JP5640764B2 - Signal processing apparatus and program - Google Patents

Description

  The present invention relates to a signal processing device and a program, and can be applied to, for example, a SIP-ALG (SIP Application Level Gateway) device arranged in a network corresponding to SIP (Session Initiation Protocol).

  Conventionally, in SIP-ALG that connects a plurality of networks corresponding to SIP (Non-Patent Documents 1 and 2), a URI (Uniform Resource Identifier) included in the SIP message is matched to the destination of the SIP message. As a technique for changing the scheme, there is a technique described in Patent Document 1.

  In the technology described in Patent Document 1, when a SIP message is converted, it is determined whether a special parameter is given in the message when the SIP request message is received, and the scheme is converted when the condition is met. It was a configuration like this.

Special table 2009-513052 gazette

IETF RFC2543 IETF RFC3261

  Patent Document 1 describes a scheme conversion function in a UNI (User-Network Interface) connection configuration when receiving a call to a terminal in its own network, but does not target an NNI (Network-Network Interface) configuration. Furthermore, since the target of the scheme conversion function described in Patent Document 1 is limited to the Request-line header, headers including other URIs (To header, From header, P-Asserted-Identity header, P-Preferred header) are included. -The scheme of Identity header etc.) is not considered.

  When the SIP-ALG device has an NNI connection configuration, the role of the SIP-ALG device is to absorb the SIP difference with another network (the SIP-ALG device is located in its own network) and follow the rules of each network. Properly generate and forward SIP messages. For example, a SIP request is transmitted depending on whether the URI scheme (format such as URI in the message) of the Request-Line header is a network handled in TEL-URI (Telephone-Subscriber) format or a network handled in SIP-URI format. There are cases where differences occur in the method of determining the destination.

  When the URI of the Request-Line header is in the TEL-URI format, a method of determining the transmission destination by the ground number (telephone number) is general, and when the URI of the Request-Line header is in the SIP-URI format, There is a case where a method of determining a transmission destination by a domain name or a host name included therein is applied. For this reason, when the SIP-ALG apparatus transmits a SIP request to the opposite apparatus, it is necessary to generate and transfer a SIP message corresponding to either one. Furthermore, depending on the connection destination server that handles the SIP message, the To header and From header may be able to read only the SIP-URI format or TEL-URI format message in addition to the Request-Line header. In the device, it is important to implement the SIP-URI and TEL-URI conversion methods.

  In view of the above problems, when processing a SIP message to be transferred, a signal processing device (for example, a SIP-ALG device) that can convert the SIP message into a format that can be processed at the transfer destination, and a signal A processing program is desired.

According to a first aspect of the present invention, there is provided a signal processing device that receives and processes a SIP message transmitted from a transmission source communication device to a transmission destination communication device, and transmits the SIP message to the transmission destination communication device. ) For each communication device that can be the target of the first transfer destination when the signal processing device processes the SIP message and sends it to the destination communication device, information on the description format of the corresponding SIP message is provided. A communication device information holding means to hold, and (2) a transfer destination is identified and received based on the first transmission destination information included in the received SIP message in accordance with the information held by the communication device information holding means. Message conversion means for converting the SIP message into a format that can be processed by the first transfer destination communication device related to the SIP message; and (3) the message conversion unit. SIP messages but converted, and a transmitting means for transmitting to the first destination of the communication device relating to the SIP message, (4) the information which the communication device information holding means for holding the above-mentioned transfer destination object Each of the possible communication devices includes information on the type of scheme related to the URI of the corresponding SIP message, and (5) the message conversion means converts the URI included in the received SIP message into the SIP message (6) The information held by the communication device information holding unit further includes a SIP message corresponding to each of the communication devices that can be the target of the transfer destination. (7) the message conversion means further includes the received SIP message. The part of the domain name which constitutes the URI included in the over-di, the first destination of the communication device relating to the SIP message and performs processing for a corresponding domain name.

The signal processing program of the second aspect of the present invention (1) receives and processes a SIP message sent from a transmission source communication device to a transmission destination communication device, and sends it to the transmission destination communication device. (2) For each communication device that can be the target of the first transfer destination when the signal processing device processes the SIP message and sends it to the destination communication device. A communication device information holding means for holding information relating to the description format of the corresponding SIP message, and (3) an initial transmission included in the received SIP message according to the information held by the communication device information holding means identifying a transfer destination on the basis of the above information, converts the SIP message received, the first transfer destination communication device can process formats relating to the SIP message message And over di conversion means (4) a SIP message in which the message conversion means is converted, to function as a transmitting means for transmitting to the first destination of the communication device relating to the SIP message, (5) the communication device information holding means Includes information on the type of scheme related to the URI of the SIP message corresponding to each of the communication devices that can be the target of the transfer destination. (6) The message conversion means receives the received SIP The URI included in the message is converted into a scheme corresponding to the first transfer destination communication device related to the SIP message. (7) The information held by the communication device information holding means further includes the target of the transfer destination. Each of the possible communication devices includes information on the domain name that constitutes the URI of the corresponding SIP message. (8) Message conversion means further characterized Rukoto performing part of the domain name which constitutes the URI included in the SIP message received, processing the first destination of the communication device relating to the SIP message with the corresponding domain name And

  ADVANTAGE OF THE INVENTION According to this invention, when processing the SIP message to transfer, the signal processing apparatus which can convert a SIP message into the format which can be processed in a transfer destination can be provided.

It is the block diagram shown about the whole network system structure provided with the SIP-ALG apparatus (signal processing apparatus) which concerns on embodiment. It is the block diagram shown about the functional structure of the SIP-ALG apparatus (signal processing apparatus) which concerns on embodiment. It is explanatory drawing shown about the example of the content of the scheme conversion corresponding | compatible table which concerns on embodiment. It is the flowchart shown about operation | movement of the SIP-ALG apparatus (signal processing apparatus) which concerns on embodiment. It is explanatory drawing shown about the specific example (only some headers are described) of the SIP message (INVITE message) which the SIP-ALG apparatus (signal processing apparatus) which concerns on embodiment processes.

(A) Main Embodiment Hereinafter, an embodiment of a signal processing device and a program according to the present invention will be described in detail with reference to the drawings. In this embodiment, an example in which the signal processing device of the present invention is applied to a SIP-ALG device is described.

(A-1) Configuration of Embodiment FIG. 2 is a block diagram showing the overall configuration of the network system 1 in which the SIP-ALG device 10 of this embodiment is arranged.

  Assume that the network system 1 includes three networks NA, NB, and NC. In FIG. 2, the SIP server 20-1 is arranged in the network NA, the SIP server 20-2 is arranged in the network NB, and the SIP server 20-3 is arranged in the NC. ing. The number of networks arranged in the network system 1, the network configuration, and the number of SIP servers are not limited.

  It is assumed that the SIP-ALG device 10 is arranged between the networks NA, NB, and NC and functions as the SIP-ALG. These networks are terminated by the SIP-ALG device 10, and SIP messages and the like are relayed for communication between the networks. In addition, when relaying a SIP message, the SIP-ALG device 10 transfers the SIP server as the transfer destination if the SIP message to be relayed and the transfer destination SIP server have different URI schemes. The data is converted into a format that can be processed in step 20, and is sent out.

  Each SIP server 20 processes, for example, a SIP message (INVITE message or the like) received from a subordinate SIP terminal (not shown) or another SIP server in the same network, and forwards it to the SIP server 20 of another network. It is assumed that the SIP message may be transferred via the SIP-ALG device 10 when it is necessary to do so. Each SIP server 20 may process a SIP message transferred from the SIP-ALG device 10 and transfer the processed SIP message to a subordinate SIP terminal (not shown) or another SIP server. In addition, since each existing SIP server 20 can be applied, detailed description is omitted.

  Furthermore, it is assumed that the network NA, NB adopts the SIP-URI format as a URI scheme constituting the SIP message. In the network NC, it is assumed that a TEL-URI is adopted as a URI scheme constituting the SIP message. That is, the SIP-ALG apparatus 10 converts the SIP message received from the SIP server 20 of any network into a format adopted by the next forwarding destination SIP server 20 (a scheme adopted at least by the forwarding destination). And processing for sending out to the transfer destination SIP server 20 is performed.

  FIG. 1 is a block diagram showing a functional configuration of the SIP-ALG device 10.

  The SIP-ALG device 10 includes a control unit 11, a scheme conversion correspondence table 12, and a message processing unit 13. Although not shown in FIG. 1, the SIP-ALG device 10 is assumed to have other configurations similar to those of the existing SIP-ALG device 10 such as an interface for connecting to the network.

  The SIP-ALG device 10 is on an information processing device (not limited to a single device, and may be configured to be capable of distributed processing of a plurality of devices) having an interface for connecting to a processor and a network. It may be constructed by installing the signal processing program of the embodiment, but even in that case, it can be functionally expressed as shown in FIG.

  The control unit 11 has a function of controlling the entire SIP-ALG device 10.

  The message processing unit 13 performs processing such as conversion processing on the SIP message (INVITE message or the like) given to the SIP-ALG device 10 and sends it to the transfer destination. When the SIP message is received, the message processing unit 13 determines the next transfer destination (first transfer destination) of the received SIP message, for example, by the same processing as that of the existing SIP server, and transfers the processed SIP message to the transfer destination. To send to.

  The message processing unit 13 includes a conversion processing unit 14. In the message processing unit 13, the content of the received SIP message is converted using the conversion processing unit 14 when necessary according to the transmission destination. The SIP message processing by the message processing unit 13 can apply the same processing as that of the existing SIP-ALG device except for the conversion processing by the conversion processing unit 14.

  The conversion processing unit 14 converts the SIP message supplied to the message processing unit 13 according to the contents of the scheme conversion correspondence table 12 according to the transmission destination.

  Next, an example of the description format of the URI constituting the SIP message transmitted by each SIP server 20 will be described.

  It is assumed that the URI constituting the SIP message corresponding to the SIP server 20 corresponding to the SIP-URI is described in a format such as “sip: 05022222222@domain.com”, for example. “Sip:” indicates that the corresponding scheme of the URI is SIP-URI. In addition, “05022222222” following “sip:” indicates a telephone number and corresponds to a user identifier (user ID) in the URI. Here, in the example of the URI corresponding to the SIP-URI scheme, a case is shown in which a telephone number is used as a user identifier as it is, but an arbitrary character string other than the telephone number is used as a user identifier. May be. Then, “domain.com” after being partitioned by “@” following the telephone number indicates the domain name related to the URI.

  Further, it is assumed that the URI constituting the SIP message transmitted by the SIP server corresponding to the SIP-TEL is described in a format such as “tel: 05022222222”, for example. “Tel:” indicates that the corresponding scheme of the URI is TEL-URI. In addition, “05022222222” following “tel:” indicates a telephone number and corresponds to a user identifier (user ID) in the URI. In the TEL-URI, the description of “@domain name” is not included in the URI unlike the normal SIP-URI.

  The URI constituting the SIP message transmitted by the SIP server has the description format as described above, and the conversion processing unit 14 performs conversion according to the description format suitable for the transfer destination SIP server.

  The scheme conversion correspondence table 12 is a table that is referred to when the SIP message conversion processing is performed by the conversion processing unit 14. Information about the description format of the URI constituting the SIP message corresponding to each SIP server 20 is registered. Yes.

  FIG. 3 is an explanatory diagram showing an example of information registered in the scheme conversion correspondence table 12.

  As shown in FIG. 3, in the scheme conversion correspondence table 12, for each SIP server 20 that can be a transfer destination of a SIP message, as information related to a URI description format, a destination SIP server name, a scheme, a domain name, Number format item information is registered. In FIG. 3, one line describes information related to one SIP server.

  The item “destination SIP server name” is information indicating the identifier of the SIP server 20. The format of the destination SIP server name is not limited as long as the SIP server 20 can be identified. For example, the IP address or host for accessing the SIP server 20 from the SIP-ALG device 10 is not limited. A name or the like may be applied.

  In FIG. 3 and the following, in order to simplify the description, the host name (identifier) of the SIP server 20-1 is “SIP server 1”, the host name of the SIP server 20-2 is “SIP server 2”, SIP The host name of the server 20-3 is represented as “SIP server 3”.

  The item “scheme” is information indicating a URI scheme corresponding to the SIP server 20. Here, “SIP” indicating SIP-URI or “TEL” indicating TEL-URI is registered in the scheme item.

  Here, as shown in FIG. 3, the scheme of the SIP server 1 (SIP server 20-1) and the SIP server 2 (SIP server 20-2) is “SIP”, and the scheme of the SIP server 3 (SIP server 20-3). Is registered as “TEL”.

  The item “domain name” is information indicating a domain name used for describing a URI corresponding to the SIP server 20.

  Here, as shown in FIG. 3, the domain name of the SIP server 1 (SIP server 20-1) is “domain.com”, and the domain name of the SIP server 2 (SIP server 20-2) is “domain.net”. It shall be registered.

  Here, when the scheme is “TEL”, a domain name is not required in the description of the URI because of the specification, and therefore “−” indicating a blank is registered. Since the scheme of the SIP server 3 (SIP server 20-3) is TEL, "-" indicating a blank is registered in the domain name item as shown in FIG.

  The item “number format” indicates the format (description format) of the telephone number (user identifier) used in the description of the URI corresponding to the SIP server 20.

  Next, the format of the telephone number used in the network system 1 will be described.

  Examples of the existing telephone number format include ITU-T E.E. There is a format defined in 164. E. 164 is a recommendation regarding a telephone number plan for a telephone network such as a public switched telephone network by ITU-T, and a format in which “+” and a country code are written at the beginning is adopted. For Japan, 81 is assigned as the country code. When a telephone number in the Japanese public telephone network is expressed in the format of 164, the telephone number starts with “+81”. On the other hand, in the public telephone network in Japan, E.I. The number starts with “0” instead of the format of 164.

  Here, in each SIP server 20, the above-mentioned E.P. It is assumed that either 164 or a Japanese format (a number starting from “0”) is adopted. Note that the type and number of telephone number formats employed by the SIP server 20 are not limited to those described above.

  The item “number format” in the scheme conversion correspondence table 12 includes E.E. It is assumed that either “E.164” indicating that the format is compatible with the format 164 or “domestic” indicating that the format is compatible with the domestic format is registered.

  Here, as shown in FIG. 3, the number format of the SIP server 1 (SIP server 20-1) and the SIP server 2 (SIP server 20-2) is “domestic”, and the SIP server 3 (SIP server 20-3). ) Is registered as “E.164”.

(A-2) Operation of Embodiment Next, the operation of the SIP-ALG apparatus 10 in the network system 1 of this embodiment having the above configuration will be described.

  Here, first, an outline of the operation of the message processing unit 13 (conversion processing unit 14) of the SIP-ALG apparatus 10 will be described, and then a specific example of SIP message processing will be described. In the following, a case where the SIP-ALG apparatus 10 processes an INVITE message will be described as an example. However, a SIP message including other URI descriptions is the same process, and the description thereof will be omitted.

  FIG. 4 is a flowchart showing the operation when the SIP-ALG device 10 receives a SIP message (INVITE message).

  Here, first, it is assumed that the INVITE message from the SIP server 20-1 is given to the message processing unit 13 of the SIP-ALG device 10 (S101).

  Then, the message processing unit 13 determines the next transfer destination (first transfer destination) SIP server from the contents of the INVITE message (S102). As the determination method of the next transfer destination by the message processing unit 13, an existing determination method may be used as described above. Specifically, for example, the determination may be made based on the URI described in the To header. Here, the message processing unit 13 determines the next transfer destination SIP server, and the following description will be made assuming that the host name is obtained as information for identifying the SIP server.

  Next, the conversion processing unit 14 of the message processing unit 13 acquires information on the next transfer destination SIP server (information on each item of the scheme, domain name, and number format) from the scheme conversion correspondence table 12 ( S103, S104). Here, it is assumed that the conversion processing unit 14 detects information of the next transfer destination SIP server from the scheme conversion correspondence table 12 using the host name as a key.

  Next, the conversion processing unit 14 grasps the URI scheme in the INVITE message to be converted and the URI scheme corresponding to the next SIP server of the transfer destination (S105).

  Here, the URI scheme supported by each SIP server is either TEL-URI or SIP-URI. Therefore, in step S105, the conversion content grasped by the conversion processing unit 14 is that the conversion target INVITE message scheme is TEL-URI and the transfer destination scheme is SIP-URI, and the conversion target INVITE message scheme is TEL-URI. When the transfer destination scheme is TEL-URI in URI, the transfer destination INVITE message scheme is SIP-URI and transfer destination is TEL-URI, or the conversion target INVITE message scheme is SIP-URI. The scheme is either SIP-URI. Then, the conversion processing unit 14 converts the INVITE message in the subsequent steps according to the determination result in step S105 described above.

  The conversion processing unit 14 may determine the URI scheme in the conversion target INVITE message by analyzing the contents of the conversion target INVITE message, or grasp the host name of the transfer source SIP server 20. Then, it may be read from the scheme conversion correspondence table 12 and grasped. When the conversion processing unit 14 analyzes the content of the conversion target INVITE message and determines the URI scheme in the conversion target INVITE message, for example, the URI included in each header starts with “sip:”. In this case, it may be determined as SIP-URI, and when it starts with “tel:”, it may be determined as TEL-URI.

  If it is determined in step S105 described above that the URI scheme in the conversion target INVITE message is TEL-URI and the scheme corresponding to the next transfer destination SIP server 20 is SIP-URI, the conversion processing unit 14 converts the conversion target. For the INVITE message, a process for converting the scheme related to the URI of each header is performed (S106).

  As described above, the URI corresponding to the TEL-URI scheme starts with “tel:”, and the URI corresponding to the SIP-URI scheme starts with “sip:”. Therefore, the conversion processing unit 14 converts the scheme by converting “tel:” to “sip:” for the URI of each header of the INVITE message to be converted.

  Further, the conversion processing unit 14 performs a process of assigning a domain name (used in the next transfer destination SIP server) to the URI of each header in the INVITE message to be converted (S107).

  As described above, the URI corresponding to the TEL-URI scheme generally has a configuration of “tel:” + “telephone number” such as “tel: 05022222222”. On the other hand, the URI corresponding to the SIP-URI scheme may have a configuration of “sip:” + “user identifier” + “@ domain name” such as “sip: 05022222222@domain.net”. It is common. That is, in the URI corresponding to the TEL-URI scheme, the “@domain name” portion is not described. Therefore, by the process in step S107 described above, a process of adding “@” and the description of the domain name used in the next transfer destination SIP server to the URI of each header to be converted is performed.

  If it is determined in step S105 described above that the URI scheme in the conversion target INVITE message is SIP-URI and the scheme corresponding to the next transfer destination SIP server 20 is TEL-URI, the conversion processing unit 14 For the INVITE message, the scheme related to the URI of each header is converted (S108).

  Specifically, the conversion processing unit 14 converts the scheme by converting “sip:” to “tel:” for the URI of each header of the INVITE message to be converted.

  Furthermore, the conversion processing unit 14 performs processing for deleting the description of the domain name from the URI of each header in the INVITE message to be converted (S109).

  As described above, in the URI corresponding to the TEL-URI scheme, the part of “@domain name” is not described. Process to delete the description.

  If it is determined in step S105 described above that the URI scheme in the conversion target INVITE message is SIP-URI and the scheme to which the next transfer destination SIP server 20 corresponds is also SIP-URI, the conversion processing unit 14 For the INVITE message, the domain name described in the URI of each header is converted to the domain name used at the next transfer destination (S110).

  Since the domain name used in the URI of the SIP message is normally different for each network, normal message processing is not performed if the domain name is different between the SIP servers 20 corresponding to the same SIP-URI scheme. Sometimes. For this reason, the conversion processing unit 14 performs processing for converting the domain name used in the URI of the INVITE message to be converted into one that can be used in the transfer destination SIP server. If the domain names used in the URI are all the same in each network, or if the SIP server 20 at the transfer destination can normally process messages even if the domain names are different, the processing in step S110 described above is omitted. You may do it.

  In the above-described step S105, when it is determined that the URI scheme in the INVITE message to be converted is TEL-URI, and the scheme to which the next transfer destination SIP server 20 corresponds is also TEL-URI, or the above-described steps S107 and S109. , S110 is completed, the conversion processing unit 14 then formats the telephone number of the URI in the INVITE message to be converted and the telephone number format corresponding to the next transfer destination SIP server. Is performed (S111).

  Here, as described above, the number format supported by each SIP server is domestic or E.E. 164. Therefore, in step S111, the contents grasped by the conversion processing unit 14 include that the number format in the INVITE message to be converted is “domestic” and the number format in the transfer destination is E.E. In the case of 164, when the number format in the INVITE message to be converted is domestic and the number format at the transfer destination is domestic, the number format in the INVITE message to be converted is E.164. If the number format at the transfer destination is domestic in 164 or the number format in the INVITE message to be converted is E.164. 164, the transfer destination number format is E.164. One of the cases of 164. And the conversion process part 14 converts the received INVITE message by the process of a subsequent step according to the determination result of the above-mentioned step S111.

  The conversion processing unit 14 may determine the number format in the conversion target INVITE message by analyzing the contents of the conversion target INVITE message, or grasp the host name of the transfer source SIP server. Thus, the information may be read from the scheme conversion correspondence table 12 and grasped. When the conversion processing unit 14 analyzes the content of the INVITE message to be converted and determines the number format in the INVITE message to be converted, for example, “sip:” or “tel” of the URI included in each header is used. If the part of the phone number following ":" starts with "+" (or "+81") If it is determined as 164 and starts with “0”, it may be determined as domestic.

  In step S111 described above, the number format in the INVITE message to be converted is domestic, and the number format corresponding to the next transfer destination SIP server is E.E. When it is determined as 164, the conversion processing unit 14 performs a process of converting the number format related to the URI of each header for the INVITE message to be converted (S112).

  As described above, when the number format corresponds to the country, the telephone number in the URI starts with, for example, “05022222222” and the head starts with “0”. The number format is E.E. In the case of corresponding to 164, the telephone number in the URI differs from that in Japan in that, for example, “+815022222222” starts with “+81”. Therefore, in this case, the conversion processing unit 14 converts the number format conversion by converting the head of the telephone number portion from “0” to “+81” for the URI of each header of the INVITE message to be converted. Do.

  Here, the number format in the destination SIP server 20 is E.P. In the case of 164, the conversion processing unit 14 processes all the country codes constituting the telephone number as Japanese (81), but registers the country code for each SIP server 20 in the scheme conversion correspondence table 12. In this case, the country code corresponding to the SIP server 20 of the transfer destination may be processed.

  On the other hand, in step S111 described above, the number format in the INVITE message to be converted is E.E. When it is determined in 164 that the number format corresponding to the next transfer destination SIP server 20 is domestic, the conversion processing unit 14 performs processing for converting the number format related to the URI of each header for the INVITE message to be converted. (S113). In this case, the conversion processing unit 14 performs processing opposite to the above-described step S112 for the URI of each header of the INVITE message to be converted, that is, the first “+ country code” portion “+81” of the telephone number portion. The number format is converted by converting "" to "0".

  In step S111 described above, the conversion processing unit 14 causes the conversion target INVITE message and the next transfer destination SIP server 20 to have the same number format, or any of the processes in steps S112 and S113 described above. Is completed, the conversion process of the INVITE message by the conversion processing unit 14 ends. Then, the converted INVITE message is transmitted by the message processing unit 13 to the next transfer destination SIP server 20 (S114).

  In the above description, the number format supported by each SIP server is domestic or E.E. However, in the SIP-URI scheme supported by the existing SIP server, the user identifier included in the URI is not a telephone number format composed of only numbers but is composed of arbitrary characters. May be in the form of a character string (hereinafter referred to as “account format”). If, in step S111 described above, the conversion processing unit 14 determines that the user identifier included in the URI constituting the conversion target INVITE message is in the account format, the number format is not converted. In addition, the process may proceed to step S114 described above. As a method in which the conversion processing unit 14 analyzes the content of the URI in the SIP-URI format and recognizes the description format of the user identifier, for example, a symbol other than a number between “sip:” and “@” is used. Is included (however, it is ignored if "+" is placed at the beginning), and if it is composed of numbers only, it is recognized as a phone number format. good.

  Next, a specific example in which the conversion processing unit 14 operates and converts the INVITE message according to the flowchart of FIG. 4 described above will be described.

  FIG. 5 is an explanatory diagram showing an example of the contents of an INVITE message processed in the SIP-ALG device 10. In addition, in each INVITE message shown in FIG. 5, in order to simplify the description, portions other than header information (that is, header information including a URI description) to be converted by the conversion processing unit 14 are omitted. ing.

  In this example, it is assumed that the INVITE message having the content shown in FIG. 5A is a conversion target of the conversion processing unit 14.

  First, the conversion by the conversion processing unit 14 when the SIP server 20 of the next transfer destination related to the INVITE message of FIG. 5A is determined as the SIP server 20-2 by the process of step S102 described above. Processing will be described.

  In this case, in the conversion processing unit 14, the information of the SIP server 20-2 (scheme: SIP, domain name: domain.net, number format: domestic) is obtained from the scheme conversion correspondence table 12 in the processes of steps S 103 and S 104 described above. Is acquired.

  For the SIP server 20-1, “scheme: SIP, domain name: domain.com, number” is determined from the contents of the scheme conversion correspondence table 12 or the configuration of the URI included in the INVITE message shown in FIG. Format: domestic ”. For example, the URI described in the INVITE header of the INVITE message in FIG. 5A is “sip: 05022222222@domain.com”. Since this URI starts from “sip:”, the URI scheme can be understood as SIP-URI. Further, since the telephone number following the URI “sip:” starts from “0”, the number format can be grasped as domestic. Also, since “@ domain.com” follows the phone number, the domain name can be understood as “domain.com”.

  Next, the determination in the above-described step S105 is performed. In this case, the URI scheme in the conversion target INVITE message is SIP-URI, and the next transfer destination URI scheme is also SIP-URI. Then, the process proceeds to step S110 described above.

  In step S110, as described above, the domain name described in the URI of each header of the INVITE message is converted into the domain name used at the next transfer destination. In this case, “domain.com” of each URI is converted to “domain.net”.

  FIG. 5B shows the contents after the above-described INVITE message of FIG. 5A has been converted according to the process of step S110 described above.

  As shown in FIG. 5B, the URI description “sip: 05022222222@domain.com” before conversion is converted into a description “sip: 05022222222@domain.net”. In FIG. 5B, the URI description “sip: 05011111111@domain.com” before conversion is converted into a description “sip: 05011111111@domain.net”.

  Next, the determination at the above-described step S111 is performed. In this case, the number format in the INVITE message to be converted is domestic and the number format of the next transfer destination URI is also domestic. Conversion is not performed, the process proceeds to step S114 described above, and the conversion process by the conversion processing unit 14 ends.

  Next, the conversion processing by the conversion processing unit 14 when the SIP server of the next transfer destination related to the INVITE message of FIG. 5A is determined as the SIP server 20-3 by the processing in step S102 described above will be described. .

  In this case, in the conversion processing unit 14, the information of the SIP server 20-3 (scheme: TEL, domain name: “−” (blank), number format is obtained from the scheme conversion correspondence table 12 in the processes of steps S 103 and S 104 described above. : E.164) is obtained.

  Next, the determination in step S105 described above is performed. In this case, the URI scheme in the conversion target INVITE message is SIP-URI, and the next transfer destination URI scheme is TEL-URI. Then, the process proceeds to step S108 described above.

  In the process of step S108, as described above, the process of converting the scheme (converting from SIP-URI to TEL-URI) is performed on the URI of each header of the INVITE message. In this case, all “sip:” at the beginning of each URI is converted to “tel:”.

  In subsequent step S109, as described above, the domain name described in the URI of each header of the INVITE message is deleted. In this case, the description of the “@ domain.com” portion of each URI is deleted.

  FIG. 5C shows an example of contents after the above-described INVITE message of FIG. 5A has been converted according to the above-described processing of step S108 and step S109.

  As shown in FIG. 5C, the URI description “sip: 05022222222@domain.com” before conversion is converted to the description “tel: 05022222222”. In FIG. 5B, the URI description “sip: 05011111111@domain.com” before conversion is converted into a description “tel: 05011111111”.

  Next, the determination in step S111 described above is performed. In this case, the number format in the INVITE message to be converted is domestic, and the number format of the next transfer destination URI is E.E. Therefore, the process proceeds to step S112 described above.

  In the process of step S112, as described above, the process of converting the number format (converted from domestic to E.164) is performed for the URI of each header of the INVITE message. In this case, the head of the telephone number (user ID) portion of each URI is converted from “+81” to “0”.

  FIG. 5D shows an example of the content after the above-described INVITE message in FIG. 5C is converted according to the process in step S112 described above.

  As shown in FIG. 5D, the URI description “tel: 05022222222” before conversion is converted into the description “tel: +815022222222”. In FIG. 5B, the URI description “tel: 05011111111” before conversion is converted to the description “tel: +815011111111”.

(A-3) Effects of Embodiment According to this embodiment, the following effects can be achieved.

  The SIP-ALG device 10 realizes processing such as scheme conversion of a URI constituting a SIP message using the scheme conversion correspondence table 12. As a result, the SIP server 20 of each network via the SIP-ALG device 10 generates and forwards a SIP message in accordance with the rules to which the transfer destination SIP server 20 corresponds even if the corresponding URI scheme or the like is different. Connection affinity between networks can be increased.

(B) Other Embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments as exemplified below.

(B-1) In the above embodiment, the protocol supported by each network (network NA, NB, NC) constituting the network system 1 may be IPv4 or IPv6. In addition, all the protocols supported by each network may be the same (for example, all support IPv6), or a plurality of protocols are mixed (for example, some networks support IPv4 and other networks support IPv6). It is good also as a structure which does.

  In the above-described embodiment, the SIP-ALG apparatus 10 has been described as processing SIP messages between networks. However, the SIP-ALG apparatus 10 may be configured to perform SIP message processing between SIP servers in the same network.

  Furthermore, in the above embodiment, the SIP-ALG device 10 has been described as performing a SIP message. However, the SIP-ALG device 10 is constructed as a gateway (signal processing device) that also transfers data (IP packets) other than SIP messages. Also good.

(B-2) In the above embodiment, the scheme conversion correspondence table 12 shows an example of registering URI description format information for each SIP server as shown in FIG. The unit is not limited to this. For example, if the information regarding the SIP servers in the same network is the same, the information is registered for each transfer destination network in the scheme conversion correspondence table 12, and the conversion processing unit 14 transfers the next transfer destination of the SIP message to be converted. Information of a network to which the SIP server belongs may be acquired as information of the SIP server.

(B-3) In the above embodiment, when the number formats corresponding to all networks are the same, the SIP-ALG device 10 may omit the number format conversion processing. In this case, the items related to the number format may be omitted from the scheme conversion correspondence table 12.

(B-4) In the above embodiment, when the user identifier constituting the conversion target SIP message is a telephone number, the conversion processing unit 14 supports the next transfer destination SIP server for the number format of the telephone number. The process of converting to the number format to be performed has been described (see steps S111 to 113 in FIG. 4 described above). Here, the conversion of the user identifier by the conversion processing unit 14 may be performed not by converting the number format but by converting the user identifier itself. For example, it is assumed that a user is given a telephone number format identifier “05011111111” and an account format identifier “abcdef” as user identifiers. In addition, a description item of the user identifier corresponding to each SIP server 20 (an item indicated by “phone number format” or “account format”) is added to the scheme conversion correspondence table 12 and registered. And Furthermore, it is assumed that the SIP-ALG device 10 also includes a correspondence table (hereinafter referred to as “identifier correspondence table”) between a user identifier in an account format for each user and a user identifier in a telephone number format. Then, the conversion processing unit 14 grasps the description format of the user identifier in the SIP message to be converted and the description format of the user identifier corresponding to the next transfer destination SIP server 20. May be converted using the above-mentioned identifier correspondence table.

  As a method for the conversion processing unit 14 to recognize the description format of the corresponding user identifier in the SIP message to be converted, for example, it may be recognized from the contents of the scheme conversion correspondence table 12, or the SIP message The contents of the URI included in the URL may be analyzed and recognized.

  Here, as an example, a case is assumed in which “05011111111” is given as a user identifier in a telephone number format and “abcdef” is given as a user identifier in an account format. When the conversion processing unit 14 converts the SIP message including the user's URI, the description format in the SIP message to be converted is the telephone number format, and the description format corresponding to the next SIP server of the transfer destination is the account format. Suppose it was in the form. In this case, the conversion processing unit 14 detects “abcdef” as the user identifier corresponding to “05011111111” using the above-described identifier correspondence table, and further, the user “05011111111” included in the URI of the SIP message. A process of converting the identifier into a user identifier “abcdef” is performed. For example, when the URI before conversion is “sip: 05011111111@domain.com”, it is converted to “sip: abcdef@domain.com”.

  DESCRIPTION OF SYMBOLS 1 ... Network system 20, 20-1-20-3 ... SIP server, 10 ... SIP-ALG apparatus (signal processing apparatus), 11 ... Control part, 12 ... Scheme conversion correspondence table, 13 ... Message processing part, 14 ... Conversion processing unit, NA, NB, NC ... network.

Claims (6)

In the signal processing device that receives and processes the SIP message sent from the transmission source communication device to the transmission destination communication device, and sends the SIP message to the transmission destination communication device.
Holds information related to the description format of the corresponding SIP message for each communication device that can be the target of the first transfer destination when the signal processing device processes the SIP message and sends it to the destination communication device. Communication device information holding means for
According to the information held by the communication device information holding means , the transfer destination is specified based on the first destination information included in the received SIP message , and the received SIP message is transferred to the first transfer related to the SIP message. Message conversion means for converting to a format that can be processed by the previous communication device;
A transmission means for transmitting the SIP message converted by the message conversion means to the first transfer destination communication device related to the SIP message ;
The information held by the communication device information holding means includes information on the type of scheme related to the URI of the SIP message corresponding to each of the communication devices that can be the target of the transfer destination,
The message conversion means converts the URI included in the received SIP message into a scheme corresponding to the first transfer destination communication device related to the SIP message,
The information held by the communication device information holding means further includes domain name information constituting the URI of the SIP message corresponding to each of the communication devices that can be the target of the transfer destination,
The message conversion means further performs a process of setting a domain name part constituting a URI included in the received SIP message as a domain name corresponding to a first transfer destination communication device related to the SIP message. A signal processing device. The information held by the communication device information holding means further includes type information related to the description format of the user identifier that constitutes the URI of the SIP message corresponding to each of the communication devices that can be the transfer destination. And
The message conversion means further performs a process of converting the part of the user identifier constituting the URI included in the received SIP message into a description format corresponding to the first transfer destination communication device related to the SIP message. The signal processing device according to claim 1 , wherein: The signal processing apparatus according to claim 2 , wherein the user identifier is in a telephone number format. A computer mounted on a signal processing device that receives and processes a SIP message sent from a source communication device to a destination communication device, and sends the SIP message to a destination communication device.
Holds information related to the description format of the corresponding SIP message for each communication device that can be the target of the first transfer destination when the signal processing device processes the SIP message and sends it to the destination communication device. Communication device information holding means for
According to the information held by the communication device information holding means , the transfer destination is specified based on the first destination information included in the received SIP message , and the received SIP message is transferred to the first transfer related to the SIP message. Message conversion means for converting to a format that can be processed by the previous communication device;
A SIP message the message conversion means is converted, to function as a transmitting means for transmitting to the first destination of the communication device relating to the SIP message,
The information held by the communication device information holding means includes information on the type of scheme related to the URI of the SIP message corresponding to each of the communication devices that can be the target of the transfer destination,
The message conversion means converts the URI included in the received SIP message into a scheme corresponding to the first transfer destination communication device related to the SIP message,
The information held by the communication device information holding means further includes domain name information constituting the URI of the SIP message corresponding to each of the communication devices that can be the target of the transfer destination,
The message conversion means further performs a process of setting a domain name part constituting a URI included in the received SIP message as a domain name corresponding to a first transfer destination communication device related to the SIP message. A signal processing program. The information held by the communication device information holding means further includes type information related to the description format of the user identifier that constitutes the URI of the SIP message corresponding to each of the communication devices that can be the transfer destination. And
The message conversion means further performs a process of converting the part of the user identifier constituting the URI included in the received SIP message into a description format corresponding to the first transfer destination communication device related to the SIP message.
The signal processing program according to claim 4. 6. The signal processing program according to claim 5, wherein the user identifier is in a telephone number format.

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