JP2005210378A - Session manager, communication system, and communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of simply and quickly acquiring an IP address and port information for session transition and building up a reception environment at a client terminal of a transition destination, eliminating the need for re-boosting of an application at session switching at a server side of a distribution destination, and capable of allowing the different client terminal to take over sessions such as broadcast having been so far carried out as they are. <P>SOLUTION: In a communication system and method disclosed herein, when a network controller makes a session takeover request to a first client terminal being a session takeover destination, the first client terminal requests a session manager to transmit session information, and when the session manager transmits the session information of a management table, the first client terminal receives the session information to set the reception environment and informs the network controller about the completion of session takeover preparation and the network controller switches the session. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a communication system for controlling switching of a session related to, for example, RTP over UDP on ASTN (Automatic switched transfer networks) / ASON (Automatic switched optical networks).

  Conventionally, when a stream that uses IP flows through a switch-type network such as ASON, the server cannot take over the previous stream to the newly connected client terminal when the network is reconfigured, and re-pauses the session. It is necessary. Therefore, it is difficult to smoothly transfer the stream reproduction to another client terminal.

  Here, there is Mobile IP as a technology similar to the switch type network such as the ASON. This Mobile IP is characterized in that a gateway is placed in the middle of a route and session transfer processing is performed by this gateway.

  As described above, in the Mobile IP, a gateway is placed in the middle of a route, and a session transfer process is performed by the gateway. Therefore, there are costs related to relaying (management cost / transmission delay, etc.). Furthermore, Mobile IP is a technology for holding a session for the same terminal, and is not a technology for transferring a session to a different client. Therefore, the adaptation area (application) is different from ASON in the first place.

  An object of the present invention is to easily and quickly acquire an IP address and port information for session transition, and to construct a reception environment at the client terminal of the transition destination, and switch the session on the server side of the distribution destination. This makes it unnecessary to restart the application at the time, and allows different client terminals to take over the session such as broadcasting that has been performed so far.

  In order to achieve the above object, according to a first aspect of the present invention, in a communication system for controlling a session on a dynamically reconfigurable network, a server that performs communication using the session, the first and first 2, a session manager having a management table for managing session information, and a network controller as a control plane. The network controller sends a session takeover request to the first client terminal as a session takeover destination. Then, when the first client terminal requests session information from the session manager and the session manager transmits session information in the management table, the first client terminal receives the session information and receives the session information. Set Performs session takeover preparation completion notification to the network controller, the network controller for switching a session, there is provided a communication system, characterized in that.

  According to a second aspect of the present invention, in the first aspect, the network controller makes a session switching request to the second client terminal that takes over the session, and the second client terminal receives the request and receives a session manager. The session manager sends session information in the management table to the second client terminal, and the second client terminal changes at least the IP address and port settings based on the session information. There is provided a communication system further characterized in that it does.

  According to a third aspect of the present invention, in the first aspect, the server requests the session manager to delete session information, and the session manager deletes an entry related to the session information based on the request and sets the session information. There is provided a communication system further characterized by notifying the server of the deletion notification.

  The fourth aspect of the present invention includes at least a server that communicates with at least a client terminal using a dynamically reconfigurable session on the network, and the server includes a session from the client terminal. When a request for generation is received, the client terminal is negotiated to generate a session, the session manager is notified of unregistered session information, and the session manager is urged to register the session information in the management table. A featured communication system is provided.

  According to a fifth aspect of the present invention, in the fourth aspect, when the server receives a session information deletion request when a session is switched, the session manager deletes the session information. And a communication system that prompts the user to delete the registration of the session information in the management table of the session manager.

  According to a sixth aspect of the present invention, there is provided a communication system according to any one of the first to fifth aspects, wherein the dynamically reconfigurable network is ASTN or ASON.

  In the seventh aspect of the present invention, a session manager applied to a communication system having a server, a client terminal, and a network controller as a control plane that communicate using a dynamically reconfigurable network session A management table for managing session information, and when receiving session information from the server, the session information is registered in the management table, a registration completion notification is sent to the server, and the client terminal When a request for session information is received, the management table is searched and the session information is notified to the client terminal. When a session information deletion request is received from the server, the management table is searched and the session information is deleted. A session characterized by Manager is provided.

  According to an eighth aspect of the present invention, in a communication method for controlling a dynamically reconfigurable session on a network, when a network controller makes a session takeover request to a first client terminal that is a session takeover destination, When the client terminal requests session information from the session manager and the session manager transmits the session information in the management table, the first client terminal receives the session information and sets a reception environment. A communication method is provided in which a session takeover preparation completion notification is sent to the network controller and the session is switched by the network controller.

  According to a ninth aspect of the present invention, in the eighth aspect, the network controller makes a session switching request to the second client terminal that takes over the session, and the second client terminal receives the request and receives a session manager. The session manager sends session information in the management table to the second client terminal, and the second client terminal changes at least the IP address and port settings based on the session information. There is provided a communication method further characterized in that it is performed.

  According to a tenth aspect of the present invention, in the ninth aspect, the server makes a session information deletion request to the session manager, and the session manager deletes an entry related to the session information based on the request and sets the session information. There is provided a communication method further characterized by sending a deletion notification to the server.

  According to the present invention, acquisition of an IP address, port information, and the like for a session transition and a construction of a reception environment at a transition destination client terminal can be performed easily and quickly, and at the time of session switching on the distribution destination server side. It is possible to provide a session manager, a communication system, and a communication method that make it unnecessary to restart an application and allow a different client terminal to take over a broadcast session or the like that has been performed so far.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  First, in order to deepen the understanding of the present invention, the basic principle of an ASON that is the basis of a communication system according to an embodiment of the present invention will be described.

  In ASON, a server and a client terminal are connected via a photonic cross connect (PXC). This PXC is an apparatus for exchanging optical signals as light without going through electrical processing. When stream information is transmitted from a server to a client terminal via a path, the stream information is reproduced at the client terminal.

  If various failures occur in the PXC during this communication process, the failure is automatically detected by the control plane, another route is calculated, and the path is reattached. If a failure occurs again, a new path is pasted by the same method. Such a session on ASON is maintained while the server and the client terminal recognize each other's IP address and port number. The communication system according to the embodiment of the present invention is an extension of the above-mentioned ASON and ASTN technologies. When the client terminal of a transmission destination such as video or audio information related to broadcasting is changed, the server setting is changed. For example, it is possible to automatically switch sessions in units of schedules divided by time or the like.

  In Mobile IP, which is a similar technology, a gateway is placed in the middle of a route, and session switching processing is performed by this gateway. In this case, there is a cost (management cost / transmission delay, etc.) related to the relay. In this respect, the communication system according to the present embodiment does not require an intermediate node, so that such a cost does not occur.

  Based on the above, a communication system according to an embodiment of the present invention will be described in detail.

  1 to 4 show and explain the configuration and operation of a communication system according to an embodiment of the present invention. The communication system according to this embodiment receives a stream server 3 for performing communication using a session on ASTN / ASON, which is a dynamically reconfigurable network, and stream information from the stream server 3 The client terminals 1a, 1b, 1c,... For reproduction, a session manager 4 for managing the session, and a network controller 5 as a control plane. In the following, the reference numeral 1 is used to collectively refer to the client terminals 1a, 1b, 1c.

  In such a configuration, the physical network of the ASON is automatically switched by commanding the device from another network called a control plane. When a link failure is detected on the device side, a notification is made to the control plane, and the link failure is recognized and a path is recalculated on the control plane side. From this point of view, this communication system includes the network controller 5 as a control plane as described above.

  In general, when sessions A and B are pasted between the client terminals 1, registration of the sessions A and B is unnecessary. However, in the communication system according to the embodiment of the present invention, the sessions A and B Is pasted, the stream server 3 registers the session information in the session manager 4 (# 1). On the session manager 4 side, the session information is registered in the management table while defining the session information.

  Next, when a session switching request is made from the application side (not shown) to the network controller 5 side, the network controller 5 makes a session takeover request to the switching destination client terminal 1 (# 2). In this example, since it is assumed that the session A is taken over from the client terminal 1a to the client terminal 1b, the takeover request for the session is made to the client terminal 1b.

  Subsequently, the client terminal 1b requests the session manager 4 for session A information (# 3). The session manager 4 that has received the request for the session A information notifies the client terminal 1b that is the request source of the session A information (# 4).

  By receiving this session A information, the client terminal 1b can know the labels at both ends of the session A, so the reception environment is set based on the information (in this example, the IP address is IP-B, the port is (Set to Port-5) (# 5).

  When this setting is completed, the client terminal 1b transmits a session takeover preparation completion notification to the network controller 5 to notify that the reception environment is ready (# 6). Upon receiving this session takeover preparation completion notification, the network controller 5 switches the path route of ASON / ASTN (# 7).

  As a result, one label of session A is switched to the client terminal 1b, and an environment in which stream information or the like is transmitted to the client terminal 1b is prepared.

  Thus, the environment in which IP or higher layers than IP can be received is prepared, but it is necessary to refresh the setting of the client terminal 1b in layer 2 communication such as Ethernet. Therefore, the network controller 5 transmits a session switching completion notification to the client terminal 1b when the path route is switched (# 8). Upon receiving this session switching completion notification, the client terminal 1b resets the lower layer reception (communication) environment such as ARP (# 9). The client terminal 1b completes the process related to session switching.

  On the other hand, for the client terminal 1a, the network controller 5 issues a port close request for session A (# 10). Upon receiving this request, the client terminal 1a requests the session manager 4 for session A information (# 11).

  Upon receiving this request, the session manager 4 notifies the client terminal 1a of session A information (# 12). Upon receiving this session A information, the client terminal 1a releases IP-A and closes Port-5 (# 13). This completes the process related to session switching for the client terminal 1a.

  After the above processing, the stream server 3 sends a session A information deletion request to the session manager 4 (# 14). Upon receiving this request, the session manager 4 deletes the entry related to the session A information (# 15), and notifies the stream server 3 of deletion of the session A information (# 16).

  Thus, a series of processing by the communication system is completed.

  Hereinafter, a communication method using a communication system according to an embodiment of the present invention will be described.

  First, with reference to the flowchart of FIG. 5, the process procedure by the whole communication system which concerns on one embodiment of this invention, ie, the communication method, is demonstrated in detail.

  When a session is generated between the client terminal 1a and the stream server 3 (step S1), the IP address and port information of the client 1a are registered in the stream server 3 (step S2). (Step S3), the session manager 4 registers the session information in the management table (step S4), and the session manager 4 transmits a registration completion notification to the stream server 3 (step S5).

  Next, when there is a session change request (step S6), the network controller 5 determines whether or not a new session is to be generated (step S7). If a new session is to be generated, the process proceeds to step S3. The process as described above is performed after the migration.

  On the other hand, when a new session is not generated, the network controller 5 determines whether or not to take over the session (step S8). If it is determined in step S8 that the session will be taken over, the process proceeds to step S9.

  That is, when a session takeover request is made from the network controller 5 to the client terminal 1b (step S9), the client terminal 1b requests session information from the session manager 4 (step S10). The session manager 4 retrieves the session information from the management table (step S11), and notifies the client terminal 1b of the session information (step S12). The client terminal 1b sets a reception environment according to the notified session information (step S13), and transmits a session takeover preparation completion notification to the network controller 5 (step S14). Upon receiving this notification, the network controller 5 switches the path route (step S15) and notifies the client terminal 1b of the session switching completion (step S16). Then, the client terminal 1b refreshes the reception environment of the layer 2 communication (step S17), and ends the process related to the session change (takeover here) (step S22).

  On the other hand, if it is determined in step S8 that the session is not taken over, the network controller 5 determines whether or not to delete the session (step S18). If it is determined that the session is to be deleted, the stream server 3 sends a session information (entry) deletion request to the session manager 4 (step S19), and the session information ( (Entry) is deleted (step S20), and the session manager 4 notifies the server 3 of deletion of session information (entry) (step S21). In this way, the process related to the session change (deletion here) is terminated (step S22).

  Thus, a series of processing ends.

  Next, a processing procedure by the stream server 3 in the communication system according to an embodiment of the present invention, that is, a communication method will be described in detail with reference to the flowchart of FIG.

  When the stream server 3 receives a session generation request from the client terminal 1b (step S30), the stream server 3 negotiates with the client terminal 1b, generates a session (step S31), and stores unregistered session information in the session manager 4. Notification is made (step S32). Next, a registration completion notification is received from the session manager 4 (step S33). Then, the application process with the client terminal 1b is executed and continued (step S34).

  Subsequently, the stream server 3 determines whether or not there is a session deletion request from the client terminal 1b side (step S35). Here, if there is no deletion request, the processing of step S34 is carried out and continued. On the other hand, when there is a deletion request, negotiation with the client terminal 1b is performed (step S36), the session manager 4 is requested to delete the session information (step S37), and the session information is deleted from the session manager 4. When the notification is received (step S38), the session process with the client terminal 1b is completed (step S39).

  Next, a processing procedure on the client terminal 1a side, which is a session takeover source in the communication system according to the embodiment of the present invention, that is, a communication method will be described in detail with reference to the flowchart of FIG. When the client terminal 1a acquires server information such as port information and IP address of the stream server 3 (step S40), it makes a session connection request to the stream server 3 (step S41). Next, when a session permission notification is received from the stream server 3 (step S42), a session with the stream server 3 is established, that is, the IP address and port information of the stream server 3 are registered in the management table in the client terminal 1a (step S43). ) Implement and continue the application process with the stream server 3 (step S44). Next, it is determined whether there is a session delivery request from the network controller 5 (step S45).

  If there is such a request in step S45, the client terminal 1a requests the session manager 4 for the session information (step S46), and receives the session information from the session manager 4 (step S47), the IP and port Is deleted, the session is deleted from its own management table (step S48), and the session processing with the stream server 3 is completed (step S49).

  On the other hand, if there is no session delivery request in step S45, it is determined whether there is a session information deletion request from the stream server 3 or the client terminal 1a side (step S50). If there is no such request, the process returns to step S44 to repeat the above operation. On the other hand, if there is such a request, negotiation with the stream server 3 is performed, the session is deleted (step S51), and thus the session processing with the stream server 3 is completed (step S52).

  Next, with reference to the flowchart of FIG. 8, the processing procedure on the side of the client terminal 1b that is the takeover destination of the session in the communication system according to the embodiment of the present invention, that is, the communication method will be described in detail. When the client terminal 1b receives the session takeover request from the network controller 5 (step S60), the client terminal 1b requests the session manager 4 for the session information in order to take over the session (step S61).

  When the session information is notified from the session manager 4 (step S62), the reception environment is set according to the session information (step S63), and the session information is registered in its own management table (step S63). S64). Subsequently, a notification of completion of preparation for session takeover is transmitted to the network controller 5 (step S65). When a notification of completion of switching of the session (L1 path route) is received from the network controller 5 (step S66), the L2 reception environment of the lower layer is refreshed (Step S67), session takeover, that is, reception of data from the stream server 3 is started (Step S68), and session takeover is completed (Step S69).

  Next, with reference to the flowchart of FIG. 9, the process procedure by the session manager 4 in the communication system which concerns on one embodiment of this invention, ie, the communication method, is demonstrated in detail.

  The session manager 4 initializes the management table (step S70).

  Thereafter, when the session manager 4 receives the session information from the stream server 3 (step S71), the session manager 4 registers the session information in the management table (step S72), and notifies the stream server 3 of the registration completion (step S73). .

  Subsequently, the process waits until a session registration / deletion or session information request is received (step S74). When a message is received (step S75), it is determined whether the request is a session registration request from the stream server 3 (step S75). Step S76). If it is the request, the process returns to step S72 and the above process is repeated.

  On the other hand, if it is not the request, it is determined whether or not it is a request for session information from the client terminal 1 (step S77). If the request is made, the management table is searched (step S82), the session information is notified to the client terminal 1 (step S83), and the process returns to step S74. On the other hand, if it is not a request for session information, it is determined whether or not it is a request for deleting session information from the stream server 3 (step S78). If it is not the deletion request, the process returns to step S74 to repeat the above operation. On the other hand, if it is the deletion request, the management table is searched (step S79), the session information (entry) is deleted (step S80), and the session information deletion notification is sent to the stream server 3 (step S80). S81), the process returns to step S74. Thereafter, the process waits until the next message is received, and when the message is received, the processes after step S74 are repeated.

  As described above, according to the communication system, method, and the like according to the embodiment of the present invention, it is easy to obtain an IP address and port information for session migration and to construct a reception environment at the migration destination client terminal. In addition, it is quick and does not require application re-launch at the time of session switching on the delivery destination server side, so that it is possible to take over a broadcast session or the like that has been performed for different client terminals as it is. Session manager, communication system, and communication method can be provided.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this, and it is needless to say that various improvements and modifications can be made without departing from the spirit of the present invention. For example, the above-described embodiment can be applied to a GMPLS-based optical wavelength path service or the like in which GMPLS technology is mounted on PXC.

The figure which shows the structure and effect | action of a communication system which concern on one embodiment of this invention. The figure which shows the structure and effect | action of a communication system which concern on one embodiment of this invention. The figure which shows the structure and effect | action of a communication system which concern on one embodiment of this invention. The figure which shows the structure and effect | action of a communication system which concern on one embodiment of this invention. The flowchart explaining in detail the processing procedure by the whole communication system which concerns on one embodiment of this invention, ie, the communication method. The flowchart which shows the process sequence by the stream server 3 in the communication system which concerns on one embodiment of this invention. The flowchart which shows the process sequence by the side of the client terminal 1a which is the session takeover origin in the communication system which concerns on one embodiment of this invention. The flowchart which shows the process sequence by the side of the client terminal 1b which is the takeover destination of the session in the communication system which concerns on one embodiment of this invention. The flowchart which shows the process sequence by the session manager 4 in the communication system which concerns on one embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Client terminal, 2 ... Server, 3 ... Stream server, 4 ... Session manager, 5 ... Network controller.

Claims (10)

In a communication system controlling a session on a dynamically reconfigurable network,
A server that communicates using the session, first and second client terminals;
A session manager with a management table for managing session information;
A network controller as a control plane;
And when the network controller makes a session takeover request to the first client terminal as a session takeover destination, the first client terminal requests session information from the session manager, and the session manager When the session information is transmitted, the first client terminal receives the session information, sets the reception environment, notifies the network controller of completion of session takeover preparation, and the network controller switches the session.
A communication system characterized by the above.   The network controller makes a session switching request to the second client terminal that is the session takeover source, and the second client terminal receives the request and requests session information from the session manager. The communication system according to claim 1, further comprising: transmitting session information to a second client terminal, wherein the second client terminal changes at least an IP address and a port setting based on the session information.   Further characterized in that the server makes a session information deletion request to the session manager, the session manager deletes an entry related to the session information based on the request, and sends a session information deletion notification to the server. The communication system according to claim 1. At least a server that communicates with at least a client terminal using a dynamically reconfigurable network session;
When the server receives a session generation request from the client terminal, the server negotiates with the client terminal to generate a session, notifies the session manager of unregistered session information, and stores the session in the session manager management table. A communication system characterized by prompting to register information.   When the server receives a session information deletion request when a session is switched, the server requests the session manager to delete the session information, and registers the session information in the management table of the session manager. The communication system according to claim 4, wherein the communication system prompts deletion.   6. The communication system according to claim 1, wherein the dynamically reconfigurable network is ASTN or ASON. A session manager applied to a communication system having a server, a client terminal, and a network controller as a control plane, which communicate using a session on a dynamically reconfigurable network,
It has a management table for managing session information,
When session information is received from the server, the session information is registered in the management table, a registration completion notification is sent to the server,
Upon receiving a request for session information from the client terminal, the management table is searched and the session information is notified to the client terminal.
When a session information deletion request is received from the server, the management table is searched and the session information is deleted.
A session manager characterized by that. In a communication method for controlling a session on a dynamically reconfigurable network,
When the network controller makes a session takeover request to the first client terminal that takes over the session, the first client terminal requests session information from the session manager, and the session manager sends the session information in the management table. Then, the communication method is characterized in that the first client terminal receives the session information, sets a reception environment, notifies the network controller of completion of preparation for taking over the session, and the network controller switches the session.   The network controller makes a session switching request to the second client terminal that is the session takeover source, and the second client terminal receives the request and requests session information from the session manager. 9. The communication method according to claim 8, further comprising: transmitting session information to a second client terminal, wherein the second client terminal changes at least an IP address and port setting based on the session information.   Further characterized in that the server makes a session information deletion request to the session manager, the session manager deletes an entry related to the session information based on the request, and sends a session information deletion notification to the server. The communication method according to claim 8.

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