JP5140107B2 - Media session termination method and program, and media session termination device - Google Patents

Description

  The present invention relates to software and hardware that terminates session control and facilitates the development of applications that perform termination of media streams sent and received over connected sessions.

  In an IP (Internet Protocol) telephone network realized by NGN (Next Generation Network), two types of a session control protocol and a media stream control protocol are used when making a call. The session control protocol is a protocol for controlling a call (session) which is a connection state between IP telephones, and a typical one is SIP (Session Initiation Protocol). The SIP specification is standardized by IETF (Internet Engineering Task Force) (see Chapters 1 to 4 of Non-Patent Document 1). The media stream control protocol is a protocol for controlling transmission and reception of media streams such as audio and video on a connected session, and a typical one is RTP (Real-time transport Protocol) (non-patent). (Refer to Chapter 1 of Document 2).

  That is, an apparatus used by connecting to a network (session control network) that performs session control such as NGN terminates a session for a call and terminates the media stream. You are running an application that has both control protocols. Therefore, when developing a new application that transmits and receives media streams such as audio and video, it is necessary to be familiar with the specifications of both the session control protocol and the media stream control protocol. There is a high hurdle at. Even with knowledge of at least one protocol, if there is software that automatically compensates for the lack of knowledge, high hurdles in application development can be lowered.

  As such an example, SIP Servlet (see Non-Patent Document 3) for the purpose of facilitating the development of an application without knowing all the SIP specifications is disclosed. SIP Servlet provides the basic functions of SIP that are commonly used for various applications as an input / output interface, and makes it possible to detect complex exception patterns and generate / interpret / order control of SIP messages as a black box. Process on the Servlet side. As a result, in application development, it is only necessary to create an application having a media stream control protocol, so that the height of the hurdle can be slightly lowered.

J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, and E. Schooler, "SIP: Session Initiation Protocol," Internet Engineering Task Force, RFC 3261, June 2002 H. Schulzrinne, S. Casner, R. Frederick, and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications," Internet Engineering Task Force, RFC 3550, July 2003 Java Community Process, "SIP Servlet v1.1," Java Specification Requests (JSR) 289, August 2008

However, there is no study example that makes it easy to develop an application for use in a device connected to a session control network, even if both the session control protocol and media stream control protocol specifications are not familiar. Moreover, although the above-described SIP Servlet has an effect of lowering the hurdle of application development, it takes time and effort to learn how to use it.
Accordingly, an object of the present invention is to provide software and hardware that facilitate application development even if the user is not familiar with the specifications of both the session control protocol and the media stream control protocol.

  The present invention relates to a media session that forms a file system, connects to a session control network that performs session control, is provided in an apparatus that transmits and receives media information on a session based on an application, and terminates session control based on a session control protocol A media session termination method used in a termination device, wherein the media session termination device receives an instruction to execute file creation from the application, generates a file, and connects a session based on the session control protocol A step of associating the connected session with the file name of the generated file and storing it in a storage unit; and executing the file deletion by specifying the file name from the application Receiving the notification, deleting the file with the specified file name, disconnecting the session associated with the file name based on the session control protocol, and from the storage unit to the disconnected session. Deleting the file name of the associated file.

  The present invention relates to a media session that forms a file system, connects to a session control network that performs session control, is provided in an apparatus that transmits and receives media information on a session based on an application, and terminates session control based on a session control protocol A terminal device that receives an instruction to execute file creation from the application, generates a file, and connects a session based on the session control protocol; the connected session; and the generated file Means for storing the file name in the storage unit, receiving an instruction to execute the file deletion by specifying the file name from the application, deleting the file of the specified file name, Session control protocol Characterized in that it comprises means for disconnecting the session associated with the file name, from the storage unit, and means for deleting the file name of the file associated with the disconnected the session, the based on.

  According to such a configuration, the media session termination device receives the file creation and file deletion instructions from the application, executes the session connection and disconnection procedure in the session control protocol, and sets the session connection and disconnection to the file. Manage as creation and deletion of. Therefore, in application development using the session control protocol, application development can be facilitated if there is general knowledge about file creation and deletion.

  In the present invention, the media session termination device receives a session connection request based on the session control protocol from a connection partner device connected via the session control network; and Receiving and connecting a session based on the session control protocol to generate a file; storing the file name of the generated file in association with the connected session in the storage unit; and the application And a step of returning a file name stored in the storage unit when an instruction for requesting a list of file names is received.

  The present invention comprises the storage unit that stores the file name returned by the media session termination device in response to an instruction for requesting a list of file names received from the application, and the media session termination device includes: Receiving a session connection request based on the session control protocol from a connection partner device connected via a session control network; receiving the session connection request; and receiving a session based on the session control protocol. And generating a file, storing the file name of the generated file in association with the connected session in the storage unit, and receiving an instruction to request a list of file names from the application Instructions to request the previous list And file name reply when receiving, and executes the step of returning the difference between the file name stored in the time of receiving the instruction to request this list, the.

  In the present invention, the media session termination device receives a session disconnection request based on the session control protocol from a connection partner device connected via the session control network; and Receiving and disconnecting the session based on the session control protocol and deleting the file; deleting the file name associated with the disconnected session from the storage; and the file name from the application And a step of returning a file name stored in the storage unit when an instruction for requesting the list is received.

  The present invention comprises the storage unit that stores the file name returned by the media session termination device in response to an instruction for requesting a list of file names received from the application, and the media session termination device includes: Receiving a session disconnection request based on the session control protocol from a connection partner device connected via a session control network; receiving the session disconnection request; and receiving a session based on the session control protocol And deleting the file, deleting the file name associated with the disconnected session from the storage unit, and receiving an instruction to request a list of file names from the application, When an instruction to request the list was received last time And file name reply, and executes the step of returning the difference between the file name stored in the time of receiving the instruction to request this list, the.

  According to such a configuration, when the media session termination device receives a session connection and disconnection request based on the session control protocol from the connection partner device, the session connection and disconnection procedure in the session control protocol is executed. Execute file creation and file deletion. Then, the application can recognize the session control state by requesting a list of file names stored in the storage unit and checking whether the file has been generated or deleted. In other words, in application development using the session control protocol, application development can be facilitated if there is general knowledge for examining the existence of a file.

  The present invention is provided in an apparatus that forms a file system, connects to a session control network that performs session control, and transmits and receives media information on a session based on an application, terminates session control based on a session control protocol, A media session termination method used in a media session termination device for terminating control of media information transmitted / received on a connected session according to a media control protocol, wherein the media session termination device includes: A storage unit for storing the file name of the file on the file system and a memory location storing the media information read / written to / from the file in association with each other; Receiving an instruction to execute file creation from the application, generating a file, connecting a session based on the session control protocol, and associating the connected session with the file name of the generated file , Storing in the storage unit, receiving an instruction to execute writing of media information to a file from the application, transmitting the media information based on the media control protocol, and specifying from the application Receives an instruction to read media information from the file with the specified file name, receives the media information based on the media control protocol, refers to the storage unit, and associates the media information with the specified file name To get the specified memory location Returning a memory location to the application; receiving an instruction to execute file deletion by specifying a file name from the application; deleting the file with the specified file name; and based on the session control protocol The step of disconnecting the session associated with the file name and the step of deleting the file name associated with the disconnected session from the storage unit are executed.

  The present invention is provided in an apparatus that forms a file system, connects to a session control network that performs session control, and transmits and receives media information on a session based on an application, terminates session control based on a session control protocol, A media session termination device that terminates control of media information transmitted and received on a connected session according to a media control protocol, the connected session, a file name of a file on the file system, and the file A storage unit that associates and stores a memory location storing the media information to be read and written, receives an instruction to execute file creation from the application, generates a file, and is based on the session control protocol The A means for connecting a session, a means for associating the connected session with the file name of the generated file and storing the file in the storage unit, and an instruction to write media information from the application to the file. Means for receiving and transmitting the media information based on the media control protocol, and receiving an instruction to read the media information from the file of the specified file name from the application, and based on the media control protocol Means for receiving the media information, referring to the storage unit, obtaining a memory location associated with the designated file name, and returning the memory location to the application; and a file name from the application To delete the specified file. A means for deleting the file with the specified file name and disconnecting the session associated with the file name based on the session control protocol; and from the storage unit, associated with the disconnected session. Means for deleting a file name.

  According to such a configuration, the media session termination device receives the file creation and file deletion instructions from the application, executes the session connection and disconnection procedure in the session control protocol, and sets the session connection and disconnection to the file. Manage as creation and deletion of. Also, the media session termination device receives an instruction to write data to the file and read data from the file from the application, and executes a procedure for transmitting and receiving media information based on the media control protocol. Therefore, in application development using the session control protocol and the media stream control protocol, application development can be facilitated if there is general knowledge about file creation, file deletion, file writing, and file reading. become able to.

The present invention provides a program for causing a media session termination device as a computer to execute the media session termination method.
A computer in which such a program is installed can realize functions based on this program.

  According to the present invention, it is possible to provide software and hardware that facilitates application development without being familiar with the specifications of both the session control protocol and the media stream control protocol.

It is a figure which shows the outline | summary of the function of the apparatus provided with the media session termination | terminus means. It is a figure which shows the example of a sequence in the case of requesting a connection from an own apparatus. It is a figure which shows the example of a sequence in the case of requesting a connection from a partner apparatus. It is a figure which shows the example of a sequence in the case of request | requiring a cutting | disconnection from an own apparatus. It is a figure which shows the example of a sequence in the case of requesting | disconnecting from the other party apparatus. It is a figure which shows the example of mounting of a media session termination | terminus means. It is a figure which shows an example of file session DB.

  A mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as appropriate.

(Overview)
The outline of the function of the device provided with the media session termination means will be described with reference to FIG. The media session termination means 30 may be configured by software or hardware, but first, a case where it is configured by software will be described.

  The apparatus 40 includes at least a CPU (Central Processing Unit) (not shown) and a main memory (not shown), and starts an operating system 20 generally called an OS (Operating System). The operating system 20 provides file system (file management) functions such as memory and disk management and data input / output. Further, the apparatus 40 operates the application 10 and the media session termination means 30 as software on the operating system 20. That is, the application 10 and the media session termination unit 30 operate using functions provided by the operating system 20.

  The device 40 establishes a session with the connection partner device 40a (40) or device 41 via the session control network 50, and a media stream such as audio or video (hereinafter also referred to as media information or data). ). The session control network 50 is provided with a session control server (for example, a SIP server) (not shown) for performing session control, and call control for establishing a session between the device 40 and the devices 40a and 41 via the session control server. Is done. In FIG. 1, only one device 40, 40a, 41 is shown, but two or more devices may be used.

  In the device 40, the application 10 instructs the media session control unit 30 to connect or disconnect a session and to transmit / receive a media stream. Further, the media session control means 30 receives an instruction from the application 10 and executes control based on both the session control protocol and the media stream control protocol (media control protocol).

The device 41 may not include the media session termination unit 30 as long as the device 41 includes a unit that executes control based on both the session control protocol and the media stream control protocol (media control protocol).
In FIG. 1, both the session control signal and the media stream signal are described as flowing through one session control network 50, but the network configuration is such that each signal flows through a separate network. It doesn't matter.

  The media session termination unit 30 is a file creation unit 31 for creating a file, a file deletion unit 32 for deleting a file, and a data writing unit for writing data, which are instructed by the application 10 via the operating system 20. Either the writing unit 33 or the reading unit 34 for reading data from the file is performed. The file operated by the media session termination unit 30 is stored in the storage unit 60. The storage unit 60 may be a RAM (Random Access Memory) or an HDD (Hard Disc).

  The media session termination unit 30 includes a session control unit 35 that performs a session control protocol process, and a media stream control unit 36 that performs a media stream control protocol process. The session control unit 35 links the operation of the connection unit 351 that connects the session between the device 40 and the connection partner devices 40 a and 41 corresponding to the file creation unit 31, and corresponds to the file deletion unit 32. The operation of the disconnecting means 352 for disconnecting the session between the device 40 and the devices 40a and 41 of the connection partner is linked. Further, the media stream control unit 36 corresponds to the reading unit 34 by linking the operation of the transmission unit 363 indicating that the media information is transmitted from the device 40 to the connected devices 40 a and 41 corresponding to the writing unit 33. Thus, the operation of the receiving means 364 indicating that the device 40 receives media information from the connection partner devices 40a and 41 is linked.

  The session management unit 37 holds and manages the state of each connected session as a session 371,. In addition, the session management unit 37 manages a file generated or deleted by the file creation unit 31 or the file deletion unit 32 and a memory location where data read / written by the writing unit 33 or the reading unit 34 is stored. . The memory location is a memory address in the storage unit 60. Then, as shown in FIG. 7, the session management unit 37 associates the session ID for identifying the connected session, the file name (name of the generated file), and the memory location where the data is stored. The file session DB (database) 701 is stored in the storage unit 60 and managed. That is, the session management unit 37 adds a session ID and a file name to the file session DB 701 corresponding to the newly connected session and the generated file, and corresponds to the newly disconnected session and the deleted file. The session ID and file name are deleted from the file session DB 701.

Further, the session management unit 37 receives an inquiry about a list of file names from the application 10, refers to the file session DB 701, and returns the file names stored in the file session DB 701. That is, the session associated with the returned file name corresponds to the currently connected session.
In addition, the session management unit 37 specifies a file name from the application 10 and receives an instruction from the reading unit 34, refers to the file session DB 701, and returns a memory location associated with the file name. Thereby, the application 10 can acquire the media information received from the devices 40a and 41 of the connection partner based on the memory location.

  When the processing in the media session termination unit 30 is realized by hardware, the file creation unit 31, the file deletion unit 32, the writing unit 33, the reading unit 34, the session control unit 35, and the media stream control shown in FIG. The means 36 and the session management means 37 serve as a processing unit that executes calculations in a CPU (not shown). Further, the sessions 371 and 372 shown in FIG. 1, the file session DB 701 shown in FIG. 7, and the file and data input to and output from the file are stored in the storage unit 60.

Next, an outline of the operation of the media session termination unit 30 will be described with reference to FIG.
In the present embodiment, the media session termination means 30 is on a file system provided in the operating system 20 with instructions for session connection and disconnection in the session control protocol and instructions for transmission and reception of media streams in the media stream control protocol. It provides an interface that has been replaced with file operation instructions. Therefore, if there is knowledge of general file operations, the media session termination unit 30 can facilitate the creation of the application 10.
Specifically, as shown in FIG. 1, the file creation means 31 is associated with the session connection means 351, the file deletion means 32 is associated with the session disconnection means 352, and the file writing means 33 is transmitted to the media stream. Corresponding to the means 363 and reading means 34 for the file are associated with the media stream receiving means 364.

There are two cases in which a session is connected between the device 40 and the devices 40a and 41, a connection is started from the device 40, and a connection is started from the connection partner devices 40a and 41. Similarly, in the case of session disconnection, there are two cases: a case where the disconnection is started from the device 40 and a case where the disconnection is started from the connection partner devices 40a and 41.
First, a case where the application 10 of the apparatus 40 starts connection or disconnection using the media session termination unit 30 will be described.
The application 10 of the device 40 causes the file creation means 31 to execute, and transmits a session connection request to the devices 40a and 41 of the connection partner. In addition, when the application 10 of the device 40 starts the disconnection using the media session termination unit 30, the application 10 causes the file deletion unit 32 to be executed, and transmits a session disconnection request to the connection partner devices 40 a and 41.

  Next, when the application 10 of the device 40 is waiting for a session connection request sent from the connection partner devices 40a and 41, the session control unit 35 of the media session termination unit 30 receives the connection request. Since the file is created on the file system based on the execution of the file creation means 31, it can be recognized that the connection request has been received. When the application 10 of the device 40 is waiting for a session disconnection request from the connection partner devices 40a and 41, the session control unit 35 of the media session termination unit 30 receives the disconnection request. Since the file on the file system is automatically deleted based on the execution of the file deletion means 32, it can be recognized that the disconnect request has been received.

  Regarding the transmission of the media stream, the application 10 of the device 40 transmits the media stream to the devices 40a and 41 of the connection partner based on the execution of the file writing means 33. As for the reception of the media stream, the application 10 of the device 40 acquires the media stream received from the devices 40a and 41 of the connection partner based on the execution of the reading means 34 from the file.

  As described above, when the application 10 is developed using the media stream termination unit 30, files such as the file creation unit 31, the file deletion unit 32, the writing unit 33, and the reading unit 34 included in the media stream termination unit 30. If there is knowledge of general operations on files on the system, the application 10 can be easily developed.

(Processing flow in media session termination means)
Next, the flow of processing in the media session termination unit 30 will be described with reference to FIG. As a specific example, a command used in UNIX (registered trademark) is also described.

  When the application 10 executes an instruction (open system call or the like) or a command for creating a file to the operating system 20, the file creation means 31 of the media session termination means 30 is executed. For example, the file creation unit 31 generates a file having the file name of the identifier (eg, SIP URI (Uniform Resource Identifier) in SIP) of the connection partner devices 40a and 41. Further, based on the execution of the file creation unit 31, the connection unit 351 of the session control unit 35 sends a session connection request (INVITE in SIP, etc.) using the identifiers of the devices 40a and 41 of the connection partner as the connection destination. Start the session connection sequence. Details of the session connection sequence will be described later.

When the session is connected (established), the session management unit 37 of the media session termination unit 30 holds the state of the connected session, for example, as a session 371 that can be identified by the identifiers of the devices 40a and 41 of the connection partner. .
That is, the session management unit 37 can handle the file generated on the file system and the connected session 371 in association with the identifiers of the devices 40a and 41 of the connection partner.

When the application 10 inquires about the file list (for example, a file list acquisition request), the session management unit 37 returns the identifiers of the devices 40a and 41 of the connection partner as the file names.
Note that the identifiers of the devices 40a and 41 of the connection partner include path names such as directories or folders. This is because when a plurality of media streams such as audio and video are included in one session, a file for identifying each media stream is included under the same directory.

  Further, when the application 10 executes a command (such as a close system call) or a command for deleting a file by specifying a file name to the operating system 20, the file deletion unit 32 of the media session termination unit 30 is executed. . The file deletion unit 32 deletes the file with the specified file name. Further, based on the execution of the file deletion unit 32, the disconnection unit 352 of the session control unit 35 sends a session disconnection request (such as BYE in SIP) and starts a session disconnection sequence. Details of the session disconnection sequence will be described later.

Next, the writing unit 33 and the reading unit 34 in the media session termination unit 30 will be described.
First, the writing means 33 will be described. When the application 10 executes an instruction (such as a write system call) or a command for writing data by specifying a file name to the operating system 20, the operating system 20 Send the data to be written. Then, the writing unit 33 uses the transmission unit 363 of the media stream control unit 36 to send the received data as media information to the connection destination of the session associated with the file name.

  Next, the reading unit 34 will be described. When the application 10 executes an instruction (read system call or the like) or a command for reading data by designating a file name to the operating system 20, the operating system 20 reads the reading means 34 of the media session termination means 30. Requesting an address (memory location) on the memory storing the received media information. The reading unit 34 returns the address on the memory via the operating system 20. Thereby, the application 10 can acquire the media information received from the devices 40a and 41 of the connection partner.

  Note that the data to be read from and written to the file may be in a data format in which the original data is compressed or in an uncompressed data format. When the compressed data format is used, the media stream control unit 36 may have a function of converting the data format of the data received from the session control network 50 into the data format of the data handled by the application 10. The specification for data format conversion and the type of data format are specified by an option or the like when the file system is mounted.

  As described above, the application 10 only handles commands and commands related to file operations such as file creation, file deletion, file write, and file read in the file system, and the session with the connection partner devices 40a and 41 is performed. Control and media stream control can be performed.

The application 10 can recognize each session 371, 372 as a file via the operating system 20, and therefore may be a script executed on the command line instead of as a program.
For example, in UNIX (registered trademark), audio data of a media stream read from a file corresponding to the session 371 is written to an audio device using a shell (an interface program that receives a command input and interactively outputs it). Can be played. Specifically, it is described by a shell “tail -f /sipfs/sip:alice@atlanta.com> / dev / audio”. Here, the “tail -f” command continuously reads from the session 371 (the file path name is “/sipfs/sip:alice@atlanta.com”). The read audio data is output to the audio device “/ dev / audio” by the shell redirection function “>”. However, the above-described command line script is an example of a script that is assumed, and is not limited to this command.

  Next, detailed examples of the session connection sequence and the session disconnection sequence will be described with reference to FIGS.

(Session connection request)
A sequence example in the case where a session connection request is made from the device 40 (self device) when a session is established between the device 40 and the connection partner devices 40a and 41 will be described with reference to FIG. (See FIG. 1). In FIG. 2, the description of the operating system 20 is omitted.

  The file creation instruction issued by the application 10 of the device 40 is transmitted to the media session termination means 30 (step S201). By this step S201, the file creation means 31 creates a file.

  Then, based on the execution of the file creation means 31, the session control means 35 of the media session termination means 30 transmits a SIP INVITE request to the devices 40a and 41 (step S202). After step S202, session connection processing from step S203 to step S209 is executed between the session control unit 35 of the media session termination unit 30 and the devices 40a and 41. Specifically, the connection means 351 of the session control means 35 and the devices 40a and 41 of the connection partner determine the SIP INVITE request, 100 response, 200 response, and ACK request via the session control network 50. To establish a session. After the session is established, transmission / reception of the media stream is started (step S210).

  Next, a sequence example when a session connection request is made from the devices 40a and 41 (the partner device) will be described with reference to FIG. 3 (see FIG. 1 as appropriate). In FIG. 3, the description of the operating system 20 is omitted.

  First, the devices 40a and 41 transmit a SIP INVITE request using the device 40 as a connection partner (step S301). In steps S302 to S308 after step S301, the devices 40a and 41 and the session control unit 35 of the media session termination unit 30 of the device 40 transmit and receive INVITE requests, 100 responses, 200 responses, and ACK requests in a predetermined procedure. To establish a session. After the session is established, transmission / reception of the media stream is started (step S309).

When the session control unit 35 of the device 40 receives ACK (step S308), the file creation unit 31 creates a file.
However, since the application 10 has not transmitted a file creation request, the application 10 needs to confirm whether or not a file has been created in order to know whether or not a session has been established. Therefore, an instruction or command prepared in the operating system 20 is used to confirm that the file has been created. For example, in the case of a Linux (registered trademark) operating system, the state of a file or directory can be monitored by an instruction “notify”, so that it is possible to recognize that a file has been created under the file system.

  As described above, the application 10 periodically transmits a file list request to the media session termination unit 30 (step S310), and checks whether or not the file exists. The session management unit 37 of the media session termination unit 30 returns the file names associated with the sessions 371 and 372 stored in the storage unit 60 (step S311). Then, the application 10 can acquire a newly created file name by examining the difference between the previously received file list and the currently received file list, and can handle transmission / reception of media information by reading and writing the file. Become.

(Session disconnection request)
A sequence example when a session disconnection request is made from the device 40 (self device) when the session is disconnected between the device 40 and the connection partner devices 40a and 41 will be described with reference to FIG. (See FIG. 1). In FIG. 4, the description of the operating system 20 is omitted.

  Media stream transmission / reception is being executed between the device 40 and the connected devices 40a and 41 (step S401). In this state, the file deletion instruction issued by the application 10 of the device 40 is transmitted to the media session termination unit 30 (step S402). By this step S402, the file deleting means 32 deletes the file.

  Then, based on the execution of the file creation means 31, the session control means 35 of the media session termination means 30 transmits a SIP BYE request to the devices 40a and 41 (step S403). After step S403, session connection processing from step S404 to S406 is executed between the session control means 35 of the media session termination means 30 and the devices 40a and 41. Specifically, the disconnection means 352 of the session control means 35 and the devices 40a and 41 of the connection partner send and receive SIP BYE requests and 200 responses via the session control network 50 according to a predetermined procedure, and session Disconnect. After the session is disconnected, the transmission / reception of the media stream ends (step S407).

  Next, a sequence example when a session disconnection request is made from the connection partner devices 40a and 41 (partner device) will be described with reference to FIG. 5 (see FIG. 1 as appropriate). In FIG. 5, the description of the operating system 20 is omitted.

  Media stream transmission / reception is being executed between the device 40 and the connected devices 40a and 41 (step S501). In this state, the devices 40a and 41 transmit a SIP BYE request to the device 40 (step S502). In steps S503 to S505 after step S502, the devices 40a and 41 and the session control unit 35 of the media session termination unit 30 of the device 40 transmit and receive a BYE request and a 200 response according to a predetermined procedure, and disconnect the session. To do. After the session is disconnected, the transmission / reception of the media stream ends (step S506).

Note that when the session control unit 35 of the apparatus 40 receives the BYE request (step S503), the file deletion unit 32 deletes the file.
However, since the application 10 has not transmitted a file deletion request, the application 10 needs to confirm whether or not the file has been deleted in order to know whether or not the session has been disconnected. Therefore, as described above, the application 10 periodically transmits a file list request to the media session termination unit 30 (step S507), and checks whether or not the file exists. Then, the session management unit 37 of the media session termination unit 30 returns the file names associated with the sessions 371 and 372 stored in the storage unit 60 (step S508). Then, the application 10 can acquire the newly deleted file name by examining the difference between the file list received last time and the file list received this time.

  When the application 10 reads data from the file with the file opened, an EOF (End of File) indicating that the file has been read to the end of the file is returned via the operating system 20. Thus, the disconnection of the session can be recognized.

(Implementation example)
A configuration example in which the media session termination unit 30 of this embodiment is implemented using Linux (registered trademark) as the operating system 20 will be described with reference to FIG. 6 (see FIG. 1 as appropriate).
The virtual address space in the device 40 is divided into a kernel space and a user space. The kernel space includes a VFS (Virtual File System) 21 that is a mechanism for operating a plurality of file systems, a FUSE (File system in Userspace) 22 that is a mechanism for executing a file system that operates in a user space, and session control. A NIC (Network Interface Card) 23 for exchanging signals with the network 50 is arranged. In the user space, an application 10 and media session termination means 30 are arranged.

  The FUSE 22 is well-known software provided so that a file system program in the user space can be easily developed without knowledge of the file system and the kernel. Using this FUSE 22, the file operation in the media session termination means 30 is realized in the user space.

Commands and commands output from the application 10 are transmitted to the media session termination unit 30 via the VFS 21 and the FUSE 22. Further, the media session termination unit 30 establishes a session and transmits / receives media information to / from the connection partner devices 40a and 41 via the NIC 23 based on the session control protocol and the media stream control protocol.
If there is knowledge about the kernel, the file system may be configured using the VFS 21 directly without using the FUSE 22.

  As described above, the media session termination unit 30 described in the present embodiment performs session control in the session control protocol and media stream control in the media stream control protocol as an operation instruction to a file on the file system included in the operating system 20. It provides a replacement interface. Therefore, if there is general knowledge about the file operation, the application 10 can be easily produced.

  In step S311 shown in FIG. 3, the session management unit 37 has been described as returning a list of file names. On the other hand, the session management unit 37 stores a list of file names sent back last time, and when receiving a file list request from the application 10, a file name different from the file name list sent back last time The state (newly created) may be returned.

  In step S508 shown in FIG. 5, the session management unit 37 has been described as returning a list of file names. On the other hand, the session management unit 37 stores a list of file names sent back last time, and when receiving a file list request from the application 10, a file name different from the file name list sent back last time The state (deleted) may be returned. Further, the application 10 may specify a file name and search for whether or not the file exists.

  The terminals 40a and 41 shown in FIG. 1 are devices such as an IP telephone and a computer that can terminate the session control protocol and the media stream control protocol, and are not used even if the media session termination means 30 is used. It doesn't matter.

  In this embodiment, the case of UNIX (registered trademark) or Linux (registered trademark) is exemplified as the operating system. However, the present invention is not limited to this, and any other system having a file system may be used. It may be an operating system.

DESCRIPTION OF SYMBOLS 10 Application 20 Operating system 30 Media session termination means 31 File creation means 32 File deletion means 33 Write means 34 Read means 35 Session control means 36 Media stream control means 37 Session management means 40, 40a, 41 Apparatus 50 Session control network 60 Storage part 371, 372 Session 701 File Session DB

Claims (9)

Connected to a session control network that forms a file system, performs session control, is provided in a device that transmits and receives media information on a session based on an application, and is used in a media session termination device that terminates session control based on a session control protocol A media session termination method, comprising:
The media session termination device is:
Receiving an instruction to perform file creation from the application, generating a file, and connecting a session based on the session control protocol;
Associating the connected session with the file name of the generated file and storing it in a storage unit;
Receives an instruction to execute file deletion by specifying the file name from the application, deletes the file of the specified file name, and disconnects the session associated with the file name based on the session control protocol And steps to
Deleting the file name of the file associated with the disconnected session from the storage unit;
A method for terminating a media session, comprising: The media session termination device is:
Receiving a session connection request based on the session control protocol from a connection partner device connected via the session control network;
Receiving the session connection request, connecting a session based on the session control protocol, and generating a file;
Storing the file name of the generated file in association with the connected session in the storage unit;
When receiving an instruction to request a list of file names from the application, returning a file name stored in the storage unit;
The media session termination method according to claim 1, wherein: The media session termination device is:
The storage unit storing a file name returned in response to an instruction to request a list of file names received from the application;
The media session termination device is:
Receiving a session connection request based on the session control protocol from a connection partner device connected via the session control network;
Receiving the session connection request, connecting a session based on the session control protocol, and generating a file;
Storing the file name of the generated file in association with the connected session in the storage unit;
When receiving an instruction requesting a list of file names from the application, a file name returned when receiving an instruction requesting a previous list, and a file stored when receiving an instruction requesting a current list Returning the difference from the name,
The media session termination method according to claim 1, wherein: The media session termination device is:
Receiving a session disconnection request based on the session control protocol from a connected device connected via the session control network;
Receiving the session disconnection request, disconnecting the session based on the session control protocol, and deleting the file;
Deleting a file name associated with the disconnected session from the storage unit;
When receiving an instruction to request a list of file names from the application, returning a file name stored in the storage unit;
The media session termination method according to claim 1, wherein: The media session termination device is:
The storage unit storing a file name returned in response to an instruction to request a list of file names received from the application;
The media session termination device is:
Receiving a session disconnection request based on the session control protocol from a connected device connected via the session control network;
Receiving the session disconnection request, disconnecting the session based on the session control protocol, and deleting the file;
Deleting a file name associated with the disconnected session from the storage unit;
When receiving an instruction requesting a list of file names from the application, a file name returned when receiving an instruction requesting a previous list, and a file stored when receiving an instruction requesting a current list Returning the difference from the name,
The media session termination method according to claim 1, wherein: It is provided in a device that forms a file system, connects to a session control network that performs session control, and transmits and receives media information on a session based on an application, terminates session control based on the session control protocol, and is based on the media control protocol A media session termination method used in a media session termination device for terminating control of media information transmitted / received on a connected session,
The media session termination device is:
A storage unit that associates and stores the connected session, a file name of a file on the file system, and a memory location that stores the media information that is read and written to the file;
The media session termination device is:
Receiving an instruction to perform file creation from the application, generating a file, and connecting a session based on the session control protocol;
Associating the connected session with the file name of the generated file and storing it in the storage unit;
Receiving an instruction to write media information from the application to the file and transmitting the media information based on the media control protocol;
An instruction to read media information from a file having a specified file name is received from the application, the media information is received based on the media control protocol, and the storage unit is referred to and specified. Obtaining a memory location associated with the file name and returning the memory location to the application;
Receives an instruction to execute file deletion by specifying a file name from the application, deletes the file with the specified file name, and disconnects the session associated with the file name based on the session control protocol Steps,
Deleting a file name associated with the disconnected session from the storage unit;
A method for terminating a media session, comprising:   A program for causing a media session termination device as a computer to execute the media session termination method according to any one of claims 1 to 6. It is a media session termination device that is connected to a session control network that forms a file system and performs session control, and that is provided in a device that transmits and receives media information on a session based on an application and terminates session control based on a session control protocol. And
Means for receiving an instruction to execute file creation from the application, generating a file, and connecting a session based on the session control protocol;
Means for associating the connected session with the file name of the generated file and storing it in a storage unit;
Receives an instruction to execute file deletion by specifying the file name from the application, deletes the file of the specified file name, and disconnects the session associated with the file name based on the session control protocol Means to
Means for deleting the file name of the file associated with the disconnected session from the storage unit;
A media session termination apparatus comprising: It is provided in a device that forms a file system, connects to a session control network that performs session control, and transmits and receives media information on a session based on an application, terminates session control based on the session control protocol, and is based on the media control protocol A media session termination device for terminating control of media information transmitted / received on a connected session,
A storage unit that associates and stores the connected session, a file name of a file on the file system, and a memory location that stores the media information that is read and written to the file;
Means for receiving an instruction to execute file creation from the application, generating a file, and connecting a session based on the session control protocol;
Means for associating the connected session with the file name of the generated file, and storing it in the storage unit;
Means for receiving an instruction to write media information to a file from the application and transmitting the media information based on the media control protocol;
An instruction to read media information from a file having a specified file name is received from the application, the media information is received based on the media control protocol, and the specified Means for obtaining a memory location associated with a file name and returning the memory location to the application;
Receives an instruction to execute file deletion by specifying a file name from the application, deletes the file with the specified file name, and disconnects the session associated with the file name based on the session control protocol Means,
Means for deleting a file name associated with the disconnected session from the storage unit;
A media session termination apparatus comprising:

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