JP4541333B2 - Terminal device, system, method, and program - Google Patents

Description

  The present invention relates to an IP packet communication service using SIP (Session Initiation Protocol), and more particularly, to abnormality determination of a SIP message.

  Currently, IP packet communication services using SIP such as IP telephones are widespread. Taking an IP phone as an example, an example of call connection operation between terminals using SIP will be described with reference to FIG.

  FIG. 1 shows an example in which a terminal 1 and a terminal 2 are connected to a SIP server 3 that relays a SIP message. In the connection configuration shown in FIG. 1, the SIP server 3 associates the IP addresses of the terminals 1 and 2 with the SIP URI (hereinafter referred to as “identification name”) based on the requests from the terminals 1 and 2. And register. Further, when the SIP server 3 receives an INVITE request (session establishment request) destined for the identification name of the connection destination terminal 2 from the terminal 1, the SIP server 3 searches for the IP address of the connection destination terminal 2 based on the identification name, It has a function of transferring an INVITE request to the terminal 2. In the following, it is assumed that the IP address and identification name have been registered. In this example, a telephone number is used as the identification name.

  In FIG. 1, when a caller specifies a telephone number of the terminal 2 using the terminal 1 and performs a call operation, the terminal 1 transmits an INVITE request addressed to the telephone number of the terminal 2 to the SIP server 3 ( Step 1). The SIP server 3 that has received the INVITTE request transmits the INVITTE request to the terminal 2 (step 2).

  The terminal 2 emits a ringing tone and transmits a 180 Ringing response indicating that the calling is in progress (step 3). The 180 Ringing response is sent to the terminal 1 via the SIP server 3 (step 4). When the callee performs a response operation at the terminal 2, a 200 OK response is sent from the terminal 2 (step 5), and the 200 OK response is sent to the terminal 1 via the SIP server 3 (step 6). Thereafter, an ACK request is sent from the terminal 1 to the terminal 2 (steps 7 and 8), whereby a call (transmission and reception of voice packets by RTP) is performed between the terminal 1 and the terminal 2 (step 9). .

  FIG. 2 shows a configuration example of the INVITE request. FIG. 2 shows only information related to the present application. As shown in FIG. 2, the INVITE request includes a start line, a header part, and a body part in which media information is described. The start line includes the type of request (INVITE) and the identification name of the connection partner.

  The header part includes Via, From, to, and Call-ID headers. The Via header describes the route information of the device through which the message passes. In the example of FIG. 1, the identification name (or IP address) of the SIP server 3 is described in the Via header that has arrived at the terminal 2. When sending a response, the response is sent to the device immediately before the route information described in the Via header. The branch described in the Via header is transaction identification information, and a unique predetermined character string is assigned to each request.

  In the From header, the identification name of the request source terminal is described, and in the To header, the identification name of the request destination is described. The CAll-ID header describes identification information (referred to as CAll-ID) that groups a series of SIP messages related to one call and distinguishes them from the SIP messages of other calls.

  FIG. 3 shows a 180 Ringing response as an example of the response. As with the request, it includes a start line, a header part, and a body part. Note that a dialog ID is configured by a combination of a tag described in the From header field, a tag described in the to header, and Call-ID. A dialog is a connection relationship between a sender and a receiver in one session, and a dialog is uniquely identified by a dialog ID. Elements that make up a dialog include a sequence ID, URI, etc. in addition to the dialog ID. Hereinafter, information that can uniquely identify a connection between a sender and a receiver among elements constituting the dialog is referred to as dialog information.

  The SIP server 3 can store the dialog information described in the message and manage the dialog state. For example, when the INVITE request in FIG. 1 is received, the SIP server 3 records message type (INVITE), From tag information, and dialog information such as Call-ID. Then, the terminal 2 transmits a 180 Ringing response to the SIP server 3 according to the contents of the Via header, and when the SIP server 3 receives the 180 Ringing response, the SIP server 3 associates the response with the request previously transferred by itself. , 180 Check whether the dialog information described in the Ringing response exists in the dialog information already recorded in the SIP server 3, and if it does not exist, determine that there is no request corresponding to the response. Then, the response is discarded as an abnormal state.

For example, Patent Document 1 is a prior art document related to call control by SIP.
JP 2005-148794 A

  In the above prior art, since the terminal 2 sends a response to the device immediately before indicated in the route information of the Via header, the terminal that should not originally send the response to the Via header (other than the SIP server 3 in the above example) If the other party) is described as the immediately preceding device, there is a problem that a response is transmitted to the other party.

  Also, depending on the occurrence status and frequency of the abnormal state detected by comparing dialog information, it is necessary to analyze the abnormal state and grasp the cause of the occurrence, etc., but the conventional technology only discards the response as invalid traffic, There is a problem that an abnormal state cannot be analyzed.

  The present invention has been made in view of the above points, and enables a terminal to return a response only to a correct partner and to analyze an abnormal state detected by a SIP server based on comparison of dialog information. The purpose is to provide technology.

  The above-described problem is a terminal device having a function of establishing a session with another terminal device by performing transmission / reception of a request message and a response message with another terminal device via the session management device, Storage means for storing identification information of the session management device in which the address information of the terminal device is registered, and a request message originating from another terminal device are received, and the request message is transmitted from the request message to the terminal device. Of the session management device in which the immediately preceding device identification information indicating the device immediately preceding the terminal device among the devices that have passed through until reaching the terminal is extracted, and the immediately preceding device identification information stored in the storage device Determining means for determining whether the information is the same as the information; and by the determining means, the immediately preceding device identification information and the session management device And another information is resolved by the terminal device, characterized in that it comprises a reply message sending means for sending only a response message to the session management apparatus when it is determined to be the same.

  The determination means in the terminal device further determines whether the address of the transmission source of the request message is the same as the address of the session management device in which the address information of the terminal device is registered. When it is determined that the immediately preceding device identification information and the session management device identification information are the same, and the source address and the session management device address are not the same, the response message transmitting means An error response message including the address of the transmission source may be transmitted to the session management device.

  The present invention is a session management device that relays request messages and response messages transmitted and received between a plurality of terminal devices and manages a session between the plurality of terminal devices, and identifies a connection relationship between two terminal devices. Connection relation identification information for acquiring the connection relation identification information from a message transmitted and received between the two terminal devices, and storing the connection relation identification information in the storage means, and the connection relation identification included in the response message received from a certain terminal device A determination unit that determines whether information is stored in the storage unit; and the determination unit determines that the connection relationship identification information included in the response message is not stored in the storage unit. And an information storage means for storing predetermined information in the response message in the log storage means. It can also be configured as a device.

  The determination unit of the session management apparatus further determines whether or not the response message is a predetermined type of message, and the information storage unit is configured to identify a connection relationship included in the response message by the determination unit. When it is determined that information is not stored in the storage unit and the response message is a predetermined type of message, predetermined information in the response message may be stored in the log storage unit. Good.

  The “session management device” in the present specification and claims is a device for establishing and managing a communication session between terminals, and a SIP server is an example of a session management device. The dialog information in the specification is an example of connection relationship identification information.

  According to the present invention, the terminal device transmits a response message only when the immediately preceding device identification information is the same as the identification information of the session management device to which the terminal information is registered. Sending a message can be prevented. In addition, since the session management apparatus records the predetermined information of the response message determined to be in an abnormal state without the matching connection relationship identification information, it is possible to analyze the abnormal state thereafter.

  Embodiments of the present invention will be described below with reference to the drawings.

(Overview)
An outline of processing in the present embodiment will be described with reference to a sequence chart shown in FIG. Also in this embodiment, a configuration in which the terminal 1 and the terminal 2 are connected to the SIP server 3 is assumed as in FIG. In the present embodiment, it is assumed that each terminal holds the identification name and IP address of the SIP server 3 that is the registration destination of its information in the storage device.

  Terminal 1 sends an INVITE request to terminal 2 (step 11). The SIP server 3 that has received the INVITE request records the dialog information included in the INVITE request in the storage device. The SIP server 3 extracts the IP address of the terminal 2 from the identification name of the terminal 2 included as the destination in the INVITE request, and sends out the INVITE request with the IP address as the destination (step 12).

  The terminal 2 that received the INVITE request determines whether or not the transfer destination of the response described in the Via header is indeed the SIP server 3 that is the registration destination of the terminal information in addition to the normal operation in SIP (step) 13). If this determination result is OK, a response is transmitted to the SIP server 3 in the same manner as a normal operation (step 14). If this determination result is NG, the request is discarded and no response is transmitted (step 15).

  The SIP server 3 that has received the response determines whether or not the dialog information included in the response matches any of the dialog information held by the SIP server 3 (step 16). ) Performs a normal operation (step 17), but if they do not match (NG), it is determined to be in an abnormal state, and predetermined information in the response is recorded in the storage device as a log, and the response No transfer is performed (step 18).

  The processing according to the present embodiment makes it possible to send a response only to a legitimate partner. Further, since the SIP server 3 records the information of the response determined as an abnormal state, it is possible to analyze the abnormal state after that.

(Detailed configuration and detailed operation of terminal 2)
Next, the configuration and operation of the terminals 1 and 2 will be described in more detail. Since the terminals 1 and 2 have the same configuration, the configuration of the terminal 2 will be described as an example.

  The terminal 2 is realized by mounting a program for executing processing according to the present invention on an IP telephone terminal or a PC (personal computer) having a computer configuration including a CPU and a storage device. This program can be stored in a recording medium such as a CD-ROM or a memory and distributed, or can be distributed by downloading from a server on the network.

  The main functional configuration of the terminal 2 is shown in FIG. As illustrated in FIG. 5, the terminal 2 includes a network communication unit 21, an application unit 22, a SIP function unit 23, a validity determination unit 24, and a data storage unit 25.

  The network communication unit 21 has a function for performing data communication via the IP network. The application unit 22 has application functions such as a data communication function between terminals and a user interface function. The SIP function unit 23 has a function of establishing a call (session) by transmitting / receiving a message based on SIP. Further, the validity determination unit 24 has a function of determining the validity of a request including the function of performing the determination by checking the Via header described above. The data storage unit 25 is a functional unit that stores data referred to by the validity determination unit 24, and stores the identification name and IP address of the SIP server 3 to which the terminal information is registered.

  Next, the operation of the terminal 2 will be described in detail with reference to the flowchart of FIG.

  When the terminal 2 receives a request such as an INVITE request (step 21), it extracts the previous device identification name from the route information described in the Via header of the request, and the terminal information held in the data storage unit 25 It is determined whether or not it matches the identification name of the registration destination SIP server 3 (step 22). Of course, when an IP address is described instead of an identification name in the Via header, the IP address of the SIP server 3 is compared.

  As a result of the determination in step 22, if they match (Yes in step 22), the process proceeds to the next step. If they do not match (No in step 22), the received request is discarded and no response is returned (step 23).

  If the result of determination in step 22 is a match, it is determined whether or not the source IP address described in the header of the IP packet including the request matches the IP address of the SIP server 3 (step 24). . If they match (Yes in step 24), the process proceeds to the next step. If they do not match (No in step 24), an error response in which the transmission source IP address is described in the message (warning header or the like) is transmitted to the SIP server 3 (step 25).

  If the result of the determination in step 24 is a match, it is determined whether or not the request destination name (SIP URI described in the start line) matches its own identification name (step 26). If they match (Yes in step 26), the process proceeds to the next step. If they do not match (No in step 26), an error response is transmitted to the SIP server 3 (step 27).

  If it is determined in step 26 that they match, a response to the received request is transmitted to the SIP server 3 (step 28).

  In the flow shown in FIG. 6, the priority of determination is Via header> source IP address> destination name of request. The request determination process is not limited to that shown in FIG. Any process capable of realizing the operation shown in FIG. 7 may be used for each NG pattern of the determination result of each parameter.

  In the above processing, if the information of the immediately preceding device in the Via header route information is incorrect, the request is discarded and the response is not sent. In this case as well, an error response including incorrect route information is included. May be transmitted to the SIP server 3.

(Detailed configuration and detailed operation of SIP server)
Next, the configuration and operation of the SIP server 3 will be described in detail.

  The SIP server 3 is realized by mounting a program for executing processing according to the present invention in a computer including a CPU and a storage device. This program can be stored in a recording medium such as a CD-ROM or a memory and distributed, or can be distributed by downloading from a server on the network.

  The main functional configuration of the SIP server 3 is shown in FIG. As shown in FIG. 8, the SIP server 3 includes a network communication unit 31, a SIP function unit 32, an abnormal state detection unit 33, a log management unit 34, and a data storage unit 35.

  The network communication unit 31 has a function for performing data communication via the IP network. The SIP function unit 32 includes SIP-related functions such as a SIP proxy function, a SIP registrar function, and a function for accumulating dialog information in the data storage unit 35.

  The abnormal state detection unit 33 has a function of determining whether or not the response is abnormal based on the dialog information, and storing predetermined information included in the abnormal response in the data storage unit 35 as a log. The log management unit 34 has a function of shaping the log into information that can be easily viewed by the administrator, and notifying the monitoring apparatus of the information via the network, and a function of transmitting log information to the monitoring apparatus in response to a request from the monitoring apparatus. I have.

  Next, the operation of the SIP server 3 will be described with reference to the flowchart of FIG. As a premise of the processing of FIG. 9, the SIP server 3 is assumed to include means for accumulating and managing dialog information described in the request and response in the data storage unit 35.

  When the SIP server 3 receives the response (step 31), it searches the data storage unit 35 using the dialog information included in the response (step 32), and the dialog information that matches the dialog information in the response is stored in the data storage unit 35. It is determined whether it exists (step 33). If it exists (Yes in step 33), the normal processing is performed on the received response (step 34).

  Note that the error response transmitted to the SIP server 3 in steps 25 and 27 in FIG. 6 is highly likely that the corresponding request does not pass through the SIP server 3, so the determination in step 33 is No. Probability is high.

  If the determination result in step 33 is No, it is determined whether the received response is a log output target response (step 35). For example, a response to an INVITE request that has a predetermined response code is a log output target. In this case, it is determined in step 35 whether this condition is met. If it is determined in step 35 that the response is a log output target response (Yes in step 35), the log is stored in the data storage unit 35 (step 36), and the response is discarded (step 37). If it is not a log output target response (No in step 35), the response is discarded without storing the log.

  An example of the format of information stored in the data storage unit 35 as a log is shown in FIG. As shown in FIG. 10, the date and time when the log is stored, information indicating that it is an abnormal response (Illegal Response), response code (xxx), From information, to information, and warning header information are stored in association with each other. The As the From information, for example, a caller telephone number is recorded, and as the To information, for example, a callee number is recorded. As the warning information, the transmission source IP address included in the response message by the terminal 2 as described above is recorded.

  When an abnormal state is detected for the target response, the log may be stored in the data storage unit 35 and the log management unit 34 may notify the monitoring apparatus of the log information. Further, the log information may be referred to from the monitoring device without notifying the monitoring device of the log information when an abnormality is detected. By referring to the log information shown in FIG. 10, for example, the IP address of the transmission source that has transmitted the invalid request message can be known.

  The SIP server 3 according to the present embodiment, in addition to the message sent from the terminal having the function of judging the validity of the request message like the terminal 2 described above, the message from the terminal having no function of judging the validity It is also effective against In this case, for example, it is possible to identify the terminal that is the source of the abnormal state based on the From information of the response in which the dialog information is unmatched, and it is possible to take appropriate measures such as notification to the user .

(Effect of embodiment)
Since the request validity check function in the terminal 2 of the present embodiment returns the response only when the response to the request is returned to the correct return destination (registration destination SIP server), the terminal information included in the response is It can be prevented from being sent to a device other than the correct return destination, and unauthorized use of terminal information can be prevented. Further, the log storage function in the SIP server 3 makes it possible to analyze the abnormal state of the response and grasp the cause of the abnormality.

  The present invention is not limited to the above-described embodiment, and various modifications and applications can be made within the scope of the claims.

It is a figure which shows an example of the call connection operation | movement between the terminals using SIP. It is a figure which shows the structural example of an INVITE request. It is a figure which shows the structural example of a 180Ringing response. It is a sequence chart which shows the outline | summary of the process in embodiment of this invention. 3 is a diagram illustrating a main functional configuration of a terminal 2. FIG. 4 is a flowchart showing the operation of the terminal 2. It is a table | surface which shows the operation | movement for every pattern of the determination result of each parameter. 2 is a diagram showing a main functional configuration of a SIP server 3. FIG. 3 is a flowchart showing the operation of the SIP server 3. It is a figure which shows an example of the format of log information.

Explanation of symbols

1, 2 Terminal 3 SIP server 21 Network communication unit 22 Application unit 23 SIP function unit 24 Validity determination unit 25 Data storage unit 31 Network communication unit 32 SIP function unit 33 Abnormal state detection unit 34 Log management unit 35 Data storage unit

Claims (5)

A terminal device having a function of establishing a session with another terminal device by transmitting / receiving a request message and a response message with the other terminal device via the session management device,
Storage means for storing identification information of the session management device in which the address information of the terminal device is registered;
An immediately preceding device identification indicating a device immediately preceding the terminal device among devices that have been received from the request message until the request message arrives at the terminal device. Extraction means for extracting information;
Determination means for determining whether the immediately preceding apparatus identification information is the same as the identification information of the session management apparatus stored in the storage means;
Response message transmitting means for transmitting a response message to the session management apparatus only when the determination means determines that the immediately preceding apparatus identification information and the identification information of the session management apparatus are the same. A terminal device. The determination means further determines whether or not the address of the transmission source of the request message and the address of the session management device in which the address information of the terminal device is registered,
When the determination unit determines that the immediately preceding device identification information and the session management device identification information are the same, and the transmission source address and the session management device address are not the same, The terminal apparatus according to claim 1, wherein the response message transmitting unit transmits an error response message including the transmission source address to the session management apparatus. A terminal device having a function of establishing a session with another terminal device by transmitting / receiving a request message and a response message to / from another terminal device, and address information of the terminal device are registered, and the request message And a session management device that relays response messages,
The terminal device
Storage means for storing identification information of the session management device;
An immediately preceding device identification indicating a device immediately preceding the terminal device among devices that have been received from the request message until the request message arrives at the terminal device. Extraction means for extracting information;
Determination means for determining whether the immediately preceding apparatus identification information is the same as the identification information of the session management apparatus stored in the storage means;
Response message transmitting means for transmitting a response message to the session management apparatus only when the determination means determines that the immediately preceding apparatus identification information and the identification information of the session management apparatus are the same,
The session management device includes:
Connection relation identification information acquisition means for acquiring connection relation identification information for identifying a connection relation between two terminal apparatuses from a message transmitted and received between the two terminal apparatuses, and storing the connection relation identification information in the connection relation identification information storage means;
Determining means for determining whether or not the connection relation identification information included in the response message received from the terminal device is stored in the connection relation identification information storage means;
When the determination unit determines that the connection relationship identification information included in the response message is not stored in the connection relationship identification information storage unit, the predetermined information in the response message is stored in the log storage unit And a system for storing information. A terminal device having a function of establishing a session with another terminal device by transmitting / receiving a request message and a response message to / from another terminal device, and address information of the terminal device are registered, and the request message And a method executed by a system including a session management device that relays response messages,
A storage step in which the terminal device stores identification information of the session management device in a storage means;
The device immediately before the terminal device among the devices through which the terminal device has received a request message originating from another terminal device and the request message arrives at the terminal device from the request message A determination step of determining whether or not the immediately preceding device identification information indicating the same is the same as the identification information of the session management device stored in the storage unit;
A response message transmission step of transmitting a response message to the session management device only when the terminal device determines that the previous device identification information and the identification information of the session management device are the same in the determination step; ,
The session management device receives a request message originating from the other terminal device, and obtains connection relationship identification information for identifying a connection relationship between the other terminal device and the terminal device from the request message. A connection relationship identification information acquisition step for storing in the connection relationship identification information storage means;
The session management device receives a response message from the terminal device, and determines whether or not the connection relationship identification information included in the response message is stored in the connection relationship identification information storage unit;
When it is determined by the determination step that the connection relationship identification information included in the response message is not stored in the connection relationship identification information storage unit, the session management device stores predetermined information in the response message. An information storage step of storing in the log storage means. A terminal device having a function of establishing a session with another terminal device by transmitting / receiving a request message and a response message to / from another terminal device via the session management device,
An immediately preceding device identification indicating a device immediately preceding the terminal device among devices that have been received from the request message until the request message arrives at the terminal device. Extraction means for extracting information,
Determining means for reading out identification information of the session management device in which the address information of the terminal device is registered from a storage device, and determining whether the immediately preceding device identification information is the same as the identification information of the session management device;
A response message transmitting means for transmitting a response message to the session management apparatus only when the determination means determines that the immediately preceding apparatus identification information and the identification information of the session management apparatus are the same;
Program to function as.

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