication. There is almost no delay for.

The host 10 measures a time (RTT: Round Trip Time) between transmission of each SYN control packet in step S12 and reception of the corresponding SYN + ACK control packet (step S13). Here, if SYN + ACK does not return even after a predetermined time (retransmission timeout), the RTT is set to a predetermined large value. Examples of measurement results are shown in Table 1.

The host 10 selects the allowed combination of one-to-one connection address pair the sum of the RTT is minimized, ACK and transmits the (acknowledgment) control packet to the host 20 three-way hand for that address pair Communication establishment by shaking is completed (step S14).

  In this example, the total RTT of {A⇔C, B⇔D} is 100 + 30 = 130 (ms), whereas the total RTT of {A⇔D, B⇔C} is 20 + 10 = 30 (ms). Therefore, {A⇔D, B⇔C} is selected as an address pair having a small total RTT.

  As the number of communication interfaces held by the host increases, the number of address pairs also increases significantly. As described above, the communication interface information of each host is exchanged between the communicating hosts, and the communication interface type of the communication partner is changed. Knowing that the same type must be connected, it is possible to select the smallest RTT address pair from the number of combinations that are limited by the number of combinations. The processing speed can be increased.

  The low RTT and low network congestion are not necessarily equivalent, but the address pair selection method using SYN is effective from the viewpoint of suppressing useless network traffic, selecting address pairs, and speeding up the start of communication. . In addition, since RTT is measured by transmitting SYN on a path actually formed by all address pairs, there is an advantage that the current network state can be reflected.

  In addition, this invention is not limited to the said Example.

  The communication apparatus of the present invention is also realized by a program for causing a computer to function as the communication apparatus. This program may be stored in a computer-readable recording medium.

  The recording medium on which the program is recorded may be the ROM itself of the communication device, or a program reading device such as a CD-ROM drive is provided as an external storage device, and the program is read by inserting the recording medium therein. A possible CD-ROM or the like may be used.

  The recording medium may be a magnetic tape, a cassette tape, a flexible disk, a hard disk, an MO / MD / DVD, or a semiconductor memory.

It is a figure which shows the structure of the communication apparatus by one Example of this invention. It is a flowchart which shows the procedure of the communication establishment by the communication apparatus of a present Example.

Explanation of symbols

10, 20 Host 11, 21 Communication control unit A, B, C, D Communication interface

Claims (5)

Multiple communication interfaces;
Address information obtaining means for obtaining address information of a plurality of communication interfaces of the communication partner to establish communication partner a connection by one of the communication interfaces,
Transmitting means for transmitting connection establishment requests for requesting establishment of all one-to-one connections between each communication interface of the plurality of communication interfaces of the own machine and each communication interface of the plurality of communication interfaces of the communication partner ;
And RTT measuring means for measuring a time (RTT) to each acknowledgment to the transmitted connection establishment request by said transmitting means,
Calculate the sum of the RTTs of each address pair in a combination of address pairs of a one-to-one connection that can be simultaneously established between the plurality of communication interfaces of the own device and the plurality of communication interfaces of the communication partner. A communication apparatus comprising: an address pair selecting unit that selects a combination of address pairs that minimizes RTT and establishes a multilink. 2. The communication apparatus according to claim 1, wherein the address information acquisition unit establishes a connection with a communication partner using a communication interface having a maximum speed in the own apparatus. The address information acquisition means also acquires information on the type of the communication interface as well as the address information of a plurality of communication interfaces of the communication partner, and the address pair selection means selects the same type of communication interface between the communication partner and the own device. 3. The communication apparatus according to claim 1, wherein a multi-link is established by selecting an address pair having a minimum total RTT on the premise of connection. Comprising a plurality of communication interfaces, the address information acquisition step of acquiring address information of a plurality of communication interfaces established by communication partner communication partners and connection by one of the communication interfaces,
A transmission step of transmitting a connection establishment request for requesting establishment of all one-to-one connections between each communication interface of the plurality of communication interfaces of the own machine and each communication interface of the plurality of communication interfaces of a communication partner ;
An RTT measurement step of measuring a time (RTT) until each confirmation response to the connection establishment request transmitted by the transmission step;
Calculate the sum of the RTTs of each address pair in a combination of address pairs of a one-to-one connection that can be simultaneously established between the plurality of communication interfaces of the own device and the plurality of communication interfaces of the communication partner. An address pair selection step of establishing a multi-link by selecting a combination of address pairs that minimizes the RTT. Computer
A plurality of communication interfaces, the address information obtaining means for obtaining address information of a plurality of communication interfaces established by communication partner communication partners and connection by one of the communication interfaces,
Transmitting means for transmitting connection establishment requests for requesting establishment of all one-to-one connections between the communication interfaces of the plurality of communication interfaces of the own device and the communication interfaces of the plurality of communication interfaces of the communication partner ;
And RTT measuring means for measuring a time (RTT) to each acknowledgment to the transmitted connection establishment request by said transmitting means,
Calculate the sum of the RTTs of each address pair in a combination of address pairs of a one-to-one connection that can be simultaneously established between the plurality of communication interfaces of the own device and the plurality of communication interfaces of the communication partner. A program for causing a communication apparatus to function as an address pair selection unit that selects a combination of address pairs that minimizes RTT and establishes a multilink.

Images