JP2012129897A - Communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement migration from old communication middleware to new communication middleware easily and at low cost.SOLUTION: A communication device comprises: a first packet creation part creating a first packet by encapsulating data by using a destination address designating another communication device; a processing part executing predetermined processing by using the first packet; a second packet creation part creating a second packet by encapsulating again the first packet by using the destination address; and a transmission part transmitting the second packet to the other communication device.

Description

  The present invention relates to communication middleware provided in a communication device.

  Railway operation management systems and financial systems are often large and complicated due to system expansion and integration with other systems, even if the system is small at the beginning. And if the system is updated as the performance of the devices that make up the system increases and the technology advances (hereinafter also referred to as “migrating to a new system” or “system migrating”), the scale of those systems The development cost becomes enormous because the number of corrections is diversified as the value increases.

  Here, a general problem in system migration (in particular, change of communication middleware) will be described with reference to FIG.

FIG. 19 shows a case where system transition is performed from the communication device 1901 of the old system to the communication device 1906 of the new system. The configuration shown in the communication device 1901 of the old system is a general one. That is, a communication application 1902 that provides various services operates on the old communication middleware 1903 that is a communication infrastructure unique to the system. When the communication application 1902 operates to transmit data to a communication partner, the old communication middleware 1903 and protocol stack 1904 (TCP (Transmission Control Protocol), IP (Internet Protocol), etc.) located in the lower hierarchy are used. A packet is transmitted to a network via a communication interface (I / F) 1905 using a protocol group.
Here, consider a case where the system is shifted from the old system to the new system, and the communication middleware is switched from the old communication middleware 1903 to the new communication middleware 1907.

  While the system scale is small, it is common to change the communication middleware and switch the communication application 1902 to a new one. However, when the system scale is large, the development cost of the communication application 1902 becomes enormous. For this reason, in order to reduce development costs, it is desirable to use the communication application 1902 of the old system in the communication apparatus 1906 of the new system.

  As described above, the communication application 1902 of the old system is developed on the assumption that it operates on the old communication middleware 1903. Therefore, when the system is migrated, the difference between the old communication middleware 1903 and the new communication middleware 1908 is compensated in order to run the communication application 1902 on the new communication middleware 1908 of the new system as shown in the lower part of FIG. It is necessary to provide an old and new middle conversion unit 1908.

  In a large-scale system, the development cost of the new and old middle conversion unit 1908 is lower than the case where the entire communication application 1902 is recreated. However, the development cost of the old and new middle conversion unit 1908 is still high. For example, the old and new middle conversion unit 1908 includes at least (1) an I / F (Interface) portion with the communication application 1902, (2) an I / F portion with the new communication middleware 1908, (3) the old communication middleware 1903 and the new A function is required for the part that simulates the internal behavior (timeout conditions, etc.) of each communication middleware 1908. In particular, in order to carry out the development of (3), it is necessary to be familiar with the internal operations of the old communication middleware 1903 and the new communication middleware 1908 in detail. Inefficient from the viewpoint of reusability of the program of the application 1902.

  In order to solve the above problem, for example, in Patent Document 1, an encapsulation device (tunneling device) that encapsulates a packet transmitted from the communication device of the old system is provided between the communication device of the old system and the network. . Then, the encapsulating apparatus transmits each encapsulated packet to the network via the new communication middleware of the new system. Further, the encapsulating device decapsulates the encapsulated packet received from the network, extracts the packet of the old system, and transmits it to the communication device of the old system.

  Further, for example, Non-Patent Document 1 discloses a technology in which a virtual Ethernet I / F (Ethernet is a registered trademark) is provided in a communication device itself, and a packet of an old system is encapsulated by the communication device alone. Specifically, the communication device assigns a new IP address to the virtual Ethernet I / F, and sets a routing table or the like so that all communications pass through the virtual Ethernet I / F. Then, the communication apparatus can transmit the packet of the new system by encapsulating the packet (Ethernet frame) of the old system via the virtual Ethernet I / F and passing it to the new communication middleware.

  As described above, in the techniques described in Patent Literature 1 and Non-Patent Literature 1, a newly developed object passes a packet (Ethernet frame) of the old system received via the new communication middleware to the old system (the above (1 )) And a part (the part (2)) for passing a packet (Ethernet frame) to the new communication middleware. Therefore, compared with the case where the old and new middle conversion unit 2107 that mutually converts the old communication middleware and the new communication middleware is developed, the technical difficulty level is low and the development cost can be greatly reduced.

JP 2008-078966 A1

Todai Dai, “Internal structure of SoftEther”, [online], [Search September 7, 2010], Internet <URL: http://www.softether.co.jp/jp/company/media/ academic / data / softetherpaper002.pdf>

  As described in the background art, in the technique disclosed in Patent Document 1, the system setting (IP address, etc.) of the old system is not changed at all, and the transition to the new system can be performed only by installing the encapsulation device. It becomes possible. However, there is a problem that encapsulating devices are required for the number of communication devices, resulting in a huge hardware cost.

  Further, with the technology disclosed in Non-Patent Document 1, since it is possible to move to a new system with a single communication device, no additional hardware cost is required. However, since the virtual Ethernet I / F is recognized by the OS in the same manner as the physical Ethernet I / F, it is necessary to set an IP address different from that of the physical Ethernet I / F. Therefore, it takes time and labor to change the system settings of the old system and to take into account IP address restrictions when designing the new system (for example, it must not overlap with the IP address of the old system).

  Also, in order to reduce the risk of system migration, instead of switching all communication devices to a new device at once, a method may be used in which several units are switched in stages over a certain period. In that case, until the migration is completely completed, the packets of the IP address of the old system and the IP address of the new system will be mixed on the same network, which may not be supported by general routers and switches. There is. Such a problem that a plurality of IP addresses coexist on a single network cannot be solved by Patent Document 1 and Non-Patent Document 1.

  Therefore, there is a need for a technique that enables a communication application that transmits and receives information via the old communication middleware to transmit and receive information via the new communication middleware without changing the IP address or adding hardware.

  A communication device encapsulates data using a destination address that designates another communication device to create a first packet, and a processing unit that executes a predetermined process using the first packet And a second packet creation unit that encapsulates the first packet again using the destination address to create a second packet, and a transmission unit that transmits the second packet to the other communication device.

  Without changing the IP address or adding hardware, communication applications that send and receive data via the old communication middleware can send and receive data via the new communication middleware.

It is a figure which shows an example of the functional block structure of a communication apparatus. 3 is a diagram illustrating an example of a functional block configuration of an encapsulation processing unit 105. FIG. It is a figure which shows an example of the hardware constitutions of a communication apparatus. It is a figure which shows an example of the table which manages the communication protocol corresponding to a connecting point address and a port. It is a figure which shows an example of an Ethernet frame. It is a figure which shows an example of a communication information corresponding table. It is a figure which shows an example of a communication flow in case a new apparatus transmits data to a new apparatus. It is a figure which shows an example of a communication flow in case a new apparatus transmits data to an old apparatus. It is a figure which shows an example of a communication flow in case an old apparatus transmits data to a new apparatus. It is a flowchart which shows an example of the process which a RAW receiving part performs. It is a flowchart which shows an example of the process which a middle receiving part performs. It is a flowchart which shows an example of the process which an encapsulation determination part performs. It is a flowchart which shows an example of the process which a RAW transmission part performs. It is a flowchart which shows an example of the process which a middle transmission part performs. It is a flowchart which shows an example of the process which a RAW receiving part performs. It is a flowchart which shows an example of the process which a middle receiving part performs. It is a flowchart which shows an example of the process which a RAW transmission part performs. It is a figure which shows an example of the functional block structure of a communication apparatus. It is a figure which shows an example of system transfer.

An example of an embodiment (hereinafter referred to as “this embodiment”) will be described in detail with reference to the drawings as appropriate.
<First Embodiment>
In the first embodiment, a case will be described in which new communication middleware is installed in addition to the old communication middleware in some of a plurality of communication devices in the system in accordance with system migration. Here, it is assumed that the packet to be encapsulated is an Ethernet frame that is layer 2 in the OSI model.
(Function of communication device)
The function of the communication apparatus in this embodiment will be described with reference to FIG.

  As shown in FIG. 1, the communication devices 101 in the present embodiment are connected so as to communicate with each other via a network 102. The network 102 is described as an IP network, but is not limited to this. The signal used for communication may be, for example, any one of electricity, light, radio waves, sound, or a combination thereof.

  The communication device 101 includes a communication application execution unit 103, a first communication middleware execution unit 104, an encapsulation processing unit 105, a second communication middleware execution unit 106, a protocol stack 107, a virtual communication I / F (Interface) 108, a communication I / F109, a protocol management table 110, and a communication information correspondence table 112 are provided. The communication application execution unit 103 executes a communication application program that provides various services to other communication devices and requests various services from other communication devices.

  Note that a communication application program (also referred to as APP in the following description) executed in the communication application execution unit 103 corresponds to the communication application 1902 shown in FIG. 19, and is executed in the first communication middleware execution unit 104. It operates on the first communication middleware (old communication middleware before system transition).

  The first communication middleware execution unit 104 executes a program that provides a commonly used function when a plurality of APPs are executed. For example, the program includes a socket I / F, and generally has a security function such as authentication and encryption, a complicated communication processing function such as socket initialization and termination processing, and the like. Note that the program executed in the first communication middleware execution unit 104 uses the old communication protocol, and corresponds to the old communication middleware 1903 shown in FIG.

  The encapsulation processing unit 105 checks the transmission packet (hereinafter also referred to as a frame or an Ethernet frame) received from the virtual communication I / F 108, and executes the second communication middleware if it is a packet to be encapsulated that requires encapsulation. If the packet is not encapsulated and does not need to be encapsulated, it is transmitted as it is via the communication I / F 109. Further, the received packet received from the communication I / F 109 or the second communication middleware execution unit 106 is transferred to the virtual communication I / F 108. The detailed configuration of the encapsulation processing unit 105 will be described with reference to FIG.

  The second communication middleware execution unit 106 executes a program that provides a commonly used function when a plurality of APPs are executed. For example, the program includes a socket I / F, and generally has a security function such as authentication and encryption, a complicated communication processing function such as socket initialization and termination processing, and the like. The program executed in the second communication middleware execution unit 106 uses a new communication protocol, and corresponds to the new communication middleware 1908 shown in FIG. 19, and the second communication middleware execution unit 106 Communication protocol processing different from the middleware execution unit 104 is executed.

  The protocol stack 107 is a program group (for example, TCP, UDP (User Datagram Protocol), IP, etc.) that performs protocol processing. The protocol stack 107 can pass transmission / reception information between the first communication middleware execution unit 104 and the second communication middleware execution unit 106 via the socket I / F.

  The virtual communication I / F 108 is a virtual communication I / F that simulates the communication I / F function with software, and is equivalent to a normal communication I / F (communication I / F 109, etc.) from the OS (Operating System). Be treated. However, a normal communication I / F is associated with specific communication hardware (for example, an Ethernet controller chip, etc.) and sends / receives packets to / from that hardware, whereas a virtual communication I / F 108 has a specific communication hardware. It is associated with a program, and exchanges transmission / reception packets with the program. In this embodiment, the virtual communication I / F 108 is associated with the encapsulation processing unit 105 and passes the transmission packet (Ethernet frame) passed from the protocol stack 107 to the encapsulation processing 105. The data passed from the encapsulation processing unit 105 is regarded as a received packet (Ethernet frame) and passed to the protocol stack 107.

  The communication I / F 109 performs processing necessary for transmission, such as checksum calculation, on the transmission packet (Ethernet frame) passed from the encapsulation processing unit 105 and transmits it to the network 102 via associated hardware. Further, the packet (Ethernet frame) received from the network 102 is passed to the encapsulation processing unit 105.

  As described above, the virtual communication I / F 108 and the communication I / F 109 are treated equivalently when viewed from the OS, but in this embodiment, an IP address is assigned only to the virtual communication I / F 108, and the communication I / F 109 Do not assign an IP address. As a result, only the virtual communication I / F 108 is recognized as the only communication I / F from the protocol stack 107, and the communication I / F 109 transmits an Ethernet frame between the network 102 and the encapsulation processing unit 105. Only the function to transfer will be provided.

The protocol management table 110 and the communication information correspondence table 112 are information referred to by the encapsulation processing unit 105. Details will be described later.
(Details of encapsulation processing unit)
Next, a detailed configuration of the encapsulation processing unit 105 will be described with reference to FIG.

  The encapsulation processing unit 105 includes a RAW reception unit 201, a middle reception unit 202, an encapsulation determination unit 203, a RAW transmission unit 204, and a middle transmission unit 205.

  The RAW reception unit 201 receives a received packet (Ethernet frame) that has arrived at the communication I / F 109 via the network 102 by RAW reception from the communication I / F 109, and performs processing to pass the Ethernet frame as it is to the virtual communication I / F 108. Details of the processing of the RAW reception unit 201 are shown in FIG.

  The middle receiving unit 202 performs a process of passing the application data (decapsulated Ethernet frame) passed from the second communication middleware executing unit to the virtual communication I / F 108 as it is. Details of the processing of the middle receiving unit 202 are shown in FIG.

  The encapsulation determination unit 203 checks the packet received from the virtual communication I / F 108, and if it is a packet to be encapsulated, passes it to the middle transmission unit 205. To the unit 204. Details of the processing of the encapsulation determination unit 203 are shown in FIG.

  The middle transmission unit 205 adds a header described later to the packet received from the encapsulation determination unit 203 and passes the packet to the second communication middleware execution unit 106. Details of the processing of the middle transmission unit 205 are shown in FIG.

The RAW transmission unit 204 passes the packet received from the encapsulation determination unit 203 to the communication I / F 109. Details of the processing of the RAW transmission unit 204 are shown in FIG.
(Hardware configuration of communication device)
Next, the hardware configuration of the communication apparatus 101 will be described with reference to FIG. 3 (see FIG. 1 as appropriate).

  The communication device 101 includes a host CPU (Central Processing Unit) 301 that performs various processes, a host memory 302, a peripheral I / F 303, a storage device 304, a communication I / F 305, and a bus 307. The host CPU 301, the host memory 302, the peripheral I / F 310, the storage device 304, and the communication I / F 305 are communicably connected via a bus 307.

  The host CPU 301 is a processor that executes a program.

  The host memory 302 is used as a working memory and a temporary buffer for input / output data when the host CPU 301 executes a program.

  The peripheral I / F 303 is an interface for connecting to input / output devices such as a mouse, a keyboard, and a monitor, and various peripheral devices such as an external storage such as a USB (Universal Serial Bus) memory.

  The storage device 304 includes a magnetic disk device, a flash ROM (Read Only Memory), and the like, and is set by the OS, various drivers, various application programs, and various information used in the programs (for example, an administrator or a maintenance person). Information).

  The communication I / F 305 provides an interface when the communication device 101 communicates with another communication device 101 via the network 102. The communication I / F 305 may be, for example, a NIC (Network Interface Card).

  In FIG. 3, only one communication I / F 305 is shown, but two or more may be used.

The communication application execution unit 103, the first communication middleware execution unit 104, the encapsulation processing unit 105, the second communication middleware execution unit 106, the protocol stack 107, the virtual communication I / F 108, and the communication I / F 109 shown in FIG. It is a functional element configured by a program stored in the storage device 304 being read into the host memory 302 and executed by the host CPU 301. Note that the function of the communication I / F 109 shown in FIG. 1 is implemented on the communication I / F 305 shown in FIG. Further, the protocol management table 110 and the communication information target table 112 illustrated in FIG. 1 are stored in the storage device 304.
(Protocol management table)
Information stored in the protocol management table 110 will be described with reference to FIG. 4 (see FIG. 1 as appropriate).

  The protocol management table 110 stores a packet type 410, an IP address 401, a port number 402, and a protocol 403 when transmitting a packet. The protocol management table 110 is used when the encapsulation determining unit 203 receives a transmission packet from the virtual communication I / F 108 and determines whether or not the transmission packet should be encapsulated. The information in this table may be set in advance by an administrator or maintenance person of the communication device 101, may be set by a program that exchanges protocol information with each device individually, or the protocol of all devices. It may be set by inquiring to a server that collectively manages information.

  The column of packet type 410 is an area for storing the type of packet. Examples of the packet type include IP indicating an IP packet, ARP indicating an ARP (Address Resolution Protocol) packet, and the like. .

  The column of the IP address 401 is an area that stores an IP address for identifying the communication device 101 that is the transmission destination of the packet.

  The port number 402 column is an area for storing the destination port number of the packet. The port number is generally used to identify a communication service (FTP (File Transfer Protocol), HTTP (HyperText Transfer Protocol), etc.), and by using different port numbers even if the transmission destination is the same communication device 101. The type of communication service can be changed. In this embodiment, the port number is used to specify the destination communication middleware of the packet.

  The protocol 403 column is an area in which information indicating the type of processing to be performed on the packet is stored. When a protocol name is specified (protocol A, protocol B, etc.), it means that the packet must be encapsulated using that protocol. When “RAW transmission” is specified, the packet is left as it is. Means to send.

  In FIG. 4, for example, a line 404 is a case where communication is performed using a communication device having an IP address of 192.168.0.1 and communication middleware of the communication device specified by the port number 80 using an IP packet. This indicates that the packet is transmitted as it is without being encapsulated (RAW transmission). The other line 405 uses an IP packet to communicate with a communication device having an IP address of 192.168.0.1 (that is, the same communication device) using the communication middleware of the communication device specified by port number 23. In this case, the packet encapsulation using the protocol A is necessary. A row 408 represents that the ARP packet is transmitted without being encapsulated regardless of the address.

In FIG. 4, the protocol 403 describes three types of protocols (RAW transmission, protocol A, protocol B), but may be one type or three or more types. In addition, the * mark described in the port number 402 indicates that any port number may be used.
(Communication information correspondence table)
Next, information stored in the communication information correspondence table 112 will be described with reference to FIG.

  The communication information correspondence table 112 stores communication information 601 of the first communication middleware and communication information 602 of the second communication middleware. Then, when the middle transmission unit 205 receives the transmission packet from the encapsulation determination unit 203, the communication information correspondence table 112 corresponds to the communication information of the first communication middleware of the transmission destination communication device included in the transmission packet. Used to acquire communication information of the second communication middleware of the destination communication device.

  In FIG. 6, for example, in line 603, when the communication information of the first communication middleware included in the transmission packet is transmitted using the second communication middleware when the IP address is IP_A, the port number is B, and the service ID is C. The communication information of the second communication middleware necessary for the above indicates that the IP address is IP_A, the port number is b, and the service ID is c. Here, since the IP address is an address assigned to the virtual communication I / F of the destination communication device, the same value is used for both the first communication middleware and the second communication middleware, but the port number uniquely identifies the communication middleware. Because it is used for identification, it has a different value. The service ID is an ID indicating where the transmission destination communication middleware delivers the transmission packet. In the case of this embodiment, the service ID is the communication application execution when the port number indicates the first communication middleware. When the port number indicates the second communication middleware, the service ID indicates the encapsulation processing unit. However, it is not necessarily limited to this. For example, when the second communication middleware communicates with the communication application execution unit without going through the encapsulation processing unit, the service ID indicates the communication application execution unit when the port number indicates the second communication middleware.

Here, IP addresses and port numbers are given as examples of communication information. However, the present invention is not limited to this, and any information can be used as long as the information indicates the correspondence between the first communication middleware and the second communication middleware.
(Encapsulated communication processing sequence during data transmission from new device to new device)
Next, an encapsulated communication processing sequence when data is transmitted from the communication apparatus A101a after the transition to the new system to the communication apparatus B101b after the transition to the new system will be described using FIG. 5 and FIG. Here, both the communication device A 101a and the communication device B 101b have a first communication middleware execution unit 104 and a second communication middleware execution unit 106.

  First, the communication application execution unit 103a of the communication device A 101a passes the application data 501 to the first communication middleware execution unit 104a. At this time, the communication application execution unit 103a includes information for specifying the transmission destination first communication middleware execution unit 104b (including the IP address of the communication device B101b and the port number of the first communication middleware execution unit 104b in FIG. 6). Information corresponding to the first middle communication information 601) is passed to the first communication middleware execution unit 104a.

  Next, the first communication middleware execution unit 104a gives information for designating the received first communication middleware execution unit 104b to the received application data 501 as a first header, which is used as application data 502. Passed to protocol stack 107a. At this time, the first communication middleware execution unit 104a designates the IP address of the communication device B 101b and the port number of the first communication middleware execution unit 104b in the protocol stack.

  Next, the protocol stack 107a assigns the received IP address of the communication apparatus B 101b as the IP header (first IP header) and the port number as the TCP header (first TCP header) to the received application data 502, and further transmits the packet. A destination MAC address (first MAC) is also assigned to generate a transmission packet (Ethernet frame) 503. The protocol stack 107a passes this transmission packet 503 to the virtual communication I / F 108a.

  Next, the virtual communication I / F 108a passes the received transmission packet 503 as it is to the encapsulation processing unit 105a.

  Next, the encapsulation processing unit 105a stores the destination information (the IP address of the communication device B 101b and the first communication middleware execution unit 104b) included in the IP header (first IP header) and the TCP header (first TCP header) of the transmission packet 503. By referring to the protocol management table 110 using the designated port number), it is determined whether or not the transmission packet is to be encapsulated.

  When the communication partner is a communication apparatus having the second communication middleware execution unit 106 (that is, having a new communication middleware) and the destination port number of the transmission packet indicates the first communication middleware, the protocol column 403 of the protocol management table 110 is displayed. Specifies a protocol for encapsulating the transmission packet. Therefore, the encapsulation processing unit 105a determines that the encapsulation is performed, and passes the transmission packet 503 received from the virtual communication I / F 108a to the second communication middleware execution unit 106a as application data 503. At this time, the encapsulation processing unit 105a refers to the communication information correspondence table 112 to specify information for specifying the second communication middleware execution unit 106b as the transmission destination (the IP address of the communication device B 101b, the second communication middleware execution unit 106b 6) (information corresponding to the second middle communication information 602 in FIG. 6 including the port number) is acquired and passed to the second communication middleware execution unit 106a.

  Next, the second communication middleware execution unit 106a gives information for designating the received second communication middleware execution unit 106b as the second header to the received application data 503, which is used as application data 504. Passed to protocol stack 107a. At this time, the second communication middleware executing unit 106a designates the IP address of the communication device B 101b and the port number of the second communication middleware executing unit 106b in the protocol stack.

  Next, the protocol stack 107a assigns the received IP address of the communication apparatus B 101b as the IP header (second IP header) and the port number as the TCP header (second TCP header) to the received application data 504, and further transmits the packet. A destination MAC address (second MAC) is also assigned to generate a transmission packet (encapsulated) 505, and the generated packet is passed to the virtual communication I / F 108a. Here, the IP address assigned by the protocol stack 107a to the application data 504 as an IP header (second IP header) is an IP address assigned to the virtual communication I / F of the transmission destination communication device B 101b. 107a is the same as the IP address assigned to the application data 502 as an IP header (first IP header).

  Next, the virtual communication I / F 108a passes the transmission packet 505 as it is to the encapsulation processing unit 105a.

  Next, the encapsulation processing unit 105a receives the destination information (the IP address of the communication device B 101b and the second communication middleware execution) included in the IP header (second IP header) and TCP header (second TCP header) of the received transmission packet 505. The protocol management table 110 is referred to using the port number that designates the unit 106b), and it is determined whether or not the transmission packet 505 is to be encapsulated.

  When the communication partner is a communication device having the second communication middleware execution unit 106 (that is, having a new communication middleware) and the destination port number stored in the TCP header indicates the second communication middleware, the protocol of the protocol management table 110 A field 403 specifies that the transmission packet is transmitted as it is without being encapsulated. Therefore, the encapsulation processing unit 105a determines that encapsulation is not necessary, and passes the transmission packet 505 as it is to the communication I / F 109a.

  Next, the communication I / F 109a transmits the transmission packet 505 to the communication I / F 109b of the communication apparatus B 101b via the network.

  Next, the communication I / F 109b of the communication apparatus B 101b receives the packet 505 from the network and passes the received packet to the encapsulation processing unit 105b as it is.

  Next, the encapsulation processing unit 105b passes the received packet 505 as it is to the virtual communication I / F 108b.

  Next, the virtual communication I / F 108b passes the received packet 505 to the protocol stack 107b.

  Next, the protocol stack 107b performs protocol processing on the received packet 505, and extracts the application data portion 504 of the received packet 505. Then, in accordance with the designation by the TCP header (second TCP header) of the received packet 505, the extracted application data portion 504 is transferred to the second communication middleware execution unit 106b.

  Next, the second communication middleware execution unit 106b removes the second header from the received application data 504 and passes the remaining portion 503 to the encapsulation processing unit 105b.

  Next, the encapsulation processing unit 105b passes the received packet 503 to the virtual communication I / F 108b.

  Next, the virtual communication I / F 108b passes the received packet 503 to the protocol stack 107b.

  Next, the protocol stack 107b performs protocol processing on the received packet 503, extracts the application data portion 502 of the packet 503, and extracts it from the first communication middleware execution unit 104b according to the TCP header (first TCP header) of the packet 503. To pass.

Next, the first communication middleware execution unit 104b removes the first header from the received application data 502 and passes it to the communication application execution unit 103b.
(Decapsulated communication processing sequence when sending data from the new device to the old device)
Next, an unencapsulated communication processing sequence when data is transmitted from the communication device C101c after the transition to the new system to the communication device D801d of the old system will be described with reference to FIGS. Here, the communication device C101c includes a first communication middleware execution unit 104 and a second communication middleware execution unit 106, and the communication device D101d includes the first communication middleware execution unit 104 but the second communication middleware execution unit 106 I don't have it.

  First, the communication application execution unit 103c of the communication device C101c passes the application data 501 to the first communication middleware execution unit 104c. At this time, the communication application execution unit 103c includes information for specifying the transmission destination first communication middleware execution unit 104d (including the IP address of the communication device D101d and the port number of the first communication middleware execution unit 104d in FIG. 6). Information corresponding to the first middle communication information 601) is passed to the first communication middleware execution unit 104c together.

  Next, the first communication middleware execution unit 104c gives the received application data 501 with information for designating the received first communication middleware execution unit 104d as the first header, which is used as application data 502. Pass to protocol stack 107c. At this time, the first communication middleware execution unit 104c designates the IP address of the communication device D101d and the port number of the first communication middleware execution unit 104d in the protocol stack.

  Next, the protocol stack 107c assigns the received IP address of the communication device D101d as the IP header (first IP header) and the port number as the TCP header (first TCP header) to the received application data 502, and further transmits the packet. A destination MAC address (first MAC) is also assigned to generate a transmission packet (Ethernet frame) 503, and the generated packet is passed to the virtual communication I / F 108c.

  Next, the virtual communication I / F 108c passes the transmission packet 503 as it is to the encapsulation processing unit 105c. Next, the encapsulation processing unit 105c stores the destination information (the IP address of the communication device D101d and the first communication middleware execution unit 104d) included in the IP header (first IP header) and the TCP header (first TCP header) of the transmission packet 503. By referring to the protocol management table 110 using the designated port number), it is determined whether or not the transmission packet is to be encapsulated. When the communication partner is a communication apparatus that does not have the second communication middleware execution unit 106, the protocol column 403 of the protocol management table 110 is designated to transmit the transmission packet as it is without being encapsulated (RAW transmission). ing. Accordingly, the encapsulation processing unit 105c determines that the encapsulation processing is not performed, and passes the transmission packet 503 as it is to the communication I / F 109c. Next, the communication I / F 109c transmits the transmission packet 503 to the communication I / F 109d of the communication device D801d via the network.

  Next, the communication I / F 109d of the communication device D801d receives the packet 503 from the network and passes the received packet to the protocol stack 107d.

  Next, the protocol stack 107d performs protocol processing on the received packet, extracts the application data 502 portion of the packet, and uses the application data 502 as the first communication middleware according to the designation of the TCP header (first TCP header) of the packet 503. Passed to the execution unit 104d.

Next, the first communication middleware execution unit 104d removes the first header from the received application data 502 and passes the remaining portion 501 to the communication application execution unit 103d.
(Decapsulated communication processing sequence when sending data from the old device to the new device)
Next, an unencapsulated communication processing sequence when data is transmitted from the communication device E801e of the old system to the communication device F101f after the transition to the new system will be described with reference to FIGS. Here, the communication device E101e has the first communication middleware execution unit 104 but not the second communication middleware execution unit 106, and the communication device F101f has the first communication middleware execution unit 104 and the second communication middleware execution unit 106. Is a communication device.

  First, the communication application execution unit 103e of the communication device E801e passes application data 501 to the first communication middleware execution unit 104e. At this time, the communication application execution unit 103e includes information for specifying the destination first communication middleware execution unit 104f (including the IP address of the communication device F101f and the port number of the first communication middleware execution unit 104f in FIG. 6). Information corresponding to the communication information 601 of the first middle) is passed to the first communication middleware executing unit 104f together.

  Next, the first communication middleware executing unit 104e gives the received application data 501 with information for designating the received first communication middleware executing unit 104f as the first header, and this is given as application data 502. Passed to protocol stack 107e. At this time, the first communication middleware execution unit 104e designates the IP address of the communication device F101f and the port number of the first communication middleware execution unit 104f in the protocol stack.

  Next, the protocol stack 107e assigns the received IP address of the communication device F101f as the IP header (first IP header) and the port number as the TCP header (first TCP header) to the received application data 502, and further transmits the packet. A destination MAC address (first MAC) is also assigned to generate a transmission packet (Ethernet frame) 503, and the generated packet 503 is passed to the communication I / F 109e.

  Next, the communication I / F 109e transmits the transmission packet 503 to the communication I / F 109f of the communication device F101f via the network.

  Next, the communication I / F 109f of the communication device F801f receives the packet 503 from the network and passes the received packet to the encapsulation processing unit 105f as it is. Next, the encapsulation processing unit 105f passes the received packet 503 as it is to the virtual communication I / F 108f.

  Next, the virtual communication I / F 108f passes the received packet 503 to the protocol stack 107f.

  Next, the protocol stack 107f performs protocol processing on the received packet 503, extracts the application data portion 502 of the received packet, and converts the application data portion 502 into the first communication middleware according to the designation of the first TCP header of the received packet 503. Passed to the execution unit 104f.

  Next, the first communication middleware execution unit 104f removes the first header from the received application data 502 and passes the remaining portion 501 to the communication application execution unit 103f.

In the packet transmission / reception processing shown in FIGS. 7 to 9, regardless of whether or not the receiving communication device and the transmitting communication device are communication devices after the transition to the new system having the second communication middleware execution unit 106. In the IP header, an IP address assigned to the virtual communication I / F is used. That is, in the present embodiment, it is not necessary to change the IP address in accordance with the transition to the new system, and it can be seen that packets can be transmitted and received even if the previous IP address is continuously used.
(Flowchart of the RAW receiver in the first embodiment)
Next, a processing flow at the time of packet reception executed by the RAW reception unit 201 in the encapsulation processing unit 105 in the first embodiment will be described with reference to FIG.

  In step 1001, the RAW reception unit 201 receives a received packet (Ethernet frame) from the communication I / F 109 in RAW (received as it is).

In step 1002, the raw reception unit 201 passes the received packet (Ethernet frame) to the virtual communication I / F 108. After this process is completed, the process returns to step 1001.
(Flowchart of the middle receiving unit in the first embodiment)
Next, a processing flow at the time of packet reception executed by the middle reception unit 202 in the encapsulation processing unit 105 in the first embodiment will be described with reference to FIG.

  In step 1101, the middle reception unit 202 receives application data (that is, an Ethernet frame after decapsulation) from the second communication middleware execution unit 106.

  In step 1102, the middle receiving unit 202 checks the destination MAC address of the received Ethernet frame. If the destination is a unicast address, go to Step 1104. If it is not a unicast address, go to Step 1105.

  In step 1104, the middle receiving unit 202 rewrites the destination MAC address of the Ethernet frame with the MAC address of its own virtual communication I / F 108.

In step 1105, the middle receiving unit 202 passes the Ethernet frame to the virtual communication I / F 108. After this processing is completed, the process returns to step 1101.
(Flowchart of encapsulation determination unit in the first embodiment)
Next, a processing flow at the time of packet transmission executed by the encapsulation determination unit 203 in the encapsulation processing unit 105 in the first embodiment will be described with reference to FIG.

  In step 1201, the encapsulation determination unit 203 acquires a transmission packet (Ethernet frame) from the virtual communication I / F 108.

  In step 1202, the encapsulation determination unit 203 determines whether or not the acquired Ethernet frame should be encapsulated. This determination is made by referring to the protocol management table 110 using the destination information specified in the IP header and TCP header of the received Ethernet frame.

  If the Ethernet frame does not require encapsulation, the process proceeds to step 1204. If the Ethernet frame needs to be encapsulated, the process proceeds to step 1207.

  In step 1204, the encapsulation determination unit 203 passes the Ethernet frame to the RAW transmission unit 204. After this process is completed, the process returns to step 1201.

In step 1207, the encapsulation determination unit 203 passes the Ethernet frame to the middle transmission unit 205. At this time, the encapsulation determination unit 203 includes information for specifying the second communication middleware execution unit of the transmission destination (including the IP address of the transmission destination communication device and the port number of the second communication middleware execution unit 106 of FIG. Information corresponding to the second middle communication information 602) is passed to the middle transmitter 205 together. After this process is completed, the process returns to step 1201.
(Flow chart of the RAW transmission unit in the first embodiment)
Next, a processing flow at the time of packet transmission executed by the RAW transmission unit 204 in the encapsulation processing unit 105 in the first embodiment will be described with reference to FIG.

  In step 1301, the RAW transmission unit 204 acquires an Ethernet frame from the encapsulation determination unit 105.

In step 1302, the RAW transmission unit 204 RAW-transmits (transmits as it is) the acquired Ethernet frame using the communication I / F 109. After this processing is completed, the process returns to step 1301.
(Flowchart of middle transmission unit in the first embodiment)
Next, a processing flow at the time of packet transmission executed by the middle transmission unit 205 in the encapsulation processing unit 105 in the first embodiment will be described with reference to FIG.

  In step 1401, the middle transmission unit acquires an Ethernet frame from the encapsulation determination unit.

  In step 1402, the middle transmission unit acquires address information (the IP address of the transmission destination communication device and the port number for identifying the first communication middleware of the communication device) included in the IP header and TCIP header of the Ethernet frame.

  In step 1403, the middle transmission unit refers to the communication information correspondence table 112 based on the acquired IP address of the transmission destination communication device and the port number for identifying the first communication middleware, toward the second communication middleware of the transmission destination communication device. An IP address of a destination communication device and a port number for identifying the second communication middleware of the communication device, which are necessary for transmitting the Ethernet frame, are acquired.

  In step 1404, the middle transmission unit delivers the IP address of the transmission destination communication device acquired in step 1403 and the port number of the second communication middleware of the communication device to the second communication middleware execution unit, and the Ethernet received in step 1401. Instruct the frame to be transmitted as a group of application data. After completion of this step, the process returns to step 1401.

Second Embodiment
In the second embodiment, an example in which an IP datagram (hereinafter referred to as an IP packet) that is Layer 3 as referred to in the OSI model is assumed as a packet to be encapsulated will be described. Note that the system configuration of the communication apparatus 101 according to the second embodiment is the same as the system configuration (FIGS. 1 and 2) according to the first embodiment, and a description thereof will be omitted.

  Hereinafter, the virtual communication I / F 108, the RAW reception unit 201, the middle reception unit 202, the encapsulation determination unit 203, the RAW transmission unit 204, and the middle transmission unit 205 that have different functions from the first embodiment will be described.

Since the encapsulation target is an IP packet, the virtual communication I / F 108 of the second embodiment exchanges an IP packet with the encapsulation processing unit 105 instead of an Ethernet frame.
(Flowchart of RAW receiver in the second embodiment)
Next, a processing flow at the time of packet reception of the RAW reception unit 201 in the encapsulation processing unit 105 in the second embodiment will be described with reference to FIG.

  In step 1501, the RAW reception unit 201 receives an Ethernet frame from the communication I / F 109 as RAW data.

  In step 1502, the RAW reception unit 201 checks the destination MAC address of the received Ethernet frame, and checks whether the Ethernet frame is correct.

  In step 1503, the RAW reception unit 201 extracts an IP packet from the received Ethernet frame.

In step 1504, the RAW reception unit 201 passes the extracted IP packet to the virtual communication I / F 108.
(Flowchart of the middle receiving unit in the second embodiment)
Next, in the second embodiment, a processing flow at the time of packet reception of the middle reception unit 202 in the encapsulation processing unit 105 will be described with reference to FIG.

  In step 1601, the middle receiving unit 202 receives application data (= IP packet before encapsulation) from the second communication middleware executing unit.

In step 1602, the middle receiving unit 202 passes the received IP packet to the virtual communication I / F 109.
(Flowchart of encapsulation determination unit in the second embodiment)
In the second embodiment, the processing flow at the time of packet transmission of the encapsulation determination unit 203 in the encapsulation processing unit 105 is the same processing flow if the Ethernet frame in FIG. 12 is replaced with an IP packet. Description is omitted.
(Flowchart of RAW transmission unit in the second embodiment)
Next, a processing flow at the time of packet transmission of the RAW transmission unit 204 in the encapsulation processing unit 105 in the second embodiment will be described with reference to FIG.

  In step 1701, the RAW transmission unit 204 acquires an IP packet from the encapsulation determination unit.

  In step 1702, the RAW transmission unit 204 creates an Ethernet frame. At this time, the MAC address of its own virtual communication I / F 108 is used as the source MAC address. Further, the destination MAC address may be acquired from the destination IP address by ARP processing in the same manner as the protocol stack, or a table corresponding to the ARP table may be managed independently and referred to.

In step 1703, the RAW transmission unit 204 RAW-transmits the Ethernet frame created in step 1702 using the communication I / F. When this process ends, the process returns to step 1701.
(Flowchart of middle transmission unit in the second embodiment)
The processing flow at the time of packet transmission of the middle transmission unit 205 in the encapsulation processing unit 105 in the second embodiment will be the same processing flow if the Ethernet frame in FIG. Is omitted.

<Third Embodiment>
An example in which duplex communication is performed will be described with reference to FIG.

  A communication apparatus 101 illustrated in FIG. 18 illustrates a case where the second communication middleware execution unit 106 provides a duplex communication function. Each functional block shown in FIG. 18 has the same configuration as each functional block shown in FIG.

  In FIG. 18, the communication apparatus 101 is connected to a network A (for example, 192.168.1. *) And a network B (for example, 10.232.10. *) Having different network address systems. The virtual communication I / F 108A is assigned an IP address (eg, 192.168.0.1) belonging to the network A, and the virtual communication I / F 108B is assigned an IP address (eg, 10.232.10.1) belonging to the network B. Assigned.

  Of the processes executed when the communication apparatuses having dual or communication functions transmit and receive packets, processes different from the first embodiment will be described below. Other processes are the same as those in the first embodiment.

  The first communication middleware execution unit 104 adds a first header to the application data 501 received from the application execution unit 103. The first header identifies one of the two IP addresses assigned to the two virtual communication I / Fs of the communication partner communication device and the first communication middleware of the communication partner communication device. Port number to be included.

  The first communication middleware execution unit 104 delivers the application data 502 created in this way to the protocol stack 107. At this time, the first communication middleware execution unit 104 specifies the IP address and the port number assigned to the first header.

  The protocol stack creates a transmission packet 503 having the designated IP address in the first IP header, the designated port number in the first TCP header, and further assigned with the first MAC address. The data is transferred to the encapsulation processing unit 105 via the I / F.

  In the encapsulation processing unit 105, the necessity of encapsulation is determined using the protocol management table as in the first embodiment. In this case, since it is determined that encapsulation is necessary, the encapsulation processing unit 105 delivers the transmission packet 503 to the second communication middleware execution unit 106. At this time, the encapsulation processing unit 105 sends the two IP addresses assigned to the communication device of the communication partner and the identification information (port number) of the second communication middleware of the communication device together to the second communication middleware execution unit 106. Notice.

  When receiving the application data for transmission (= transmission packet before encapsulation) 503 from the encapsulation processing unit 105, the second communication middleware execution unit 106 duplicates it. Then, the second header having the IP address of the communication device of the communication partner and the port number of the second communication middleware execution unit 106 of the communication device is added to the original application data 503 and each of the duplicates, thereby encapsulating To do. At this time, the IP address included in the second header assigned to the original application data 503 and the second header assigned to the duplicate are different IP addresses assigned to the same communication device (that is, the communication partner's IP address). Different IP addresses assigned to the two virtual communication I / Fs of the communication device).

  Then, the second communication middleware execution unit 106 passes two packets 504 each having a different IP address in the second header to the protocol stack 107. At this time, the second communication middleware executing unit 106 notifies the protocol stack of the IP address and port number stored in the second header of each communication packet 504 as the destination of the communication packet 504.

  The packet 504 is given a second MAC, a second IP header, and a second TCP header by the protocol stack 107. Here, the IP address and the port number designated by the second communication middleware execution unit 106 are stored in the second IP header and the second TCP header. The two communication packets 505 created in this way are each passed to different virtual communication I / F 108A or virtual communication I / F 108B, and further passed to different communication I / F 109A or communication I / F 109B by the encapsulation processing unit 105. RAW transmission. Then, the double-encapsulated encapsulated packet arrives at the destination communication device 101 via a different network.

  In the communication apparatus 101 that has received the duplicated encapsulated packet from different networks, each of the two virtual communication I / Fs receives the packet 505 whose destination is its own IP address via the encapsulation processing unit 105. To do. This IP packet has the MAC address, the second IP header, and the second TCP header removed by the protocol stack 107, and the second communication middleware execution unit 106 receives the duplicated application data (= received packet after decapsulation) from the protocol stack 107. ) 504 is received.

  The second communication middleware 106 removes the second header from each of the two received packets 504, and determines whether there is an abnormality such as an error. Then, application data (= received packet after decapsulation) 503 having no abnormality is passed to the encapsulation processing unit 105. Note that the second communication middleware execution unit 106 passes only the application data having no abnormality in the received two application data 503 to the encapsulation processing unit 105. When there is no abnormality in both of the two application data, either one (for example, late arrival packet) is discarded and only the other is passed to the encapsulation processing unit 105. Subsequent processing is the same as in the first embodiment.

  In the third embodiment, an example in which data is duplicated and transmitted / received has been described. However, the present invention is not limited to this, and it may be configured to be multiplexed more than triple. .

  Further, in this embodiment, the case where the network A and the network B have different address systems has been described as an example, but the same address system may be used. In this case, the virtual communication I / F 108A and the virtual communication I / F 108B Are assigned IP addresses belonging to the same network. In this embodiment, the case where there are two communication I / Fs has been described as an example, but three or more may be used.

  Further, each communication device 101 described in the first embodiment, the second embodiment, and the third embodiment can be realized by causing a general computer to execute the program of each unit described above. The program can be provided via a communication line, or can be written and distributed on a recording medium such as a CD-ROM (Compact Disc-Read Only Memory).

101 ... Communication device
102 ... Network
103 ... Communication application execution part
104 ... 1st communication middleware execution part
105 ... Encapsulation processing unit
106… Second communication middleware execution unit
107 ... Protocol stack
108… Virtual communication I / F
109… Communication I / F
110: Protocol management table
112 ... Communication information correspondence table
201 ... RAW receiver
202 ... Middle receiver
203 ... Encapsulation judgment unit
204 ... RAW transmission section
205 ... Middle transmitter
301 ... Host CPU
302 ... Host memory
303… Peripheral I / F
304 ... Storage device
305 ... Communication I / F
306 ... Bus
1901 ... Old system communication device
1902: Communication application
1903 ... Old communication middleware
1904: Protocol stack
1905 Communication I / F
1906 ... New system communication device
1907… New and old middle converter
1908 ... New communication middleware

Claims (11)

A communication device that communicates with other communication devices,
A first packet creating unit that encapsulates data using a destination address that specifies the other communication device and creates a first packet;
A processing unit that executes predetermined processing using the first packet;
Re-encapsulating the first packet using the destination address to create a second packet, a second packet creation unit;
A communication apparatus having a transmission unit for transmitting the second packet to the other communication apparatus. The communication apparatus according to claim 1, further comprising a management table that specifies whether or not the second packet needs to be created for each destination address,
The processing unit refers to the management table, and whether or not the second packet creation unit should encapsulate the first packet based on a destination address included in the first packet created by the first packet creation unit A communication device that determines whether or not.   The communication device according to claim 2, wherein when the processing unit determines that encapsulation of the first packet is unnecessary, the transmission unit transmits the first packet to the other communication device. apparatus. The communication device according to claim 1, further comprising:
When receiving the second packet from another communication device, a first packet extraction unit that decapsulates the second packet with the address of the communication device itself and extracts the first packet;
A communication device having a data extraction unit that decapsulates the first packet again with the address of the communication device itself and extracts data. A first communication middleware execution unit that passes application data to and from a communication application and uses a first communication protocol;
A second communication middleware execution unit that uses the second communication protocol;
A protocol stack unit that executes communication packet processing based on instructions from the first communication middleware execution unit and the second communication middleware execution unit;
A virtual communication interface unit that exchanges communication packets with the protocol stack unit;
A processing unit that transfers a communication packet between the virtual communication interface unit and a communication interface unit connected to a network,
Based on an instruction from the first communication middleware execution unit, the protocol stack unit includes a first IP address assigned to the virtual communication interface of the application data transmission destination communication device and the first communication middleware execution unit of the transmission destination communication device. The first port number assigned to the application data is assigned to create the first communication packet, the first communication packet is passed to the virtual communication interface unit,
The processing unit that has received the first communication packet from the virtual communication interface unit passes the first communication packet to the second communication middleware execution unit,
The second communication middleware execution unit passes the first communication packet to the protocol stack unit,
The protocol stack unit, based on an instruction from the second communication middleware execution unit, displays the first IP address and a second port number assigned to the second communication middleware execution unit of the transmission destination communication device. Create a second communication packet attached to the packet and pass to the virtual communication interface unit,
The communication device that receives the second communication packet via the virtual communication interface unit and the processing unit transmits the second communication packet to the network. The communication device according to claim 5,
The processing unit determines whether the first communication packet is sent to the second communication middleware execution unit or the communication interface unit based on the first IP address and the first port number assigned to the first communication packet. A communication device that determines whether or not to hand over. The communication device according to claim 6, wherein
When the processing unit determines to deliver the first communication packet to the communication interface unit, the communication interface unit that has received the first communication packet from the processing unit transmits the first communication packet to the network. Communication device. The communication device according to claim 5,
When the protocol stack receives the second communication packet via the communication interface unit, the processing unit, and the virtual communication interface unit, the protocol stack extracts the first communication packet from the second communication packet. Pass the first communication packet to the second communication middleware execution unit indicated by the second port number given to the second communication packet,
The protocol stack that has received the first communication packet via the second communication middleware execution unit and the virtual communication interface unit extracts application data from the first communication packet, and extracts the application data from the first communication packet. A communication device for passing to the first communication middleware execution unit indicated by a first port number assigned to a communication packet. The communication device according to claim 5,
When the protocol stack receives the first communication packet via the communication interface unit, the processing unit, and the virtual communication interface unit, the protocol stack extracts application data from the first communication packet, A communication device that passes the application data to the first communication middleware execution unit indicated by a first port number assigned to the first communication packet. The communication device according to claim 5,
Furthermore, it has another virtual communication interface unit provided with an IP address different from the first IP address, and another communication interface unit,
The second communication middleware execution unit creates a duplicate first communication packet that is a duplicate of the first communication packet and passes it to the protocol stack unit,
The protocol stack unit, in accordance with an instruction from the second communication middleware execution unit, sets the second IP address and the second port number assigned to another virtual communication interface unit included in the destination communication device to the duplicate first communication. Generate other second communication packet by giving to the packet, and pass to the other virtual communication interface unit,
The other communication interface unit that has received the other second communication packet via the other virtual communication interface unit and the processing unit transmits the other second communication packet to the network. The communication device according to claim 10,
The second communication packet is transmitted through the communication interface unit, the processing unit, and the virtual communication interface unit, and the second communication packet is transmitted through the other communication interface unit, the processing unit, and the other virtual communication interface unit. The protocol stack unit that has received the communication packet extracts the first communication packet from the second communication packet, extracts the duplicate first communication packet from the other second communication packet, and extracts the first communication packet and the duplicate Pass the first communication packet to the second communication middleware execution unit,
The communication device, wherein the second communication middleware execution unit executes an error check process using the first communication packet and the duplicate communication packet, and passes either one to the processing unit.

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