JP5498443B2 - Session control method and session control apparatus - Google Patents

Description

  The present invention relates to a technique for matching band information with an actual value in a communication system that manages band information.

  In a network that guarantees communication quality (for example, NGN (Next Generation Network)), a session control server that performs session control while managing a bandwidth is arranged. The session control server has a call processing function (for example, CSCF (Call Session Control Function)) and a resource management / acceptance control function (for example, RACF (Resource and Admission Control Function)). The call processing function confirms a caller and a callee based on a signal from a terminal, for example, a signal by SIP (Session Initiation Protocol), and performs session establishment / release processing. The resource management / acceptance control function manages the amount of bandwidth allocated for communication in the transfer network, and realizes an admission determination function and a QoS (Quality of Service) control function.

  The session control server manages and holds the bandwidth amount allocated to the session established by the call processing function as bandwidth information. Further, call information such as calling / receiving terminal information, requested bandwidth, and session status is managed and held as information on the session being set.

  When the session control server accepts a new session establishment request and establishes a session, the amount of bandwidth requested by the session is added to the currently managed bandwidth information according to the calculation formula held. This is called band accumulation processing. Note that processing in response to a request to change the increase / decrease of the bandwidth used during the session is also referred to as stacking processing. On the other hand, when releasing an established session, the amount of bandwidth requested by the session is subtracted from the currently managed bandwidth information according to the calculation formula held. This is referred to as band loading processing.

ITU-T recommendation 2012 ITU-T recommendation 2111

  Anomalies may occur, such as a gap between the bandwidth information held in the session control server and the bandwidth value actually reserved. In particular, there may be a gap between the total bandwidth request amount recorded in each call information and the bandwidth information. If operation is continued with the band information shifted, there is a problem that the resource management / admission control function does not operate as expected and QoS cannot be maintained.

  Conventionally, when an abnormality occurs in the bandwidth information, a method has been adopted in which the session control server is restarted, the bandwidth information and call information are cleared, and the initial settings are restored. However, when the session control server is restarted, all sessions in communication are released, which causes a problem that service reliability decreases.

  The present invention has been made in view of the above, and an object of the present invention is to match a bandwidth request amount recorded in call information with bandwidth information without disconnecting a session.

  A session control method according to a first aspect of the present invention is a session control method for establishing a session between terminals, securing a bandwidth used in the session, and managing bandwidth information of the secured bandwidth. In the normal processing, the bandwidth processing for the established session uses the bandwidth information stored in the first storage means, and during the matching processing, the processing for the session existing before the matching processing is performed. The bandwidth processing continues using the bandwidth information stored in the first storage means, and the bandwidth processing for the session established during the matching processing uses the bandwidth information stored in the second storage means. And

  The session control method may further include a step of moving the bandwidth information stored in the second storage unit to the first storage unit after completion of the matching process.

  A session control device according to a second aspect of the present invention is a session control device that establishes a session between terminals, secures a bandwidth to be used in the session, and manages bandwidth information of the secured bandwidth. The first and second storage means for storing, the matching processing means for performing matching processing for matching the bandwidth information, and the bandwidth processing for the established session is normally stored in the first storage means. During the matching process using the band information, the band process for the session existing before the matching process continues using the band information stored in the first storage means, and the band process for the session established during the matching process is performed as described above. Call processing means using bandwidth information stored in the second storage means.

  According to the present invention, it is possible to match the bandwidth request amount recorded in the call information with the bandwidth information without disconnecting the session.

It is a whole block diagram containing the session control server in this Embodiment. It is a flowchart which shows the flow of the bandwidth information matching process of the session control server in this Embodiment.

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

  FIG. 1 shows an overall configuration diagram including a session control server in the present embodiment. The session control server 1 is a device that receives a signal from the terminal 3 to establish a session between the terminals 3 and secures a band between the edge nodes 2 so that communication can be performed between the terminals 3. In addition, the session control server 1 manages and holds bandwidth information including the amount of bandwidth allocated to the session. Hereinafter, the configuration of the session control server 1 will be described.

  The session control server 1 shown in FIG. 1 includes call processing units 11 and 12, memories 12 </ b> A and 12 </ b> B, and a bandwidth information matching processing unit 13. Each unit included in the session control server 1 may be configured by a computer including an arithmetic processing device, a storage device, and the like, and the processing of each unit may be executed by a program. This program is stored in a storage device included in the session control server 1, and can be recorded on a recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, or provided through a network.

  The call processing unit 11 performs processing related to call control, such as session establishment, release, band accumulation processing required for the session, and stacking processing. The bandwidth information stored in the memories 12A and 12B is stored by the stacking processing and the loading processing. Increase or decrease the bandwidth. The call processing unit 11 uses the memories 12A and 12B properly depending on whether it is in normal time or in the band information matching process. The bandwidth information matching process is a process for matching the bandwidth information stored in the memory 12A with the total bandwidth request amount of each call information. The call processing unit 11 normally performs call control processing using only the memory 12A, and uses both the memories 12A and 12B during the bandwidth information matching processing.

  The specific use of the memories 12A and 12B by the call processing unit 11 will be described in detail. For the call information of the session established at the start of the band information matching process, the band information stored in the memory 12A is used to match the band information. Band information stored in the memory 12B is used for call information of a session established during processing. Whether or not the call information is a session established during the bandwidth information matching process is determined by a call information flag. In the present embodiment, by setting a flag for the call information existing at the start of the bandwidth information matching process, the call information of the session established at the start of the bandwidth information matching process or the session information established during the bandwidth information matching process It is determined whether it is call information. The call information includes calling / receiving terminal information, requested bandwidth, session state, etc., and is stored in a storage device such as a memory provided in the call processing unit 11.

  The memories 12A and 12B may be prepared by being physically separated into different memory devices, or two areas may be prepared as areas within the same memory device physically.

  The bandwidth information matching processing unit 13 performs bandwidth information matching processing when a command is input from the maintenance device 4 by the maintenance person or when the system is switched when the session control server 1 is duplicated.

  Next, the flow of processing of the session control server in this embodiment will be described. Here, processing for matching the bandwidth request amount of each session and the bandwidth information recorded in the call information will be described.

  FIG. 2 is a flowchart showing a flow of bandwidth information matching processing of the session control server in the present embodiment.

  When the bandwidth information matching processing unit 13 starts the bandwidth information matching processing, the call processing unit 11 sets a flag on the call information existing at the start of the bandwidth information matching processing (step S11). At this time, if the bandwidth information exists only in the memory 12A and there is no deviation in the bandwidth information, the bandwidth information is equal to the total amount of bandwidth requests recorded in each call information.

  The session control server 1 accepts a signal even during the band information matching process (step S12).

  If the received signal is a signal for instructing the band processing related to the flagged call information, the stacking process and the unloading process are performed using the band information of the memory 12A (step S13). When the session is released by the received signal, the band information requested by the corresponding call information is loaded using the band information of the memory 12A, and the call information is deleted.

  On the other hand, when the received signal is a signal for instructing band processing regarding an incoming call after the start of band information processing, stacking processing and stacking processing are performed using the band information of the memory 12B (step S14). When a new session is established during the bandwidth information matching process, the bandwidth request amount of call information related to the session is added to the bandwidth information in the memory 12B. The call information of the session established during the band information matching process, that is, the stacking process and the unloading process for the call information for which no flag is set, uses the band information of the memory 12B.

  After performing the stacking process and the unloading process for the flagged call information, it is determined whether there is any remaining flagged call information (step S15). If there is still flagged call information, the process returns to step S12 to wait for a signal.

  If there is no flagged call information, the bandwidth information in the memory 12B is copied to the memory 12A, the memory 12B is cleared, and the bandwidth information matching process is terminated (step S16). When all the flagged call information is released, the band information in the memory 12B is obtained by performing the stacking process and the unloading process after starting the band information matching process, and the correct band value at that time It has become. After the bandwidth information matching process is completed, the bandwidth information in the memory 12B is copied to the memory 12A to return to the normal state, and only the bandwidth information in the memory 12A is used. At the end of the bandwidth information matching process, the call information of the memory 12B is not copied to the memory 12A, but the roles of the memories 12A and 12B are logically switched, that is, only the bandwidth information of the memory 12B is used at normal times. It may be.

  In this way, during the bandwidth information matching process, the stacking process for the new session is not performed on the bandwidth information in the memory 12A. Therefore, as the session existing before the bandwidth information matching process is released, The number of calls and bandwidth managed by the bandwidth information will decrease. During the bandwidth information matching process, the total bandwidth amount of the bandwidth information of each of the memories 12A and 12B is the total bandwidth amount secured.

  As described above, according to the present embodiment, the two memories 12A and 12B for storing the bandwidth information are prepared. In normal times, only the bandwidth information of the memory 12A is used, and during the bandwidth information matching process, In addition to setting a flag for call information existing before the bandwidth information matching process, the bandwidth information in the memory 12A is used, and the call received during the bandwidth information matching process is stacked using the bandwidth information in the memory 12B. When the flag information is not used and the bandwidth information matching process is completed, the bandwidth information in the memory 12B is moved to the memory 12A, so that the bandwidth information is set to the correct value without disconnecting the session during communication. Can be matched. As a result, QoS can be ensured and service reliability can be improved.

DESCRIPTION OF SYMBOLS 1 ... Session control server 11 ... Call processing part 12A, 12B ... Memory 13 ... Band information matching processing part 2 ... Edge node 3 ... Terminal 4 ... Maintenance apparatus

Claims (4)

A session control method for establishing a session between terminals, securing a bandwidth to be used in the session, and managing bandwidth information of the secured bandwidth,
A matching process for matching the bandwidth information;
Normally, the bandwidth processing for the established session uses the bandwidth information stored in the first storage means, and during the matching processing, the bandwidth processing for the session existing before the matching processing continues to the first storage means. Using the stored bandwidth information, the bandwidth processing for the session established during the matching processing uses the bandwidth information stored in the second storage means;
A session control method characterized by comprising:   2. The session control method according to claim 1, further comprising a step of moving the bandwidth information stored in the second storage means to the first storage means after completion of the matching process. A session control device that establishes a session between terminals, secures a bandwidth to be used in the session, and manages bandwidth information of the secured bandwidth,
First and second storage means for storing the bandwidth information;
A matching processing means for performing matching processing for matching the bandwidth information;
Normally, the bandwidth processing for the established session uses the bandwidth information stored in the first storage means, and during the matching processing, the bandwidth processing for the session existing before the matching processing continues. Call processing means using the bandwidth information stored in the second storage means for bandwidth processing for the session established during the matching process,
A session control apparatus comprising:   4. The session control apparatus according to claim 3, wherein the call processing unit moves the bandwidth information stored in the second storage unit to the first storage unit after the matching process is completed.

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