JP3732745B2 - Communication connection establishment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a communication connection establishment method used for switching communication paths when a plurality of terminals connected on a network communicate with each other by a server application and a client application.
[0002]
[Prior art]
When a user stops using an application with which communication is performed and tries to perform communication with another application, it is necessary to interrupt communication and then resume communication with the other application. However, in this case, since communication is disconnected, it is necessary to start the communication procedure with the partner application from the beginning. That is, the communication service for a certain application cannot be switched to another application from the middle.
[0003]
For example, a mobile terminal such as a notebook personal computer or PDA can be carried so that it may be used in various places, and may be used while moving. When such a mobile terminal is used online, for example, the mobile terminal is moved using a communication adapter corresponding to Ethernet, a local wireless LAN (Local Area Network), public wireless communication (for example, PHS (Personal Handy-phone System)) The terminal needs to be connected to the network.
[0004]
In various places where a mobile terminal is used, it is possible to connect the mobile terminal to a network using one or more communication media. If a plurality of communication adapters corresponding to a plurality of types of communication media are installed in advance, one mobile terminal can be connected to a network at various locations by switching the communication method as necessary.
[0005]
When a plurality of terminals actually communicate with each other using a server application and a client application, first, the terminal hardware is connected to the network, and a communication connection is established between the server application that provides the service and the client application that uses the service. Need to be established.
Also, in order to allow communication to continue even if communication is temporarily interrupted due to a failure, for example, a communication path is constructed so that a relay device called a proxy is interposed between the server application and the client application. Is common.
[0006]
[Problems to be solved by the invention]
In the conventional communication system as described above, the communication path is determined when communication between the server application and the client application is started. Therefore, the combination of the server application, client application, and proxy to be used cannot be changed during communication.
[0007]
When changing the server application, the client application, or the proxy, it is necessary to once terminate communication, release the communication connection, and reconnect each communication connection between the server application and the client application.
However, when the mobile terminal communicates while moving, the positional relationship among the server application, the client application, and the proxy changes with movement, so that a redundant communication path may be formed. For example, there is a case where communication is continued by relaying an unnecessary proxy.
[0008]
Also, for example, when a failure occurs in a communicating terminal, communication is temporarily terminated, the communication connection is released, and the communication path is changed so that the application or proxy function of the failed terminal is replaced with another terminal. It is necessary to rebuild and start communication from the beginning.
Further, for example, when switching a terminal used by a user from a mobile terminal having a small screen to a fixed terminal having a large screen (for example, a desktop personal computer), the communication of the mobile terminal is terminated, the communication connection is released, and the fixed terminal It is necessary to construct a new communication path using and to start communication from the beginning.
[0009]
Therefore, an object of the present invention is to enable switching of applications and switching of communication paths without ending communication between a server application and a client application.
[0010]
[Means for Solving the Problems]
Claim 1 is a communication connection establishment method used for control of a communication system provided with a plurality of applications, a plurality of proxies for relaying communication, and a network for connecting them, and there are two or more applications. In response to a predetermined switching request, the first proxy placed on the communication path replaces the second proxy to be connected with the third proxy. It is characterized by switching to a proxy and continuing communication.
[0011]
In the first aspect, when the communication path needs to be switched, the connection destination of the first proxy is switched from the second proxy to the third proxy by the control of the first proxy. Therefore, after switching, communication can be continued without using the second proxy.
Note that the third proxy as the switching destination needs to be specified at the time of switching or predetermined.
[0012]
Claim 2 is a communication connection establishment method used for control of a communication system provided with a plurality of applications, a plurality of proxies for relaying communication, and a network connecting them, wherein the first application and the second A second application that communicates with each other via a communication path that passes through two or more proxies and that relays between the first application and the first proxy that are arranged on the communication path. The proxy is characterized in that in response to a predetermined switching request, the first application of the communication partner is switched to another third application and communication is continued.
[0013]
In the second aspect, when it is necessary to switch the application to be used, the application that communicates with the second proxy is changed from the first application to the third application under the control of the second proxy. The communication is continued as it is.
Therefore, the user can switch the application used for communication without disconnecting the communication. Note that the third application to be switched needs to be designated at the time of switching or predetermined.
[0014]
According to a third aspect of the present invention, in the communication connection establishment method according to the first aspect, when the client application and the server application communicate via a plurality of proxies, a response from the server application to the client application connection request is sent to the client application. When transferred, the transfer route is managed as a session, and a session ID is assigned to each session. When the first proxy receives a switching request for moving a service, it relays communication. After suspending, connect to the third proxy of the destination, and then resume relaying, and the third proxy is started by starting a new client application using an argument including the corresponding session ID New client account The application connects to the third proxy and transmits information including the specified session ID to the third proxy, and the third proxy communicates with the first proxy based on the session ID. And relaying data by combining communication with the new client application.
[0015]
In the third aspect, the plurality of sessions are distinguished from each other by using the session ID. Further, the connection destination of the first proxy is switched to the third proxy as the movement destination by the control of the first proxy. Furthermore, a new client application is automatically activated by the control of the third proxy, and the communication of the new client application and the communication of the first proxy are automatically linked.
[0016]
Therefore, the server application communication service provider can be moved from the original client application to a new client application without disconnecting the communication. Moreover, the continuity of the communication service can be ensured.
According to a fourth aspect of the present invention, in the communication connection establishment method according to the second aspect, when the client application and the server application communicate via a plurality of proxies, a response from the server application to the connection request of the client application is sent to the client application. When transferred, the transfer route is managed as a session, and a session ID is assigned to each session. When the second proxy receives a switching request for moving a service, it relays communication. Suspend and start a new client application using an argument including the corresponding session ID, and the started new client application connects to the second proxy and forwards information including the specified session ID. To the second proxy, and based on the session ID, the second proxy combines the communication of the proxy having a communication path with the server application and the communication of the new client application to relay data. It is characterized by restarting.
[0017]
In claim 4, a plurality of sessions are distinguished from each other using session IDs. When a request occurs, a new client application is automatically activated under the control of the second proxy. Furthermore, a communication path is formed between the new client application and the second proxy under the control of the activated new client application. Further, under the control of the second proxy, the path of the communication service is switched so that communication is performed between the server application and the new client application activated using the corresponding session.
[0018]
Therefore, the server application communication service provider can be moved from the original client application to a new client application without disconnecting the communication. Moreover, the continuity of the communication service can be ensured.
The communication connection establishment method according to claim 5 is a communication in which a terminal including a client application requesting a service, a terminal including a server application providing the service, and a terminal including a proxy for storing and relaying communication contents are connected. A communication connection establishment method used for system control, which holds first information representing a client application or a server application and a proxy existing in each terminal, and second information used for specifying each terminal A client manages a communication path between a server application and a client application formed by relaying one or more proxies as a session, and uses at least a session identifier and the session for each session. Application And the third information for specifying the server application, the fourth information for specifying the proxy used by the session, and the fifth information indicating the connection point of the proxy used by the session. When switching of a terminal that provides a server application or a client application or switching of a proxy on a communication path used for communication between the server application and the client application is necessary, information on the corresponding session and the first Proxy that relays between the server application and the proxy connected thereto, between the client application and the proxy connected thereto, and between the server application and the client application using the information of the second and the second information Little between And it switches Kutomo one communication connection automatically.
[0019]
In Claim 5, the communication path between a server application and a client application is managed as a session, and for each session, the identifier of the session, the third information for specifying the client application and the server application using the session , 4th information specifying the proxy used by the session and 5th information indicating the connection point of the proxy used by the session are held. In addition, first information representing a client application or a server application and a proxy existing in each terminal and second information used for specifying each terminal are held.
[0020]
By referring to the first information, it is possible to check the client application, the server application, and the proxy that exist in each terminal. Therefore, for example, when a client application or a server application is switched, a terminal in which the same application exists can be automatically detected.
[0021]
Further, by referring to the second information, the address of each terminal can be specified.
Furthermore, since the client application, server application, and proxy that are being used can be identified and the connection point of the proxy can be detected from the information of each session that is distinguished by the session identifier, for example, the session that is currently being used A specific proxy included in can be switched to another proxy.
[0022]
Since the switching in this case is automatically performed, the communication path can be switched during the communication without ending the communication. The contents of communication during switching are accumulated in the proxy as necessary, and the proxy performs a relay operation so that communication continues after switching is completed.
For this reason, for example, when a failure occurs in a terminal (switching source) including the server application being used, the configuration of the session is changed to switch to another terminal (switching destination) including the same server application, Communication can be continued as it is using the switching destination terminal. Even when such switching is performed, the continuity of the communication service is guaranteed.
[0023]
Similarly, the client application can be switched, and the number of proxies constituting the session and the relay route can be changed.
6. The communication connection establishment method according to claim 5, wherein at least one mobile terminal provided with a proxy and a server application or a client application on the same terminal is used as a terminal of the communication system. Is characterized in that the change of the second information associated with the switching of the communication device used for actual communication is absorbed by a proxy arranged on the same mobile terminal.
[0024]
In claim 6, since the proxy and the server application or the client application exist on the same terminal to be used, even if the address of the terminal changes as the terminal moves, the terminal Above, there is no need to change the communication connection between the server application or client application and the proxy.
[0025]
For this reason, since communication contents are held by the proxy storage function when switching other communication connections, communication can be continued after switching the communication connection.
The communication connection establishment method according to claim 7, wherein a session management unit that manages the session information exists, and the proxy is different from the first proxy that is a proxy that actually relays a certain session. When a switching request to the second proxy is generated, any one terminal notifies the session management unit of the switching request, and the session management unit switches to the second proxy of the switching destination. A communication connection is established with the first proxy when a notification indicating that the preparation for switching is completed is received from the second proxy to the session management unit. A switching request is transmitted from the session management unit to the proxy of the second proxy together with information on the second proxy of the switching destination, and the third proxy Established a new communication connection with the second proxy of the switching destination using the session identifier, and the communication performed via the communication connection between the first proxy and the third proxy Switch to pass the communication connection between the third proxy and the second proxy, and when switching of all the communication connections is completed, the switching is notified to the session management unit, and the switching destination The second proxy, when the establishment of the first communication connection with the third proxy is completed, between the second proxy and the server application or the client application based on the notified session identifier The communication path of the session is switched by associating the second communication connection established with the first communication connection with the first communication connection. And it features.
[0026]
According to the seventh aspect of the present invention, switching from the first proxy to the second proxy can be automatically performed for one session. Thereby, the function (service) of the application connected to the first proxy can be moved to the application connected to the second proxy.
The communication connection establishment method according to claim 8, wherein a session management unit that manages the session information exists, and a first proxy and a second proxy that actually relay communication for a session When a request for adding a proxy for adding a new third proxy occurs between the two, any one terminal notifies the session management unit of the addition request and adds it from the session management unit When the session management unit receives a notification indicating the completion of preparation from the third proxy, the session management unit receives the first proxy and the third proxy. Sending an add request to each of the second proxies, and each of the first proxy and the second proxy responding to the add request A new first communication connection or second communication connection is established with the third proxy using the session identifier, and the communication relayed by the first proxy and the second proxy is the first When switching is made to pass through the communication connection or the second communication connection and the switching of the communication connection used for all communications is completed, the session management unit is notified of the switching completion, and the first proxy and the second proxy If both the first communication connection between the third proxy and the second communication connection between the second proxy and the third proxy are established, based on the notified session identifier, The first communication connection and the second communication connection are associated with each other.
[0027]
In claim 8, a new third proxy can be added between the first proxy and the second proxy that are actually relaying communication for one session.
Moreover, since the state of the proxy of a switching destination is confirmed before switching in Claim 8, it can switch with respect to the proxy which can be switched reliably. In addition, since the completion notification is performed after the switching, the switching source proxy can release the resources used so far after the switching.
[0028]
9. The communication connection establishment method according to claim 5, wherein there is a session management unit that manages the session information, and a deletion request for the first proxy that actually relays communication is generated for a session. In such a case, any one terminal notifies the deletion request to the session management unit, and the session management unit establishes a first communication connection and a second communication connection with the first proxy. A deletion request is sent to each of the second proxy and the third proxy, and the second proxy and the third proxy establish a third communication connection therebetween, and the first communication When the communication using the connection and the second communication connection is switched to the third communication connection and the switching of the communication connection is completed. The second proxy, and the third proxy and notifies the completion of switching to each said session management unit.
[0029]
According to the ninth aspect of the present invention, the first proxy that is actually relaying communication can be excluded from the session. For example, when the communication path becomes shorter when the first proxy is deleted, or when the first proxy becomes unnecessary, the communication path can be optimized by deleting the first proxy. . Even when the first proxy is deleted during communication, the continuity of the communication service is guaranteed by the control sequence of claim 9 and the actions of other proxies.
[0030]
A communication connection establishment method according to claim 10, wherein a session management unit that manages the information of the session exists, and the first communication is performed between the first proxy and the second proxy for a certain session. A connection is established, a second communication connection is established between the second proxy and the third proxy, and the first proxy and the second proxy are used by using the first communication connection and the second communication connection. When a replacement request from the second proxy to the new fourth proxy occurs in a state where communication is performed via the proxy and the third proxy, any one terminal receives the replacement request from the second proxy. The session manager notifies the fourth proxy about the preparation for replacement to the fourth proxy, and indicates that the fourth proxy is ready. When the session management unit receives the notification, the session management unit transmits a switching request to the first proxy and the third proxy, and each of the first proxy and the third proxy In response to the switching request, a third communication connection and a fourth communication connection are established with the replacement-target fourth proxy based on the session identifier, and each of the first proxy and the third proxy The communication performed through the first communication connection and the second communication connection is switched to pass through the third communication connection and the fourth communication connection, and all the switched communication connections are used for communication. After the switching of the communication connection is completed, each of the first proxy and the third proxy The completion of the replacement is notified, and after the third communication connection and the fourth communication connection are established, the third communication connection and the fourth communication connection are associated with each other based on the notified session identifier. And
[0031]
In claim 10, in a state in which communication is performed by relaying the first proxy, the second proxy, and the third proxy for one session, the second proxy to the new fourth proxy Substitution can be made. For example, when the communication path becomes shorter when the second proxy is replaced with the fourth proxy, the communication path can be optimized by performing the replacement.
[0032]
Even when replacement is performed during communication, the continuity of the communication service is guaranteed by the control sequence and the proxy function of claim 10.
For the network to which the present invention is applied, for example, various forms are possible as shown in FIG. The applications 1 and 3 that communicate with each other establish a communication path via the proxy 2. The proxy 2 relays communication.
[0033]
In FIG. 21A, a communication path is established between two applications 1 and 3 with one proxy 2 interposed. In FIG. 21B, a communication path is established between two applications 1 and 3 with two proxies 2 (1) and 2 (2) interposed therebetween.
[0034]
The applications 1 and 3 and the proxy 2 actually exist as processes inside a communication node such as a computer (hereinafter referred to as a node). Various forms of node arrangement and configuration are possible.
In FIG. 21C, application 1 and proxy 2 (1) are arranged on the same node 4 (1), proxy 2 (2) is arranged on node 4 (2), and application 3 is node 4 ( 3) Arranged above.
[0035]
As shown in FIG. 21C, each node can be equipped with a proxy and / or an application. Communication between a plurality of applications is performed via at least one proxy.
In addition, by interposing a plurality of proxies between a plurality of applications communicating with each other, it is possible to absorb a disconnection of communication or a change in communication medium that occurs between proxies, and a node can be moved. .
[0036]
In addition, it is possible to move a network service across nodes by changing the connection relationship between proxies and applications on the communication path. The first aspect is characterized in that the proxy connection relationship is changed. The second aspect of the present invention is characterized by changing the connection between applications.
By variously changing the connection relationship, it is possible to freely change the nodes and applications used for communication, and the convenience for the user can be improved.
[0037]
For example, when the user is indoors, the service is received at a large screen node using a wired broadband line, and when the user moves outdoors, the service is transferred to the node of the mobile terminal. The communication environment can be adapted to give priority to mobility.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
One embodiment of a communication connection establishment method of the present invention will be described with reference to FIGS. This form corresponds to claim 1, claim 2, and claims 5 to 10.
[0039]
FIG. 1 is a sequence diagram showing a control sequence when switching between a proxy and an application. FIG. 2 is a block diagram illustrating an example of a communication path when switching between a proxy and an application. FIG. 3 is a sequence diagram showing a control sequence when a proxy is added to a session. FIG. 4 is a block diagram illustrating an example of a communication path when a proxy is added to a session.
[0040]
FIG. 5 is a sequence diagram showing a control sequence for deleting a proxy from a session. FIG. 6 is a block diagram illustrating an example of a communication path when a proxy is deleted from a session. FIG. 7 is a sequence diagram showing a control sequence for replacing a proxy on a session. FIG. 8 is a block diagram illustrating an example of a communication path when a proxy on a session is replaced.
[0041]
FIG. 9 is a block diagram illustrating a configuration example of a communication system. FIG. 10 is a block diagram illustrating a configuration example of a mobile terminal. FIG. 11 is a schematic diagram illustrating an example of information held by the service management unit SR. FIG. 12 is a schematic diagram illustrating an example of information held by the position management unit LR. FIG. 13 is a schematic diagram illustrating an example of information held by the session management unit SM.
FIG. 14 is a block diagram illustrating a configuration example of a communication system. FIG. 15 is a block diagram illustrating a configuration example of a network. FIG. 16 is a block diagram showing a movement model of nodes and services. FIG. 17 is a sequence diagram showing a location information update procedure when the terminal is moving.
[0042]
In this embodiment, the first information in claim 5 corresponds to B11 to B13 and C11 to C13 in FIG. 11, and the second information corresponds to E10 and E12 in FIG. Further, the session identifier of claim 5 corresponds to G11 in FIG. 13, the third information corresponds to G12 to G15 in FIG. 13, the fourth information corresponds to G16 in FIG. 13, and the fifth information Corresponds to G17 in FIG.
[0043]
In this embodiment, it is assumed that the present invention is applied to a communication system as shown in FIG. In the example of FIG. 9, three types of sub-networks 51, 52 and 53 are connected to each other via a wide area network 54.
In the sub-network 51, a large number of terminals (55, 56) can be connected in a communicable state via a communication interface configured in accordance with the Ethernet standard.
[0044]
The sub network 52 constitutes a wireless LAN. Mobile terminals 59 and 60 having a wireless communication interface conforming to this standard can perform wireless communication with the base stations 57 and 58 and are connected to the sub-network 52 wirelessly. Of course, communication with the base stations 57 and 58 is not possible outside a specific communicable area.
The sub-network 53 is a PHS network that is a public wireless communication system. In the example of FIG. 9, a mobile terminal 61, a fixed terminal 62, and a TAP (PIAFS terminal adapter) 63 are connected to the subnetwork 53, and base stations 64 and 65 are connected to the TAP 63. Mobile terminals 66 and 67 having a wireless communication interface configured in accordance with the PHS communication standard can perform wireless communication with the base stations 64 and 65. Of course, communication with the base stations 64 and 65 is not possible outside a specific communicable area.
[0045]
For example, when the mobile terminal 59 shown in FIG. 9 moves to the vicinity of the mobile terminal 55, the mobile terminal 59 may not be able to perform wireless communication with the base station 57. However, at that position, the mobile terminal 59 can be connected to the sub-network 51 by wire.
In the case of a general system, when the network used for communication by the terminal is switched between the sub-networks 51, 52, and 53, it is necessary to once terminate communication of the application and reconstruct the communication path. It takes time and effort.
[0046]
When the present invention is implemented, even when the network used by the terminal for communication is switched between the sub-networks 51, 52, and 53, the application is automatically switched without ending the communication of the application. be able to.
Further, for example, when the same application program exists in the mobile terminal 55 and the fixed terminal 56, the application on the fixed terminal 56 is in progress while one user is communicating using the application program on the mobile terminal 55. You can also switch to the program and continue to communicate.
[0047]
Each terminal (mobile terminal in this example) used to implement the present invention is configured as shown in FIG. The mobile terminal in FIG. 10 includes the Ethernet communication adapter 21 to enable connection with the subnetwork 51, and includes the wireless LAN adapter 22 to enable connection with the subnetwork 52. In order to enable connection, a PHS communication adapter 23 is provided.
[0048]
Further, the mobile terminal of FIG. 10 includes, as software 10, a server application 11, a client application 12, a proxy 13, an agent 14, a link switching unit 15, links 16, 17, 18, a location management unit LR, a session management unit SM, and a service management unit. SR is provided.
The server application 11 is a program for providing a specific application service. The client application 12 is a program for using a service provided by the server for a specific application.
[0049]
The proxy 13 relays communication from a certain transmission source to a certain reception destination, and accumulates the contents of communication in its own storage device. For example, even if communication between the proxy 13 and the destination is temporarily disabled, the contents of communication input from the transmission source to the proxy 13 are accumulated in the proxy 13. When communication with the receiver is restored, the information stored in the proxy 13 can be transmitted to the receiver and communication can be continued.
[0050]
The proxy 13 in FIG. 10 can relay the communication of the server application 11 or the communication of the client application 12.
The link switching unit 15 switches the links 16, 17, and 18 used for communication with other terminals. The link 16 is connected to the Ethernet communication adapter 21, the link 17 is connected to the wireless LAN adapter 22, and the link 18 is connected to the PHS communication adapter 23.
[0051]
When communicating using the link 16 and the Ethernet communication adapter 21, communication can be performed via the subnetwork 51. When communicating via the link 17 and the wireless LAN adapter 22, the communication can be performed via the subnetwork 52. When the link 18 and the PHS communication adapter 23 are used, communication can be performed via the sub-network 53.
[0052]
That is, the communication method can be switched by switching the links 16, 17, and 18 used by the link switching unit 15 to connect to any of the sub-networks 51, 52, and 53.
Each terminal that performs communication is assigned an IP (Internet Protocol) address. Further, when the terminal switches the communication method, the terminal moves on the network beyond the subnet boundary, which is an address allocation unit. Therefore, a new address is used every time switching is performed.
[0053]
The service management unit SR manages information on the types and functions of the server application 11, the client application 12, and the proxy 13 provided in each terminal.
Actually, for example, the contents shown in FIG. 11 are held in the service management unit SR. In the example of FIG. 11, the terminal A11 holds a server B11 as an application program and includes a proxy C11. The terminal A12 holds a server B12 as an application program and includes a proxy C12. Further, the terminal A13 holds a client B13 as an application program and includes a proxy C13.
[0054]
The location management unit LR manages the IP address for each terminal. The location management unit LR can manage the IP addresses of a large number of terminals as well as terminals equipped with the position management unit LR. However, in order to improve the efficiency of location management and to enable location management even for a terminal with few resources, the amount of movement of the terminal and the storage capacity relating to location management are also managed. Further, in order to limit the range of terminals to be managed, a plurality of terminals are divided into groups and managed.
[0055]
Actually, as shown in FIG. 12, for example, terminal identification name E10, group name E11, IP address E12, status (usability) E13 of each IP address, movement amount E14, storage capacity of LR and information on update time Is held for each terminal of a specific group managed by the.
Further, when the communication device is switched along with the movement of the terminal or the like, the IP address of the terminal changes. In this case, the content held by the location management unit LR is updated. At the same time, if there is a communication partner, a position information update command is transmitted to the communication partner. That is, the update procedure shown in FIG. 17 is executed.
[0056]
Further, when each terminal transmits a position information update command, the order in which the commands are transmitted is determined in consideration of a predetermined priority. For example, a high priority is given to a terminal with a small amount of movement such as a fixed terminal (desktop personal computer or the like) 56. Also, a high priority is given to a terminal having a large storage capacity (E15) of position information.
[0057]
Each group used for management of the location management unit LR can include a plurality of terminals existing in a range exceeding the boundary of the subnet. A plurality of groups can coexist in one subnet.
[0058]
The terminal (X1) newly joining the group acquires its IP address and broadcasts a group search request in the subnetwork or transmits a group search request to a known specific terminal (X2). To do.
Thereafter, when the terminal (X1) receives a response from the terminal (X2) that has received the group search request, the terminal (X1) acquires group information from the content and selects a group to join.
[0059]
The terminal (X1) transmits a registration request for the selected group to the terminal (X2). The terminal (X2) acquires the position information of the terminal (X1) that transmitted this registration request.
Also, the terminal (X2) that has received the registration request transmits the information of the location management unit LR included therein to the terminal (X1), and adds the location information of the subscribed terminal (X1) to the contents of the location management unit LR. This completes the procedure for joining the group.
[0060]
When searching for location information regarding each terminal, the location information is searched from information held by the location management unit LR included in the terminal itself. If the search cannot be performed, a search request is sent to an arbitrary terminal included in the information held by the location management unit LR. When a result is returned in response to this search request, the position information is added to the position management unit LR.
[0061]
When searching for terminals belonging to the same group in the subnet, a broadcast packet is transmitted, and location information is registered in the location management unit LR based on a response to the broadcast packet.
The location management unit LR includes the following functions.
(1) IP address change due to movement of terminal location
(2) IP address status change due to node disconnection, line disconnection, failure, etc.
(3) Notification of change to agent 14
(4) Joining and leaving the group
(5) Transmission / reception of position information to / from the position management unit LR of the node in the group
The session management unit SM in FIG. 10 manages the entire communication path as a session for each communication. For example, in FIG. 15, communication can be performed between the application 101 and the application 102 using the session 103. In this case, the session 103 includes proxies 104, 105, and 106.
[0062]
The session 103 uses communication connections 107, 108, 109 and 110. A communication connection 107 is a communication path established between the application 102 and the proxy 104. The communication connection 108 is a communication path established between the proxies 104 and 105. The communication connection 109 is a communication path established between the proxies 105 and 106. The communication connection 110 is a communication path established between the application 101 and the proxy 106.
[0063]
The actual session management unit SM holds information G11 to G18 as shown in FIG. 13, for example. Information G11 is an identifier for distinguishing a plurality of sessions. The information G12 represents the name of the node (terminal) where the server application to be used exists. Information G13 represents a port number given to the server application to be used.
[0064]
Information G14 represents the name of the node where the client application to be used exists. Information G15 represents a port number given to the client application to be used. Information G16 represents the name of the node where the proxy to be used exists. Information G17 represents the port number given to the proxy to be used. When a communication path of one session is configured to relay a plurality of proxies, each node name, port number, and connection state of the plurality of proxies to be used are one session ID (G11 ) And stored in the session management unit SM.
[0065]
Functions performed by the session management unit SM include addition of a proxy to each session, deletion of a proxy, switching of a proxy, and communication with the session management unit SM existing in another terminal.
The agent 14 in FIG. 10 mediates various information held by the location management unit LR, the session management unit SM, and the service management unit SR, and determines the proxy 13 and the link switching unit 15 by comprehensively determining these information. To control.
[0066]
For example, when it is desired to terminate a server application that currently provides a predetermined communication service while continuing a predetermined communication service, it is possible to search for an alternative server application of the same type using the service management unit SR. .
Further, since the location management unit LR holds the terminal identification name and its IP address, the location of the terminal where the switching destination server application exists can be specified. Furthermore, by performing processing described later using information on a specific session managed by the session management unit SM, it is possible to switch the server application and continue the communication service.
[0067]
The agent 14 instructs the link switching unit 15 to switch the link, and requests the proxy to restart the communication connection after the link is switched. The link switching unit 15 has functions such as connection to a new link, link disconnection, and routing management. In addition, the proxy has a function of concealing disconnection or change of the link under the connection (see FIG. 16).
[0068]
When a service is moved from a certain source to a certain destination, the status of the source service is changed from the session used for communication of the service to the service built on the destination application or proxy. It can be realized by transferring. The status of the service to be transferred includes the connection status of the applications and proxies constituting the session, the number of bytes of data being transmitted and received, the number of frames, and the like.
[0069]
For example, when a portable mobile terminal is used to receive and browse stream data from a specific server application via a wireless line and a network, a high-quality service can be received because the display capability of the terminal is low. Can not. However, if a user moves a service from a mobile terminal to a fixed terminal having a large screen, a high quality service can be received. Even in the case of such movement, the service can be continuously used.
[0070]
Further, when the same server application exists in a plurality of terminals, the communication path used for providing the service can be switched so as to switch the terminal and the application on the server side. It is also possible to improve the communication speed of the service by switching terminals.
A specific example of switching the communication path used for providing the service or switching the server application or the client application will be described below. Here, a communication system as shown in FIG. 14 is assumed.
[0071]
In FIG. 14, the functions of the mobile terminals 30 (1) to 30 (5) are simplified. Actually, each of the mobile terminals 30 (1) to 30 (5) has the same function as the mobile terminal shown in FIG.
However, the server application 11 is provided only in the mobile terminal 30 (1), and the client application 12 is provided only in the mobile terminals 30 (2) and 30 (3). Further, the mobile terminal 30 (5) is not provided with the session management unit SM. When the proxy 13 of the mobile terminal 30 (5) is used, control may be performed using the session management unit SM provided in the mobile terminal 30 other than the mobile terminal 30 (5).
[0072]
First, a case where proxy and application are switched will be described. Specifically, in the state before switching, the communication connection 201 is established between the server application 11 (1) of the mobile terminal 30 (1) and the proxy 13 (1) in FIG. 2, and the proxy 13 (1) and the proxy 13 The communication connection 202 is established between the client application 12 (2) and the proxy 13 (2), and the server application 11 (1) -proxy 13 (1) is established. It is assumed that the session is formed so as to pass through the communication path of the proxy 13 (2) -client application 12 (2).
[0073]
Here, instead of the client application 12 (2) on the mobile terminal 30 (2), the client application 12 (3) on the mobile terminal 30 (3) is used to continuously provide the service of the server application 11 (1). In order to receive, the control sequence shown in FIG. 1 is executed using the function of the session management unit SM (2). That is, the proxy 13 (2) is switched to the proxy 13 (3).
[0074]
The agent 14 of the terminal that manages the usage state of the user and the connection state between the terminals generates an application (AP) switching request as necessary (for example, according to a user instruction).
This switching request is notified to, for example, the session management unit SM (2). In this case, the session management unit SM (2) executes step S11 in FIG. That is, in order to switch to the switching destination proxy 13 (3) in which the communication connection 204 has been established with the switching destination client application 12 (3), an inquiry about switching is made to the proxy 13 (3). When making this inquiry, the session ID of the corresponding session and information on the connection status of the proxy are also transmitted as parameters from the session management unit SM (2) to the proxy 13 (3).
[0075]
This parameter also includes the file name of the file being relayed by the switching source proxy 13 (2) and the number of bytes that have been transferred (current transfer position on the file).
Upon receiving the inquiry, the proxy 13 (3) activates necessary processes and the like based on the received parameters, and prepares for relaying communication in step S12. The proxy 13 (3) inherits the state of the switching source proxy 13 (2) based on the received parameters.
[0076]
In this preparation, when the necessary application 12 (3) is not activated, the proxy 13 (3) activates the application 12 (3). If the communication connection 204 between the application 12 (3) and the proxy 13 (3) has not been established, the communication connection 204 is established.
When the preparation is completed, in step S13, the proxy 13 (3) transmits a preparation completion notification to the session management unit SM (2).
[0077]
When the session management unit SM (2) receives the preparation completion notification, in step S14, the session management unit SM (2) issues a switching request to the proxy 13 (1) that has established the communication connection 202 with the switching source proxy 13 (2). Send. This switching request includes a node name (G16) and a port number (G17) related to the proxy 13 (3) to be switched as parameters.
[0078]
When the proxy 13 (1) receives the switching request, the proxy 13 (1) uses the switching request parameter and the session ID to connect the proxy 13 (3) connection point (the IP address of the terminal and the port number of the proxy 13 (3)). ) Is established (S15).
When the communication connection 205 is established between the proxy 13 (3) and the proxy 13 (1), the communication connection 204 and the client application 12 (3) for the specific session determined by the session ID received when the communication connection 205 is established. ) Are associated (S16). Thus, the preparation of the proxy 13 (3) for relaying (accumulating and transferring) communication between the communication connection 205 and the communication connection 204 is completed.
[0079]
Further, the proxy 13 (1) switches all the communications that have been performed through the communication connection 202 to the communication connection 205 (S17). After the switching is completed, the proxy 13 (1) transmits a switching completion notification to the session management unit SM (2) (S18).
[0080]
When the session management unit SM (2) receives the completion notification, the session management unit SM (2) updates the contents of the managed table (S19). In other words, the node name and port number of the client application 12 (3) and the proxy 13 (3) after switching and the connection relationship thereof are reflected with respect to a specific session determined by the session ID (session switched in this processing). Update the information as you do.
[0081]
Also, the session management unit SM (2) notifies the changed information to the other session management units SM (1), SM (3), SM (4) that manage the information of the changed session. (S21).
As a result of the above control sequence, as shown in FIG. 2, the service provided by the communication between the server application 11 (1) and the client application 12 (2) is the server application 11 (1) and the client application 12 ( The content of the session (communication path) is changed so that the communication with 3) is switched to.
[0082]
Next, a case where a proxy is added to a session will be described. Specifically, in the state before the addition, as shown in FIG. 4, the communication connection 211 is established between the server application 11 (1) and the proxy 13 (1), and the proxy 13 (1), 13 (2) A communication connection 212 is established between them, a communication connection 213 is established between the proxy 13 (2) and the client application 12 (2), and the two proxies 13 (1) and 13 (2) are connected to the server application 11 (1 ) And the client application 12 (2), the session is constructed so as to relay the communication.
[0083]
In this state, when adding the proxy 13 (3) between the proxy 13 (1) and the proxy 13 (2) while continuing communication, the function of the session management unit SM (2) is used. The control sequence shown in FIG. 3 is executed.
The terminal agent 14 generates a proxy addition request as required (for example, according to a user instruction). This addition request is notified to, for example, the session management unit SM (2). In this case, the session management unit SM (2) executes step S31 of FIG.
[0084]
That is, in order to make the proxy 13 (3) to be added prepare for addition, the session management unit SM (2) makes an additional inquiry. When making this inquiry, the session ID of the corresponding session and information on the connection status of the proxy are also transmitted as parameters from the session management unit SM (2) to the proxy 13 (3).
This parameter includes the file name of the file relayed by the proxy 13 (2) and the number of bytes that have been transferred (current transfer position on the file).
[0085]
Upon receiving the inquiry, the proxy 13 (3) activates necessary processes and the like based on the received parameters, and prepares for relaying communication in step S32. The proxy 13 (3) inherits the state of the proxy 13 (2) based on the received parameter. When the preparation is completed, in step S33, the proxy 13 (3) transmits a preparation completion notification to the session management unit SM (2).
[0086]
Upon receiving the preparation completion notification, the session management unit SM (2) transmits a switching request to the proxies 13 (1) and 13 (2) to be connected to the proxy 13 (3) to be added in steps S34 and S35. To do. This switching request includes the node name (G16) and port number (G17) related to the proxy 13 (3) to be added as parameters.
When the proxy 13 (1) and 13 (2) receive the switching request, the proxy 13 (3) connection point (the IP address of the terminal and the proxy 13 (3) Communication connection 214 or 215 is established for (port number) (S36, S37).
[0087]
When the communication connections 214 and 215 are established, the proxy 13 (3) associates the communication connection 214 and the communication connection 215 with respect to a specific session determined by the session ID received when these connections are established (S38). Thereby, the preparation of the proxy 13 (3) for relaying (accumulating and transferring) the communication between the communication connection 214 and the communication connection 215 is completed.
[0088]
On the other hand, the proxy 13 (1) switches all communications that have been performed through the communication connection 212 to the communication connection 214 (S41). After the switching is completed, the proxy 13 (1) transmits a switching completion notification to the session management unit SM (2) (S44).
Similarly, the proxy 13 (2) switches all communications that have been performed through the communication connection 212 to the communication connection 215 (S40). After the switching is completed, the proxy 13 (2) transmits a switching completion notification to the session management unit SM (2) (S42).
[0089]
When the session management unit SM (2) receives the completion notification, the session management unit SM (2) updates the contents of the managed table (S45). That is, for a specific session determined by the session ID (the session in which the proxy is added in this process), information is added to reflect the node name and port number of the added proxy 13 (3) and the connection relationship between the proxies. Update.
[0090]
Also, the session management unit SM (2) notifies the changed information to the other session management units SM (1), SM (3), SM (4) that manage the information of the changed session. (S46).
As a result of the above control sequence, as shown in FIG. 4, communication between the server application 11 (1) and the client application 12 (2) is the proxy 13 (1) -proxy 13 (3) -proxy 13 (2). The content of the session is changed so that it is relayed on the route.
[0091]
Next, the case where the proxy used until then is deleted from the session will be described. Specifically, in the state before the addition, as shown in FIG. 6, a communication connection 221 is established between the server application 11 (1) and the proxy 13 (1), and the proxy 13 (1), 13 (3) A communication connection 222 is established between them, a communication connection 223 is established between the proxies 13 (3) and 13 (2), and a communication connection 224 is established between the proxy 13 (2) and the client application 12 (2). A session is constructed so that the three proxies 13 (1), 13 (3), and 13 (2) relay the communication between the server application 11 (1) and the client application 12 (2). .
[0092]
When the proxy 13 (3) between the proxy 13 (1) and the proxy 13 (2) is deleted (excluded from the session) while communication is continued from that state, the function of the session management unit SM (2) Is used to execute the control sequence shown in FIG.
The terminal agent 14 generates a proxy deletion request as required (for example, according to a user instruction). This deletion request is notified to, for example, the session management unit SM (2). In this case, the session management unit SM (2) executes processing in order from step S51 of FIG.
[0093]
The session management unit SM (2) sends a proxy 13 (1) and 13 (2) to each of the proxies 13 (1) and 13 (2) that establish communication connections 222 and 223 with the proxy 13 (3) to be deleted. A deletion request relating to 3) is transmitted (S51, S52).
Upon receiving the deletion request, the proxy 13 (2) establishes a communication connection 225 between the proxy 13 (2) and the proxy 13 (1) using the session ID (S53).
[0094]
Further, the proxy 13 (2) switches all communications that have been performed through the communication connection 223 to the communication connection 225 (S54). After the switching is completed, the proxy 13 (2) transmits a switching completion notification to the session management unit SM (2) (S58). The communication connection 223 between the proxy 13 (2) and the proxy 13 (3) is disconnected by the proxy 13 (2) (S56).
[0095]
Similarly, the proxy 13 (1) switches all communications that have been performed through the communication connection 222 to the communication connection 225 (S55). After the switching is completed, the proxy 13 (1) transmits a switching completion notification to the session management unit SM (2) (S59). The communication connection 222 between the proxy 13 (1) and the proxy 13 (3) is disconnected by the proxy 13 (1) (S57).
[0096]
When the session management unit SM (2) receives the completion notification, the session management unit SM (2) updates the contents of the managed table (S60). That is, for a specific session determined by the session ID (the session in which the proxy is deleted in the current process), the information is updated to reflect the deletion result in the connection relationship between the proxies.
Also, the session management unit SM (2) notifies the changed information to the other session management units SM (1), SM (3), SM (4) that manage the information of the changed session. (S61).
[0097]
As a result of the above control sequence, as shown in FIG. 6, the communication between the server application 11 (1) and the client application 12 (2) is relayed through the route of the proxy 13 (1) -proxy 13 (2). The contents of the session are changed.
Next, a case where a proxy used on a specific session is replaced with another proxy will be described. Specifically, in the state before the addition, as shown in FIG. 8, a communication connection 231 is established between the server application 11 (1) and the proxy 13 (1), and the proxy 13 (1), 13 (4) A communication connection 232 is established between them, a communication connection 233 is established between the proxies 13 (4) and 13 (2), and a communication connection 234 is established between the proxy 13 (2) and the client application 12 (2). The session is constructed so that the three proxies 13 (1), 13 (4), and 13 (2) relay the communication between the server application 11 (1) and the client application 12 (2). .
[0098]
In this state, when the proxy 13 (4) used while continuing communication is replaced with the proxy 13 (5), the function shown in FIG. 7 is used by utilizing the function of the session management unit SM (2). Run the sequence.
[0099]
The terminal agent 14 generates a proxy replacement request as required (for example, according to a user instruction). This replacement request is notified to the session management unit SM (2), for example. In this case, the session management unit SM (2) executes step S71 in FIG.
In other words, the session management unit SM (2) makes a replacement inquiry in order to prepare the replacement destination proxy 13 (5) for relaying. At the time of this inquiry, the session ID of the corresponding session and the connection state information of the proxy are also transmitted as parameters from the session management unit SM (2) to the proxy 13 (5).
[0100]
This parameter includes the file name of the file being relayed by the proxy 13 (4) as the replacement source, and the number of bytes that have been transferred (current transfer position on the file).
Upon receiving the inquiry, the proxy 13 (5) activates necessary processes and the like based on the received parameters, and prepares to relay communication in step S72. The proxy 13 (5) inherits the state of the replacement source proxy 13 (4) based on the received parameters. When the preparation is completed, in step S73, the proxy 13 (5) transmits a preparation completion notification to the session management unit SM (2).
[0101]
When the session management unit SM (2) receives the preparation completion notification, the proxy 13 (1), having established the communication connections 232, 233 with the replacement source proxy 13 (4) in steps S74 and S75. A switching request is transmitted to 13 (2). This switching request includes the node name (G16) and port number (G17) related to the proxy 13 (5) to be replaced as parameters.
[0102]
When the proxy 13 (1) and 13 (2) receive the switching request, the proxy 13 (5) connection point (the IP address of the terminal and the proxy 13 (3) Communication connection 235 or 236 is established for (port number) (S76, S77).
[0103]
When the communication connections 235 and 236 are established, the replacement proxy 13 (5) associates the communication connection 235 and the communication connection 236 with respect to a specific session determined by the session ID received when the connections are established (S78). ). Thereby, the preparation of the proxy 13 (5) for relaying (accumulating and transferring) the communication between the communication connection 235 and the communication connection 236 is completed.
[0104]
On the other hand, the proxy 13 (2) switches all communications that have been performed through the communication connection 233 to the communication connection 236 (S80). After the switching is completed, the proxy 13 (2) transmits a switching completion notification to the session management unit SM (2) (S82).
Similarly, the proxy 13 (1) switches all communications that have been performed through the communication connection 232 to the communication connection 235 (S81). After the switching is completed, the proxy 13 (1) transmits a switching completion notification to the session management unit SM (2) (S83).
[0105]
After the switching from the communication connections 232 and 233 to the communication connections 235 and 236 is completed, the unnecessary communication connections 232 and 233 are disconnected (S84, S85).
When the session management unit SM (2) receives the completion notification, the session management unit SM (2) updates the contents of the managed table (S86). That is, for a specific session determined by the session ID (the session in which proxy replacement is performed in the current process), information is updated so that the result of replacement is reflected in the connection relationship between proxies.
[0106]
Also, the session management unit SM (2) notifies the changed information to the other session management units SM (1), SM (3), SM (4) that manage the information of the changed session. (S87).
As a result of the above control sequence, as shown in FIG. 8, communication between the server application 11 (1) and the client application 12 (2) is proxy 13 (1) -proxy 13 (5) -proxy 13 (2). The content of the session is changed so that it is relayed on the route.
[0107]
A unique session ID that is different for each session is assigned to the communication performed between the server application 11 and the client application 12. The proxy connection point represents a position on the network and a connection request receiving port. When TCP / IP is assumed as the protocol, the connection point is an IP address and a port number on which the proxy is listening.
[0108]
In addition, for example, when switching a communication connection in order to switch the communication path of a session, communication is temporarily disabled. However, at least one proxy included in the session accumulates communication contents transmitted by the application and performs communication. When it becomes possible, the stored information is transmitted to automatically perform communication recovery work. Therefore, even when the communication path is switched in the middle of communication, the user can continue the communication without performing any special operation.
[0109]
The outline of the function of the present invention can be expressed by a movement model shown in FIG. That is, the same service can be continuously provided to the same user even when the terminal used by the user moves and the communication method is switched or when the terminal used by the user is switched.
The service handled here means communication contents transmitted / received between applications through each session, a communication protocol (such as http) associated therewith, and an expression method (reproduction, browsing, etc.).
[0110]
When the service is moved, the service can be continued in the same state by transferring the service state from the movement source session indicated by the same session ID to the movement destination session.
Each terminal (node) is mapped to a link layer address space as shown in FIG. Therefore, the movement of the node can be realized by changing the correspondence between the node and the address. Each terminal can have a plurality of communication devices, and each terminal can hold a unique address.
[0111]
In order to evaluate the performance of the location management method in the communication system of the above embodiment, a simulation was performed using a computer. The simulation conditions are as follows.
(1) Terminal movement interval: Among a large number of terminals constituting a group, (1/3) has an average movement time of 30 minutes, and the remaining (2/3) terminals have an average movement time of 10 minutes. .
[0112]
(2) The communication standby time of the terminal is 20 minutes, and the communication time is 50 minutes.
(3) Storage capacity of location management unit LR: Among a large number of terminals, (1/3) LRs can hold location information of all terminals, and other (1/3) terminals have LRs of (1/2 ) Terminal position information can be held, and the remaining (1/3) terminal LRs can hold (1/4) terminal position information.
[0113]
(4) The number of location information update commands issued during 1200 minutes and the search success rate of the location management unit LR were measured for 400 trials. However, the first 100 minutes are excluded from the statistics.
(5) When the position management unit LR sends a position information update command, all position information held by itself is transmitted. In the LR on the receiving side, the position information that is selected and held by the time stamp of the position information is updated.
[0114]
(6) Two kinds of methods are evaluated for the priority order of the terminal when issuing the location information update command. In the “Method A” method, when the location management unit LR updates the location information held by itself, the location management unit LR issues a location information update command to all terminals. In the method of “Method B”, only the LR of the terminal having a storage capacity that can hold the position information of all terminals with a movement interval of 30 minutes issues a position information update command to all the terminals, and the remaining For the location management unit LR of the terminal, the location information update command is issued only to the terminal having a storage interval of 30 minutes and capable of holding the location information of all the terminals.
[0115]
In the “Method A” method, a location update command is issued to all terminals each time the location of each terminal is updated, so the communication volume increases, but excellent location management capability is obtained.
The simulation results are shown in FIGS. FIG. 18 shows the number of issued position information update instructions. 19 and 20 show the position search success rate. The location search success rate in FIG. 19 is a rate at which the location information of the other terminal is successfully acquired by searching the location information held by the location management unit LR of the specific terminal and searching the location management unit LR of another terminal. is there. Further, the location search success rate in FIG. 20 is a rate at which only the location information held by the location management unit LR of a specific terminal is searched to successfully acquire the location information of the counterpart terminal.
[0116]
Referring to FIGS. 18 and 19, it is understood that “Method B” has a communication cost reduced (60 to 80% reduction) and “Position search capability” is also acceptable in comparison with “Method A”. . In addition, this effect becomes more prominent as the number of terminals constituting the group increases, and the difference in the location search success rate also decreases. Therefore, by limiting the terminals to which location information update commands are issued in consideration of the movement amount of each terminal and the storage capacity of the location management unit LR, the location management load of each terminal is shared and the communication volume is suppressed. can do.
[0117]
As can be seen from FIG. 20, it is possible to correctly detect the positions of 25 to 45% of terminals without searching for position information existing in other terminals. Therefore, even when the terminal is temporarily disconnected from the network, it is possible to obtain a clue for reconnection to the network by searching only the position information held by its own position management unit LR. .
[0118]
(Second Embodiment)
Another embodiment of the communication connection establishment method of the present invention will be described with reference to FIGS. This form corresponds to claims 1 to 4. 22 and 23 are sequence diagrams showing service movement examples (1, 2), respectively.
[0119]
In this embodiment, since it is assumed that HTTP communication is performed, the browser 5 and the Web server 7 are used as applications.
In the example of FIG. 22, since the browser 5 that operates as a client application is arranged in the nodes 8 (A) and 8 (B), the nodes 8 (A) and 8 (B) function as client nodes. Further, since the Web server 7 that operates as a server application is arranged in the node 8 (C), the node 8 (C) functions as a server node.
[0120]
In the example of FIG. 23, since the browsers 5 (A) and 5 (B) that operate as client applications are arranged in the node 8 (A), the node 8 (A) functions as a client node. Further, since the Web server 7 that operates as a server application is arranged at the node 8 (C) in FIG. 23, the node 8 (C) functions as a server node.
[0121]
The operation of the example of FIG. 22 will be described.
First, a request is sent from the browser 5 (A) to the Web server 7 via the proxy 6 (A), 6 (B) (C11). The response of the Web server 7 to this request is transmitted to the browser 5 (A) via the proxies 6 (C) and 6 (A) (C12). At this time, a session is established. In addition, a session ID for distinguishing each session is assigned.
[0122]
Thereafter, the proxy 6 (C) accepts the service movement request (C13). In this case, the proxy 6 (C) interrupts communication (C14) and connects to the proxy 6 (B1) of the destination node 8 (B) (C15).
In this case, the destination proxy 6 (B1) starts the browser 5 (B) with the URL including the session ID of the corresponding session as an argument (C16).
[0123]
The activated browser 5 (B) connects to the proxy 6 (B2) using the URL specified at the time of activation (C17). Based on the session ID, the proxy 6 (B2) links the communication of the browser 5 (B) and the proxy 6 (C) of the node 8 (C) that is the server node to transfer data (C18).
In this way, the service moves through the client node while maintaining the continuity of the service.
[0124]
Next, the operation of the example of FIG. 23 will be described.
First, a request is made from the browser 5 (A) to the Web server 7 via the proxy 6 (A), 6 (C) (C21). The response of the Web server 7 is transferred to the browser 5 (A) via the proxies 6 (C) and 6 (A) (C22). At this time, a session is established. In addition, a session ID for distinguishing each session is assigned.
[0125]
Thereafter, the proxy 6 (A) accepts the service movement request (C23). In that case, the proxy 6 (A) starts the browser 5 (B) with the URL including the session ID of the corresponding session as an argument (C24).
The activated browser 5 (B) connects to the proxy 6 (B2) using the URL specified at the time of activation (C25). Based on the session ID, the proxy 6 (B2) links the communication of the browser 5 (B) and the proxy 6 (C) of the node 8 (C), which is the server node, to transfer data (C26).
[0126]
In this way, the service moves through the client node while maintaining the continuity of the service.
(Third embodiment)
Another embodiment of the present invention will be described with reference to FIGS. This form corresponds to claims 1 and 2.
[0127]
FIG. 24 is a sequence diagram illustrating a simplified control sequence when a proxy is added to a session. FIG. 25 is a sequence diagram showing a simplified control sequence when a proxy is deleted from a session. FIG. 26 is a sequence diagram showing a simplified control sequence in the case of replacing a proxy on a session.
[0128]
This form is a modification of the first embodiment, and the contents of the control sequence are simplified as compared with the first embodiment. Also in this embodiment, it is assumed that a mobile terminal having a configuration as shown in FIG. 10 is used. However, the location management unit LR, service management unit SR, and link switching unit 15 shown in FIG. 10 are not necessarily required.
[0129]
The contents of the operations shown in FIGS. 24 to 26 are the same as those in the first embodiment, but the contents of the control in each figure will be described below.
First, the case of adding the proxy 13 (3) to the session as in the case of FIG. 4 will be described with reference to FIG.
In this example, in FIG. 4, a communication connection is established in the order of the client application 12 (2), the proxy 13 (2), the proxy 13 (1), and the server application 11 (1), and the client application 12 (2) and the server application From the state in which a session is established with 11 (1), client application 12 (2), proxy 13 (2), proxy 13 (3), proxy 13 (1), and server application 11 (1) are in this order. It is assumed that a session connection between the client application 12 (2) and the server application 11 (1) is changed after a communication connection is established.
[0130]
That is, it represents an operation for adding another proxy 13 (3) between the proxy 13 (2) and the proxy 13 (1).
The agent software (14 in FIG. 10) controls commands and management related to the connection status between users or terminals. When the mobile terminal 30 (2) receives the proxy switching request from the agent software, the mobile terminal 30 (2) notifies the session management unit SM (2) of it.
[0131]
In this case, the session management unit SM (2) sets the name and connection point of the proxy 13 (3) as parameters for the proxies 13 (1) and 13 (2) connected to the added proxy 13 (3). The switching request is transmitted as (S34, S35). The proxy 13 (1), 13 (2) having received the switching request establishes a communication connection corresponding to the session identifier to the connection point of the proxy 13 (3) using the received parameter and the session identifier (ID). (S36, S37).
[0132]
After that, the proxy 13 (1) switches all the communication that has been performed through the communication connection with the proxy 13 (2) to the communication connection of the proxy 13 (3) (S40, S41).
Two communication connections are established in the added proxy 13 (3). The proxy 13 (3) associates two communication connections based on the session identifier received when the communication connection is established, and makes a state in which accumulation and transfer are possible.
[0133]
Next, a case where the proxy 13 (3) is deleted from the session as in the case of FIG. 6 will be described with reference to FIG.
In this example, in FIG. 6, the communication connection is established in the order of the client application 12 (2), the proxy 13 (2), the proxy 13 (3), the proxy 13 (1), and the server application 11 (1). From the state in which the session between (2) and the server application 11 (1) is established, the client application 12 (2), the proxy 13 (2), the proxy 13 (1), and the server application 11 (1) in this order. It is assumed that a communication connection is established and the session path is changed between the client application 12 (2) and the server application 11 (1).
[0134]
That is, it represents an operation for deleting the proxy 13 (3) from the session.
When the mobile terminal 30 (2) receives the proxy deletion request from the agent software, the mobile terminal 30 (2) notifies the session management unit SM (2) of it.
In this case, the session management unit SM (2) transmits a deletion request to the proxies 13 (1) and 13 (2) (S51, S52).
[0135]
When the proxy 13 (2) receives the deletion request, the proxy 13 (2) establishes a connection with the proxy 13 (1) using the session identifier. In addition, all the communication performed with the proxy 13 (3) is switched to the communication connection with the proxy 13 (1).
In addition, when the proxy 13 (1) receives the deletion request and establishes a communication connection from the proxy 13 (2), the proxy 13 (1) is performed through a communication connection with the proxy 13 (3). All the communication that has been made is switched to the communication connection with the proxy 13 (2).
[0136]
Next, the case of replacing the proxy 13 (4), 13 (5) on the session as in the case of FIG. 8 will be described with reference to FIG.
In this example, in FIG. 8, the communication connection is established in the order of the client application 12 (2), the proxy 13 (2), the proxy 13 (4), the proxy 13 (1), and the server application 11 (1). From the state in which a session is established between (2) and the server application 11 (1), the client application 12 (2), the proxy 13 (2), the proxy 13 (5), the proxy 13 (1), and the server application It is assumed that the communication connection is established in the order of 11 (1) and the session path between the client application 12 (2) and the server application 11 (1) is changed.
[0137]
That is, it represents an operation for replacing the proxy 13 (4) on the session with the proxy 13 (5).
When the mobile terminal 30 (2) receives the proxy replacement request from the agent software, the mobile terminal 30 (2) notifies the session management unit SM (2) of it.
[0138]
In this case, the session management unit SM (2) transmits a switching request including the name of the proxy 13 (5) and the connection point as parameters to the proxies 13 (1) and 13 (2) having the communication connection. (S74, S75).
The proxy 13 (1), 13 (2) that has received the switching request establishes a communication connection corresponding to the session identifier with respect to the connection point of the proxy 13 (5) based on the received parameter.
[0139]
After that, the proxy 13 (1) switches all the communication performed in the communication connection with the proxy 13 (4) to the communication connection with the proxy 13 (5).
Similarly, the proxy 13 (2) switches all communication performed in the communication connection with the proxy 13 (4) to the communication connection with the proxy 13 (5).
[0140]
After the two communication connections are established, the proxy 13 (5) added to the session associates the two communication connections based on the session identifier received at the time of establishing the connection, and makes the state capable of storing and transferring.
[0141]
【The invention's effect】
As described above, according to the communication connection establishment method of the present invention, a terminal on which an application used by a user is executed can be switched or a communication path used can be switched even during communication. Moreover, even when such switching is performed, it is not necessary for the user to perform a special operation for restarting an application or establishing a communication connection, and the user can continuously receive a communication service.
[0142]
In addition, when switching communication paths and the like, communication connections between a plurality of proxies are switched in a predetermined procedure so that service continuity is not impaired, so service continuity for the same user is guaranteed.
In addition, since the proxy can be switched, added, deleted, and replaced in the communication path, when using the same terminal at various positions while moving, the communication path can be switched to avoid redundant paths, Proxies that perform unnecessary relay processing can be deleted from the communication path, improving communication efficiency, reducing network resources, ensuring service continuity of leaving the terminal where the proxy is operating, and when a failure occurs Improves fault tolerant property.
[0143]
Furthermore, since the application used during communication can be switched, the user can selectively use the most suitable application at each time point in the mobile environment, which improves convenience. Even when switching applications, continuity of communication services is guaranteed.
[Brief description of the drawings]
FIG. 1 is a sequence diagram showing a control sequence when switching between a proxy and an application.
FIG. 2 is a block diagram illustrating an example of a communication path when switching between a proxy and an application.
FIG. 3 is a sequence diagram showing a control sequence when a proxy is added to a session.
FIG. 4 is a block diagram illustrating an example of a communication path when a proxy is added to a session.
FIG. 5 is a sequence diagram showing a control sequence when a proxy is deleted from a session.
FIG. 6 is a block diagram illustrating an example of a communication path when a proxy is deleted from a session.
FIG. 7 is a sequence diagram showing a control sequence when a proxy on a session is replaced.
FIG. 8 is a block diagram illustrating an example of a communication path when a proxy on a session is replaced.
FIG. 9 is a block diagram illustrating a configuration example of a communication system.
FIG. 10 is a block diagram illustrating a configuration example of a mobile terminal.
FIG. 11 is a schematic diagram illustrating an example of information held by a service management unit SR.
FIG. 12 is a schematic diagram illustrating an example of information held by a location management unit LR.
FIG. 13 is a schematic diagram illustrating an example of information held by a session management unit SM.
FIG. 14 is a block diagram illustrating a configuration example of a communication system.
FIG. 15 is a block diagram illustrating a configuration example of a network.
FIG. 16 is a block diagram showing a movement model of nodes and services.
FIG. 17 is a sequence diagram illustrating a location information update procedure when the terminal is moving.
FIG. 18 is a graph showing the number of issued position information update instructions.
FIG. 19 is a graph showing a location search success rate.
FIG. 20 is a graph showing a location search success rate.
FIG. 21 is a block diagram illustrating a configuration example of a network.
FIG. 22 is a sequence diagram showing a service movement example (1).
FIG. 23 is a sequence diagram showing a service movement example (2).
FIG. 24 is a sequence diagram showing a simplified control sequence when a proxy is added to a session.
FIG. 25 is a sequence diagram showing a simplified control sequence when a proxy is deleted from a session.
FIG. 26 is a sequence diagram showing a simplified control sequence when replacing a proxy on a session.
[Explanation of symbols]
1,3 application
2 proxy
4 nodes
5 Browser
6 Proxy
7 Web server
8 nodes
9 Database
10 software
11 Server application
12 Client application
13 Proxy
14 Agent
15 Link switching unit
16, 17, 18 links
21 Ethernet communication adapter
22 Wireless LAN adapter
23 PHS communication adapter
30 Mobile terminal
40 network
51, 52, 53 Subnetwork
54 Wide area network
55, 59, 60, 61, 66, 67 Mobile terminal
56,62 fixed terminal
57, 58, 64, 65 base station
63 TAP
101,102 application
103 sessions
104, 105, 106 proxy
107, 108, 109, 110 Communication connection
LR Location Management Department
SM Session Management Department
SR Service Management Department

Claims (10)

A communication connection establishment method used for control of a communication system provided with a plurality of applications, a plurality of proxies that relay communication, and a network that connects them,
If multiple applications are communicating with each other via a communication path through two or more proxies,
In response to a predetermined switching request, the first proxy arranged on the communication path switches the second proxy as the connection destination to the third proxy and continues the communication. . A communication connection establishment method used for control of a communication system provided with a plurality of applications, a plurality of proxies that relay communication, and a network that connects them,
When the first application and the second application are communicating with each other via a communication path through two or more proxies,
A second proxy that is arranged on the communication path and relays between the first application and the first proxy sends the first application of the communication partner to the other third in response to a predetermined switching request. A communication connection establishment method, characterized in that communication is continued by switching to an application. In the communication connection establishment method of Claim 1,
When client application and server application communicate through multiple proxies,
When a response from the server application is transferred to the client application in response to the connection request of the client application, the transfer path is managed as a session, and a session ID is assigned to each session,
When the first proxy receives a switching request for moving a service, the first proxy interrupts communication relay and then connects to the third proxy at the destination, and then resumes relaying,
The third proxy starts a new client application using an argument including the corresponding session ID,
The launched new client application connects to the third proxy and sends information including the specified session ID to the third proxy,
The communication proxy establishment method, wherein the third proxy relays data by combining communication of the first proxy and communication of the new client application based on a session ID. In the communication connection establishment method of Claim 2,
When client application and server application communicate through multiple proxies,
When a response from the server application is transferred to the client application in response to the connection request of the client application, the transfer path is managed as a session, and a session ID is assigned to each session,
When the second proxy receives a switching request for service movement, the second proxy interrupts communication relay and starts a new client application using an argument including the corresponding session ID,
The launched new client application connects to the second proxy and sends information including the specified session ID to the second proxy,
The second proxy restarts data relay by combining communication of a proxy having a communication path with a server application and communication of the new client application based on a session ID. Connection establishment method. A communication connection establishment method used for controlling a communication system in which a terminal including a client application that requests a service, a terminal including a server application that provides a service, and a terminal including a proxy that stores and relays communication contents is connected. There,
Holding first information representing a client application or server application and proxy existing in each terminal, and second information used to identify each terminal;
Managing a communication path between a server application and a client application formed by relaying one or more proxies as a session;
For each session, at least the identifier of the session, the third information specifying the client application and the server application using the session, the fourth information specifying the proxy used by the session, and the session Holding fifth information representing the proxy's connection point,
If it is necessary to switch the terminal that provides the server application or client application to be used, or to switch the proxy on the communication path used for communication between the server application and the client application, the corresponding session information and the above Using the first information and the second information, relaying is performed between the server application and the proxy connected thereto, between the client application and the proxy connected thereto, and between the server application and the client application. A communication connection establishment method, wherein at least one communication connection between a plurality of proxies is automatically switched. 6. The communication connection establishment method according to claim 5, wherein at least one mobile terminal provided with a proxy and a server application or a client application on the same terminal is used as a terminal of the communication system, and the mobile terminal performs actual communication. A communication connection establishment method, characterized in that a change of the second information accompanying switching of a communication device to be used is absorbed by a proxy arranged on the same mobile terminal. 6. The communication connection establishment method according to claim 5, wherein there is a session management unit that manages the session information, and the second proxy is a proxy that is different from the first proxy that is a proxy that actually relays a session. When a request to switch to a proxy occurs,
Any one terminal notifies the session management unit of the switching request,
Inquiry about the switching preparation status from the session management unit to the second proxy of the switching destination,
When a notification indicating that the switching preparation is completed is received from the second proxy to the session management unit, the session is established with respect to the third proxy that has established a communication connection with the first proxy. A switching request is transmitted from the management unit together with information on the second proxy of the switching destination,
The third proxy establishes a new communication connection with the second proxy to be switched using the session identifier,
Switching so that the communication that has been performed via the communication connection between the first proxy and the third proxy passes through the communication connection between the third proxy and the second proxy,
When switching of all communication connections is completed, the session management unit is notified of switching completion,
When the establishment of the first communication connection with the third proxy is completed, the second proxy that is the switching destination, the second proxy and the server application or the client application, based on the notified session identifier A communication connection establishment method, wherein the communication path of the session is switched by associating the second communication connection established between and the first communication connection. The communication connection establishment method according to claim 5, wherein there is a session management unit that manages information on the session, and between a first proxy and a second proxy that are actually relaying communication for a certain session, If a request to add a proxy to add a new third proxy occurs,
Any one terminal notifies the session management unit of the addition request,
Inquiry about the additional preparation status to the third proxy added from the session management unit,
When the session management unit receives a notification indicating the completion of preparation from the third proxy, the session management unit transmits an addition request to each of the first proxy and the second proxy,
Each of the first proxy and the second proxy establishes a new first communication connection or second communication connection with the third proxy using the session identifier in response to the addition request. Then, the communication relayed by the first proxy and the second proxy is switched to pass through the first communication connection or the second communication connection,
When switching of the communication connection used for all communications is completed, the session management unit is notified of switching completion,
The notified session when both the first communication connection between the first proxy and the third proxy and the second communication connection between the second proxy and the third proxy are established. A communication connection establishment method, wherein the first communication connection and the second communication connection are associated with each other based on the identifier. The communication connection establishment method according to claim 5, wherein there is a session management unit that manages information on the session, and when a deletion request for the first proxy that actually relays communication occurs for a certain session,
Any one terminal notifies the session management unit of the deletion request,
The session management unit transmits a deletion request to each of the second proxy and the third proxy that have established the first communication connection and the second communication connection with the first proxy,
The second proxy and the third proxy establish a third communication connection between them, and switch the communication using the first communication connection and the second communication connection to the third communication connection. ,
The communication connection establishment method, wherein when the switching of the communication connection is completed, the second proxy and the third proxy respectively notify the session management unit of the switching completion. The communication connection establishment method according to claim 5, wherein there is a session management unit that manages information on the session, and a first communication connection is established between the first proxy and the second proxy for a certain session, A second communication connection is established between the second proxy and the third proxy, and the first proxy, the second proxy, and the third proxy are used by using the first communication connection and the second communication connection. When a request for replacement from the second proxy to a new fourth proxy occurs in a state where communication is performed via the proxy,
Any one terminal notifies the session management unit of the replacement request,
The session management unit makes an inquiry to the fourth proxy regarding preparation for replacement,
When the session manager receives a notification indicating the completion of preparation from the fourth proxy, the session manager sends a switching request to the first proxy and the third proxy,
In response to the switching request, each of the first proxy and the third proxy establishes a third communication connection and a fourth communication connection with the replacement-target fourth proxy based on the session identifier. And
Each of the first proxy and the third proxy switches the communication performed through the first communication connection and the second communication connection to pass through the third communication connection and the fourth communication connection. ,
After the switching of communication connections used for communication is completed for all the switched communication connections, each of the first proxy and the third proxy notifies the session management unit of the completion of switching,
A communication connection establishment method, wherein after the third communication connection and the fourth communication connection are established, the third communication connection and the fourth communication connection are associated with each other based on the notified session identifier. .

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