JP4962854B2 - Priority control apparatus, SIP system, priority control program, and priority control method - Google Patents

Description

  The present invention relates to an apparatus, a method, and a program for transferring a SIP request to a SIP server according to the priority of the SIP request, which is preferably used in a communication network that performs signaling using SIP (session initiation protocol).

  In recent years, as seen in VoIP (voice over IP), real-time communication using an IP network has become widespread. For example, a situation in which SIP (session initiation protocol) is adopted as an international standard protocol for establishing a connection between terminals at both ends, such as a telephone terminal and a personal computer, is increasing. In this specification, a communication network that performs signaling using SIP is referred to as a SIP network.

  A general configuration of the SIP network is described in Non-Patent Document 1. The SIP network includes a location server, a SIP server, and a user agent (UA). Regarding UA, P.A. 76, “SIP is based on a client-server model between end systems. The end system is equivalent to a user agent (UA). It is actually an end system such as a telephone or a personal computer, but a service is realized by exchanging a request (request) and a response (response) between these end systems. In this specification, the request described in the above description is called a SIP request, and the response is called a SIP response.

  The SIP server is a P.A. 77, (1) a proxy server function that relays a SIP request or SIP response, (2) a redirect server function that is used to query the destination of the SIP request, and (3) on the SIP network And a registration server function for accepting registration of UA information. Here, the UA information is, for example, a URI (Uniform Resource Identifier) that is an identifier for accessing the UA or an IP address used by the UA.

  FIG. 23 shows an operation sequence when communication is performed between UAs in a general SIP network.

  First, the UA sends an INVITE request to the SIP server. In this specification, the INVITE request that the UA first transmits to the SIP server is referred to as an initial INVITE request. Upon receiving the initial INVITE request from the UA, the SIP server calculates a nonce to be used for digest authentication, adds the nonce value to the SIP response (407 proxy authorization required), and returns the nonce to the UA.

  The UA hashes the secret (user identifier and password) using the received nonce as a key. This result is stored in the Authorization header of the INVITE request and transferred to the SIP server. In this specification, the INVITE request to which the Authorization header is added is called an authentication INVITE request.

  The SIP server that has received the authentication INVITE request performs UA (calling side) authentication processing. Specifically, (1) Like the UA (calling side), it uses the nonce value generated by itself to hash the user identifier and password of the UA. (2) Stored in the authentication INVITE request from the UA If they are the same, the authentication header value is judged to be an authentication INVITE request from a valid UA. As a result of this authentication processing, when it is determined that the authentication INVITE request is from a valid UA, the authentication INVITE request is transferred to the called UA (UA (called side in FIG. 23)) designated by the To field. .

  Thereafter, after receiving the authentication INVITE request, the UA (calling side) returns a temporary response (100 trying and 180 Ringing in FIG. 23) indicating that the processing of the authentication INVITE request is being continued to the SIP server, Call the person. When the caller answers, the UA (calling side) returns a SIP response (200 OK) indicating that the processing of the authentication INVITE request is completed to the SIP server. The UA (calling side) sends an ACK request to inform the UA (calling side) that the SIP response (200 OK), which is the final response of the authentication INVITE request, has been received.

  Thereby, a session for a call between UA (calling side) and UA (calling side) is established. At the end of the call, a BYE request for ending the session is issued from a UA that wishes to end the call (UA (calling side) in FIG. 23). Upon receiving the BYE request via the SIP server, the UA (calling side) transmits a SIP response (200 OK) after the BYE request processing, thereby transmitting the completion of the session termination processing. As a result, the call between the UA (calling side) and the UA (calling side) ends.

  In addition to the operation at the time of calling from the UA, the update of the UA information frequently occurs in a general SIP network. This UA information update process is shown in FIG.

  First, the UA sends a REGISTER request to the SIP server. In this specification, the REGISTER request that the UA first transmits to the SIP server is referred to as an initial REGISTER request. The SIP server that has received the initial REGISTER request from the UA calculates a nonce to be used in digest authentication, adds the nonce value to the SIP response (401 Unauthorized), and returns it to the UA, as in FIG. The UA hashes the secret (user identifier and password) using the received nonce as a key. This result is stored in the Authorization header of the REGISTER request and transferred to the SIP server. In this specification, the REGISTER request with the authorization header added is called an authentication REGISTER request.

  The SIP server that has received the authentication REGISTER request performs the same authentication process as in FIG. 23. If it is determined that the authentication REGISTER request is from a valid UA, the UA information is updated, and the update result is the SIP response (200 in FIG. 24). OK) and forward to UA. Note that this update of the UA information is generally performed periodically because it also serves as a confirmation of the existence of the UA.

  The communication shown in FIG. 23 and FIG. 24 for exchanging from a SIP request such as an initial INVITE request or an initial REGISTER request to a SIP response (200 OK) is generally called a “SIP transaction”.

  When a SIP server that performs such processing falls into a congested state due to simultaneous arrival of an enormous amount of SIP requests, 1) the SIP server cannot receive calls to the UA that manages UA information, and 2) the SIP. There arises a problem that it is difficult to connect the telephone to the UA managed by the server. Problem (1) is that the update process of UA information from the UA is not executed, the UA information expires, and the SIP server is ready to receive the UA for which the UA information has expired. This is to recognize that there is no. Problem (2) is because an INVITE request transferred from another SIP server cannot be processed due to a high load on the corresponding SIP server even in a situation where the UA information has not expired.

  In order to prevent such congestion of the SIP server, a priority control apparatus is arranged between the SIP server and the UA, and for example, a SIP request (initial / authentication REGISTER request) for updating UA information or an existing session is provided. SIP requests (ACK request and BYE request) that control the process are set to high priority, initial INVITE requests from the UA are set to low priority, etc., the priority is set for the SIP request sent from the UA and processed per unit time of the SIP server In order not to exceed the number of possible SIP requests, a method in which the priority control apparatus sequentially transfers the SIP requests with high priority to the SIP server can be considered.

  A general priority control system having such a feature is disclosed in Patent Document 1. The prior art described in Patent Document 1 discloses a priority control method for packets. However, it can be applied to prevent congestion of the SIP server, which is a problem in the present invention, by replacing the packets with SIP requests. .

  FIG. 25 shows a block diagram of the prior art described in Patent Document 1. As shown in this figure, in the prior art described in Patent Document 1, when passing a packet to the packet relay processing mechanism and the packet transmission mechanism, the priority control mechanism changes the queue to be inserted in consideration of the packet priority. is doing. By introducing the priority control mechanism in two places in this way, it becomes possible to take the initiative and process high priority packets at the time of packet relay processing and transmission. Furthermore, the prior art described in Patent Document 1 solves the problem that a low-priority packet is not processed indefinitely because a high-priority packet is exclusively processed. Specifically, the check counter is managed, and when the check counter exceeds a certain threshold value (100 in Patent Document 1), the packets existing in the queues with the priority or lower being processed are processed one by one ( The check counter value is cleared only after the processing to the lowest priority queue is completed.

In addition to the priority control method described in Patent Document 1, as means for preventing congestion of the SIP server, there is a method of discarding the SIP request reissued from the UA caused by the processing delay of the SIP server before the SIP server. Conceivable. In the present invention, the SIP request reissued from the UA is called a SIP retransmission request.
Thus, a general relay apparatus that is arranged between a UA and a SIP server and blocks a SIP retransmission request reissued from the UA is disclosed in Patent Document 2. In the prior art described in Patent Document 2, a packet in TCP (transmission control protocol) / IP (internet protocol) communication is targeted, but the SIP that is a problem in the present invention can be obtained by replacing this packet with a SIP request. It can be applied to prevent server congestion.

  FIG. 26 shows an outline of the prior art described in Patent Document 2. As shown in this figure, in the prior art described in Patent Document 2, an ACK / SACK packet transmitted from the receiving side is detected, and the identification number of the reception completion packet described in the packet is determined as a congestion control network relay device. Save it temporarily in. In this state, the identification number described in the packet transmitted from the transmission side is checked and compared with the identification number temporarily stored. As a result, when it can be determined that the reception side has already received, it is discarded as a retransmission packet. With this method, an extra retransmission packet is transferred from the transmission side to the reception side to prevent the congestion on the reception side from increasing.

  Furthermore, Patent Document 3 discloses a general relay apparatus that is arranged between a UA and a SIP server and blocks a SIP retransmission request that is reissued from the UA. The prior art described in Patent Document 3 is a method for avoiding an infinite loop transfer of a frame generated in a loop transmission path, particularly in a frame relay device that relays a frame handled in layer 2 of a general network hierarchical model. However, it is considered that the present invention can be applied to the congestion prevention of the SIP server, which is a problem in the present invention, by replacing the frame as a SIP request and replacing the loop forwarded frame as a SIP retransmission request.

FIG. 27 is a diagram illustrating the principle in the prior art described in Patent Document 3. As shown in this figure, in the prior art described in Patent Document 3, in order to detect a loop, information indicating the received frame (loop detection table FIG. 27C) is held and stored in the loop detection table. When a frame holding information is received again, it is determined that a loop has occurred and is discarded. In addition, when the information stored in the loop detection table does not completely match (even if the source IP address is the same, the received frame ID is different from the registered frame ID), it is checked whether the predetermined conditional expression is satisfied. By doing so, the occurrence of a loop is determined. In the loop detection table, when there is no entry at the time of searching at the time of frame reception, a new entry is added, and the frame ID and fragment offset are updated before frame transmission even if an entry exists.
Patent No. 3296001 JP 2006-287331 A JP 2001-197114 A “Revised SIP Textbook” p. 78 Figure 3-2 “Relationship between User Agent and SIP Server”

  The problem (first problem) in the prior art described in Patent Document 1 is that the number of SIP transactions that the SIP server can process per unit time is suppressed. This is because all SIP requests and SIP retransmission requests are inserted into the low priority queue without being distinguished. In the SIP protocol, generally, in the case of an initial INVITE request, a total of six SIP retransmission requests of 0.5 seconds, 1 second, 2 seconds, 4 seconds, 8 seconds, and 16 seconds are issued from the UA. Therefore, as a result of transferring the SIP request from the priority control device to the SIP server so as not to exceed the number of SIP requests that can be processed per unit time of the SIP server, for example, the initial INVITE request stays in the low priority queue for 2 seconds. In this case, three initial INVITE requests are reissued from the UA.

  In the prior art described in Patent Document 1, all these retransmission initial INVITE requests are added to the low priority queue. This means that even though the initial INVITE request has already been sent to the SIP server and the SIP transaction for processing the initial INVITE request has been started, the retransmission initial INVITE request is transferred to the SIP server again. Then, the SIP server induces an extra process of a retransmission initial INVITE request. As a result, the number of SIP transactions that can be processed per unit time in the SIP server decreases.

  The problem (second problem) in the prior art described in Patent Document 2 is that the SIP retransmission request cannot be blocked by the congestion control network relay device in the congestion state of the SIP server. This is because in the prior art described in Patent Document 2, the retransmission of the packet is determined based on the identification number described in the ACK packet transferred from the receiving side. In the state where the SIP requests are temporarily stored in the congestion control network relay device in consideration of the processing performance of the SIP server, as described above, depending on the residence time in the congestion control network relay device, several SIPs from the UA A resend request is issued. At this time, since the congestion control network relay device stores the SIP request in itself and does not transfer it to the SIP server, it cannot receive the SIP response corresponding to the ACK packet from the SIP server. That is, the identification number of the SIP request that has been processed by the SIP server cannot be acquired.

  This means that until the SIP response is received, the congestion control network relay device cannot reliably determine whether the SIP request received from the UA is retransmitted. It will be mistakenly recognized as a request and inserted into the queue. As a result, the same situation as the first problem described above is caused.

  A problem (third problem) in the prior art described in Patent Document 2 and Patent Document 3 is that information for determining whether a received SIP request is a retransmission increases with time. This is because the prior art described in Patent Document 2 and Patent Document 3 does not mention the timing for deleting the entry of information used to determine whether or not to retransmit.

  First, in the prior art described in Patent Document 2, an identifier that is a continuous value described in an ACK packet in TCP / IP is premised as corresponding information, and if the identifier is overwritten when an ACK packet is received, a value smaller than the corresponding identifier This is because a packet having can be regarded as having been received.

  Further, in the prior art described in Patent Document 3, it is considered that the entry in the loop detection table is a personal computer unit, and it is assumed that the increase or decrease of the personal computer does not occur so frequently. However, in a SIP network to which the present invention is applied, in general, information that can be handled as an identifier of a SIP request, such as a value of a Call-ID header, can be arbitrarily set by the UA, and thus is not always a continuous value. Further, for example, in the case of a call, the lifetime of the call is generally on the order of a few minutes. This means that information that can be used as an identifier of a SIP request has a short valid period and is likely to be transient.

  As described above, in the SIP network, when an identifier that does not exist in the information used for retransmission determination is received, the identifier can only be added. Further, even if the SIP transaction processing has already been completed and does not exist on the SIP network, it is applicable. The identifier indicating the SIP transaction is stored without being deleted.

  It is an object of the present invention to prevent loss of SIP network setting information such as UA information by giving priority to a SIP request, and to ensure that a SIP retransmission request for a low priority SIP request is made before reaching the SIP server. The SIP request can be retransmitted by increasing the number of SIP transactions that can be processed by the SIP server per unit time, adding an identifier when receiving a SIP request, and deleting the identifier when receiving a SIP response. It is an object of the present invention to provide a priority control apparatus, a SIP system, a priority control program, and a priority control method that can suppress an increase in information used for the above.

  In order to solve the first and second problems, the identifier stored in the SIP request determined to be low priority, and the identifier of the SIP request that has already been received by the priority control device and is being processed or waiting for processing (hereinafter referred to as the request) A function for determining whether the corresponding SIP request is a SIP retransmission request, a function for deleting the identifier stored in the corresponding SIP response when receiving the SIP response, A function for adding an identifier of a SIP request that is a priority and not a SIP retransmission request to the in-process identifier is introduced.

  With these functions, the in-process identifier includes “storing in low priority queue” or “transferring SIP request between SIP server and priority control device” or “processing in SIP server” or “priority control with SIP server” Only the identifier of the SIP request that is in the state of “transferring the processing result (SIP response) between devices” is stored. That is, the SIP request indicated by the identifier stored in the in-process identifier already exists in the priority control apparatus or SIP server, and indicates that the SIP request is being processed (or scheduled to be processed). For this reason, when a SIP request holding an identifier existing in the in-process identifier is received from the UA, it can be determined that it is not necessary to transfer the SIP request to the SIP server. By executing this determination before inserting the SIP request into the low priority queue, it is possible to prevent an extra SIP retransmission request from being inserted into the low priority queue.

  Furthermore, the third problem is that the low priority and the function of adding the identifier of the SIP request that is not the SIP retransmission request to the processing identifier, and the identifier stored in the SIP response when the SIP response is received are being processed. It can be solved with the function of deleting from the identifier.

  With these functions, the identifier stored in the priority control device can be limited to only those that already exist in the priority control device or SIP server and identify a SIP request that is being processed (or scheduled to be processed), and the processing is already completed. This is because storage of the identifier of the SIP request that has been made can be prevented.

  According to the present invention, the effects described below can be achieved.

  The first effect is that the number of SIP transactions that can be processed by the SIP server per unit time can be increased.

  This is because the processing request identifier always stores only the identifier of the SIP request that is already present in the priority control apparatus or SIP server and is being processed (or scheduled to be processed), and the identifier held by the SIP request received from the UA is By checking whether it exists in the in-process identifier, it is determined whether it is necessary to forward to the SIP server, and this determination is performed before inserting the SIP request into the low priority queue. This is because an extra SIP retransmission request can be prevented from being inserted.

  A second effect is that an increase in information for determining whether a received SIP request is a retransmission can be suppressed.

  This is due to the low priority and the function of adding an identifier of a SIP request that is not a SIP retransmission request to the in-process identifier, and the function of deleting the identifier stored in the SIP response when receiving the SIP response from the in-process identifier This is because the identifier stored in the priority control apparatus can be limited to only an identifier that already exists in the priority control apparatus or SIP server and indicates a SIP request that is being processed (or scheduled to be processed).

(First embodiment)
Next, the first embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of the first embodiment)
FIG. 1 shows a configuration diagram of a priority control apparatus 101 according to the first embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the first embodiment of the present invention includes a general SIP proxy server function 111 and whether the message received by the SIP proxy server function 111 is a SIP request or SIP. A message type determination function 102 for determining whether it is a response, a SIP request priority determination function 105 for determining the priority of a SIP request according to the type of SIP request received by the SIP proxy server function 111, and a SIP request priority When the identifier stored in the SIP request determined by the determination function 105 as low priority is present in the in-process identifier, and when the identifier of the SIP request exists in the in-process identifier The SIP request discard function 107 for discarding the SIP request and the SIP request priority determination function 105 determine that the priority is low. In addition, an identifier adding function 108 for adding an identifier of a SIP request whose identifier does not exist in the in-process identifier to the in-process identifier, a in-process identifier storage function 104 for storing the in-process identifier, and storing in the SIP response when the SIP response is received Identifier deletion function 103 that deletes the generated identifier from the processing identifier, and a queue for each priority of the SIP request, and the SIP request received from the SIP request priority determination function 105 or the identifier addition function 108 according to the priority. The SIP request temporary storage function 109 to be inserted into the queue and the SIP request stored in the queue of the SIP request temporary storage function 109 have a priority so as not to exceed the SIP request processing capacity per unit time of the SIP server. Transfer SI that is extracted in accordance with and transferred to the SIP server via the SIP proxy server function 111 It consists request extractor 110.. Here, the in-process identifier is, for example, the value of the Call-ID header stored in the SIP request as shown in FIG.

(Operation of the first embodiment)
Next, the operation of the priority control apparatus 101 according to the first embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 3 is a flowchart showing an operation when receiving a message from the outside in the priority control apparatus 101 according to the first embodiment of the present invention. In this operation, the priority of the received SIP request is assumed to be “high priority” and “low priority”, but the same operation is performed even when multi-level priority is introduced.

  Now, it is assumed that the SIP proxy server function 111 receives a message from the outside (step S301). Then, the message type determination function 102 investigates the type of the received message (step S302).

  When the message received in step S301 is a SIP response as a result of step 302, the identifier deletion function 103 uses the identifier stored in the SIP response received in step S301 from the processing identifier held by the processing identifier storage function 104. Is deleted (step S303). This process can be realized as follows, for example. If the in-process identifier is in a table format as shown in FIG. 2, the value of the Call-ID header included in the SIP response received in step S301 is extracted, and the in-process identifier is searched using this value as a key. If an entry is found for the in-process identifier, the entry is deleted.

  After deleting the identifier in step S303, the SIP proxy server function 111 transmits a SIP response to the destination described in the SIP response (step S304). Then, it repeats again from step S301.

  As a result of step S302, when the message received by the SIP proxy server function 111 is a SIP request, the SIP request priority determination function 105 determines the priority of the SIP request (step S305). This process can be realized by, for example, predetermining the priority according to the type of SIP request, such as “low priority” for the initial INVITE request and “high priority” for the other SIP requests.

  If it is determined in step S305 that the priority of the SIP request is low priority, the identifier existence confirmation function 106 has the identifier stored in the SIP request received by the SIP proxy server function 111 in the in-process identifier. It is confirmed whether to do (step S306). This process can be realized as follows, for example. If the in-process identifier has a table format as shown in FIG. 2, the value of the Call-ID header included in the SIP request received in step S301 is extracted, and the in-process identifier is searched using this value as a key. As a result of this search, when there is an entry holding the value of the corresponding Call-ID header, it is determined as “existing”, and when it does not exist, it is determined as “not existing”.

  As a result of step S306, when the identifier of the SIP request received in step S301 exists in the in-process identifier, the SIP request discard function 107 discards the corresponding SIP request as a SIP retransmission request (step 307). Then, it repeats from step S301.

  As a result of step S306, when the identifier of the SIP request received in step S301 does not exist in the processing identifier, the identifier adding function 108 adds the identifier of the corresponding SIP request to the processing identifier (step S308). This process can be realized as follows, for example. If the in-process identifier is in a table format as shown in FIG. 2, the value of the Call-ID header included in the SIP request received in step S301 is extracted, and the entry storing this value is added to the in-process identifier. .

  As a result of step S305, when it is determined that the SIP request received in step S301 is of high priority, or as a result of step S308, addition processing to the in-process identifier is completed, the SIP request temporary storage function 109 performs SIP request. The request is stored in a queue corresponding to the priority (step S309). Then, it repeats from step S301.

  Next, an operation when the priority control apparatus 101 according to the first embodiment of the present invention transfers a SIP request to the SIP server will be described.

  FIG. 4 shows a case where the priority control apparatus 101 according to the first embodiment of the present invention transfers the SIP request stored in the SIP request temporary storage function 109 to the SIP server via the SIP proxy server function 111. It is a flowchart which shows operation | movement.

  First, the transfer SIP request extraction function 110 extracts a SIP request from the SIP request temporary storage function 109 to determine whether the SIP server reaches a SIP request amount that can be processed per unit time (step 401). This process can be realized as follows, for example. The transfer SIP request extraction function 110 stores in advance the number of SIP requests that can be processed by the SIP server per unit time, and sets a timer for each unit time. Further, the transfer SIP request extraction function 110 manages the number of transferred SIP requests as a variable.

  The transfer SIP request extraction function 110 checks whether the number of transferred SIP requests is equal to the number of SIP requests that the SIP server can process per unit time, and if not, the SIP server can process per unit time. It is determined that the number of SIP requests has not been reached, and the number of transferred SIP requests is increased by one. On the other hand, if equal, it is determined that the SIP server has reached the number of SIP requests that can be processed per unit time. The number of transferred SIP requests is reset to 0 every time the timer expires.

  As a result of step S401, when it is determined that the SIP server has not reached the number of SIP requests that can be processed per unit time, the transfer SIP request extraction function 110 further transfers the SIP request to be transferred to the SIP request temporary storage function. 109 is extracted (step S402). This process, for example, confirms the existence of SIP requests in order from the high priority queue while preventing the sinking of SIP requests stored in the low priority queue, as in the prior art described in Patent Document 1. This can be realized by extracting the corresponding SIP request.

  If the extraction of the SIP request to be transferred is completed as a result of step S402, the SIP proxy server function 111 transfers the SIP request to the SIP server (step S403).

  As a result of step S401, when it is determined that the SIP server has reached the number of SIP requests that can be processed per unit time, or as a result of step S403, the SIP proxy server function 111 forwards the SIP request to the SIP server. If so, repeat from step S401.

(Effects of the first embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  This is because the identifier of the SIP request already existing in the priority control apparatus or SIP server and being processed (or scheduled to be processed) is always stored in the processing identifier, so that the SIP request received from the UA is transferred to the SIP server. This is because it is possible to prevent an extra SIP retransmission request from being inserted into the low priority queue by determining whether it is necessary and executing this determination before inserting the SIP request into the low priority queue.

  Furthermore, according to the present embodiment, it is possible to suppress an increase in the in-process identifier for determining whether the received SIP request is a retransmission.

  This is because the identifier addition function 108 determines that the SIP request priority determination function 105 determines low priority, and inserts the identifier of the SIP request whose identifier does not exist in the in-process identifier into the low priority queue. And the identifier deletion function 103 deletes the identifier stored in the SIP response when receiving the SIP response from the in-process identifier so that the identifier stored in the in-process identifier This is because it can be limited to only those that exist in the SIP server and indicate a SIP request that is being processed (or scheduled to be processed).

(Second Embodiment)
Next, a second embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of Second Embodiment)
FIG. 5 shows a configuration diagram of the priority control apparatus 101 according to the second embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the second embodiment of the present invention includes an identifier deletion function 103 and other functions in the configuration of the priority control apparatus 101 according to the first embodiment of the present invention. The connection relationship is changed. Specifically, not the message type determination function 102 but the transfer SIP request extraction function 110 activates the identifier deletion function 103. As a result, only the identifier of the SIP request in the state of “stored in the low priority queue” is stored in the in-process identifier stored by the in-process identifier storage function 104. Note that each function constituting the priority control apparatus 101 according to the second embodiment of the present invention has the same function as each function constituting the priority control apparatus 101 according to the first embodiment of the present invention.

(Operation of Second Embodiment)
Next, the operation of the priority control apparatus 101 according to the second embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 6 is a flowchart showing an operation when receiving a message from the outside in the priority control apparatus 101 according to the second embodiment of the present invention. The difference between the flowchart in FIG. 6 and the flowchart in the priority control apparatus 101 according to the first embodiment of the present invention shown in FIG. 3 is received by the message type determination function 102 and the SIP proxy server function 111. When it is determined that the received message is a SIP response (the processing result of step S602), a process (step S603) in which the SIP proxy server function 111 transfers the SIP response is executed.

  Next, an operation when the priority control apparatus 101 according to the second embodiment of the present invention transfers a SIP request to the SIP server will be described.

  FIG. 7 shows an operation when the priority control apparatus 101 according to the second embodiment of the present invention transfers the SIP request stored in the SIP request temporary storage function 109 to the SIP server via the SIP proxy server function 111. It is a flowchart which shows. The difference between the flowchart in FIG. 7 and the flowchart in the priority control apparatus 101 according to the first embodiment of the present invention shown in FIG. 4 is that the transfer SIP request extraction function 110 has extracted the SIP request to be transferred. Later (step S702), the identifier deletion function 103 adds a process (step S703) for deleting the identifier stored in the SIP request from the in-process identifier. Note that the processing in step S703 is the same as the processing in step S303 in the priority control apparatus 101 according to the first embodiment of the present invention shown in FIG.

(Effect of the second embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  This is because the identifier of the SIP request that already exists in the priority control apparatus 101 is always stored in the in-process identifier, thereby determining whether the SIP request received from the UA needs to be transferred to the SIP server. This is because it is possible to prevent an extra SIP retransmission request from being inserted into the low priority queue by executing the SIP request before inserting it into the low priority queue.

  Furthermore, according to the present embodiment, it is possible to suppress an increase in the in-process identifier for determining whether the received SIP request is a retransmission.

  This is because the identifier addition function 108 determines that the SIP request priority determination function 105 determines low priority, and inserts the identifier of the SIP request whose identifier does not exist in the in-process identifier into the low priority queue. In addition, the identifier deletion function 103 deletes the identifier of the SIP request from the processing identifier before transferring the SIP request to the SIP server via the SIP proxy server function 111. This is because the identifier stored in the in-process identifier can be limited to only those indicating SIP requests existing in the priority control apparatus.

(Third embodiment)
Next, a third embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of the third embodiment)
FIG. 8 shows a configuration diagram of the priority control apparatus 101 according to the third embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the third embodiment of the present invention is the SIP proxy server function 111 in the priority control apparatus 101 according to the first and second embodiments of the present invention. In addition to the message type determination function 102, the SIP request priority determination function 105, the SIP request discard function 107, the SIP request temporary storage function 109, and the transfer SIP request extraction function 110, the SIP request priority determination function 105 determines low priority. The identifier extraction function 803 that extracts the identifier of the SIP request that has been made, and the SIP request that retains the same identifier as the identifier extracted by the identifier extraction function 803 has already been inserted into the low priority queue that the SIP request temporary storage function 109 retains A queue search function 804 for searching whether or not there is a queue. The identifier extracted by the identifier extraction function 803 is, for example, the value of the Call-ID header stored in the SIP request.

(Operation of the third embodiment)
Next, the operation of the priority control apparatus 101 according to the third embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 9 is a flowchart showing the operation when a priority control apparatus 101 according to the third embodiment of the present invention receives a message from the outside.

  Now, it is assumed that the SIP proxy server function 111 receives a message from the outside (step S901). Then, the message type determination function 102 investigates the type of the received message (step S902).

  If the message received in step S901 is a SIP response as a result of step 902, the SIP proxy server function 111 transmits the SIP response to the destination described in the SIP response (step S903). Then, it repeats again from step S901.

  As a result of step S902, when the message received by the SIP proxy server function 111 is a SIP request, the SIP request priority determination function 105 determines the priority of the SIP request (step S904). This process is the same as the operation (step S305 and step S604) of the SIP request priority determination function 105 in the first and second embodiments of the present invention.

  If it is determined in step S904 that the priority of the SIP request is low priority, the identifier extraction function 803 extracts the identifier stored in the SIP request (step S905). This process can be realized, for example, by extracting the value of the Call-ID header included in the SIP request. Thereafter, the queue search function 804 searches whether a SIP request holding the identifier extracted in step S905 has already been inserted in the low priority queue (step S906).

  This process can be realized as follows, for example. First, the value of the Call-ID header stored in the SIP request at the head of the low priority queue is extracted and compared with the value of the Call-ID header received from the identifier extraction function 803. As a result, if they match, the process ends as “exist”, and if they do not match, the same process is executed again for the second SIP request from the top. This processing is executed in order from the top of the low priority queue, and if the values of the Call-ID headers of all SIP requests do not match, the processing ends as “does not exist”.

  As a result of step S906, if there is a SIP request holding the same identifier in the queue, it is recognized as a SIP retransmission request, and the SIP request discard function 107 discards the corresponding SIP request (step 907). Then, it repeats from step S901.

  As a result of step S904, if it is determined that the SIP request received in step S901 has high priority, or if it is determined in step S906 that there is no SIP request holding the same identifier in the queue, the SIP request The request temporary storage function 109 stores the SIP request in a queue corresponding to the priority (step S908). Then, it repeats from step S901.

  Next, the operation when the priority control apparatus 101 according to the third embodiment of the present invention transfers a SIP request to the SIP server will be described. The operation when the priority control apparatus 101 according to the third embodiment of the present invention forwards the SIP request to the SIP server is the same as the priority control apparatus according to the first embodiment of the present invention shown in FIG. The operation is the same as that in 101.

(Effect of the third embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  This determines whether the SIP request received from the UA needs to be transferred to the SIP server by comparing the received SIP request identifier with the identifier of the SIP request already inserted in the low priority queue. This is because it is possible to prevent an extra SIP retransmission request from being inserted into the low priority queue by executing the determination before inserting the SIP request into the low priority queue.

  Furthermore, according to the present embodiment, it is possible to determine retransmission of a SIP request without using information for determining whether the received SIP request is retransmission.

  This is realized by sequentially comparing the identifier of the received SIP request with the identifier of the SIP request inserted in the low priority queue held by the SIP request temporary storage function 109. Because it is.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of the fourth embodiment)
FIG. 10 shows a configuration diagram of the priority control apparatus 101 according to the fourth embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the fourth embodiment of the present invention is the same as the SIP proxy in the priority control apparatus 101 according to the first, second, and third embodiments of the present invention. In addition to the server function 111, the message type determination function 102, the SIP request priority determination function 105, the SIP request discard function 107, the SIP request temporary storage function 109, and the transfer SIP request extraction function 110, the SIP request priority determination function 105 is low. Insertion time adding function 1002 for adding a time when a SIP request determined to be priority is inserted into the low priority queue held by the SIP request temporary storage function 109, and an insertion time for storing the time when the SIP request is inserted into the low priority queue Check whether the SIP requests extracted by the storage function 1001 and the forwarding SIP request extraction function 110 have expired. And expiration date confirmation function 1004, and a insertion time deletion function 1003 Metropolitan Remove insertion time of the corresponding SIP request from the insertion time for inserting time storage function 1001 is held.

  Here, the insertion time stored by the insertion time storage function 1001 is, for example, in the form shown in FIG. In FIG. 11, the value of the Call-ID header that is the identifier of the SIP request and the insertion time expressed as milliseconds are stored in pairs. In the SIP protocol, the time during which the SIP request is valid is defined, and if the SIP response is not returned even after the corresponding time is exceeded, a timeout occurs and the SIP transaction ends. For example, in the case of an INVITE request, the timeout time is generally 32 seconds. That is, an INVITE request that has been retained for 32 seconds or more in the priority control apparatus 101 becomes meaningless because the UA that is the transmission source has timed out even if the processing is completed in the SIP server. In the fourth embodiment of the present invention, the insertion time is temporarily stored at the time of queue insertion, the expiration date confirmation function 1004 confirms whether it is timed out, and if it is timed out, discards the processing, meaningless processing to the SIP server SIP request forwarding that triggers

(Operation of the fourth embodiment)
Next, the operation of the priority control apparatus 101 according to the fourth embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 12 is a flowchart showing an operation when receiving a message from the outside in the priority control apparatus 101 according to the fourth embodiment of the present invention.

  Now, it is assumed that the SIP proxy server function 111 receives a message (step S1201). Next, the message type determination function 102 investigates the type of the corresponding message (step S1202).

  If the received message is a SIP response as a result of step S1202, the SIP proxy server function 111 transmits the SIP response to the destination described in the SIP response (step S1206). Then, it repeats from step S1201.

  If the received message is a SIP request as a result of step S1202, the SIP request priority determination function 105 determines the priority of the corresponding SIP request (step S1203). This processing is the same as the processing (step S305, step S604, step S904) in the priority control apparatus 101 according to the first, second, and third embodiments of the present invention.

  If it is determined in step S1203 that the priority of the SIP request is low priority, the insertion time addition function 1002 adds the insertion time of the SIP request to the insertion time held by the insertion time storage function 1001 ( Step S1204). This processing is as follows, for example, when the insertion time is in the form shown in FIG. The insertion time addition function 1002 extracts the value of the Call-ID header of the SIP request received from the SIP request priority determination function 105, and further acquires the current time expressed as milliseconds. Thereafter, the value of the Call-ID header and the current time are added as a set to the insertion time.

  If the SIP request priority is determined to be high priority as a result of step S1203, or if the insertion time addition processing is completed as a result of step S1204, the SIP request temporary storage function is in accordance with the priority. The corresponding SIP request is inserted into the queue (step S1205). Then, it repeats from step S1201.

  Next, an operation when the priority control apparatus 101 according to the fourth embodiment of the present invention transfers a SIP request to the SIP server will be described.

  FIG. 13 shows the operation when the priority control apparatus 101 according to the fourth embodiment of the present invention transfers the SIP request stored in the SIP request temporary storage function 109 to the SIP server via the SIP proxy server function 111. It is a flowchart which shows.

  Now, the transfer SIP request extraction function 110 checks whether the SIP server can be processed by extracting the SIP request next (step S1301). This process is the same as the process (step S401) in the priority control apparatus 101 according to the first embodiment of the present invention.

  As a result of step S1301, when it is determined that the processing capacity of the SIP server has been reached, the processing is repeated again from step S1301.

  If it is determined as a result of step S1301 that the processing capacity of the SIP server has not been reached, the transfer SIP request extraction function 110 further extracts the SIP request to be transferred (step S1302). This process is the same as the process (step S402) in the priority control apparatus 101 according to the first embodiment of the present invention. Next, the expiration date checking function 110 checks whether the SIP request insertion time extracted as a result of step S1302 exists (step S1303).

  This processing can be realized as follows, for example, when the insertion time stored by the insertion time storage function 1001 is realized in the form shown in FIG. First, the insertion time storage function 1004 extracts the value of the Call-ID header stored in the SIP request received from the transfer SIP request extraction function 110. Next, the insertion time held by the insertion time storage function 1001 is searched using the value of the Call-ID header as a key. As a result, when an entry holding the value of the corresponding Call-ID header is searched, “exist” is determined, and when not searched, it is determined “not exist”.

  If the insertion time exists as a result of step S1303, the expiration date checking function 1004 further checks whether the expiration date of the SIP request extracted in step S1302 is invalid (step S1304). This processing can be realized as follows, for example, when the insertion time stored by the insertion time storage function 1001 is realized in the form shown in FIG. First, the expiration date confirmation function 1004 extracts the value of the Call-ID header of the SIP request extracted as a result of step S1302, and uses the value of the corresponding Call-ID header as a key to determine the insertion time stored by the insertion time storage function 1001. Search for. As a result, the time (in milliseconds) when the SIP request having the value of the corresponding Call-ID header is inserted into the queue is obtained.

  Next, the expiry date confirmation function 1004 acquires the current time in milliseconds and compares it with the queue insertion time acquired earlier. In general, in the SIP protocol, the expiration date of the INVITE request is 32 seconds (32000 milliseconds). Therefore, if the difference between the insertion time and the current time is 32000 milliseconds or more, the SIP extracted in step S1302 The request is determined as “expired”, while if the difference between the insertion time and the current time is less than 32000 milliseconds, it is determined as “not expired”.

  As a result of step S1304, when it is determined that the SIP request extracted as a result of step S1302 has expired, the SIP request discard function 107 discards the corresponding SIP request (step S1306). Thereafter, the insertion time deletion function 1003 deletes the insertion time of the corresponding SIP request (step S1305).

  This processing can be realized as follows, for example, when the insertion time stored by the insertion time storage function 1001 is realized in the form shown in FIG. First, the insertion time deletion function 1003 extracts the value of the Call-ID header of the SIP request extracted in step S1302. Next, the insertion time deletion function 1003 searches for and deletes the entry holding the value of the corresponding Call-ID header at the insertion time held by the insertion time storage function 1001. Then, it repeats from step S1302.

  If it is determined as a result of step S1304 that the SIP request extracted as a result of step S1302 has not expired, the insertion time deletion function 1003 deletes the insertion time of the corresponding SIP request (step S1305). The contents of this processing are as described above.

  When the insertion time does not exist as a result of step S1303, or when the insertion time deletion function 1003 deletes the insertion time regarding the SIP request extracted as a result of step S1302 as a result of step S1305, the SIP proxy server function 111. However, the SIP request extracted in step S1302 is transferred to the SIP server (step S1307). Then, it repeats from step S1307.

(Effect of the fourth embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  This is because, in the SIP protocol, considering that the SIP request transmitted from the UA has an expiration date, the expiration time is confirmed when the insertion time is temporarily stored when the queue is inserted and the SIP request is transferred to the SIP server. 1004 checks whether the SIP request to be forwarded has expired, and if it expires, discards it and induces meaningless processing to the SIP server. This is because forwarding of SIP requests is suppressed.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of Fifth Embodiment)
FIG. 14 shows a configuration diagram of the priority control apparatus 101 according to the fifth embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the fifth embodiment of the present invention includes the configuration of the priority control apparatus 101 according to the first embodiment of the present invention shown in FIG. And the configuration of the priority control apparatus 101 according to the fourth embodiment of the present invention shown in FIG. The function group constituting the priority control apparatus 101 according to the fifth embodiment of the present invention includes the function group constituting the priority control apparatus 101 according to the first embodiment of the present invention, and It has the same function as the function group which comprises the priority control apparatus 101 which concerns on 4th Embodiment.

(Operation of the fifth embodiment)
Next, the operation of the priority control apparatus 101 according to the fifth embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 15 is a flowchart showing an operation when receiving a message from the outside in the priority control apparatus 101 according to the fifth embodiment of the present invention.

  As shown in this figure, this flowchart shows the identifier addition processing (step S1508) to the in-process identifier in the operation of the priority control apparatus 101 according to the first embodiment of the present invention shown in FIG. In this mode, the processing of the insertion time addition function 1002 (step S1509) is inserted.

  Next, the operation when the priority control apparatus 101 according to the fifth embodiment of the present invention transfers a SIP request to the SIP server will be described. This operation is the same as the operation in the priority control apparatus 101 according to the fourth embodiment of the present invention shown in FIG.

(Effect of 5th Embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  First, the SIP request received from the UA is stored in the SIP server by always storing the identifier of the SIP request already existing in the priority control device or SIP server and being processed (or scheduled to be processed). It is determined whether transfer is necessary, and this determination is performed before the SIP request is inserted into the low priority queue, thereby preventing an extra SIP retransmission request from being inserted into the low priority queue. In the protocol, considering that the SIP request transmitted from the UA has an expiration date, the insertion time is temporarily stored when the queue is inserted, and the expiration date confirmation function 1004 transfers the SIP request when transferring the SIP request to the SIP server. A priority system that induces meaningless processing in the SIP server by checking whether the SIP request has expired and discarding it if it has expired. And expiration date or the residence in the apparatus 101 because that suppresses the transfer of the SIP request.

  Furthermore, according to the present embodiment, it is possible to suppress an increase in the in-process identifier for determining whether the received SIP request is a retransmission.

  This is because the identifier addition function 108 determines that the SIP request priority determination function 105 determines low priority, and inserts the identifier of the SIP request whose identifier does not exist in the in-process identifier into the low priority queue. And the identifier deletion function 103 deletes the identifier stored in the SIP response when receiving the SIP response from the in-process identifier so that the identifier stored in the in-process identifier This is because it can be limited to only those that exist in the SIP server and indicate a SIP request that is being processed (or scheduled to be processed).

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of the sixth embodiment)
FIG. 16 shows a configuration diagram of the priority control apparatus 101 according to the sixth embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the sixth embodiment of the present invention includes the configuration of the priority control apparatus 101 according to the second embodiment of the present invention shown in FIG. And the configuration of the priority control apparatus 101 according to the fourth embodiment of the present invention shown in FIG. Note that the function group constituting the priority control apparatus 101 according to the sixth embodiment of the present invention includes the function group constituting the priority control apparatus 101 according to the second embodiment of the present invention and the function group of the present invention. It has the same function as the function group which comprises the priority control apparatus 101 which concerns on 4th Embodiment.

(Operation of the sixth embodiment)
Next, the operation of the priority control apparatus 101 according to the sixth embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 17 is a flowchart showing an operation when receiving a message from the outside in the priority control apparatus 101 according to the fifth embodiment of the present invention.

  As shown in this figure, this flowchart shows the identifier addition process (step S1707) to the in-process identifier in the operation of the priority control apparatus 101 according to the second embodiment of the present invention shown in FIG. In this mode, the processing of the insertion time addition function 1002 (step S1708) is inserted.

  Next, an operation when the priority control apparatus 101 according to the sixth embodiment of the present invention transfers a SIP request to the SIP server will be described.

  FIG. 18 is a flowchart showing an operation when the priority control apparatus 101 according to the sixth embodiment of the present invention transfers a SIP request to the SIP server. As shown in this figure, this flowchart shows after the processing (step S1806) of deleting the SIP request insertion time in the operation of the priority control apparatus 101 according to the fourth embodiment of the invention shown in FIG. This is a form in which processing for deleting the identifier described in the SIP request (step S1807) is inserted from the in-process identifier in the identifier deletion function 103.

(Effect of 6th Embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  First, it is determined whether or not the SIP request received from the UA needs to be transferred to the SIP server by always storing the identifier of the SIP request already existing in the priority control apparatus as the in-process identifier. Is executed before the SIP request is inserted into the low-priority queue, so that an extra SIP retransmission request is prevented from being inserted into the low-priority queue. Further, in the SIP protocol, the SIP request is valid for the SIP request transmitted from the UA. Considering the existence of a time limit, the insertion time is temporarily saved when a queue is inserted, and at the time when the SIP request is transferred to the SIP server, it is confirmed whether the SIP request transferred by the expiration date checking function 1004 has expired. However, if the expiration date has expired, the SIP request that causes meaningless processing to the SIP server is retained, and the priority control apparatus 101 stays above the expiration date. This is because that suppresses the transfer.

  Furthermore, according to the present embodiment, it is possible to suppress an increase in the in-process identifier for determining whether the received SIP request is a retransmission.

  This is because the identifier addition function 108 determines that the SIP request priority determination function 105 determines low priority, and inserts the identifier of the SIP request whose identifier does not exist in the in-process identifier into the low priority queue. In addition, the identifier deletion function 103 deletes the identifier of the SIP request from the processing identifier before transferring the SIP request to the SIP server via the SIP proxy server function 111. This is because the identifier stored in the in-process identifier can be limited to only those indicating SIP requests existing in the priority control apparatus.

(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described in detail with reference to the drawings.

(Configuration of the seventh embodiment)
FIG. 19 shows a configuration diagram of the priority control apparatus 101 according to the seventh embodiment of the present invention. As shown in this figure, the priority control apparatus 101 according to the seventh embodiment of the present invention includes the configuration of the priority control apparatus 101 according to the third embodiment of the present invention shown in FIG. And the configuration of the priority control apparatus 101 according to the fourth embodiment of the present invention shown in FIG. Note that the function group constituting the priority control apparatus 101 according to the seventh embodiment of the present invention includes the function group constituting the priority control apparatus 101 according to the third embodiment of the present invention, and the function group of the present invention. It has the same function as the function group which comprises the priority control apparatus 101 which concerns on 4th Embodiment.

(Operation of the seventh embodiment)
Next, the operation of the priority control apparatus 101 according to the seventh embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 20 is a flowchart showing an operation when receiving a message from the outside in the priority control apparatus 101 according to the seventh embodiment of the present invention.

  As shown in this figure, this flowchart shows whether the same identifier exists in the queue of the queue search function 804 in the operation of the priority control apparatus 101 according to the third embodiment of the present invention shown in FIG. When there is no result of the investigation (step S2006), the processing of the insertion time addition function 1002 (step S2008) is inserted.

  Next, an operation when the priority control apparatus 101 according to the sixth embodiment of the present invention transfers a SIP request to the SIP server will be described. This operation is the same as the operation in the priority control apparatus 101 according to the fourth embodiment of the present invention shown in FIG.

(Effect of 7th Embodiment)
Thus, according to the present embodiment, it is possible to increase the number of SIP transactions that the SIP server can process per unit time.

  This is done by first comparing the received SIP request identifier with the SIP request identifier already inserted in the low priority queue to determine whether the SIP request received from the UA needs to be forwarded to the SIP server. This determination is performed before the SIP request is inserted into the low priority queue, thereby preventing an extra SIP retransmission request from being inserted into the low priority queue. Considering the existence of an expiration date in the request, the SIP request transferred by the expiration date confirmation function 1004 has not expired when the insertion time is temporarily stored when the queue is inserted and the SIP request is transferred to the SIP server. The priority control device 101 stays over the expiration date, inducing meaningless processing to the SIP server by discarding the expiration date. This is because that suppresses the transfer of the SIP request.

  Furthermore, according to the present embodiment, it is possible to determine retransmission of a SIP request without using information for determining whether the received SIP request is retransmission.

  This is realized by sequentially comparing the identifier of the received SIP request with the identifier of the SIP request inserted in the low priority queue held by the SIP request temporary storage function 109. Because it is.

(SIP network configuration including priority control device)
Next, the SIP network including the priority control apparatus 101 according to the first to seventh embodiments of the present invention will be described in detail with reference to the drawings.

(Configuration of SIP network including priority control device)
FIG. 21 is a block diagram showing a SIP network including the priority control apparatus 101 according to the first to seventh embodiments of the present invention. As shown in this figure, the SIP network includes a SIP system 2101 composed of a conventional SIP server SS1 and the priority control apparatus 101 according to the first to seventh embodiments of the present invention, and a user agent UA1. , UA2, and a network 2102 connecting the SIP system 2101 and the user agents UA1 and UA2.

(Operation of SIP network including priority control device)
Next, the operation of the SIP network including the priority control apparatus 101 according to the first to seventh embodiments of the present invention will be described.

FIG. 22 is a sequence diagram showing an operation of the SIP network including the priority control apparatus 101 according to the first to seventh embodiments of the present invention.
As shown in this figure, the initial REGISTER request and the authentication REGISTER request transferred from the UA are judged to be high priority by the priority control device 101, and are quickly transferred to the SIP server so as not to exceed the SIP server processing capacity. Is done. As a result, the update of the UA information in the SIP server is executed without delay.

  On the other hand, the initial INVITE request is determined to have low priority and is inserted into the low priority queue. If the initial INVITE request stays in the priority control apparatus 101 as a result of the low priority determination as described above, the initial INVITE request is transmitted again from the UA according to a general SIP protocol retransmission mechanism (FIG. 22). Resend initial INVITE). In the priority control apparatus 101, since the initial INVITE request is already stored in the priority control apparatus 101, the received retransmission initial INVITE request is determined to be retransmission and discarded. Thereafter, when the transfer order of the low priority queue is reached, the initial INVITE request is transferred to the SIP server.

  Thus, by inserting the priority control apparatus 101 according to the first to seventh embodiments of the present invention between the UA and the SIP server, the expiration of the UA information and the transfer of the extra SIP request In addition, it is possible to prevent a high load state of the SIP server from being transferred due to a SIP request transfer that exceeds the SIP server's processable amount.

  Although the present invention has been described with reference to the preferred embodiments and examples, the present invention is not necessarily limited to the above-described embodiments and examples, and various modifications can be made within the scope of the technical idea. Can be implemented.

  The priority control apparatus of the present invention can be used in a SIP network having a plurality of user terminals and a SIP server.

It is a block diagram which shows the structure of the priority control apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the SIP retransmission request judgment information in the priority control apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the operation | movement in the case of transferring a SIP request to a SIP server in the priority control apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the priority control apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement in the case of transferring a SIP request to a SIP server in the priority control apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structure of the priority control apparatus which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the structure of the priority control apparatus which concerns on the 4th Embodiment of this invention. It is a figure which shows an example of the insertion time in the priority control apparatus which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement in the case of transferring a SIP request to a SIP server in the priority control apparatus which concerns on the 4th Embodiment of this invention. It is a block diagram which shows the structure of the priority control apparatus which concerns on the 5th Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 5th Embodiment of this invention. It is a block diagram which shows the structure of the priority control apparatus which concerns on the 6th Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 6th Embodiment of this invention. It is a flowchart which shows the operation | movement in the case of transferring a SIP request to a SIP server in the priority control apparatus which concerns on the 6th Embodiment of this invention. It is a block diagram which shows the structure of the priority control apparatus which concerns on the 7th Embodiment of this invention. It is a flowchart which shows the operation | movement at the time of receiving the message from the outside in the priority control apparatus which concerns on the 7th Embodiment of this invention. It is a block diagram which shows the structure of a SIP network including the priority control apparatus which concerns on the 1st thru | or 7th embodiment of this invention. It is a sequence diagram which shows operation | movement of a SIP network including the priority control apparatus which concerns on the 1st thru | or 7th embodiment of this invention. It is an operation | movement sequence diagram in the case of communicating between UA in a general SIP network. It is an operation | movement sequence diagram in the case of updating UA information in a general SIP network. It is a block diagram which shows the structure of the prior art 1. FIG. It is a block diagram which shows the structure of the prior art 2. FIG. It is a figure explaining the basic principle of the prior art 3. FIG.

Explanation of symbols

101: priority control device 102: message type determination function 103: identifier deletion function 104: in-process identifier storage function 105: SIP request priority determination function 106: identifier presence confirmation function 107: SIP request discard function 108: identifier addition function 109: SIP request temporary storage function 110: Forwarding SIP request extraction function 111: SIP proxy server function 803: Identifier extraction function 804: Queue search function 1001: Insert time storage function 1002: Insert time addition function 1003: Insert time deletion function 1004: Valid Deadline confirmation function 2101: SIP system 2102: Network SS1: SIP server UA1, UA2: User agent

Claims (21)

SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An identifier presence confirmation function for confirming whether the identifier stored in the SIP request determined by the SIP request priority determination function as low priority exists in the processing identifier that is the identifier of the SIP request currently being processed or scheduled to be processed; ,
A SIP request discard function for discarding the SIP request when the identifier of the SIP request exists in the in-process identifier;
An identifier adding function that adds an identifier of a SIP request that is determined to be low priority to the SIP request priority determination function and that does not have an identifier in the processing identifier, to the processing identifier;
In-process identifier storage function for storing in-process identifiers;
An identifier deletion function for deleting the identifier stored in the SIP response from the processing-in-progress identifier when the SIP response is received;
A SIP request temporary storage function that holds a queue for each priority of the SIP request and inserts the SIP request received from the SIP request priority determination function or the identifier addition function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processing capacity per unit time of the SIP server, and the SIP proxy server function is A forwarding SIP request extraction function for forwarding to a SIP server via
A priority control device comprising: SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An identifier presence confirmation function for confirming whether the identifier stored in the SIP request determined by the SIP request priority determination function as low priority exists in the processing identifier that is the identifier of the SIP request currently being processed or scheduled to be processed; ,
A SIP request discarding function for discarding the SIP request when the identifier of the SIP request exists in the in-process identifier;
An identifier adding function that adds an identifier of a SIP request that is determined to be low priority to the SIP request priority determination function and that does not have an identifier in the processing identifier, to the processing identifier;
In-process identifier storage function for storing in-process identifiers;
A SIP request temporary storage function that holds a queue for each priority of the SIP request and inserts the SIP request received from the SIP request priority determination function or the identifier addition function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processable amount per unit time of the SIP server, and is passed through the SIP proxy server function. A transfer SIP request extraction function for transferring to a SIP server,
An identifier deletion function for deleting the identifier stored in the SIP request extracted by the transfer SIP request extraction function from the in-process identifier;
A priority control device comprising: SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An identifier extraction function for extracting an identifier of a SIP request determined to be low priority by the SIP request priority determination function;
A queue search function for searching whether a SIP request holding the same identifier as the identifier extracted by the identifier extraction function is already inserted in the queue held by the SIP request temporary storage function;
A SIP request discard function for discarding the SIP request when the SIP request received by the SIP proxy server function is already in the queue by the queue search function;
A SIP request temporary storage function that holds a queue for each priority of a SIP request and inserts the SIP request received from the SIP request priority determination function or the queue search function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processing capacity per unit time of the SIP server, and the SIP proxy server function is A forwarding SIP request extraction function for forwarding to a SIP server via
A priority control device comprising: SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An insertion time addition function for adding a time at which the SIP request determined by the SIP request priority determination function is determined to be low priority to the low priority queue held by the SIP request temporary storage function;
An insertion time storage function for storing the time when the SIP request is inserted into the low priority queue;
A SIP request temporary storage function that holds a queue for each priority of the SIP request and inserts the SIP request received from the SIP request priority determination function or the identifier addition function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processing capacity per unit time of the SIP server, and the SIP proxy server function is A forwarding SIP request extraction function for forwarding to a SIP server via
An expiration date confirmation function for confirming whether the SIP request extracted by the transfer SIP request extraction function has exceeded the expiration date;
If the SIP request extracted by the transfer SIP request extraction function exceeds the expiration date as a result of the expiration date confirmation function, a SIP request discard function for discarding the corresponding SIP request;
An insertion time deletion function for deleting the insertion time of the corresponding SIP request from the insertion time held by the insertion time storage function;
A priority control device comprising: A priority control apparatus comprising the function of the priority control apparatus according to claim 1 and the function of the priority control apparatus according to claim 4. A priority control apparatus comprising the function of the priority control apparatus according to claim 2 and the function of the priority control apparatus according to claim 4. A priority control apparatus comprising the function of the priority control apparatus according to claim 3 and the function of the priority control apparatus according to claim 4. In the priority control device according to claim 1 and claim 5,
A priority control apparatus comprising a processing identifier storage function for storing a processing identifier that stores a Call-ID header value stored in a SIP request in a table format. The number of SIP requests that the SIP server can process per unit time is stored in advance, a timer is set for each unit time, and the transfer SIP request extraction function manages the number of transferred SIP requests as a variable. The number of transferred SIP requests is equal to the number of SIP requests that the SIP server can process per unit time, and if not, the number of SIP requests that the SIP server can process per unit time A transfer SIP request extraction function for determining that the number of SIP requests that have been transferred has increased by one, and that the number of SIP requests that the SIP server can process per unit time has been reached. The priority control apparatus according to any one of claims 1 to 7, wherein the priority control apparatus comprises: The value of the Call-ID header stored in the SIP request at the head of the low priority queue is extracted and compared with the value of the Call-ID header received from the identifier extraction function. If they do not match, the same process is executed again for the second SIP request from the top in order from the top of the low priority queue, and the values of the Call-ID headers of all SIP requests match. The priority control apparatus according to any one of claims 3 to 7, further comprising: a queue search function that terminates as “not present” if not. It is composed of an insertion time storage function for storing an insertion time composed of a value of a Call-ID header which is an identifier of a SIP request and a time to be inserted into a queue stored by the SIP request temporary storage function. The priority control apparatus according to any one of claims 4 to 7, characterized by: The transfer SIP request extraction function extracts the value of the Call-ID header of the SIP request, and searches for the insertion time stored by the insertion time storage function using the value of the corresponding Call-ID header as a key. Valid when the SIP request having the header value is inserted into the queue and compared with the current time, and the difference between the insertion time and the current time is greater than or equal to the expiration date specified by the SIP protocol 5. An expiration date confirmation function that determines that the expiration date is not expired while the difference between the insertion time and the current time is less than the expiration date. 8. The priority control apparatus according to any one of 7 above. 13. A SIP system comprising the priority control device according to claim 1 and a general SIP server. In a SIP system composed of a SIP server and a priority control device,
In the priority control device,
SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An identifier presence confirmation function for confirming whether the identifier stored in the SIP request determined by the SIP request priority determination function as low priority exists in the processing identifier that is the identifier of the SIP request currently being processed or scheduled to be processed; ,
A SIP request discard function for discarding the SIP request when the identifier of the SIP request exists in the in-process identifier;
An identifier adding function that adds an identifier of a SIP request that is determined to be low priority to the SIP request priority determination function and that does not have an identifier in the processing identifier, to the processing identifier;
In-process identifier storage function for storing in-process identifiers;
An identifier deletion function for deleting the identifier stored in the SIP response from the processing-in-progress identifier when the SIP response is received;
A SIP request temporary storage function that holds a queue for each priority of the SIP request and inserts the SIP request received from the SIP request priority determination function or the identifier addition function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processing capacity per unit time of the SIP server, and the SIP proxy server function is And a transfer SIP request extraction function for transferring to a SIP server via a priority control program. In a SIP system composed of a SIP server and a priority control device,
In the priority control device,
SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An identifier presence confirmation function for confirming whether the identifier stored in the SIP request determined by the SIP request priority determination function as low priority exists in the processing identifier that is the identifier of the SIP request currently being processed or scheduled to be processed; ,
A SIP request discarding function for discarding the SIP request when the identifier of the SIP request exists in the in-process identifier;
An identifier adding function that adds an identifier of a SIP request that is determined to be low priority to the SIP request priority determination function and that does not have an identifier in the processing identifier, to the processing identifier;
In-process identifier storage function for storing in-process identifiers;
A SIP request temporary storage function that holds a queue for each priority of the SIP request and inserts the SIP request received from the SIP request priority determination function or the identifier addition function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processable amount per unit time of the SIP server, and is passed through the SIP proxy server function. A transfer SIP request extraction function for transferring to a SIP server,
A priority control program that executes an identifier deletion function that deletes an identifier stored in a SIP request extracted by the transfer SIP request extraction function from an in-process identifier. In a SIP system composed of a SIP server and a priority control device,
In the priority control device,
SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An identifier extraction function for extracting an identifier of a SIP request determined to be low priority by the SIP request priority determination function;
A queue search function for searching whether a SIP request holding the same identifier as the identifier extracted by the identifier extraction function is already inserted in the queue held by the SIP request temporary storage function;
A SIP request discard function for discarding the SIP request when the SIP request received by the SIP proxy server function is already in the queue by the queue search function;
A SIP request temporary storage function that holds a queue for each priority of a SIP request and inserts the SIP request received from the SIP request priority determination function or the queue search function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processing capacity per unit time of the SIP server, and the SIP proxy server function is And a transfer SIP request extraction function for transferring to a SIP server via a priority control program. In a SIP system composed of a SIP server and a priority control device,
In the priority control device,
SIP proxy server function,
A message type determination function for determining whether a message received by the SIP proxy server function is a SIP request or a SIP response;
A SIP request priority determination function for determining the priority of the SIP request according to the type of the SIP request received by the SIP proxy server function;
An insertion time addition function for adding a time at which the SIP request determined by the SIP request priority determination function is determined to be low priority to the low priority queue held by the SIP request temporary storage function;
An insertion time storage function for storing the time when the SIP request is inserted into the low priority queue;
A SIP request temporary storage function that holds a queue for each priority of the SIP request and inserts the SIP request received from the SIP request priority determination function or the identifier addition function into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage function is extracted according to the priority so as not to exceed the SIP request processing capacity per unit time of the SIP server, and the SIP proxy server function is A forwarding SIP request extraction function for forwarding to a SIP server via
An expiration date confirmation function for confirming whether the SIP request extracted by the transfer SIP request extraction function has exceeded the expiration date;
If the SIP request extracted by the transfer SIP request extraction function exceeds the expiration date as a result of the expiration date confirmation function, a SIP request discard function for discarding the corresponding SIP request;
An insertion time deletion function for deleting the insertion time of the SIP request from the insertion time held by the insertion time storage function. A priority control method by the priority control device of a SIP system composed of a SIP server and a priority control device,
A message type determination step of determining whether a message received by the SIP proxy server is a SIP request or a SIP response;
SIP request priority determination step for determining the priority of the SIP request according to the type of SIP request received by the SIP proxy server;
An identifier existence confirmation step for confirming whether or not the identifier stored in the SIP request determined by the SIP request priority determination step as a low priority exists in the in-process identifier that is the identifier of the SIP request currently being processed or scheduled to be processed; ,
A SIP request discarding step for discarding the SIP request when the identifier of the SIP request exists in the in-process identifier;
An identifier adding step of adding an identifier of a SIP request that is determined to be low priority in the SIP request priority determination step and that does not have an identifier in the processing identifier to the processing identifier;
A processing identifier storage step for storing a processing identifier;
An identifier deletion step of deleting the identifier stored in the SIP response from the processing-in-progress identifier when the SIP response is received;
A SIP request temporary storage step of holding a queue for each priority of the SIP request and inserting the SIP request received from the SIP request priority determination step or the identifier addition step into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage step is extracted according to the priority so as not to exceed the SIP request processable amount per unit time of the SIP server, and the SIP request is passed through the SIP proxy server. And a transfer SIP request extracting step for transferring to a SIP server. A priority control method by the priority control device of a SIP system composed of a SIP server and a priority control device,
A message type determination step of determining whether a message received by the SIP proxy server is a SIP request or a SIP response;
SIP request priority determination step for determining the priority of the SIP request according to the type of SIP request received by the SIP proxy server;
An identifier existence confirmation step for confirming whether or not the identifier stored in the SIP request determined by the SIP request priority determination step as a low priority exists in the in-process identifier that is the identifier of the SIP request currently being processed or scheduled to be processed; ,
A SIP request discarding step of discarding the SIP request when the identifier of the SIP request exists in the in-process identifier;
An identifier addition step of adding an identifier of a SIP request that is determined to be low priority in the SIP request priority determination step and has no identifier in the processing identifier to the processing identifier;
A processing identifier storage step for storing a processing identifier;
A SIP request temporary storage step of holding a queue for each priority of the SIP request and inserting the SIP request received from the SIP request priority determination step or the identifier addition step into the queue according to the priority;
The SIP request stored in the queue in the SIP request temporary storage step is extracted according to the priority so as not to exceed the SIP request processable amount per unit time of the SIP server, and is passed through the SIP proxy server. A forwarding SIP request extraction step for forwarding to a SIP server;
A priority control method comprising: an identifier deletion step of deleting the identifier stored in the SIP request extracted by the forwarding SIP request extraction step from the in-process identifier. A priority control method by the priority control device of a SIP system composed of a SIP server and a priority control device,
A message type determination step of determining whether a message received by the SIP proxy server is a SIP request or a SIP response;
SIP request priority determination step for determining the priority of the SIP request according to the type of SIP request received by the SIP proxy server;
An identifier extraction step for extracting an identifier of the SIP request determined as low priority in the SIP request priority determination step;
A queue search step for searching whether a SIP request holding the same identifier as the identifier extracted by the identifier extraction step is already inserted in the queue held by the SIP request temporary storage step;
A SIP request discarding step of discarding the SIP request when the SIP request received by the SIP proxy server is already in the queue by the queue search step;
A SIP request temporary storage step of holding a queue for each priority of the SIP request and inserting the SIP request received from the SIP request priority determination step or the queue search step into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage step is extracted according to the priority so as not to exceed the SIP request processable amount per unit time of the SIP server, and the SIP request is passed through the SIP proxy server. And a transfer SIP request extracting step for transferring to a SIP server. A priority control method by the priority control device of a SIP system composed of a SIP server and a priority control device,
A message type determination step of determining whether a message received by the SIP proxy server is a SIP request or a SIP response;
SIP request priority determination step for determining the priority of the SIP request according to the type of SIP request received by the SIP proxy server;
An insertion time adding step of adding a time at which the SIP request determined in the SIP request priority determination step is inserted into the low priority queue held by the SIP request temporary storage step;
An insertion time storage step for storing a time when the SIP request is inserted into the low priority queue;
A SIP request temporary storage step of holding a queue for each priority of the SIP request and inserting the SIP request received from the SIP request priority determination step or the identifier addition step into the queue according to the priority;
The SIP request stored in the queue of the SIP request temporary storage step is extracted according to the priority so as not to exceed the SIP request processable amount per unit time of the SIP server, and the SIP request is passed through the SIP proxy server. A transfer SIP request extraction step for transferring to the SIP server;
An expiration date confirmation step for confirming whether the SIP request extracted by the forwarding SIP request extraction step exceeds the expiration date;
A SIP request discarding step of discarding the SIP request if the SIP request extracted by the transfer SIP request extracting step exceeds the expiration date as a result of the expiration date confirmation step;
An insertion time deletion step of deleting the insertion time of the SIP request from the insertion time held by the insertion time storage step.

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