JP2006032995A - Communication support apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication support apparatus capable of executing communication using a protocol in any transport layer, in the communication between a node on a wired network and a node on a wireless network at a high speed with high quality. <P>SOLUTION: A buffering control apparatus is arranged at a border between the wired network and the wireless network. The buffering control apparatus includes an external storage device. Further, the buffering control apparatus divides data transmitted from the node on the wired network into a header part and a data part, stores only the data part to the storage device, and transmits the header part to the node on the wireless network. After receiving the header part, the node on the wireless network reads the data part from the external storage device which the buffering control apparatus has. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication support apparatus for improving communication speed and communication quality between a node existing on a wired network and a node existing on a wireless network.

  As a communication method for improving communication speed and communication quality between a node existing on a wired network and a node existing on a wireless network, a method described in Non-Patent Document 1 is known.

  The method described in this document aims to improve the communication quality and communication speed of TCP (Transmission Control Protocol) communication between the two nodes. In order to achieve this object, a TCP processing unit and a session layer processing unit called MHP (Mobile Host Protocol) are mounted on a base station located at the boundary between a wired network and a wireless network. Furthermore, in addition to the TCP processing unit, an MHP processing unit is also installed in a node existing on the wireless network.

  The MHP processing unit exists between the node existing on the wireless network and the base station and between the node existing on the wireless network and the base station and the wired network in order to realize communication between the node existing on the wireless network and the node existing on the wired network. Establish two sets of TCP connections between nodes.

  The base station transfers data received from one of the two TCP connections to the other connection. At this time, the base station appropriately converts the IP address and port number, etc., and the node existing on the wired network uses only the normal TCP processing unit without being aware of the existence of the MHP processing unit. It enables communication with nodes on the wireless network.

  In this method, two TCP connections can transfer data using different segment sizes and congestion control. Therefore, even if the MTU (Maximum Transfer Unit) size defined in the wireless network is small, it is large except between the node on the wireless network and the base station (that is, between the base station and the node on the wired network). High-speed communication using the segment size becomes possible.

  Similarly, even if the quality of the wireless network is poor and communication errors frequently occur, high-quality communication is possible without being affected by the communication error except between the node on the wireless network and the base station.

  In this method, when a MHP protocol connection is established from a node on the wireless network to a node on the wired network, and data is transmitted and received, the following procedure is performed.

  First, a node on the wireless network issues a connection establishment request to the node on the wired network to the MHP processing unit. When receiving the establishment request, the MHP processing unit of the node on the wireless network establishes a TCP connection with the base station. After this connection is established, the MHP processing unit of the base station establishes a TCP connection with a node on the wired network. At this time, the IP address of the connection establishment source designates the IP address of the node on the wireless network, not the IP address of the base station. Similarly, the port number designates the port number used by the node on the wireless network in the TCP connection established between the node on the wireless network and the base station. For this reason, the TCP processing unit of the node on the wired network performs the same operation as when a direct connection establishment request arrives from a node on the wireless network.

  When data is transferred from a node on the wireless network to a node on the wired network, first, the MHP processing unit of the node on the wireless network is established between the node on the wireless network and the base station. Send data to the connection. When the MHP processing unit of the base station receives this data, it reassembles the data and reconstructs the data into a large segment size. Then, the reconfigured data is transferred to the TCP connection between the base station and the node on the wired network. The IP address and port number assigned to this data are also the same as the IP address and port number used by the nodes on the wireless network. Therefore, the TCP processing unit of the node on the wired network performs the same operation as when data arrives directly from the node on the wireless network.

Raj Yavatkar and Namrata Bhagawat, `` Improving End-to-End Performance of TCP over Mobile Internetworks '', Proceedings of the Workshop on Mobile Computing Systems and Applications, pp.146-152, 1995.

  The above communication method is effective in speeding up and improving the quality of TCP communication between a node existing on the wireless network and a node existing on the wired network. However, since a session layer protocol is newly defined above TCP, an application running on a node on a wireless network can make a connection establishment request or data transmission / reception request to the session layer protocol instead of TCP. Need to be issued.

  For this reason, existing applications that issue connection establishment requests and data transmission / reception requests to TCP cannot be used. As a result, when the communication method is introduced, the cost of newly developing an application having the same function as that of an existing application operating on a node on the wireless network is unavoidable.

  Furthermore, the above communication method is aimed at speeding up and improving the quality of TCP communications, and speeding up and improving the quality of communications using other transport layer protocols (such as UDP, which is often used in streaming services, etc.). Cannot be realized.

  Therefore, in order to realize high-speed communication and quality improvement of other transport layer protocols, it is necessary to introduce a proxy server for streaming servers in addition to the base station equipped with the MHP protocol stack, There is also a problem that a large equipment cost is required to realize high-speed communication and quality improvement in all services.

The present invention provides a communication support apparatus that solves the problems described above, specifically, a communication support apparatus that simultaneously realizes the following two points.
1) In a node on a wireless network, communication speed can be improved and quality can be improved without modifying the application interface defined between the application and TCP.
2) Communication speed and quality improvement using any transport layer protocol operating on IP (Internet Protocol) can be realized.

  The present invention provides a buffering control device arranged at the boundary between a wired network and a wireless network.

  This buffering control device has a function of dividing an IP packet transmitted from a node on the wired network to a node on the wireless network into a header portion and a data portion. Further, the buffering control device has a function of holding or connecting an external storage device and storing only the data portion in the external storage device. Further, it has a function of transmitting the address information of the external storage device storing the data part and the header part to the node on the wireless network. Further, it has a function of accepting a request for reading a data portion stored in an external storage device from a node on the wireless network and transmitting the data portion to a node on the wireless network.

  When communication is performed using this buffering control device, the data portion reaches the buffering control device from the node on the wired network, and the header portion (and the address information of the external storage device) is wireless from the node on the wired network. If the node on the network is reached, the IP packet communication from the node on the wired network to the node on the wireless network is successful.

  This is because the data part is stored (buffered) in the external storage device until the node on the wireless network successfully reads the data part from the external storage device of the buffering control device. Therefore, improvement in communication quality can be expected as compared with conventional IP packet communication that is not successful unless both the header part and the data part are transmitted without error from the node on the wired network to the node on the wireless network.

  Even if the MTU size on the wireless network is small, IP packets may be transmitted between the node on the wired network and the buffering control device using a large MTU size. This is because it is not necessary to use the same MTU size when the buffering control device receives the data part from the node on the wired network and when it transmits the received data part to the node on the wireless network. is there. That is, the buffering control apparatus can receive the data part in the external storage device with a large MTU size, and can fragment the data part into a small MTU size and transmit the data part to a node on the wireless network. As a result, the communication speed can be expected to improve compared to conventional IP communication.

  Furthermore, the transmission procedure does not depend on the transport layer protocol. This transmission procedure can speed up communication and improve communication quality for communication using any transport layer protocol. In addition, since it is not necessary to change the interface between the transport layer protocol and the application, it is not necessary to modify the application operating on the mobile terminal.

  According to the present invention, it is possible to realize high-speed communication and quality improvement without modifying an application interface defined between an application and a TCP processing unit in a node on a wireless network.

  Further, according to the present invention, it is possible to realize speeding up and quality improvement of communication using any transport layer protocol operating on IP.

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

  FIG. 1 illustrates a case where a distribution server (or proxy server) (102) (existing on a wired network (105)) is connected to a mobile terminal (using a buffering control device (103) which is a communication support device provided by the present embodiment. 101) (existing on the wireless network (104)), an outline of a procedure for transmitting an IP packet is shown.

  First, the IP processing unit (107) on the distribution server (or proxy server) transmits an IP packet (consisting of a header part and a data part) to the mobile terminal (101). The transmitted IP packet is relayed by the IP processing unit (107) on the buffering control device (103) before reaching the portable terminal (101). At this time, the IP packet to be relayed is transferred to the conversion processing unit (108) on the buffering control device (103). Then, the conversion processing unit (108) stores the data part of the IP packet in the external storage device (109). Further, a converted IP packet in which the data part is converted into the address information of the external storage device (109) is generated, and the converted IP packet is transferred again to the IP processing unit (107) on the buffering control device (103). The IP processing unit (107) transmits the converted IP packet to the IP processing unit (107) on the portable terminal (101).

  The IP processing unit (107) on the portable terminal knows the arrival of the IP packet addressed to the own node by the arrival of the converted IP packet. Then, an external storage device read request is issued to the buffering control device (103) in order to acquire the data part buffered in the external storage device (109) of the buffering control device (103). At this time, the address information of the external storage device (109) received when receiving the previous conversion data is also specified. The buffering control device (103) executes transmission of the designated data part to the IP processing part (107) of the mobile terminal (101).

  In the above transmission procedure, if the data part reaches the buffering control device from the distribution server (or proxy server) and the header part (conversion data) reaches the portable terminal from the distribution server (or proxy server), the distribution server ( Or the proxy server) considers the IP packet communication to the mobile terminal successful. In conventional IP communication, IP packet communication from the distribution server (or proxy server) to the portable terminal is not successful unless both the header part and the data part are transmitted without error on the wireless network. On the other hand, in the above procedure, the buffering control device stores (buffers) the data portion in the external storage device until the portable terminal successfully reads the data portion from the external storage device of the buffering control device. This is because reliable transmission of the part becomes possible. Therefore, improvement in communication quality can be expected compared with conventional IP communication.

  Even if the MTU size of the wireless network is small, the IP packet may be transmitted between the distribution server (or proxy server) and the buffering control device using a large MTU size. This is because it is not necessary to use the same MTU size when the buffering control device receives the data portion from the distribution server (or proxy server) and when the data portion is transmitted to the mobile terminal. That is, the buffering control device can receive a data portion having a large MTU size and store it in an external storage device, and can fragment the data portion to a small MTU size and transmit the data portion to the mobile terminal. As a result, the communication speed can be expected to improve compared to conventional IP communication.

  Furthermore, the transmission procedure does not depend on the transport layer protocol. This transmission procedure can speed up communication and improve communication quality for communication using any transport layer protocol. In addition, since it is not necessary to change the interface between the transport layer protocol and the application, it is not necessary to modify the application operating on the mobile terminal.

  FIG. 2 shows a distribution server (or proxy server) (from a mobile terminal (101) (existing on a wireless network (104)) using a buffering control device (103) which is a communication support device provided by the present embodiment. 102) (existing on the wired network (105)), an outline of a procedure for transmitting IP packets using IP is shown.

  A partial area of the buffering control device (103) is allocated in advance to each portable terminal (101). The portable terminal (101) can write arbitrary data in the area of the external storage device (109) assigned to each by designating the address. Prior to IP packet transmission, the IP processing unit (107) on the portable terminal (101) writes a data part constituting an IP packet to be transmitted in advance into the external storage device (109) of the buffering control device (103). Specifically, the address information of the external storage device (109) and the data to be written are specified, and a write request is issued to the buffering control device (103).

  Next, the IP processing unit (107) on the portable terminal (101) receives a packet (conversion IP as in FIG. 1) consisting of the header part constituting the IP packet and the address information of the external storage device designated at the time of the write request. Packet) is transmitted to the buffering control device (103). Upon receiving the converted IP packet, the IP processing unit (107) on the buffering control device (103) transfers the data to the conversion processing unit (108). The conversion processing unit replaces the address information of the converted IP packet with the data body stored in the external storage device (109), and composes the IP packet to be transmitted of the portable terminal (101) (restores the IP packet) ). Then, the restored IP packet (referred to as a restored IP packet) is delivered again to the IP processing unit (107). The IP processing unit (107) transmits the restored IP packet to the IP processing unit (107) of the distribution server (or proxy server) (102).

  As in the case of FIG. 1, the transmission procedure can be expected to improve communication quality and increase communication speed. If the data part reaches the distribution server (or proxy server) (102) from the buffering control device, and the header part of the converted IP packet reaches the distribution server (or proxy server) (102) from the portable terminal (101) The IP packet communication from the portable terminal (101) to the distribution server (or proxy server) (102) is considered successful. Furthermore, IP packet transmission can be executed between the buffering control device and the distribution server (or proxy server) using a large MTU size defined in the wired network.

  Furthermore, the transmission procedure is also independent of the transport protocol. Therefore, it is possible to increase the speed and improve communication quality for any transport layer protocol communication. Further, there is no need to modify an application that runs on the mobile terminal.

  FIG. 3 is a diagram showing a hardware configuration of the buffering control device (103). In this buffering control device (103), a CPU (301) and a memory (303) are connected via a memory controller (302).

  Programs such as an IP protocol stack for realizing the IP processing unit (107) and a conversion module for realizing the conversion processing unit (108) are stored in the memory (303). The CPU (301) executes these programs while reading them from the memory (303), and embodies each processing unit described below. The external storage device (109) is connected via an external storage device controller (304). The CPU (301) and the external storage device controller (304) execute each program to transfer data existing on the memory (303) to the external storage device (109), and the external storage device (109). Can be transferred to the memory (303).

  The external storage device (109) may be configured as one component of the buffering control device (103), or may be configured as an external device connected by a communication line.

  The buffering control device (103) is also connected to the external network (306) via the network controller (305). The data (IP packet) existing on the memory (303) is transferred to the external network (306) by the program for controlling the network controller (305), and the data (IP packet) received via the external network (306) Can be transferred to the memory (303).

  The program may be stored in advance in the external storage device (109), or a detachable storage medium or communication medium (wired, wireless, optical) that can be used by the buffering control device (103). May be introduced into the external storage device (109) via a network such as a carrier wave or a digital signal on the network.

  FIG. 4 is a diagram showing a management data group used in the buffering control device (103). The management data group is stored on the memory (303). The management data group includes a transmission buffer list (401), a reception buffer list (402), and a conversion rule table (403).

  The transmission buffer list (401) is a list of address information in the transmission buffering area in the external storage device (109) reserved for each portable terminal (101). The transmission buffer list (401) includes a buffer area that is in use (stores a valid data part) and an empty buffer area (no valid data part is stored) for each IP address of the mobile terminal (101). Keep a list of Each list entry includes address information of the external storage device, a reserved buffer size, and an effective data length. The data length field is ignored for entries in the list of free buffer areas. The buffer size is assigned a fixed length size according to the MTU size of the wired network.

  The reception buffer list (402) is a list of address information of the reception buffering area in the external storage device (109) reserved for each portable terminal (101). The reception buffer list (402) is also a list of buffers in use (in which the valid data part is stored) and free buffers (in which the valid data part is not stored) for each IP address of the mobile terminal (101). Hold. Each list entry includes address information of the external storage device, a reserved buffer size, and an effective data length. The data length field is ignored for free buffer list entries.

  The conversion rule table (403) is converted by the conversion processing unit (108) shown in FIG. 1 when the buffering control device (103) receives an IP packet from the distribution server (or proxy server) (102). It is a table that describes whether or not to convert, and what conversion should be performed in the case of conversion. This table consists of a reception IP address, a protocol number, a transmission port number, a reception port number, and a header size.

  The conversion processor (108) converts the received IP address, protocol number, transmission port number, and reception port number stored in the received IP packet when it matches any of the entries stored in this table. Execute the process. Information specified by the header size of the entry is interpreted as a header part. The remaining portion is interpreted as a data portion, and is subject to buffering to the external storage area device (109). If the received IP packet does not match any entry, the conversion processing unit (108) does not perform any conversion. That is, the buffering control device (103) performs only the IP packet transfer processing as in the conventional IP router.

  FIG. 5 to FIG. 7 and FIG. 14 to FIG. 15 are diagrams showing formats of IP packets, converted IP packets, various requests, and responses transmitted and received by the buffering control device (103). An IP packet (501) sent and received by the buffering control device shown in FIG. 5 includes fields of a Mac (Media Access Control) header, an IP header, and data. The Mac header and IP header fields include a protocol number field indicating the higher-level protocol type.

  The converted IP packet (502) sent and received by the buffering control device shown in FIG. 5 includes fields of a Mac header, an IP header, an upper layer header, and converted data. The value of the protocol number field stored in the IP header field of the IP packet (501) before conversion (or restored) is changed from the original upper layer protocol number to the protocol number indicating that it is a converted IP packet. Has been.

  The original protocol number is stored at the top of the upper layer header field of the converted IP packet (502). The upper layer header field of the converted IP packet (502) includes information on the upper layer header stored at the beginning of the data field of the IP packet (501) before (or restored), and the upper layer header length. Is also stored. The length of the upper layer header stored in this field at the time of conversion is determined by the value of the header size field of the conversion rule table (403). Also, in the conversion data field, the data part of the pre-conversion IP packet (or restored IP packet) (501) (the part excluding the upper layer header part from the data field) is stored at which address of the external storage device (109). Is stored.

  The transmission buffer securing / releasing request (601) shown in FIG. 6 is transmitted when the portable terminal requests the securing / releasing of the transmission buffer in the external storage device (109). 103).

  This request consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). In the request content field, a request type (a value indicating a request for securing / releasing a transmission buffer is stored), a request number (a unique number is assigned to each issued request), an IP address ( IP address of the portable terminal (101) is stored) and address information (address information of the external storage device (109) to be secured as a transmission buffer is stored).

  Upon receiving this request, the buffering control device (103) secures (or releases) a transmission buffer in the external storage device (109) according to the specified address information for the mobile terminal holding the specified IP address. To do.

  The reception buffer securing / releasing request (602) shown in FIG. 6 is generated when the portable terminal requests the securing / releasing of the reception buffer in the external storage device (109) when the portable terminal (101) and the buffering control device ( 103).

  This request consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). In the request content field, a request type (a value indicating a request for securing / releasing a reception buffer is stored), a request number (a unique number is assigned to each issued request), an IP address ( IP address of the portable terminal (101) is stored) and address information (address information of the external storage device (109) to be secured as a reception buffer is stored).

  Upon receiving this request, the buffering control device (103) secures (or releases) a reception buffer in the external storage device (109) for the mobile terminal holding the specified IP address according to the specified address information. To do.

  The conversion rule registration / deletion request (603) shown in FIG. 6 is generated when the portable terminal (101) requests entry registration / deletion of the conversion rule table (403) held by the buffering control device (103). ) And the buffering control device (103).

  This request consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). In the request content field, a request type (a value indicating that it is a conversion rule registration / deletion request is stored), a request number (a unique number is assigned to each issued request), an IP address ( IP address of portable terminal (101)), protocol number, transmission port number, reception port number, and header size.

  Upon receiving this request, the buffering control device (103) creates or designates a new entry in the conversion rule table (403) according to the specified IP address, protocol number, transmission port number, reception port number, and header size. Delete entries that match the specified IP address, protocol number, transmission port number, reception port number, and header size.

  The external storage device write request (701) shown in FIG. 7 is transmitted and received between the portable terminal (101) and the buffering control device (103) when requesting data write to the external storage device (109). The

  This request consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). In the request content field, a request type (a value indicating that it is a write request to the external storage device is stored), a request number (a unique number is assigned to each issued request), an IP address ( From the fields of the portable terminal (101) IP address), address information (address of the external storage device (109) to be written to), data length (length of data to be written), and data (content of data to be written) Become.

  Upon receiving this request, the buffering control device (103) writes the designated data at the address of the designated external storage device (109).

  The external storage device read request (702) shown in FIG. 7 is transmitted and received between the portable terminal (101) and the buffering control device (103) when requesting the data read from the external storage device (109). The

  This request consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). In the request content field, a request type (a value indicating a read request from an external storage device is stored), a request number (a unique number is assigned to each issued request), an IP address ( IP address of the portable terminal (101)) and address information (address of the external storage device (109) to be read).

  Upon receiving this request, the buffering control device (103) reads data from the address of the designated external storage device (109) and transmits it as a response to the portable terminal.

  The external storage device divided write request (1401) shown in FIG. 14 is transmitted to the mobile terminal (101) and the buffering control device (101) when the mobile terminal (101) requests data write to the external storage device (109). 103). Unlike the case of the external storage device write request (701), the portable terminal (101) divides the data to be written into a plurality of partial data and transmits it to the buffering control device (103). With this request (1401), even if data communication is performed between the portable terminal (101) and the buffering control device (103) using a small MTU size, the buffering control device (103) and the distribution server (102) In the meantime, communication can be performed using a large MTU size, and the communication speed can be improved.

  This request (1401) consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). The request content field includes a request type (a value indicating that it is a divided write request to an external storage device), a request number (a unique number is assigned to each request to be issued), an IP address ( IP address of portable terminal (101)), address information (address of external storage device (109) to which all data is written), total data length (length of all data to be written), partial data offset (in response to the request) The contained partial data includes fields of an offset position in all data, a partial data length (length of the partial data included in the request), and partial data (content of partial data to be written).

  The buffering control device (103) that has received this request (1401) collects the specified partial data, reconstructs all the data, and writes it to the address of the specified external storage device (109).

  The external storage device split read request (1501) shown in FIG. 8 is transmitted to the mobile terminal (101) and the buffering control device (101) when the mobile terminal (101) requests to read data from the external storage device (109). 103). Unlike the case of the external storage device read request (702), the data read from the distribution server (102) by the buffering control device (103) by this request (1501) is the size specified by this request (1501). After being divided into a plurality of partial data, it is transmitted from the buffering control device (103) to the portable terminal (101). With this request (1501), even if data communication is performed between the portable terminal (101) and the buffering control device (103) using a small MTU size, the buffering control device (103) and the distribution server (102) In the meantime, communication can be performed using a large MTU size, and the communication speed can be improved.

  This request (1501) consists of fields of Mac header and request contents. The Mac header field stores a protocol number indicating that the upper protocol is a request for the buffering control device (103). The request contents field includes a request type (a value indicating that it is a divided read request from an external storage device), a request number (a unique number is assigned to each issued request), an IP address ( The IP address of the portable terminal (101)), address information (address of the external storage device (109) to be read), and partial data length (maximum length of partial data to be stored in the response).

  The buffering control device (103) that has received this request (1501) reads the data from the address of the designated external storage device (109), divides it into partial data having the designated size, A response is transmitted to the portable terminal (101).

  The response (703) shown in FIG. 15 is used when the buffering control device (703) transmits responses to the various requests. The response (703) includes fields of a Mac header and response contents. The Mac header field stores a protocol number indicating that the upper protocol is a response from the buffering control device (103).

  The response content includes a request type (a value stored in the corresponding request is stored), a request number (a value stored in the corresponding request is stored), and an execution result. In the case of a response to the external storage device read request (702), the contents and data length of the read data are also included. Further, in the case of a response to the external storage device partial read request (1501), as shown in the figure, the contents of the partial data read, the total data length, the partial data offset, and the partial data length information are included.

  FIG. 8 is a detailed block diagram of the processing unit of the buffering control device (103). Each processing unit shown in FIG. 8 is embodied by appropriately reading out and executing a program stored in the memory (303) by the CPU (301).

  The processing unit of the buffering control device (103) includes a network transmission / reception unit (801), an IP processing unit (107), a conversion processing unit (108), a request processing unit (803), and an external storage device read / write unit (802). .

  The network transmission / reception unit (801) first receives the IP packet (501), converted IP packet (502), and various requests that have arrived at the buffering control device (103). When an IP packet or a converted IP packet is received, a reception notification is transmitted to the conversion processing unit (108) via the IP processing unit (107). In addition, when various requests are received, a reception notification is transmitted to the request processing unit (803).

  The conversion processing unit (108) performs conversion of the received IP packet or restoration from the converted IP packet while referring to the management data group (401 to 403). At this time, a read / write request for the external storage device (109) is issued to the external storage device read / write unit (802) as necessary. Then, a transmission request for the converted IP packet or the restored IP packet is issued to the network transmitting / receiving unit (801) via the IP processing unit (107).

  Upon receiving notification of various requests, the request processing unit issues an update of the management data group (401 to 403) and a read / write request to the external storage device (109). Then, in order to return the request processing result as a response, the response is notified to the network transmitting / receiving unit (801).

  The operation flow of each processing unit shown in FIG. 8 will be described below using FIGS. 9 to 13.

  FIG. 9 is a diagram showing an operation flow of the network transmission / reception unit (801). The network transmission / reception unit (801) operates upon receipt of IP packets, converted IP packets, various requests, and reception of transmission requests (or responses) from the IP processing unit (107) (or request processing unit (803)). To start.

  Reception of the IP packet, converted IP packet, and various requests is detected by receiving a reception notification from the network controller (305) (step 901). When this reception notification is received, a program for controlling the network controller (305) is operated, and data (IP packet, converted IP packet or various requests) received by the network controller (305) is transferred to the memory (303) ( Step 902). Then, the protocol number included in the Mac header field of the IP packet, converted IP packet, or various requests is inspected (step 903). If the protocol number is a value indicating IP, a reception notification is transmitted to the IP processing unit (107) (step 904). On the other hand, if the protocol number is a value indicating a request, a reception notification is transmitted to the request processing unit (803) (step 905).

  When receiving a transmission request (or response) from the IP processing unit (107) (or request processing unit (803)) (step 906), the received data (IP packet, converted IP packet or response) is included. A Mac header is added (step 907). At this time, the protocol number in the Mac header stores a value indicating IP in the case of an IP packet or a converted IP packet, and a value indicating a response in the case of a response. Then, a program for controlling the network controller (305) is operated to transfer the data generated in step 907 from the memory (303) to the external network (306) (step 908).

  FIG. 10 is a diagram showing an operation flow of the IP processing unit (107).

  The IP processing unit (107) starts operating upon reception of a reception notification from the network transmission / reception unit (801) and reception of a transmission request from the conversion processing unit (108).

  When a reception notification is received from the network transmission / reception unit (801) (step 1001), it is first checked whether the received IP packet or the converted IP packet is addressed to the own node (step 1002). If it is addressed to its own node, normal IP reception processing is performed, that is, a reception notification is transmitted to the transport layer protocol specified by the protocol number in the IP header field (step 1003). If it is not addressed to the own node, a reception notification is transmitted to the conversion processing unit (108) (step 1004).

  When a transmission request is received from the conversion processing unit (108) (step 1005), the IP packet or the converted IP packet should be sent based on the normal IP routing process, that is, the IP routing table held by itself. The network controller (305) is determined (step 1006). Then, a transmission request is issued to the network transmission / reception unit (801) (step 1007).

  FIG. 11 is a diagram showing an operation flow of the conversion processing unit (108).

  The conversion processing unit (108) starts operation upon receipt of the reception notification from the IP processing unit (107) (step 1101). When the reception notification is accepted, it is first checked whether or not the received IP packet (501) or converted IP packet (502) is transmitted from the portable terminal (101) (step 1102). This inspection is performed by inspecting the transmission source IP address in the IP header field of the IP packet (501) or the converted IP packet (502). If it is transmitted from the portable terminal (101), the process jumps to Step 1103, and otherwise, the process jumps to Step 1106.

  If it is determined in step 1102 that the packet is transmitted from the portable terminal (101), it is checked whether the packet is a packet to be converted (step 1103). This inspection checks the IP header field of the received IP packet (501) or converted IP packet (502), and determines whether the protocol number stored in the field stores a value indicating the converted IP. To do. If it is a packet to be converted, the process jumps to Step 1104; otherwise, the process jumps to Step 1110.

  If it is determined in step 1103 that the packet is to be converted, a read request is issued to the external storage device read / write unit (802) (step 1104). At this time, the read destination address is determined according to the external storage device address information stored in the conversion data field of the conversion IP packet (502). Further, a restored IP packet is constructed based on the read data (step 1105), and the process jumps to step 1110.

  If it is determined in step 1102 that the mobile terminal (101) is not a transmission node, it is determined whether or not the mobile terminal (101) is a reception node (step 1106). This inspection is performed by inspecting the transmission destination IP address in the IP header field of the IP packet (501) or the converted IP packet (502). If the portable terminal (101) is a receiving node, the process jumps to Step 1107; otherwise, the process jumps to Step 1110.

  If it is determined in step 1106 that the portable terminal (101) is a receiving node, it is checked whether the received IP packet (501) or converted IP packet (502) is a packet to be converted. (Step 1107). This inspection examines the IP header field and data field of the received IP packet (501) or converted IP packet (502), and sends the destination IP address, protocol number, transmission port number, and reception contained in the packet. This is done by checking whether all of the port numbers match any of the entries stored in the conversion rule table (403). If it is a packet to be converted, the process jumps to Step 1108; otherwise, the process jumps to Step 1110.

  If it is determined in step 1108 that the packet is to be converted, a write request is issued to the external storage device read / write unit (802) (step 1108). At this time, the write destination address is determined according to the address information stored in the first entry of the empty buffer list in the reception buffer list (402).

  The write size is determined according to the header length of the entry in the conversion rule table (403) that is matched in step 1108. In step 1109, the reception buffer list (402) is updated. Specifically, the entry used in the previous step is dequeued from the free buffer list and enqueued into the in-use buffer list. Further, the received IP packet (501) is converted. At this time, the address information of the entry used in the previous step is stored in the external storage device address information stored in the conversion data field.

  Finally, in step 1110, the IP processor (107) issues a transmission request for the IP packet that has been converted, restored, or received to complete the processing.

  12 and 16 are diagrams illustrating an operation flow of the request processing unit (803).

  The request processing unit (803) starts operation upon receipt of a reception notification from the network transmission / reception unit (801) (step 1201). Upon receiving the request, the request processing unit (803) determines the request type (step 1202). This determination is performed by reading the request type included in the request content field of the received various requests (601, 602, 603, 701, 702, 1401, 1501).

  When the request type determined in step 1202 is a transmission buffer reservation / release request or a reception buffer reservation / release request, the transmission buffer list (401) or the reception buffer list (402) is updated (step 1203).

  In the case of the transmission buffer securing request (601), a new entry is added to the empty buffer list of the transmission buffer list (401) corresponding to the IP address included in the request content field. The address information included in the request content field of the transmission buffer securing request (601) is set in the address information of this new entry. The buffer size is set to a fixed length according to the MTU size of the wired network, and the data length is not set.

  In the case of the transmission buffer release request (601), the corresponding entry is removed from the transmission buffer list (401) corresponding to the IP address included in the request content field. Here, “entry corresponds” means that the address information included in the entry matches the address information included in the request content field of the transmission buffer release request (601). The same operation as described above is performed in the case of a receive buffer securing / releasing request.

  If the request type determined in step 1202 is a conversion rule registration request, the conversion rule table is updated (step 1204). Specifically, a new entry that holds all of the IP address, protocol number, transmission port number, reception port number, and header length included in the request content field of the conversion rule registration request (603) is additionally registered.

  If the request type determined in step 102 is an external storage device read request (702), a read request is issued to the external storage device read / write unit (802) to acquire data (step 1205). The external storage device read / write unit (802) is also notified of the address information included in the request content field of the external storage device read request (702).

  If the request type determined in step 102 is an external storage device write request (701), a write request is issued to the external storage device read / write unit (802), and the result is acquired (step 1206). At this time, the address information, data length, and data included in the request content field of the external storage device write request (701) are also notified. Further, the transmission buffer list (401) is updated (step 1207). Specifically, an entry in the transmission buffer list that matches the IP address and address information included in the request content field of the external storage device write request (701) is dequeued from the free buffer list and enqueued in the in-use buffer list.

  If the request type determined in step 102 is an external storage device divided read request (1501), a read request is issued to the external storage device read / write unit (802) to acquire data (step 1601). The external storage device read / write unit (802) is also notified of the address information included in the request content field of the external storage device divided read request (1501). Further, the acquired data is divided for each partial data length included in the request content (step 1602).

  If the request type determined in step 102 is an external storage device divided write request (1401), first, the reception of the request is repeated until all the partial data is available. Then, all data is reconstructed from the divided data (step 1603). A write request is issued to the external storage device read / write unit (802), and the result is acquired (step 1604). At this time, the address information included in the request content field of the external storage device divided write request (1401), the total data length, and all the data reconstructed in step 1603 are also notified. Further, the transmission buffer list (401) is updated (step 1605). Specifically, an entry in the transmission buffer list that matches the IP address and address information included in the request content field of the external storage device write request (701) is dequeued from the free buffer list and enqueued in the in-use buffer list.

  After the processing of steps 1203, 1204, 1205, 1207, 1602, and 1605, a response (703) is transmitted to the network transmission unit (801) in step 1208. The request type and request number included in the request content field of various requests (601, 602, 603, 701, 702) are copied to the request type and request number included in the response content field of the response. The execution results store the execution results of steps 1203, 1204, 1205, and 1206. After execution of step 1205, in step 1208, the total data length and the partial data field store the data acquired in step 1205 and the data length. After executing step 1602, in step 1208, the total data length of the data acquired in step 1601 is used for the total data length, and the content of the partial data generated in step 1602 is used for the partial data offset, partial data length, and partial data. Stores the offset and length.

  FIG. 13 is a diagram showing an operation flow of the external storage device read / write unit (802).

  The external storage device read / write unit (802) starts its operation when a read request or a write request is received from the conversion processing unit (108) or the request processing unit (803).

  When the read request is accepted (step 1301), the external storage controller (304) is controlled to transfer data from the address of the external storage device (109) designated by the read request to the memory (303) (step 1302). . Furthermore, the data transferred in step 1302 is notified to the conversion processing unit (108) or the request processing unit (803) (step 1303).

  When the write request is accepted (step 1304), the external storage controller (304) is controlled to store the data specified by the write request at the address of the external storage device (109) specified by the write request. Data is transferred from the device on the memory (303) (step 1305). Furthermore, the execution result of step 1305 is notified to the conversion processing unit (108) or the request processing unit (803) (step 1306).

It is a figure which shows the procedure which transmits an IP packet with respect to a portable terminal from a delivery server (or proxy server) using the buffering control apparatus which this embodiment provides. It is a figure which shows the procedure which transmits an IP packet with respect to a delivery server (or proxy server) from a portable terminal using the buffering control apparatus which this embodiment provides. It is a figure which shows the hardware constitutions of the buffering control apparatus which this embodiment provides. It is a figure which shows the management data group used with the buffering control apparatus which this embodiment provides. It is a figure which shows the data format which the buffering control apparatus which this embodiment provides is transmitted / received. It is a figure which shows the data format which the buffering control apparatus which this embodiment provides is transmitted / received. It is a figure which shows the data format which the buffering control apparatus which this embodiment provides is transmitted / received. It is a figure which shows the software processing part structure of the buffering control apparatus which this embodiment provides. It is a figure which shows the operation | movement flow of a network transmission / reception part. It is a figure which shows the operation | movement flow of an IP process part. It is a figure which shows the operation | movement flow of a conversion process part. It is a figure which shows the operation | movement flow of a request process part. It is a figure which shows the operation | movement flow of an external storage device reading / writing part. It is a figure which shows the data format which the buffering control apparatus which this embodiment provides is transmitted / received. It is a figure which shows the data format which the buffering control apparatus which this embodiment provides is transmitted / received. It is a figure which shows the operation | movement flow of a request process part.

Explanation of symbols

101: Mobile terminal, 102: Distribution server (or proxy server), 103: Buffering control device
107: IP processing unit, 108: conversion processing unit, 109: external storage device, 403: conversion rule table, 501: IP packet, 502: converted IP packet.

Claims (10)

A communication support apparatus for performing packet relay between a first network and a second network,
Means for receiving a packet transmitted by an information processing device connected to the first network as an address to an information terminal device connected to the second network, and dividing the packet into a header portion and a data portion;
Means for storing the data portion in a storage device;
Means for transmitting to the information terminal device a converted packet comprising information specifying the data portion written in the storage device and the header portion;
Means for receiving, from the information terminal device, a read request for the data portion written in the storage device, including the information to be designated;
Means for reading out the data portion from the storage device and transmitting it to the information terminal device in response to the read request. The communication support apparatus according to claim 1,
Means for accepting a write request to the storage device including a data portion to be transmitted from the information terminal device to the information processing device;
Means for writing the data portion to the storage device in response to the write request;
Means for receiving, from the information terminal device, a conversion packet including information specifying the data part written in the storage device and a header part corresponding to the data part;
Means for reading the designated data portion from the storage device;
Means for composing a restoration packet from the read data part and the header part and transmitting the restoration packet to the information processing apparatus. The communication support apparatus according to claim 1,
The information to be specified is write address information of the data part to the storage device. The communication support apparatus according to claim 2,
The information to be specified is write address information of the data part to the storage device,
The accepting means receives the write request including the write address information from the information terminal device,
The communication support apparatus, wherein the writing means writes the data part to the storage device in accordance with the write address information. The communication support apparatus according to claim 1,
Means for receiving, from the information terminal device, a divided read request for the data portion written in the storage device, including the information to be specified and the transfer data length;
Means for reading out the data portion from the storage device in response to the division read request, dividing the data portion in accordance with the transfer data length, and transmitting the data portion to the information terminal device. The communication support apparatus according to claim 2,
Means for receiving, from the information terminal device, a partial data group obtained by dividing a data portion to be transmitted to the information processing device as a divided write request to the storage device;
Means for rewriting the data portion to be transmitted to the information processing apparatus from the partial data group, and then writing the reconstructed data portion to the storage device in accordance with the divided write request. Communication support device. The communication support apparatus according to claim 1,
Means for receiving a packet conversion request including a protocol number, a transmission port number, and a reception port number from the information terminal device;
Means for extracting a packet holding the protocol number, the transmission port number, and the reception port number from the packets addressed to the information terminal device, and transmitting the packet to the dividing unit;
Means for transmitting the received packet that has not been extracted as it is to the second information terminal device. An information terminal device connected to a second network for receiving a data part included in a packet transmitted by an information processing device connected to the first network,
A communication support device that performs packet relay between the first and second networks generates a header portion that is generated by dividing the packet, and the communication support device generates the packet that is divided and stored in the storage device. Means for receiving a converted packet comprising information specifying the data portion;
Means for transmitting a read request for the data portion written in the storage device, including the information to be specified, to the communication support device;
Means for receiving the data part transmitted from the communication support apparatus in response to the read request. The information terminal device according to claim 8, wherein
Means for transmitting a write request to the storage device of the communication support device, including a data portion to be transmitted to the information processing device;
Means for writing the data portion to the storage device in response to the write request;
Information that specifies the data part that requested to write to the storage device, and means for transmitting to the communication support apparatus a conversion packet that includes a header part corresponding to the data part. Terminal device. In the information terminal device according to claim 9,
The information to be specified is write address information of the data portion to the storage device,
Prior to receiving the converted packet, the information terminal device comprises means for transmitting the generation request for the converted packet including a protocol number, a transmission port number, and a reception port number to the communication support device. .

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