Patent Publication Number: US-2015063113-A1

Title: Traffic control method and traffic control apparatus

Description:
CLAIM OF PRIORITY 
     The present application claims priority from Japanese patent application serial no. 2013-183576, filed on Sep. 5, 2013, the content of which is hereby incorporated by reference into this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates a control apparatus and a control method for controlling traffic. 
     2. Description of the Related Art 
     A traffic control apparatus of related art implements per-packet traffic control over a total number or a total amount of packets that are transmitted and received over a link, as described in, e.g., Japanese Published Unexamined Patent Application No. 2013-042475. 
     SUMMARY OF THE INVENTION 
     As smart phones have come into popular use recently, a range of applications that can be developed for terminals broadens and a plurality of mobile communication operators and suppliers continue to develop a wide variety of applications. Among the wide variety of applications, there is an application that is arranged such that application products installed on user terminals start up simultaneously at a certain time and transmit and receive mobile communication signaling simultaneously. Such an application gives rise to a signaling burst that is unforeseeable by mobile communication operators and affects services for other end users and other applications, which becomes a problem. 
     The abovementioned traffic control apparatus of related art implements control according to a total number or a total amount of packets that are transmitted and received over a link, without being conscious of mobile communication signaling. Therefore, the traffic control apparatus of related art is unable to perform control, while identifying an application that is executed by an end user and an equipment type of a terminal that is used by an end user. Consequently, the traffic control apparatus of related art applies traffic control to not only signaling for an application that gives rise to a signaling burst, but also signaling produced by other applications, which affects overall end-user service quality. 
     The traffic control apparatus of related art implements per-packet traffic control. Therefore, in a case where one packet includes a plurality of pieces of signaling data, some of which are other than a kind of signaling that should be under traffic control, the traffic control apparatus of related art can only choose between performing traffic control on the packet data including signaling data that should not be under traffic control and not performing traffic control. In the case where one packet includes a plurality of pieces of signaling data and if traffic control is performed on the packet data including signaling data that should not be under traffic control, the traffic control is applied also to an application other than the application or the equipment type of a terminal that gives rise to a signaling burst and this affects end-user service quality. However, unless applying traffic control to the packet including a plurality of pieces of signaling data, the signaling burst cannot be controlled completely. This also affects end-user service quality. 
     As noted above, the traffic control apparatus of related art creates a situation where even signaling for which traffic control should not be performed is controlled or signaling for which traffic control should be performed is not controlled and poses a problem of affecting end-user service quality. 
     The present invention has been made to solve the above problem and is contrived to implement more granular traffic control and improve a traffic control method. 
     In order to solve the above problem and in accordance with an aspect of the present invention, by way of example, there is provided a traffic control apparatus including a packet analysis unit that analyzes a packet transmitted over a communication link, a packet control unit that performs packet processing or packet output control, and a traffic management unit that manages control information for controlling traffic. With respect to a plurality of terminals that connect to a network and perform communication via the communication link, the packet analysis unit analyzes signaling during a session performed by each terminal from a time when a terminal initially connects to the network, thereby associating a terminal, an application, and signaling required for the application, and transmits analysis results to the traffic management unit. The traffic management unit generates control information including identifiers for implementing traffic control on a per-signaling basis, based on preconfigured information on an object that should be under traffic control and analysis results. The packet analysis unit assigns to a received packet an identifier on a per-signaling basis based on the control information and transmits the packet to the packet control unit. The packet control unit refers to the identifiers and the control information and performs a specified traffic control action on signaling included in the packet. 
     More particularly, the packet control unit performs any of traffic control actions as follows: packet editing that controls traffic by changing data of signaling, which is specified signaling, within a packet; discarding signaling data in excess of a threshold value; control according to a packet transmission rate; and priority control based on priority information. 
     Also, more particularly, the traffic management unit performs statistical processing with regard to an amount of signaling occurrences by associating packet analysis results received from the packet analysis unit with temporal information, predicts signaling bursts to occur at random times or periodically, based on statistical processing results, and generates control information. 
     Also, more particularly, the packet analysis unit has a table mapping between each signaling process and an amount of load on a destination device to which a packet is transmitted for calculating an amount of load on the destination device to complete a signaling process on signaling data included in a packet, for each destination device. Upon receiving a packet, the packet analysis unit refers to the table and obtains an amount of load on a destination device for processing the packet, if transmitted to the destination device, and notifies the traffic management unit of the obtained amount of load. The traffic management unit generates control information based on the amount of load on the destination device. 
     According to the present invention, it is possible to implement more granular traffic control and improve a traffic control method. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the present invention will now be described in conjunction with the accompanying drawings, in which; 
         FIG. 1  is a block diagram to explain a network architecture; 
         FIG. 2  is a block diagram to explain placement of a control apparatus; 
         FIG. 3  is a block diagram to explain a configuration of the control apparatus; 
         FIG. 4  is a diagram to explain information elements of information configured by maintenance personnel; 
         FIG. 5  is a diagram to explain information elements of flow information; 
         FIG. 6  is a diagram to explain information elements of user information; 
         FIG. 7  is a diagram to explain information elements of log information for control and statistics information for control; 
         FIG. 8  is a diagram to explain information elements of transmission control information; 
         FIG. 9A  is a sequence diagram to explain a process for acquiring user information; 
         FIG. 9B  is a sequence diagram to explain a process for acquiring user information; 
         FIG. 10  is a sequence diagram to explain a process for acquiring user information; 
         FIG. 11  is a sequence diagram to explain a process for acquiring log information for control and statistics information for control; 
         FIG. 12  is a sequence diagram to explain a process for identifying a user engaged in transmitting/receiving user data and associating an application being executed by the user with the user; 
         FIG. 13  is a flowchart illustrating a process for clearing a counter for statistics information for control; 
         FIG. 14  is a flowchart illustrating a traffic control action; 
         FIG. 15  is a flowchart illustrating a traffic control action; 
         FIG. 16  is a flowchart illustrating a traffic control action; 
         FIG. 17  is a flowchart illustrating a traffic control action; 
         FIG. 18  is a flowchart illustrating a procedure for a traffic control action; 
         FIG. 19  is a flowchart illustrating a procedure for a traffic control action; 
         FIG. 20  presents information elements of statistics information for control which are used to acquire an anticipated transaction amount per unit time as statistics information; 
         FIG. 21  is a diagram to explain information for predicting a signaling burst occurrence; and 
         FIG. 22  is a diagram to explain signaling in which an information element that identifies an application or mobile terminal type is added. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     First Embodiment 
     First, an embodiment is described with  FIGS. 1  thru  13 . The embodiment is described here, citing an example of a Long Term Evolution (LTE) system. In the embodiment, particularly, according to Control Plane (C-Plane), General packet radio service Tunneling Protocol (GTP) tunnels for transferring packets of user data are established for each mobile terminal in a packet communication network. Packets of user data are transmitted and received via a radio network and through the use of the GTP tunnels. Note that the scope of application is not limited to LTE. 
     &lt;Network Architecture Example&gt; 
     With reference to  FIG. 1 , a network architecture is described. In a network  100 , User Equipment (UE) t1 which is a mobile terminal is connected to a base station eNB  101  via a radio bearer link. Concrete examples of mobile terminals t1 include, but not limited to, a mobile phone, smart phone, a tablet mobile terminal, a gaming console, a notebook personal computer, and a car navigator. 
     The eNB  101  is also connected to a Serving Gateway (S-GW)  107  and relays communication between the mobile terminal t1 and the S-GW  107 . 
     The S-GW  107  is a node that relays user data from the mobile terminal t1 and relays data from a server in a Packet Data Network (PDN) p1. 
     A Mobility Management Entity (MME)  106  is connected to the eNB  101 , the S-GW  107 , a Home Subscriber Server (HSS)  103 , and an Equipment Identity Register (EIR)  104 . The MME  106  is a node that performs mobility management of a mobile terminal, such as registering the location of the mobile terminal t1, calling out the terminal, and management of a handover of the mobile terminal t1 when the terminal moves from a cell of one eNB  101  to a cell of another eNB  101 . 
     A Packet Data Network Gateway (P-GW)  108  is connected to the S-GW  107  and a Policy and Charging Rule Function (PCRF)  109 . The P-GW  108  is a node that relays packets between the S-GW  107  and the PDN p1. The PDN p1 is a communication network including a server that communicates with a mobile terminal t1. Concrete examples of the server include, but not limited to, a web server, a file server, a database server, and an application server. Note that the number of terminals and nodes which are components depicted in  FIG. 1  is not limited to the number as depicted. 
     &lt;Placement of Control Apparatus&gt; 
     With reference to  FIG. 2 , the placement of the control apparatus is described. 
     A case is described where the control apparatus  105  in the present embodiment is placed between an eNB  101  and the MME  106  and between an eNB  101  and the S-GW  107 . The control apparatus  105 , depicted in  FIG. 2 , is placed in a location apt for control of mobile communication signaling toward the MME  106 . However, the location of the control apparatus  105  is not limited to that depicted in  FIG. 2 . The control apparatus  105  may be placed in any other location, provided that packets between an eNB  101  and the MME  106  pass through that location and the control apparatus in that location can monitor packets between an eNB  101  and the S-GW  107 . If control is exerted on mobile communication signaling to any other mobile communication device, the control apparatus may be placed in a location through which packets that are transmitted to and received from that device pass. Note that the number of terminals and nodes which are components depicted in  FIG. 2 , including the control apparatus  105 , is not limited to the number as depicted. 
     &lt;Configuration Example of the Control Apparatus&gt; 
     With reference to  FIG. 3 , a configuration of the control apparatus is described. 
     The control apparatus  105  includes link interfaces  301 , a processor (not depicted), a memory (not depicted), a traffic management unit  310 , a storage for information  311  configured by maintenance personnel, a packet analysis unit  320 , a packet processing unit  360 , a packet output control unit  370 , and storages for log information  380  for control, statistics information  381  for control, and transmission control information  390 . The packet analysis unit  320  includes a flow analyzer  330 , a storage for flow information  331 , a user analyzer  340 , a storage for user information  341 , and an application analyzer  350 . The packet processing unit  360  includes a priority controller  361  and a packet editor  362 . The packet output control unit  370  includes a transmission rate controller  371 . The transmission rate controller  371  includes a shaping queue  372  which is used when control of shaping is performed. 
     Note that the number of link interfaces depicted in  FIG. 3  is exemplary and there is no limitation to that number. For example, separate interfaces for information configured by maintenance personnel, signaling of mobile communication, and user data of mobile communication may be provided. 
     The functional configuration of the control apparatus depicted in  FIG. 3  is exemplary. Logical function blocks may be combined or divided, provided that procedures which will be described with regard to an embodiment can be implemented. Further, one control apparatus may be physically divided into a plurality of apparatuses. For example, the control apparatus may be divided into a server, a user and application analysis apparatus, and an apparatus for implementing traffic control. The server may include a link interface  301  and the traffic management unit  310 ; it may manage information  311  configured by maintenance personnel and set flow information  331  and transmission control information  390  into the apparatus for implementing traffic control. The user and application analysis apparatus may include a link interface  301  as well as the user analyzer  340  and the application analyzer  350  in the packet analysis unit  320 . This apparatus may manage user information  341 , log information  380  for control, and statistics information  381  for control and send information from the log information  380  for control and the statistics information  381  for control to the server, so that the server will judge which packet/flow should be under traffic control. The apparatus for implementing traffic control may include a link interface  301 , the flow analyzer  330  in the packet analysis unit  320 , the priority controller  361  and the packet editor  362  in the packet processing unit  360 , and the transmission rate controller  371  and the shaping queue  372  in the packet output control unit  370 . This apparatus may manage flow information  331  and transmission control information  390 , generate a copy of a received packet for traffic analysis, and transfer it to the user and application analysis apparatus. Also, this apparatus may perform a traffic control action on a received packet and forward the packet to an external device such as eNB  101 , HSS  103 , EIR  104 , MME  106 , or S-GW  107 . 
     The link interfaces  301  are communication interfaces for receiving and transmitting packets. One link interface  301  is adapted to receive a packet from an external device, i.e., any of the following: eNB  101 , HSS  103 , EIR  104 , MME  106 , and S-GW  107 . The received packet is input to the packet analysis unit  320  and passed to the packet processing unit  360  and to the packet output control unit  370 , and is eventually forwarded by the other link interface  301  to an external device, i.e., any of the following: eNB  101 , HSS  103 , EIR  104 , MME  106 , and S-GW  107 . The one link interface  301  also transfers information configured by a maintenance personnel interface to the traffic management unit  310 . 
     The traffic management unit  310  stores information that has been configured by a maintenance personnel, received via the link interface  301 , into the storage for information  311  configured by maintenance personnel. Also, the traffic management unit  310  sets the information  311  configured by maintenance personnel into the storage for transmission control information  390 . Also, the traffic management unit  310  converts the information  311  configured by maintenance personnel to flow information and sends the flow information to the packet analysis unit  320 . Processing for converting information configured by maintenance personnel to flow information will be described with  FIG. 5 . 
     The packet analysis unit  320  includes the flow analyzer  330 , the storage for flow information  331 , the user analyzer  340 , the storage for user information  341 , and the application analyzer  350 . The packet analysis unit  320  analyzes a packet received from an external device, i.e., any of the following: eNB  101 , HSS  103 , EIR  104 , MME  106 , and S-GW  107 . 
     The flow analyzer  330  refers to flow information  331 , determines whether a received packet meets a flow specified in the flow information, and, if so, attaches to the packet a flow ID which is the identifier of a flow associated with the packet. Here, if the packet includes a plurality of pieces of signaling data, the flow analyzer  330  determines whether each piece of signaling data belongs to a flow that should be under traffic control and assigns a separate flow ID for each piece of signaling data so determined. As a result of reference to the flow information  331 , if there is no flow that the received packet meets (that is, the packet does not include signaling or the like that should be under traffic control), the flow analyzer  330  transfers the received packet as is to the packet processing unit  360 . 
     The user analyzer  340  analyzes a received packet and acquires the following information on a mobile terminal t1: its identifier, equipment type, and session-related information. It manages these items of information as user information  341 . In mobile communication, for each of devices (nodes) participated in transmitting and receiving signaling and data to/from one mobile terminal, their uplink and downlink IDs are assigned and managed. In the present embodiment, triggered by signaling for initial connection of a mobile terminal to the network, the control apparatus continues to monitor signaling between devices (nodes) to take place subsequently, as will be described in detail with  FIG. 9 . All uplink and downlink IDs for each of devices (nodes) participated in transmitting and receiving signaling and data, as mentioned above, acquired by the monitoring are associatively stored into the storage for user information  341  on a per-user basis. The storage for user information  341  is, so to say, a list of IDs; this storage is for storing, for each mobile terminal, various kinds of IDs that the mobile terminal uses in mobile communication. 
     If a received packet is a packet for signaling of mobile communication, the user analyzer  340  stores a time instant at which the control apparatus receives the packet, the type of signaling of mobile communication received, and information on the identifier and equipment type of a mobile terminal t1 relevant to the signaling of mobile communication received into the storage for log information  380  for control. 
     The application analyzer  350  analyzes a received packet of user data of mobile communication and identifies an application according to a process which will be described with  FIG. 12 . Also, the application analyzer  350  refers to user information  341 , identifies which mobile terminal t1 is an endpoint engaged in transmitting/receiving the packet from ID data included in the received packet, and acquires the identifier information of the terminal. Here, even if ID data for communication between eNB and S-GW is only included in the packet of user data, because the storage for user information  341  stores a suite of IDs pertinent to a mobile terminal t1, the application analyzer  350  can identify the mobile terminal by associating the ID data in the user packet with a terminal unique ID such as, e.g., IMSI (International Mobile Subscriber Identity). Also, the application analyzer  350  can identify the equipment type of a mobile terminal t1 from IMEISV which is stored in the storage for user information  341 . 
     The application analyzer  350  stores into the storage for log information  380  for control the following information: a time instant at which the control apparatus first received a packet carrying data of an application after the termination of a process of signaling of mobile communication as the time instant at which the application is started after the termination of a process of signaling of mobile communication; the identifier of a mobile terminal T1 included in received user data of mobile communication; the equipment type of the mobile terminal T1 included in received user data of mobile communication; and information on an application included in received user data of mobile communication. 
     The packet processing unit  360  includes the priority controller  361  and the packet editor  362 . The packet processing unit  360  edits or discards a received packet, based on a flow ID attached to the packet and according to a way of packet processing for each flow stored in the storage for transmission control information  390 . If flow ID information is not attached to the packet, the packet processing unit  360  transfers the received packet as is to the packet output control unit  370 . 
     For a packet received from the packet analysis unit, the priority controller  361  refers to transmission control information  390 , identifies priority information for the packet associated with the flow ID of the packet, and attaches the priority information to the received packet. Here, if the packet includes a plurality of pieces of signaling data, flow IDs are assigned to the pieces of signaling data respectively. Because a way of flow control for each flow ID is stored in the storage for transmission control information  390 , control on a per-signaling basis can be implemented if one packet includes a plurality of pieces of signaling data. 
     For a packet received from the packet analysis unit, the packet editor  362  refers to transmission control information  390  and determines a way of processing the packet associated with the flow ID of the packet. If the way of processing is to discard the packet, the packet editor  362  discards the packet received from the packet analysis unit  320  and does not transfer it to the packet output control unit. If the way of processing is to edit the packet, the packet editor  362  edits the packet according to a specified way of editing and forward the packet to the packet output control unit  370 . 
     For a packet received from the packet processing unit  360 , the packet output control unit  370  refers to transmission control information  390  and determines a way of transmission of the packet associated with the flow ID of the packet. If the way of transmission is shaping, the packet output control unit  370  stores the received packet into the shaping queue  372 , performs traffic shaping according to an output rate acquired from the transmission control information  390 , and forwards the packet to an external device, i.e., any of the following: eNB  101 , HSS  103 , EIR  104 , MME  106 , and S-GW  107 . 
     If the way of transmission is policing, the packet output control unit  370  performs traffic policing according to an output rate acquired from the transmission control information  390 , and forwards the packet to an external device, i.e., any of the following: eNB  101 , HSS  103 , EIR  104 , MME  106 , and S-GW  107 . If discarding a packet is required by the traffic policing, the packet output control unit  370  discards a packet of a high discard priority first, according to discard priority attached to each packet. If flow ID information is not attached to the packet, the packet output control unit  370  forwards the received packet as is to an external device. 
     &lt;Information Configured by Maintenance Personnel&gt; 
     With reference to  FIG. 4 , information elements of information configured by maintenance personnel are described. 
     The storage for information  311  configured by maintenance personnel stores maintenance information entered by a maintenance personnel using a maintenance terminal (not depicted) or the like. As information elements of information  311  configured by maintenance personnel, to carry out one type of traffic control, the maintenance personnel configures one set of information elements as follows: information on a flow that should be under traffic control, traffic control type, a threshold for traffic control, priority of traffic, time to start traffic control, and time to end traffic control. If a plurality of types of traffic control are carried out, a plurality of sets of the above information elements are configured for the information  311  configured by maintenance personnel. It is omissible to configure the priority of traffic, time to start traffic control, and time to end traffic control. 
     Information on a flow that should be under traffic control provides prescribed conditions for sorting out a packet or signaling for which the apparatus should perform a traffic control action. Information elements of the information on a flow that should be under traffic control are listed below. An information element may be configured, which is selected from the following: application, equipment type of a mobile terminal, destination IP address, source IP address, protocol, language, signaling type, IMSI, Globally Unique Temporary Identity (GUTI), SAE-Temporary Mobile Subscriber Identity (S-TMSI), Tracking Area Identity (TAI), Global eNB ID, E-UTRAN Cell Global Identifier (ECGI), and Radio Resource Control (RRC) Establishment Cause. Among these information elements of the information on a flow that should be under traffic control, a combination of plural information elements can also be configured, not limited to one information element. Specifically, “application” and “destination IP address” may be specified in combination. Thereby, a condition of meeting both information elements can be set. 
     Note that the information elements of the information on a flow that should be under traffic control listed in  FIG. 4  are exemplary. Any information element that is included in a communication packet (specifically, an information element such as “Type of Service”) or any information element for grouping devices and persons pertinent to packet transmission (specifically, gender information such as man/woman for grouping end users pertinent to packet transmission) can be acquired by reference to a server on which subscriber information or the like is stored with a search key specified from user information  341 , and defined as an information element of the information on a flow that should be under traffic control. 
     Of the information on a flow that should be under traffic control, “application” is an information element for specifying an application as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “equipment type of a mobile terminal” is an information element for specifying the equipment type of a mobile terminal, specifically, such as “Smart Phone” provided by company A, a mobile communication operator, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “destination IP address” is an information element for specifying a destination IP address that is included in an IP header of a packet received by the control apparatus  105 , as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “source IP address” is an information element for specifying a source IP address that is included in the IP header of a received packet, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “protocol” is an information element for specifying a protocol such as SCTP, S1-AP, or HTTP that is included in a received packet, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “language” is an information element for specifying a language such as HTML5 that is included in a received packet, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “signaling type” is an information element for specifying a signaling type such as a “Service Request” message which is prescribed in a 3 rd  Generation Partnership Project (3GPP) standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “IMSI” is an information element for specifying an IMSI, i.e., a mobile terminal user identifier which is prescribed in an ITU standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “GUTI” is an information element for specifying a Global Unique Temporary Identity which is prescribed in a 3GPP standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “S-TMSI” is an information element for specifying an SAE Temporary Mobile Subscriber Identity which is prescribed in a 3GPP standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “TAI” is an information element for specifying a Tracking Area Identity which is prescribed in a 3GPP standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “Global eNB ID” is an information element for specifying a Global eNB ID which is prescribed in a 3GPP standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “ECGI” is an information element for specifying an E-UTRAN Cell Global ID which is prescribed in a 3GPP standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. 
     Of the information on a flow that should be under traffic control, “RRC Establishment Cause” is an information element for specifying an RRC Establishment Cause which is prescribed in a 3GPP standard, as a condition for sorting out a packet for which the apparatus should perform a traffic control action. “RRC Establishment Cause” is an information element that indicates a cause for connection of a mobile terminal in standby state to a mobile system, such as “emergency” meaning an emergency connection, “HighPriorityAcess” meaning a high priority connection, “mt-access” meaning a call arrival, “mo-Signaling” meaning call origination for signaling, or “mo-Data” meaning call origination for data communication. For this information element, a plurality of parameters can be selected. 
     “Traffic control type” is an information element for setting what type of a traffic control action should be performed for a flow sorted as the one to be controlled by using the information on a flow that should be under traffic control. Specifically, a selection can be made from candidates such as “0 padding”, “changing chunk type”, “chunk deletion”, “shaping”, and “policing”. How the control apparatus  105  behaves when each of the candidates has been selected will be described with  FIG. 14  and subsequent figures. 
     “Threshold for traffic control” is an information element for setting a threshold value by which a traffic control action set for “traffic control type” should be performed. As a threshold value, rates including bits/sec., packets/sec., and transactions/sec. may be specified. Note that a single threshold value is not always set. A threshold value setting may be changed depending on the following category: date, a day of the week, hour, and holiday. Time-dependent value setting is possible; specifically, for an hour after 6 p.m., when traffic is anticipated to increase, a lower threshold value is set than for other hours. If no threshold for traffic control is set, the traffic control apparatus should perform a traffic control action set for “traffic control type” for all packets meeting conditions specified by the information on a flow that should be under traffic control. 
     “Priority of traffic” is an information element for setting the priority of an action to be performed according to the information on a flow that should be under traffic control. As the priority, specifically, a discard priority or the like should be specified. If no threshold for traffic control is set, the traffic control apparatus should set the same priority for any flows sorted as those to be controlled according to the information on a flow that should be under traffic control. The Lowest discard priority should be set for packets that do not meet conditions specified by the information on a flow that should be under traffic control. 
     “Time to start traffic control” is an information element for setting a time instant to start traffic control. If the information element, “time to start traffic control”, is set, before the time to start, the apparatus should not perform traffic control for all packets meeting conditions specified by the information on a flow that should be under traffic control and should forward the packets as is. At and after the time to start, the control apparatus should make a decision by a threshold value set for “threshold for traffic control” and perform a traffic control action set for “traffic control type”. 
     “Time to end traffic control” is an information element for setting a time instant to end traffic control. If the information element, “time to end traffic control”, is set, until the time to end, the control apparatus should make a decision by a threshold value set for “threshold for traffic control” and perform a traffic control action set for “traffic control type”. After the time to end, the traffic control apparatus should not perform traffic control for any packets meeting conditions specified by the information on a flow that should be under traffic control and should forward the packets as is. 
     Unless the information elements, “time to start traffic control” and “time to end traffic control” are set, the traffic control apparatus should always make a decision by a threshold value set for “threshold for traffic control” and perform a traffic control action set for “traffic control type” for all packets meeting conditions specified by the information on a flow that should be under traffic control. 
     &lt;Flow Information&gt; 
     With reference to  FIG. 5 , information elements of flow information are described. 
     Flow information  311  is used in analyzing a packet including one or more pieces of signaling data received by the control apparatus  105  and this information provides prescribed conditions for discriminating whether or not each signaling belongs to a flow that should be under traffic control. The flow analyzer  330  compares information elements included in the received packet with the information elements of flow information. If there is a match between the information elements of both, the flow analyzer  330  determines that the packet should be under traffic control, acquires the corresponding flow ID from the flow information, and attaches the flow ID to the packet. If there is a mismatch between the information elements of the flow information and the information elements included in the packet, the flow analyzer  330  sorts the packet as the one for which the apparatus should not perform a traffic control action. 
     Flow information  311  is generated by the traffic management unit  310 , based on the information  311  configured by maintenance personnel, user information  341 , and statistics information  381  for control. A method for generating flow information from the information  311  configured by maintenance personnel, user information, and statistics information  381  for control is set forth below. 
     The flow information  311  specifically includes a flow ID and an information element which is selected from the following: destination IP address, source IP address, protocol, language, signaling type, RRC Establishment Cause, IMSI, International Mobile Equipment Identity Software Version (IMEISV), GUTI, S-TMSI, TAI, Global eNB ID, and ECGI. Among these information elements of flow information to be specified for one flow ID, a combination of plural information elements can also be configured, not limited to one information element. Specifically, “signaling type” and “RRC Establishment Cause” may be specified in combination. Thereby, a condition of meeting both information elements can be set. As for information elements of flow information, an information element, e.g., “Type of Service” that is included in a communication packet, other than those listed above, can also be defined as an information element of flow information. 
     Of the flow information  311 , “flow ID” is the identifier of a flow. When generating information on a flow, the traffic management unit assigns a unique value of flow ID to the flow for each combination of conditions for sorting out packets within the control apparatus. 
     Of the flow information  311 , “destination IP address” is set identical to the value of “destination IP address” of the information on a flow that should be under traffic control. If there is no setting of “destination IP address” in the information on a flow that should be under traffic control, the traffic management unit does not set “destination IP address” in the flow information  311 . 
     Of the flow information  311 , “source IP address” is set identical to the value of “source IP address” of the information on a flow that should be under traffic control. If there is no setting of “source IP address” in the information on a flow that should be under traffic control, the traffic management unit does not set “source IP address” in the flow information  311 . 
     Of the flow information  311 , “protocol” is set identical to the value of “protocol” of the information on a flow that should be under traffic control. If there is no setting of “protocol” in the information on a flow that should be under traffic control, the traffic management unit does not set “protocol” in the flow information  311 . 
     Of the flow information  311 , “language” is set identical to the value of “language” of the information on a flow that should be under traffic control. If there is no setting of language” in the information on a flow that should be under traffic control, the traffic management unit does not set “language” in the flow information  311 . 
     Of the flow information  311 , “signaling type” is set identical to the value of “signaling type” of the information on a flow that should be under traffic control. If there is no setting of “signaling type” in the information on a flow that should be under traffic control, the traffic management unit does not set “signaling type” in the flow information  311 . 
     Of the flow information  311 , “RRC Establishment Cause” is set identical to the value of “RRC Establishment Cause” of the information on a flow that should be under traffic control. If there is no setting of “RRC Establishment Cause” in the information on a flow that should be under traffic control, the traffic management unit does not set “RRC Establishment Cause” in the flow information  311 . 
     Of the flow information  311 , “IMSI” is set identical to the value of “IMSI” of the information on a flow that should be under traffic control. If there is no setting of “IMSI” in the information on a flow that should be under traffic control, the traffic management unit does not set an “IMSI” information element in the flow information  311 . 
     Of the flow information  311 , “IMEISV” is set as follows: if the equipment type of a mobile terminal is set in the information on a flow that should be under traffic control, “IMEISV” is set by converting the equipment type information to a value of mobile terminal equipment type described in upper 8 bits of IMEISV and acquiring a value of IMEISV including the value of mobile terminal equipment type contained in the converted IMEISV from “IMEISV” of user information  341 . If two or more values of IMEISV are acquired, the traffic management unit generates flow information separately for each value of IMEISV. Conversion of the equipment type information of a mobile terminal to a mobile terminal equipment type contained in upper 8 bits of IMEISV should comply with a rule of assignment to a mobile terminal equipment type prescribed by each mobile terminal supplier. If “IMEISV” is set in the information on a flow that should be under traffic control, “IMEISV” of the flow information  311  is set identical to the value of the “IMEISV” of the information on a flow that should be under traffic control. If there are no settings of “equipment type of a mobile terminal” and “IMEISV” in the information on a flow that should be under traffic control, the traffic management unit does not set “IMEISV” in the flow information  311 . 
     Of the flow information  311 , “GUTI” is set identical to the value of “GUTI” of the information on a flow that should be under traffic control. If, in the information on a flow that should be under traffic control, “GUTI” is not set, whereas an “application” is set, the control apparatus  105  performs processing as follows: it refers to user information  340  and log information  380  for control, extracts a time period when the specified application is executed and a value of GUTI of a mobile terminal that executes the application for the time period, determines a GUTI for which it should perform a traffic control action for each time period, and updates GUTI information for each time period. 
     If, in the information on a flow that should be under traffic control, “GUTI” is not set, whereas “equipment type of a mobile terminal” is set, the control apparatus  105  performs processing as follows: it refers to user information  340  and log information  380  for control, extracts a time period when the specified mobile terminal equipment type performs data communication and a value of GUTI of a mobile terminal that performed data communication for the time period, determines a GUTI for which it should perform a traffic control action for each time period, and updates GUTI information for each time period. If there are no settings of “application”, “equipment type of a mobile terminal”, and “GUTI” in the information on a flow that should be under traffic control, the control apparatus  105  does not set “GUTI” in the flow information  311 . 
     Of the flow information  311 , “S-TMSI” is set identical to the value of “S-TMSI” of the information on a flow that should be under traffic control. If, in the information on a flow that should be under traffic control, “S-TMSI” is not set, whereas an “application” is set, the control apparatus  105  performs processing as follows: it refers to user information  340  and log information  380  for control, extracts a time period when the specified application is executed and a value of S-TMSI of a mobile terminal that executes the application for the time period, determines an S-TMSI for which it should perform a traffic control action for each time period, and updates S-TMSI information for each time period. If, in the information on a flow that should be under traffic control, “S-TMSI” is not set, whereas “equipment type of a mobile terminal” is set, the control apparatus  105  performs processing as follows: it refers to user information  340  and log information  380  for control, extracts a time period when the specified mobile terminal equipment type performs data communication and a value of S-TMSI of a mobile terminal that performs data communication for the time period, determines an S-TMSI for which it should perform a traffic control action for each time period, and updates S-TMSI information for each time period. If there are no settings of “application”, “equipment type of a mobile terminal”, and “S-TMSI” in the information on a flow that should be under traffic control, the control apparatus  105  does not set “S-TMSI” in the flow information  311 . 
     Of the flow information  311 , “TAI” is set identical to the value of “TAI” of the information on a flow that should be under traffic control. If there is no setting of “TAI” in the information on a flow that should be under traffic control, the control apparatus  105  does not set “TAI” in the flow information  311 . 
     Of the flow information  311 , “Global eNB ID” is set identical to the value of “Global eNB ID” of the information on a flow that should be under traffic control. If there is no setting of “Global eNB ID” in the information on a flow that should be under traffic control, the control apparatus  105  does not set “Global eNB ID” in the flow information  311 . 
     Of the flow information  311 , “ECGI” is set identical to the value of “ECGI” of the information on a flow that should be under traffic control. If there is no setting of “ECGI” in the information on a flow that should be under traffic control, the control apparatus  105  does not set “ECGI” in the flow information  311 . 
     &lt;User Information&gt; 
     With reference to  FIG. 6 , information elements of user information  341  are described. 
     User information  341  is information pertinent to each mobile terminal which is used by the control apparatus  105  to control traffic. 
     As user information  341 , information elements are managed, including: IMSI, IMEISV, S1-MME MME IP address, MME Group ID, MME Code, MME-Temporary Mobile Subscriber Identity (M-TMSI), MME UE S1 Application Protocol (S1AP) ID, S1-MME eNB IP address, Global eNB ID, Cell ID, TAI, eNB UE S1AP ID, S11 MME IP address, MME TEID for C-plane, S11 S-GW IP address, S-GW TEID for C-plane, S1-U eNB IP address, eNB TEID for U-plane, S1-U S-GW IP address, and S-GW TEID for U-plane. “TEID” is a Tunnel Endpoint identifier which is prescribed in a GTP protocol. As an information element of user information  341 , any information element that is included in a communication packet such as “Type of Service” which is included in an Ether packet included in signaling can be managed in association with information such as IMSI which is a user identifier. 
     A method for acquiring each information element of user information  341  will be described with  FIGS. 9A to 10 . 
     Of the user information  341 , “IMSI” is a mobile terminal user&#39;s identifier which is prescribed by International Telecommunication Union (ITU). Because a value of IMSI is unique across the world, other information elements of user information are associated with each IMSI and managed. 
     Of the user information  341 , “IMEISV” is a mobile terminal identifier. 
     Of the user information  341 , “S1-MME MME IP address” is an IP address of an MME  106  to which the mobile terminal user is connecting for a reference point of S1-MME. “S1-MME” is a reference point that denotes a connection path between an eNB  101  and an MME  106 , which is prescribed in a 3GPP standard. 
     Of the user information  341 , “MME MCC” is an MCC of the MME  106  to which the mobile terminal user is connecting. “Mobile Country Code (MMC)” is prescribed by ITU and a value of MMC in combination with a value of Mobile Network Code (MNC) is used as a mobile communication operator&#39;s identifier which is unique across the world. This information is acquired from “S1 Setup Response”, “MME Configuration Update”, or “Initial UE Message” of S1-AP protocol which is prescribed by 3GPP. 
     Of the user information  341 , “MME MNC” is an MNC of the MME  106  to which the mobile terminal user is connecting. “Mobile Network Code (MNC)” is prescribed by ITU. “MNC” information is acquired from “S1 Setup Response”, “MME Configuration Update”, or “Initial UE Message” of S1-AP protocol which is prescribed by 3GPP. 
     Of the user information  341 , “MME Group ID” is an MME Group ID of the MME  106  to which the mobile terminal user is connecting. “MME Group ID” is the identifier of a group to which an MME belong which is prescribed in a 3GPP standard. A value of MME Group ID is unique among MCC and MNC combinations. “MME Group ID” information is acquired from “S1 Setup Response”, “MME Configuration Update”, or “Initial UE Message” of S1-AP protocol which is prescribed by 3GPP. 
     Of the user information  341 , “MME Code” is an MME code of the MME  106  to which the mobile terminal user is connecting. “MME Code” is an MME identifier within a MME group which is prescribed in a 3GPP standard and a value of MME code is unique within a group with an MME group ID. 
     Of the user information  341 , “M-TMSI” is a mobile terminal user&#39;s identifier in the MME  106  to which the mobile terminal user is connecting. “M-TMSI” is prescribed in a 3GPP standard and a value of M-TMSI is unique within a node with an MME code. 
     Of the user information  341 , “MME UE S1AP ID” is a mobile terminal user&#39;s identifier for the S1-MME path of the MME  106  to which the mobile terminal user is connecting. “MME UE S1AP ID” is prescribed in a 3GPP standard and a value of MME UE S1AP ID is unique within a node with an S1-MME MME IP address. 
     Of the user information  341 , “S1-MME eNB IP address” is an IP address of an eNB  101  to which the mobile terminal user is connecting for a reference point of S1-MME. 
     Of the user information  341 , “Global eNB ID” is an identifier of the eNB  101  to which the mobile terminal user is connecting. “Global eNB ID” is prescribed in a 3GPP standard and a value of Global eNB ID is unique around the world. 
     Of the user information  341 , “Cell ID” is an identifier of a cell to which the mobile terminal user is connecting. “Cell ID” is prescribed in a 3GPP standard and a value of Cell ID is unique within a node with a Global eNB ID. 
     Of the user information  341 , “TAI” is an identifier of a tracking area within which the mobile terminal user is located. “TAI” is prescribed in a 3GPP standard and a value of TAI is unique around the world. 
     Of the user information  341 , “eNB UE S1AP ID” is a mobile terminal user&#39;s identifier for the S1-MME path of the eNB  101  to which the mobile terminal user is connecting. “MME UE S1AP ID” is prescribed in a 3GPP standard and a value of eNB UE S1AP ID is unique within a node with an S1-MME eNB IP address. 
     Of the user information  341 , “S11 MME IP address” is an IP address of the MME  106  to which the mobile terminal user is connecting for a reference point of S1. S11 is a reference point that denotes a connection path between an MME  106  and an S-GW  107 , which is prescribed in a 3GPP standard. 
     Of the user information  341 , “MME TEID for C-plane” is a mobile terminal user identifier for the S11 path of the MME  106  to which the mobile terminal user is connecting. “TEID” is prescribed in a 3GPP standard and a value of MME TEID for C-plane is unique within a node with an S11 MME IP address. 
     Of the user information  341 , an information element “S11 S-GW IP address” is an IP address of an S-GW  107  to which the mobile terminal user is connecting for the reference point of S11. 
     Of the user information  341 , “S-GW TEID for C-plane” is a mobile terminal user&#39;s identifier for the S11 path of the MME  106  to which the mobile terminal user is connecting. “TEID” is prescribed in a 3GPP standard and a value of S-GW TEID for C-plane is unique within a node with an S11 S-GW IP address. 
     Of the user information  341 , “S1-U eNB IP address” is an IP address of the eNB  101  to which the mobile terminal user is connecting for a reference point of S1-U. “S1-U” is a reference point that denotes a communication path between an eNB  101  and an S-GW  107 , which is prescribed in a 3GPP standard. 
     Of the user information  341 , “eNB TEID for U-plane” is an identifier of a bearer for the mobile terminal user for the S1-U path of the eNB  101  to which the mobile terminal user is connecting. “Bearer and TEID” are prescribed in a 3GPP standard and a value of eNB TEID for U-plane is unique within a node with an S1-U eNB IP address. Because each mobile terminal user can have a plurality of bearers as prescribed in a 3GPP standard, there may be plural values of eNB TEID for U-plane in the user information  341 . 
     Of the user information  341 , “S1-U S-GW IP address” is an IP address of the S-GW  107  to which the mobile terminal user is connecting for the reference point of S1-U. 
     Of the user information  341 , “S-GW TEID for U-plane” is an identifier of a bearer for the mobile terminal user for the S1-U path of the S-GW  107  to which the mobile terminal user is connecting. “Bearer and TEID” are prescribed in a 3GPP standard and a value of S-GW TEID for U-plane is unique within a node with an S1-U S-GW IP address. Because each mobile terminal user can have a plurality of bearers as prescribed in a 3GPP standard, there may be plural values of S-GW TEID for U-plane in the user information  341 . 
     &lt;Log Information for Control and Statistics Information for Control&gt; 
     With reference to  FIG. 7 , information elements of log information for control and statistics information for control are described. 
     Log information for control  380  is statistical information that is used by the control apparatus  105  to determine which traffic control action should be performed at which time instant. Statistics information  381  for control is statistical information that is used to determine whether a traffic control action should be performed for a packet received by the control apparatus  105 . 
     Log information for control  380  includes log information as follows: time at which a signaling process is initiated; the user of a mobile terminal that initiates the signaling process; the equipment type of the mobile terminal that initiates the signaling process; signaling process type; time at which an application starts after the signaling process; and application. 
     Time at which a signaling process is initiated is a time instant at which the mobile terminal user initiated a signaling process. The signaling process may be “Attach”, “Service Request”, etc. which are prescribed by 3GPP. The control apparatus  105  registers a time instant at which it receives a first transmission of signaling that should be received or transmitted by an MME  106  in each signaling process into the storage for log information  380  for control. The first transmission of signaling that should be received or transmitted by an MME  106  in each signaling process is prescribed by 3GPP. Specifically, in the case of an “Attach” process, the first transmission of signaling that should be received by an MME  106  is an “Attach Request” of NAS protocol. In the case of a “Service Request” process, the first transmission of signaling that should be received by an MME  106  is a “Service Request” of NAS protocol. 
     The user of a mobile terminal that initiated the signaling process is information identifying the user of the mobile terminal that initiated the signaling process. As the information identifying the mobile terminal user, specifically, the following may be registered into the storage for log information  380  for control: IMSI; GUTI; S1-MME MME IP address and S-TMSI; S1-MME MME IP address and MME UE S1AP ID; S1-MME eNB IP address and eNB UE S1AP ID; Global eNB ID and eNB UE S1AP ID; S11 MME IP address and MME TEID for C-plane; S11 S-GW IP address and S-GW TEID for C-plane; S1-U eNB IP address and eNB TEID for U-plane; S1-U S-GW IP address and S-GW TEID for U-plane; etc. 
     The equipment type of the mobile terminal that initiates the signaling process is information indicating the equipment type of the mobile terminal used by the mobile terminal user that initiates the signaling process. The control apparatus  105  registers the information indicating the equipment type of the mobile terminal, namely, IMEISV information or a part of IMEISV information into the storage for log information  380  for control. 
     Signaling process type is a type of the signaling process initiated by the mobile terminal user. The control apparatus  105  registers, as signaling process type, specifically, “Attach” or “Service Request”, among others, into the storage for log information  380  for control. Time at which an application starts after the signaling process is information indicating a time instant at which the mobile terminal user starts an application after the signaling process. The control apparatus  105  registers a time instant at which it receives a first transmission of user data after receiving the first transmission of signaling into the storage for log information  380  for control. Taking account of a possibility that a plurality of applications are executed after the signaling process, for each of the applications executed, information on the time at which an application started after the signaling process may be registered. 
     Application is information indicating the application executed by the mobile terminal user after the signaling process. Once having acquired information identifying the application, the control apparatus  105  registers such information into the storage for log information  380  for control. Taking account of a possibility that a plurality of applications are executed after the signaling process, for each of the applications executed, information on an application may be registered in combination with information on the time at which an application starts after the signaling process. 
     Statistics information  381  for control specifically includes the following statistical information: the number of transmission packets per unit time and an anticipated transaction amount per unit time. 
     The number of transmission packets per unit time is statistical information obtained by counting the number of packets transmitted per unit time. Unit time should be defined according to granularity of traffic control, specifically, such as in units of milliseconds, 10 milliseconds, 100 milliseconds, or seconds. Packet counts for statistics are acquired at least for each period until the flow information  331  is updated. In addition to counting packets for each period until the flow information  331  is updated, statistics counting may count every packet including a particular information element or a combination of information elements mentioned below, besides the conditions specified in the information on a flow that should be under traffic control, as information for tracking a status of packet transmission and reception. Specifically, statistics counting may count every packet including particular information with respect to each of the following: destination IP address, source IP address, protocol, signaling type, RRC Establishment Cause, equipment type of a mobile terminal, TAI, Global eNB ID, ECGI or a combination of plural conditions such as, specifically, destination IP address and signaling type. 
     Items of statistics obtained by counting the number of transmission packets per unit time may be other information elements that are included in a communication packet. Such an information element can be defined as an item of statistics, i.e., every packet including it should be counted. Specifically, an information element such as “Type of Service” or an information element for grouping devices and persons pertinent to packet transmission, specifically, gender information such as man/woman for grouping end users pertinent to packet transmission can be defined as an item of statistics. 
     A description will be provided later for a statistics counting method using an information element of the information on a flow that should be under traffic control, which is not included in a packet that is received by the control apparatus  105 . 
     If a statistical count value, which is the number of transmission packets per unit time with regard to a flow that falls under the conditions set in the flow information  331 , has become larger than the threshold for traffic control in the transmission control information  390 , the control apparatus  105  performs an action specified for the traffic control type of the transmission control information  390  on a packet including the flow sorted out by using the flow information  331 . 
     Anticipated transaction amount per unit time is statistical information obtained by weighting the number of signaling packets transmitted per unit time by a processing load and counting the processing load of a signaling destination device (node). Specifically, if an Attach Request message of NAS protocol which is prescribed by 3GPP is transmitted, the weight should be 20 transactions and a counter for anticipated transaction amount per unit time counts up 20 counts. In the control apparatus, information that maps between each type of signaling and a processing load for each signaling destination device (node) is prepared. Unit time should be defined according to granularity of traffic control, specifically, such as in units of milliseconds, 10 milliseconds, 100 milliseconds, or seconds. Statistics counting is specifically performed with respect to each of the following: destination IP address, source IP address, protocol, signaling type, RRC Establishment Cause, equipment type of a mobile terminal, TAI, Global eNB ID, ECGI or a combination of plural conditions such as, specifically, destination IP address and signaling type. Items of statistics obtained by counting the number of transmission packets per unit time may be any information element that is included in a communication packet. Specifically, an information element such as “Type of Service” or an information element for grouping devices and persons pertinent to packet transmission, specifically, gender information such as man/woman for grouping end users pertinent to packet transmission can be defined as an item of statistics, i.e., every packet including it should be counted. 
     &lt;Transmission Control Information&gt; 
     With reference to  FIG. 8 , information elements of transmission control information are described. 
     Transmission control information  390  provides a threshold for traffic control and a traffic control action that should be applied to a flow that falls under the conditions specified in the flow information. 
     Transmission control information  390  includes the following information elements: flow ID, traffic control type, threshold for traffic control, and priority of traffic. 
     “Flow ID” is the identifier of a flow sorted out by the conditions specified in the flow information. 
     “Traffic control type” is an information element that specifies one of traffic control actions that should be performed for the flow sorted out by the conditions specified in the flow information. The traffic control actions are, for example, shaping, policing, 0 padding, changing chunk type, etc. The traffic control type is set identical to the setting of the traffic control type that is specified for the flow sorted out by the conditions specified in the flow information of the information  311  configured by maintenance personnel. 
     “Threshold for traffic control” is a threshold value by which traffic control should be performed for the flow sorted out by the conditions specified in the flow information. For example, 100M bits/sec., 1M packets/sec., 10K transactions/sec., etc. may be set. The threshold for traffic control is set identical to the setting of the threshold for traffic control that is specified for the flow sorted out by the conditions specified in the flow information of the information  311  configured by maintenance personnel. 
     “Priority of traffic” is an information element that specifies the priority of an action such as, e.g., discard priority on the flow sorted out by the conditions specified in the flow information. The priority of traffic is set identical to the setting of the priority of traffic that is specified for the flow sorted out by the conditions specified in the flow information of the information  311  configured by maintenance personnel. 
     &lt;Process for Acquiring User Information&gt; 
       FIGS. 9A and 9B  are sequence diagrams illustrating a process for acquiring user information. 
       FIGS. 9A and 9B  illustrate processing details for acquiring a set of IDs to be stored into the storage for user information  341  by continuing to monitor messages transmitted and received between devices (nodes), triggered by receiving an “Attach Request” included an “Initial UE Message” which is transmitted by user equipment to initially connect to an LTE network, which is prescribed by 3GPP. A first half phase of the process is illustrated in  FIG. 9A  and its second half phase is illustrated in  FIG. 9B  separately. Upon acquiring user information, if information has already been stored in a set of user information  341  into which the acquired information should be stored, the control apparatus  105  overwrites the existing information. Upon acquiring information, if a set of user information  341  into which the acquired information should be stored does not exist, the control apparatus  105  generates a new set of user information  341 . Although the control apparatus  105  performs a traffic control action if a received packet should be under traffic control, a description is provided here with  FIGS. 9A and 9B  assuming that a received packet should not be under traffic control. Concrete traffic control procedures will be described with  FIG. 13  and subsequent figures. Messages that are transmitted and received between each device (node), namely, eNB  101 , HSS  103 , EIR  104 , MME  106 , or S-GW  107  and protocols of the messages are those which are prescribed by 3GPP. 
     In  FIG. 9A , when the control apparatus  105  has received from an eNB  101  an “Attach Request” of NAS protocol (S 901 ), which includes IMSI information, the control apparatus  105  generates a new set of user information  341  (S 902 ). Also, the control apparatus  105  acquires the following information: IMSI from the “Attach Request” in the received packet; eNB UE S1AP ID from an “Initial UE Message” of S1-AP protocol in the received packet; S1-MME MME IP address from a destination IP address field in an IP header of the received packet; and S1-MME eNB IP from a source IP address field in the IP header of the received packet (S 903 ). The control apparatus  105  stores these pieces of information into the set of user information  341  newly generated at step  901 . If a value of S-TMSI is included in the “Initial UE Message” in the received packet, the control apparatus  105  also acquires the value of S-TMSI. S-TMSI is a user identifier including a MME code and M-TMSI in S1-AP protocol, which is prescribed by 3GPP. In a case where the control apparatus  105  implements area-conscious traffic control, the control apparatus  105  also acquires TAI information from the “Initial UE Message” of S1-AP protocol in the received packet. 
     In the example of user information  341  presented herein, S-TMSI is divided into MME code and M-TMSI that are stored separately; however, S-TMSI may be managed as such without being divided into MME code and M-TMSI. It is unnecessary to acquire TAI information if the control apparatus  105  does not implement traffic control using area information specified. 
     The control apparatus  105  forwards the “Attach Request” to an appropriate MME (S 904 ). 
     The control apparatus  105  acquires IMEISV information if IMEISV information is included in an “Authentication Information Request” (S 911 ) of DIAMETER protocol in a packet received from the MME  106 . Referring to IMSI information included in the “Authentication Information Request”, the apparatus stores the acquired IMEISV information into a set of user information  341  in which the same IMSI information is set (S 912 ). In  FIG. 9A , a step described in a dotted frame like step  912  means that it is optional whether or not the message includes IMEISV, as prescribed by 3GPP. The control apparatus  105  forwards the “Authentication Information Request” received from the MME  106  to an appropriate HSS  103  (S 913 ). The control apparatus  105  forwards an “Authentication Information Response” received from the HSS  103  to the MME  106  (S 921 ). 
     Upon receiving a “Downlink NAS Transfer” from the MME ( 931 ), the control apparatus  105  acquires MME UE S1AP ID information. The control apparatus  105  refers to eNB UE S1AP ID information included in the “Downlink NAS Transfer” and information of a destination IP address (equivalent to an S1-MME eNB IP address) in an IP header of the packet having the “Downlink NAS Transfer” included therein and stores the acquired MME UE S1AP ID information into a set of user information  341  in which a combination of the same eNB UE S1AP ID and S1-MME eNB IP address information is set (S 932 ). The control apparatus  105  forwards the “Downlink NAS Transfer” received from the MME  106  to an appropriate eNB  101  (S 933 ). 
     The control apparatus  105  acquires IMEISV information if IMEISV information is included in an “ME Identity Check Request” (S 941 ) of DIAMETER protocol in a packet received from the MME  106 . Referring to IMSI information included in the “ME Identity Check Request”, the apparatus stores the acquired IMEISV information into a set of user information  341  in which the same IMSI information is set. If IMSI information is not included in the “ME Identity Check Request”, the control apparatus  105  discards the acquired IMEISV information (S 942 ). The control apparatus  105  forwards the “ME Identity Check Request” received from the MME  106  to an appropriate EIR  104  (S 943 ). 
     Proceeding to  FIG. 9B , when the control apparatus  105  has received from the MME  106  a “Create Session Request” of S11 protocol (S 951 ), the control apparatus  105  acquires the following information: MME TEID for C-plane from the “Create Session Request” in the received packet; S11 MME IP address from a source IP address field in the received packet; and S11 S-GW IP address from a destination IP address field in the received packet (S 952 ). Referring to IMSI information included in the “Create Session Request”, the apparatus stores the acquired information pieces, namely MME TEID for C-plane, S11 MME IP address, and S11 S-GW IP address, into a set of user information  341  in which the same IMSI information is set. The control apparatus  105  forwards the “Create Session Request” received from the MME  106  to an appropriate S-GW  107  (S 953 ). 
     Upon receiving from the S-GW  107  a “Create Session Response” of S11 protocol (S 961 ), the control apparatus  105  acquires information of S-GW TEID for C-plane from the “Create Session Response” in the received packet (S 962 ). Referring to information of MME TEID for C-plane included in a GTP header of the “Create Session Response”, the apparatus stores the acquired information of S-GW TEID for C-plane into a set of user information  341  in which the same information of MME TEID for C-plane is set. The control apparatus  105  forwards the “Create Session Response” received from the S-GW  107  to the MME  106  (step S 963 ). Upon receiving from the MME  106  an “Initial Context Setup Request” of S1-AP protocol (S 971 ), the control apparatus  105  acquires information of S-GW TEID for U-plane from the “Initial Context Setup Request” in the received packet (S 972 ). The control apparatus  105  refers to eNB UE S1AP ID information included in the “Initial Context Setup Request” and information of a destination IP address (equivalent to an S1-MME eNB IP address) in an IP header of the packet having the “Initial Context Setup Request” included therein and stores the acquired information of S-GW TEID for U-plane into a set of user information  341  in which a combination of the same eNB UE S1AP ID and S1-MME eNB IP address information is set. The control apparatus  105  forwards the “Initial Context Setup Request” received from the MME  106  to the eNB  101  (S 973 ). 
     Upon receiving from the eNB  101  an “Initial Context Setup Response” of S1-AP protocol (S 981 ), the control apparatus  105  acquires information of eNB TEID for U-plane from the “Initial Context Setup Response” in the received packet (S 982 ). The control apparatus  105  refers to MME UE S1AP ID information included in the “Initial Context Setup Response” and information of a destination IP address (equivalent to an S1-MME MME IP address) in an IP header of the packet having the “Initial Context Setup Response” included therein and stores the acquired information of eNB TEID for U-plane into a set of user information  341  in which a combination of the same MME UE S1AP ID and S1-MME MME IP address information is set. The control apparatus  105  forwards the “Initial Context Setup Response” received from the eNB  101  to the MME  106  (step S 983 ). 
       FIG. 10  is a sequence diagram illustrating a process for acquiring user information. 
     A process for acquiring S-TMSI is described with  FIG. 10 . S-TMSI is an identifier that cannot be acquired from “Attach Request” and subsequent signaling messages transmitted and received, described with  FIGS. 9A and 9B , but S-TMSI can be acquired by detecting a particular sequence during communication. 
     A method for acquiring and storing a set of user information  341  from a “Service Request” process which is prescribed by 3GPP is set forth. Upon acquiring information, if information has already been stored in a set of user information  341  into which the acquired information should be stored, the apparatus overwrites the existing information. Upon acquiring information, if a set of user information  341  into which the acquired information should be stored does not exist, the control apparatus  105  generates a new set of user information  341 . Although the control apparatus  105  performs a traffic control action if a received packet should be under traffic control, a description is provided here with  FIG. 10  assuming that a received packet should not be under traffic control. Concrete traffic control procedures will be described with  FIG. 13  and subsequent figures. Messages that are transmitted and received between each device (node), namely, eNB  101 , HSS  103 , EIR  104 , MME  106 , or S-GW  107  and protocols of the messages are those which are prescribed by 3GPP. 
     When the control apparatus  105  has received from an eNB  101  a “Service Request” of NAS protocol (S 1001 ), the control apparatus  105  acquires the following information: S-TMSI and eNB UE S1AP ID from an “Initial UE Message” of S1-AP protocol in the received packet; S1-MME MME IP address from a destination IP address field in an IP header of the received packet; and S1-MME eNB IP from a source IP address field in the IP header of the received packet (S 1002 ). In a case where the control apparatus  105  implements area-conscious traffic control, the control apparatus  105  also acquires TAI information from the “Initial UE Message” of S1-AP protocol in the received packet. It is unnecessary to acquire TAI information if the control apparatus  105  does not implement traffic control using area information specified. The control apparatus  105  forwards the “Service Request” to an appropriate MME  106  (S 1003 ). 
     Upon receiving from the MME  106  an “Initial Context Setup Request” of S1-AP protocol (S 1011 ), the control apparatus  105  acquires information of S-GW TEID for U-plane from the “Initial Context Setup Request” in the received packet (S 1012 ). The control apparatus  105  refers to MME UE S1AP ID information included in the “Initial Context Setup Request” and information of a source IP address (equivalent to an S1-MME MME IP address) in an IP header of the packet having the “Initial Context Setup Request” included therein and stores the acquired information of S-GW TEID for U-plane into a set of user information  341  in which a combination of the same MME UE S1AP ID and S1-MME MME IP address information is set. If there is a match between a combination of eNB IP address and eNB UE S1AP ID information acquired at step  1002  and a combination of S1-MME eNB IP address and eNB UE S1AP ID information included in the “Initial Context Setup Request”, the control apparatus  105  stores the information pieces, S-TMSI, eNB UE S1AP ID, S1-MME MME IP address, and S1-MME eNB IP address acquired at step S 1002  into the same set as the set of user information  341  into which it stores the information included in the “Initial Context Setup Request”. The control apparatus  105  forwards the “Initial Context Setup Request” received from the MME  106  to the appropriate eNB  101  (S 1013 ). 
     Upon receiving from the eNB  101  an “Initial Context Setup Response” of S1-AP protocol (S 1021 ), the control apparatus  105  acquires information of eNB TEID for U-plane from the “Initial Context Setup Response” in the received packet (S 1022 ). The apparatus refers to MME UE S1AP ID information included in the “Initial Context Setup Response” and information of a destination IP address (equivalent to an S1-MME MME IP address) in an IP header of the packet having the “Initial Context Setup Response” included therein and stores the acquired information of eNB TEID for U-plane into a set of user information  341  in which a combination of the same MME UE S1AP ID and S1-MME MME IP address information is set. The control apparatus  105  forwards the “Initial Context Setup Response” received from the eNB  101  to the MME  106  (S 1023 ). 
     When having received another message of NAS protocol and an “Initial UE Message” of S1-AP protocol from an eNB  101 , the control apparatus  105  likewise stores information pieces, namely S-TMSI, eNB UE S1AP ID, MME UE S1AP ID, S1-MME eNB IP, and S1-MME MME IP, into a set of user information  341  in the same way as the steps S 1002  and S 1012 . 
     Also for a handover process which is prescribed by 3GPP, the control apparatus  105  likewise acquires information from “Path Switch Request” of S1-AP protocol, “Path Switch Request Acknowledgement” of S1-AP protocol, “Handover Request” of S1-AP protocol, “Handover Request Acknowledgement” of S1-AP protocol, “Create Session Request” of S11 protocol, and “Create Session Response” of S11 protocol and stores the acquired information into a set of user information  341 . 
     Also for a tracking area update process which is prescribed by 3GPP, the control apparatus  105  likewise acquires information from “Initial UE Message” of S1-AP protocol, “Downlink NAS Transfer” of S1-AP protocol, “Initial Context Setup Request” of S1-AP protocol, “Initial Context Setup Response” of S1-AP protocol, “Create Session Request” of S11 protocol, and “Create Session Response” of S11 protocol and stores the acquired information into a set of user information  341 . 
     In a case when the control apparatus  105  has received a “Detach Request” of NAS protocol which is prescribed by 3GPP, the control apparatus  105  deletes information pieces other than IMSI, IMEISV, S1-MME MME IP address, MME MCC, MME MNC, MME Group ID, MME code, and M-TMSI among information elements stored in a set of user information  341  in which the information on the user that transmitted the “Detach Request” is stored. 
     In a case when the control apparatus  105  has received an “Attach Request” of NAS protocol including IMSI information which is prescribed by 3GPP and if there is a set of user information  341  having that IMSI stored therein, the control apparatus  105  deletes all information elements in the set of user information  341  for the user that transmits the “Attach Request” and generates a new set of user information  341  for the user. 
     &lt;Process for Acquiring Log Information for Control and Statistics Information for Control&gt; 
       FIG. 11  is a sequence diagram illustrating the process for acquiring log information for control and statistics information for control. 
     Taking up an example of a “Service Request” process which is prescribed by 3GPP, the process for acquiring log information for control and statistics information for control is set forth. 
     Upon receiving a packet from an eNB  101  (S 1101 ), the control apparatus  105  analyzes the received packet and acquires a signaling type (S 1102 ). How to identify a signaling type should comply with a rule prescribed by 3GPP. In the present embodiment, the signaling type is a “Service Request” of NAS protocol. The control apparatus  105  acquires the following information: S-TMSI and eNB UE S1AP ID from an “Initial UE Message” of S1-AP protocol in the received packet; S1-MME MME IP address from a destination IP address field in a IP header of the received packet; and S1-MME eNB IP from a source IP address field in the IP header of the received packet. The control apparatus  105  uses the information pieces, namely S-TMSI and S1-MME MME IP address, acquired from the received packet, compares these data pieces with corresponding information elements in the storage of user information  341 , and picks out a set of user information  341  having the same data of S-TMSI and S1-MME MME IP address. If there is a set of user information  341  having the same data of S-TMSI and S1-MME MME IP address, the control apparatus  105  acquires IMSI information from that set of user information  341  and identifies the user. If there is a set of user information  341  having the same data of S-TMSI and S1-MME MME IP address but IMSI information is not set in that set of user information  341  or if there is not a set of user information  341  having the same data of S-TMSI and S1-MME MME IP address, the control apparatus  105  identifies the user by the combination of the information pieces, S-TMSI and S1-MME MME IP address (S 1103 ). The control apparatus  105  stores information, namely, the signaling type and the information identifying the user, i.e., in the present embodiment, the IMSI information or the combination of the information pieces, S-TMSI and S1-MME MME IP address into the storage for log information  380  for control (S 1104 ). The control apparatus  105  forwards the “Service Request” to an appropriate MME  106  (S 1105 ). 
     Upon receiving a packet from the MME  106  (S 1111 ), the control apparatus  105  analyzes the received packet and acquires a signaling type (S 1112 ). How to identify a signaling type should comply with a rule prescribed by 3GPP. In the present embodiment, the signaling type is an “Initial Context Setup Request”. The control apparatus  105  acquires the following information: eNB UE S1AP ID and MME UE S1AP ID from the “Initial Context Setup Request” of S1-AP protocol in the received packet; S1-MME eNB IP address from a destination IP address field in a IP header of the received packet; and S1-MME MME IP from a source IP address field in the IP header of the received packet. 
     If, at step  1103 , the control apparatus  105  identified the user by the combination of the information pieces, namely S-TMSI and S1-MME MME IP address, the control apparatus  105  uses the information pieces, MME UE S1AP ID and S1-MME MME IP address, acquired from the “Initial Context Setup Request”, compares these data pieces with corresponding information elements in the storage of user information  341 , and picks out a set of user information  341  having the same data of MME UE S1AP ID and S1-MME MME IP address. If there is a set of user information  341  having the same data of MME UE S1AP ID and S1-MME MME IP address, the control apparatus  105  acquires IMSI information from that set of user information  341  and identifies the user (S 1113 ). If the IMSI information is acquired successfully, the control apparatus  105  replaces the combination of the information pieces, namely S-TMSI and S1-MME MME IP address, which is stored at step S 1104 , by the IMSI information (step S 1114 ). The control apparatus  105  forwards the “Initial Context Setup Request” to the eNB  101  (S 1115 ). Following sequences are omitted. 
     &lt;Process for Identifying an Application&gt; 
       FIG. 12  is a sequence diagram illustrating a process for identifying a user engaged in transmitting/receiving user data and associating an application being executed by the user with the user. 
       FIG. 12  illustrates an example of a process in which the control apparatus  105  analyzes user data being transmitted/received between an eNB  101  and an S-GW  107 , identifies a user engaged in transmitting/receiving the user data, identifies an application being transmitted/received, and, for management, associates an executed application with a signaling process such as “Service Request” initiated by the user for user data transmission. 
     Upon receiving from an eNB  101  a GTP-U packet of GTP protocol (S 1201 ), the control apparatus  105  acquires the following information: S-GW TEID for U-plane from TEID information in a GTP header of GTP protocol in the received packet; and S1-U S-GW IP address from a destination IP address field in an IP header of the received packet. The control apparatus  105  identifies the user by comparing the acquired information pieces with user information  341  and searching for a set of user information  341  having the same data of S-GW TEID for U-plane and S-GW IP address (S 1202 ). GTP-U is a message of GTP protocol which is used to transfer user data, as prescribed by 3GPP. The control apparatus  105  acquires L7 (Layer 7) information in order to analyze an application (S 1203 ). The control apparatus  105  forwards the GTP-U received from the eNB  101  to an appropriate S-GW  107  (S 1204 ). 
     Upon receiving from the S-GW  107  a GTP-U packet of GTP protocol (S 1211 ), the control apparatus  105  acquires the following information: eNB TEID for U-plane from TEID information in a GTP header of GTP protocol in the received packet; and S1-U eNB IP address from a destination IP address field in an IP header of the received packet. The control apparatus  105  identifies the user by comparing these data pieces with user information  341  and searching for a set of user information  341  having the same data of eNB TEID for U-plane and eNB IP address (S 1212 ). The control apparatus  105  acquires L7 (Layer 7) information in order to analyze an application (S 1213 ). The control apparatus  105  forwards the GTP-I received from the S-GW  107  to the eNB  101  (S 1214 ). 
     The application analyzer  350  in the control apparatus  105  compares L7 information acquired at step  1203  and step  1213  with “Signature” information of applications and identifies an application from protocol information included in L7 and information on packets which have been transmitted and received (S 1221 ). The control apparatus  105  creates and stores information associating the identified application with the user that executes the application into the storage for log information  380  for control (S 1222 ). 
     &lt;Process for Controlling a Counter for Statistics Information for Traffic Control&gt; 
       FIG. 13  is a flowchart illustrating a process for clearing a statistics counter for statistics information for control by which the apparatus determines whether a traffic control action should be performed. 
     The traffic management unit  310  in the control apparatus  105  clears a statistics counter for statistics information  381  for control to 0 at the time of startup of the apparatus (S 1301 ). Also, the traffic management unit  310  in the control apparatus sets a timer for clearing the statistics counter for statistics information  381  for control (S 1302 ). The apparatus may have different timers for respective statistics counters to clear the statistics counters for statistics information  381  for control. When the timer for clearing the statistics counter for statistics information  381  for control has expired (S 1303 ), the traffic management unit  310  in the control apparatus resets the statistic counter for statistics information  381  for control to 0 (S 1301 ) and sets the timer for clearing the statistics counter for statistics information  381  for control again (S 1302 ). 
     &lt;Traffic Control Processes&gt; 
     Using  FIGS. 14 to 19 , descriptions are provided for a plurality of types of traffic control actions that are performed in the present embodiment.  FIGS. 14 and 15  illustrate a traffic control action by packet editing.  FIGS. 16 and 17  illustrate a traffic control action by shaping.  FIG. 18  illustrates a traffic control action by shaping overall packet transmissions.  FIG. 19  illustrates a traffic control action by packet discard control. 
       FIG. 14  is a flowchart illustrating an example of a procedure for a traffic control action using chunk type. 
     The following sets forth an example of a traffic control action in a case where “Service Request” which is prescribed by 3GPP is set for the signaling type for which traffic control should be performed in the flow information  331  and an action “Set 190 for chunk type” is set for the traffic control type in the transmission control information  390 . Traffic control according to signaling type and on a per-user basis can also be implemented by setting information elements of the flow information  331  as follows: “Service Request” which is prescribed by 3GPP for the signaling type; S1-MME MME IP address of an MME that should be under traffic control for the destination IP address; and S-TMSI assigned to the user of a mobile terminal that should be under traffic control for an S-TMSI parameter. 
     The traffic control apparatus  105  can perform a traffic control action on signaling transmissions occurring attributed by the run of a particular application by setting S1-MME MME IP address of an MME that should be under traffic control and setting, for an S-TMSI parameter, S1-MME MME IP address of an MME to which a mobile terminal user that executes the particular application is connecting and S-TMSI of the mobile terminal user that executes the particular application for only a time segment corresponding to an application run pattern of the mobile terminal user that executes the particular application. 
     The traffic control apparatus  105  can perform a traffic control action on signaling transmissions occurring attributed by the run of a particular application by setting S1-MME MME IP address of an MME that should be under traffic control and setting, for an S-TMSI parameter, S1-MME MME IP address of an MME to which the equipment type of a mobile terminal that executes the particular application is connecting and S-TMSI of a user who uses the equipment type of the mobile terminal that executes the particular application for only a time segment corresponding to an application run pattern of the equipment type of the mobile terminal that executes the particular application. 
     Upon receiving a packet (S 1401 ), the control apparatus  105  refers to information in the flow information  331  and sorts out a flow for which it should perform a traffic control action. In the present embodiment, because “Service Request” which is prescribed by 3GPP is set for the signaling type in the flow information  331 , the apparatus analyzes the received packet and checks whether a “Service Request” is included in the received packet. As prescribed by 3GPP, a message of NAS protocol is set as a message of S1-AP protocol and a message of S1-AP protocol is transmitted over a Stream Control Transmission Protocol (SCTP). Since it is prescribed by Request For Comment (RFC) that a packet of SCTP protocol has a packet structure in which a plurality of chunks can be included in one packet of SCTP protocol, there is a possibility that a plurality of messages of S1-AP protocol are included in the received packet. The control apparatus  105  checks all chunks in the received packet and checks to see whether a “Service Request” is included in the received packet (S 1402 ). 
     If one or more “Service Requests” are included in the received packet, the control apparatus  105  refers to a statistics counter counting the number of “Service Request” transmissions per unit time for statistics information  381  for control (S 1403 ). 
     If the sum of the value of the counter counting the number of “Service Request” transmissions per unit time for statistics information  381  for control and the number or size of “Service Requests” included in the received packet is larger than the appropriate threshold for traffic control in the transmission control information  390  (S 1404 ), the control apparatus  105  performs a traffic control action set for the traffic control type in the transmission control information  390  on “Service Request(s)” in excess of the threshold for traffic control in the transmission control information  390 . Because, in the present embodiment, an action “set 190 for chunk type” is set for the traffic control type in the transmission control information  390 , the control apparatus  105  sets “190” for the chunk type of a data chunk including “Service Request” as many as the number of “Service Requests” more than the threshold for traffic control in the transmission control information  390  (S 1405 ). “Chunk type 190” is a reserve value which is normally unassigned for practical use and a device (node) that receives a chunk set to “chunk type 190” skips the chunk and continues packet receive processing according to a standard operation rule. Then, the apparatus recalculates a checksum value and updates the checksum value included in the received packet. For the packet with one or more data chunks for which “190” is set for chunk type, the apparatus recalculates its Frame Check Sequence number and updates the Frame Check Sequence number included in the received packet (S 1406 ). 
     If no “Service Request” is included in the received packet, found by the check at step  1402 , the control apparatus  105  makes no change to information in the packet and forwards the received packet according to the destination IP address included in the received packet. If, at step  1404 , the sum of the value of the counter counting the number of “Service Request” transmissions per unit time for statistics information  381  for control and the number or size of “Service Requests” included in the received packet is less than or equal to the appropriate threshold for traffic control in the transmission control information  390 , the control apparatus  105  makes no change to information in the received packet and the packet structure and forwards the received packet according to the destination IP address included in the received packet. If, at step S 1404 , the sum of the value of the counter counting the number of “Service Request” transmissions per unit time for statistics information  381  for control and the number or size of “Service Requests” included in the received packet is larger than the appropriate threshold for traffic control in the transmission control information  390 , the control apparatus  105  forwards the received packet subjected to the processing in the steps  1405  and  1406  according to the destination IP address included in the received packet (S 1407 ). 
       FIG. 15  is a flowchart illustrating an example of a procedure for a traffic control action using a chunk&#39;s payload part. 
     The following sets forth an example of a traffic control action in a case where “Service Request” which is prescribed by 3GPP is set for the signaling type for which traffic control should be performed in the flow information  331  and an action “Delete a NAS PDU part within an “Initial UE Message” and insert all 0s data” is set for the traffic control type in the transmission control information  390 . Although an example of a control action of deleting a NAS PDU part within an “Initial UE Message” is set forth in the present embodiment, a control action may delete an “Initial UE Message”. Alternatively, all 0s data may be replaced by bit string data that is judged invalid at a device (node) with a destination IP address to which the packet is forwarded. Alternatively, a data chunk including an “Initial UE Message” may be deleted from the packet. Processing in step  1501  is the same as processing in the foregoing step  1401 . Processing in step  1502  is the same as processing in the foregoing step  1402 . Processing in step  1503  is the same as processing in the foregoing step  1403 . Processing in step  1504  is the same as processing in the foregoing step  1404 . 
     The control apparatus  105  performs a traffic control action set for the traffic control type in the transmission control information  390  on “Service Request(s)” in excess of the appropriate threshold for traffic control in the transmission control information  390 . Because, in the present embodiment, the action “Delete a NAS PDU part within an “Initial UE Message” and insert all 0s data” is set for the traffic control type in the transmission control information  390 , control apparatus  105  deletes a NAS PDU part and inserts all 0s data within an “Initial UE Message” included in a data chunk including “Service Request” as many as the number of “Service Requests” more than the threshold for traffic control in the transmission control information  390 . If the size of all 0s data inserted differs from the size of deleted NAS PDU part(s), the apparatus recalculates a Length value in each protocol within the received packet in which all 0s data is inserted and update the Length value in each protocol (S 1505 ). The apparatus also recalculates a checksum value of the received packet in which all 0s data is inserted and updates the checksum value included in the received packet. The apparatus also recalculates a Frame Check Sequence number of the received packet in which all 0s data is inserted and updates the Frame Check Sequence number included in the received packet (S 1506 ). 
     If no “Service Request” is included in the received packet, found by the check at step  1502 , the control apparatus  105  makes no change to information in the packet and forwards the received packet according to the destination IP address included in the received packet. If, at step  1504 , the sum of the value of the counter counting the number of “Service Request” transmissions per unit time for statistics information  381  for control and the number or size of “Service Requests” included in the received packet is less than or equal to the appropriate threshold for traffic control in the transmission control information  390 , the control apparatus  105  makes no change to information in the received packet and the packet structure and forwards the received packet according to the destination IP address included in the received packet. If, at step S 1504 , the sum of the value of the counter counting the number of “Service Request” transmissions per unit time for statistics information  381  for control and the number or size of “Service Requests” included in the received packet is larger than the appropriate threshold for traffic control in the transmission control information  390 , the control apparatus  105  forwards the received packet subjected to the processing in the steps  1505  and  1506  according to the destination IP address included in the received packet (S 1507 ). 
       FIG. 16  is a flowchart illustrating an example of a procedure for a traffic control action using traffic shaping that should be applied to a particular flow. 
     The following sets forth an example of a traffic control action in a case where “Service Request” which is prescribed by 3GPP is set for the signaling type for which traffic control should be performed in the flow information  331  and “shaping” is set for the traffic control type in the transmission control information  390 . Processing in step  1601  is the same as processing in the foregoing step  1401 . Processing in step  1602  is the same as processing in the foregoing step  1402 . 
     The control apparatus  105  compares a Transmission Sequence Number (TSN) included in a data chunk in the received packet with TSN held on the control apparatus  105 . Upon the startup of the control apparatus  105 , TSN held on the control apparatus  105  should be 0. As a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105 , if the TSN included in a data chunk in the received packet is larger, the control apparatus  105  sorts out the packet as the one to be subjected to shaping. By this processing, when packet transfer sequence is controlled by SCTP protocol, it is possible to exclude a retransmission packet from packets that should be under traffic control. Although an example of a case where retransmission packets are exempted from traffic control is set forth in the present embodiment, it is also possible to include some of retransmission packets in packets that should be under traffic control by using a conditional expression for decision “TSN held−α&lt;received TSN?” and adjusting a value of α (S 1603 ). 
     As a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105 , if the TSN included in a data chunk in the received packet is larger, the control apparatus  105  updates the TSN held on the control apparatus  105  to the TSN included in a data chunk in the received packet (S 1604 ). 
     As a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105 , if the TSN included in a data chunk in the received packet is larger, the control apparatus  105  inputs the received packet to the shaping queue (S 1605 ). 
     The control apparatus  105  refers to information on the threshold for traffic control in the transmission control information  390  and transmits the packet(s) inputted to the shaping queue according to a transmission rate set for a threshold value for traffic control in the transmission control information  390  (S 1606 ). 
     If no “Service Request” is included in the received packet, found by the check at step  1602 , the control apparatus  105  makes no change to information in the packet and forwards the received packet according to the destination IP address included in the received packet. At step  1603 , as a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105 , if the TSN included in a data chunk in the received packet is the same number or smaller, the control apparatus  105  makes no change to information in the received packet and the packet structure and forwards the received packet according to the destination IP address included in the received packet (S 1607 ). 
       FIG. 17  is a flowchart illustrating an example of a procedure for a traffic control action using traffic shaping that should be applied to a particular flow and unordered bits. 
     The following sets forth an example of a traffic control action in a case where “Service Request” which is prescribed by 3GPP is set for the signaling type for which traffic control should be performed in the flow information  331  and an action “shaping and set unordered bits to 1” is set for the traffic control type in the transmission control information  390 . 
     Upon receiving a packet (S 1701 ), the control apparatus  105  sets unordered bits included in chunks in the received packet to 1. By this processing, at a device (node) with a destination IP address in the received packet, to which the packet is forwarded, when receiving a SCTP packet with a non-serial TSN, it is possible to transfer data in the SCTP packet to a higher layer without waiting for a retransmission of SCTP protocol (S 1702 ). 
     If the apparatus changes the values of unordered bits, the control apparatus  105  recalculates a checksum value of the packet in which the values of unordered bits are changed and updates the checksum value included in the received packet. The apparatus also recalculates a Frame Check Sequence number of the packet in which the values of unordered bits are changed and updates the Frame Check Sequence number included in the received packet. Processing in step  1704  is the same as processing in the foregoing step  1402 . Processing in step  1705  is the same as processing in the foregoing step  1603 . Processing in step  1706  is the same as processing in the foregoing step  1604 . Processing in step  1707  is the same as processing in the foregoing step  1605 . Processing in step  1708  is the same as processing in the foregoing step  1606 . Processing in step  1709  is the same as processing in the foregoing step  1607 . 
       FIG. 18  is a flowchart illustrating an example of a procedure for a traffic control action using traffic shaping that should be applied to all received packets. 
     The following sets forth an example of a traffic control action in a case where “Service Request” which is prescribed by 3GPP is set for the signaling type for which traffic control should be performed in the flow information  331  and an action “shaping all received packets” is set for the traffic control type in the transmission control information  390 . Although two levels of discard priority, high and low, are assumed in the present embodiment, more than two levels of discard priority may be set to control traffic if a larger number of flows has to be sorted. Processing in step  1801  is the same as processing in the foregoing step  1401 . Processing in step  1802  is the same as processing in the foregoing step  1402 . Processing in step  1803  is the same as processing in the foregoing step  1603 . Processing in step  1804  is the same as processing in the foregoing step  1604 . 
     As a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105 , if the TSN included in a data chunk in the received packet is larger, the control apparatus  105  sets the discard priority of the packet at high (S 1805 ). 
     If no “Service Request” is included in the received packet, found by the check at step  1802 , the control apparatus  105  sets the discard priority of the packet at low. As a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105 , if the TSN included in a data chunk in the received packet is the same number or smaller, the control apparatus  105  sets the discard priority of the packet at low. In the present embodiment, an example is set forth in which the discard priority to be set in a case where no “Service Request” is included in the received packet and the discard priority to be set in a case where the TSN included in a data chunk in the received packet is the same number or smaller as a result of comparing TSN included in a data chunk in the received packet with TSN held on the control apparatus  105  are the same low level; however, different levels of discard priority may be set for each of these cases (S 1806 ). 
     The control apparatus  105  inputs all received packets to the shaping queue (S 1807 ). If packets staying in the shaping queue have overflowed (S 1808 ), the control apparatus  105  preferentially discards packets of high discard priority (S 1809 ). The control apparatus  105  refers to information on the threshold for traffic control in the transmission control information  390  and transmits packets inputted to the shaping queue according to a transmission rate set for a threshold value for traffic control in the transmission control information  390  (S 1810 ). 
       FIG. 19  is a flowchart illustrating an example of a procedure for a traffic control action using traffic policing. 
     The following sets forth an example of a traffic control action in a case where “Service Request” which is prescribed by 3GPP is set for the signaling type for which traffic control should be performed in the flow information  331  and “policing” is set for the traffic control type in the transmission control information  390 . Although two levels of discard priority, high and low, are assumed in the present embodiment, more than two levels of discard priority may be set to control traffic if a larger number of flows has to be sorted. Processing in step  1901  is the same as processing in the foregoing step  1401 . Processing in step  1902  is the same as processing in the foregoing step  1402 . Processing in step  1903  is the same as processing in the foregoing step  1603 . Processing in step  1904  is the same as processing in the foregoing step  1604 . Processing in step  1905  is the same as processing in the foregoing step  1805 . Processing in step  1906  is the same as processing in the foregoing step  1806 . 
     By referring to the threshold for traffic control in the transmission control information  390 , if the apparatus receives an amount of packets in excess of a transmission rate set for a threshold value for traffic control in the transmission control information  390  (S 1907 ), the control apparatus  105  preferentially discards packets of high discard priority (S 1908 ). 
     The control apparatus  105  refers to information on the threshold for traffic control in the transmission control information  390  and transmits packets according to the transmission rate set for a threshold value for traffic control in the transmission control information  390  (S 1909 ). If the control apparatus  105  receives an amount of packets less than the transmission rate set for a threshold value for traffic control in the transmission control information  390  (S 1907 ), the control apparatus  105  makes no change to information in the received packet and the packet structure and forwards the received packet according to the destination IP address included in the received packet (S 1910 ). 
     &lt;Traffic Control Based on Transaction Amount&gt; 
       FIG. 20  presents an example of information elements that are used to acquire an anticipated transaction amount per unit time for statistics information for control. 
       FIG. 20  is a table that defines costs (coefficients) for calculating the amount of transactions at MME  106  to complete each signaling process. Here, processing costs are defined for, for example, the following processes which are prescribed by 3GPP: attach, tracking area update, detach, service request, extended service request, adding a PDN connection, deleting a PDN connection, adding a dedicated bearer, deleting a dedicated bearer, handover, and S1 release. For example, a definition is such that the cost of transactions A is required for MME  106  to complete an attach process. These costs of transactions are defined for each device (node) to which signaling data is transmitted. 
     Upon receiving a first message destined for MME  106  for a process which is prescribed by 3GPP, if the sum of the value of a statistics counter of anticipated transaction amount per unit time for statistics information  381  for control and the cost of the process relevant to the first message destined for MME  106  for a process which is prescribed by 3GPP is larger than a threshold value for traffic control in the transmission control information  390 , the control apparatus  105  performs a traffic control action according to information set in the transmission control information  390  and by an appropriate one of the procedures described previously. 
     &lt;Process for Predicting Signaling Burst&gt; 
       FIG. 21  is a diagram to explain about application startup prediction. 
       FIG. 21  is an explanatory diagram that presents information for predicting a phenomenon in which one application starts to run on a plurality of mobile terminals in one time segment and signaling processes for mobile communication occur simultaneously. 
     The control apparatus  105  aggregates the number of occurrences of mobile communication signaling processes, per application, for each time segment. The control apparatus  105  also aggregates the number of occurrences of mobile communication signaling processes, per equipment type of a mobile terminal, for each time segment. The control apparatus  105  analyzes a pattern of variation in the number of occurrences of mobile communication signaling processes, per application, for each time segment and then predicts a time segment during which the number of occurrences of mobile communication signaling processes per application will increase significantly. 
     The control apparatus  105  also analyzes a pattern of variation in the number of occurrences of mobile communication signaling processes, per equipment type of a mobile terminal, for each time segment and then predicts a time segment during which the number of occurrences of mobile communication signaling processes per equipment type of a mobile terminal will increase significantly. To predict a time segment during which the number of occurrences of mobile communication signaling processes per application will increase secondly or the number of occurrences of mobile communication signaling processes per equipment type of a mobile terminal will increase secondly, the control apparatus  105  uses the following parameters: year, month, day, a day of week, hour, minute, second, kind of holiday, area, season, or a combination of these parameters. Among these parameters, the control apparatus  105  uses a parameter for prediction according to order in which the number of mobile communication signaling processes is assumed to increase in shorter cycles and feeds back resulting information to enhance accuracy of prediction. 
     Specifically, the control apparatus  105  first uses information relevant to a second during which mobile communication signaling processes frequently occur and checks to see whether mobile communication signaling processes frequently occur for a corresponding second that follows. If mobile communication signaling processes frequently occur for the corresponding second that follows, the control apparatus  105  predicts that mobile communication signaling processes frequently occur in second cycles and starts traffic control in second cycles on mobile terminal users that use the relevant application or equipment type of mobile terminal. Unless mobile communication signaling processes frequently occur for the corresponding second that follows, the control apparatus  105  uses information relevant to a minute during which mobile communication signaling processes frequently occur and checks to see whether mobile communication signaling processes frequently occur for a corresponding minute and seconds that follows. Likewise, the apparatus predicts signaling occurrence in order of hour, day, a day of week, month, season, and year, checks resulting data to see whether a prediction coincides with a signal burst occurrence, and feeds back the result to traffic control. 
     Events or the like may lead to frequent occurrences of mobile communication signaling processes at random times. Taking this fact into consideration, information such as a schedule of yearly fireworks events or a schedule of events to happen for a time when online game participants tend to increase should be input beforehand. By inputting event information, it is also possible to predict signaling bursts to occur at random times in addition to predicting signaling bursts to occur periodically in order of second, minute, hour, day, a day of week, month, season, and year, as described above. 
     If the number of occurrences of mobile communication signaling processes significantly increases only in a certain area where an event or the like takes place, the apparatus may acquire TAI, ECGI, Global eNB ID, etc. that can identify the area where mobile communication signaling processes occur frequently. The control apparatus  105  may thus pick out information relevant to the area where the number of occurrences of mobile communication signaling processes significantly increases and determine whether or not to implement traffic control on a per-area basis. Also, by inputting information relevant to certain areas where events take place beforehand, the control apparatus  105  may be configured to predict an area where the number of occurrences of mobile communication signaling processes significantly increases. Also, the apparatus may be configured to calculate time-series differences in the number of occurrences of mobile communication signaling processes, per application, for each time segment, predict a tendency of increase in the number of occurrences of mobile communication signaling processes for a certain application, and automatically perform a traffic control action set for the traffic control type, if a preset threshold has been exceeded. 
     Second Embodiment 
     Currently, there is no information element indicating an application in signaling schemes prescribed by 3GPPT. Therefore, according to the first embodiment described above, the control apparatus  105  continues to monitor signaling for initial connection of a mobile terminal to the network, collects necessary information from signaling, associates a mobile terminal with its equipment type and an application, and implements traffic control. However, if an information element that indicates an application or mobile terminal type is included in signaling, it is possible to implement traffic control taking an application into consideration more simply. A second embodiment is described below, assuming a case where an information element that indicates an application or mobile terminal type is included in signaling. 
       FIG. 22  is an explanatory diagram illustrating signaling in which an information element that indicates an application or mobile terminal type is added to signaling which is prescribed by 3GPP. 
     An information element, “application ID” for identifying an application is added to, for example, signaling of RRC (Radio Resource Control) protocol and of S1-AP protocol which are prescribed by 3GPP. An information element, “terminal type” for identifying a mobile terminal type is added to, for example, signaling of RRC protocol and of S1-AP protocol which are prescribed by 3GPP. Although it is proposed in the present embodiment that an information element is added to signaling of RRC protocol and of S1-AP protocol, the information element, “application ID” or information element, “terminal type” may be added to other protocols such as GTP and DIAMETER for implementing a mobile communication signaling process. Instead of adding a new information element, such a way of identifying an application or mobile terminal type may be used that a value that identifies an application or mobile terminal type is added as one value of an existing information element, e.g., “RRC Establishment Cause”. 
     Maintenance personnel specifies an application as information on a flow that should be under traffic control and gives a command to implement traffic control. The traffic management unit  310  holds information mapping between application information that is specified by the maintenance personnel and an application ID and converts the application information specified by the maintenance personnel to its corresponding “application ID”. The traffic management unit  310  sets the “application ID” information as one information element in the flow information  331 . Upon receiving a packet, the traffic control apparatus  105  analyzes the packet and compares application ID information included in the received packet with application ID information which is set in the flow information  331  according to an information element set in the flow information  331  as a condition for sorting flows. If there is a match between both application IDs, the apparatus sorts the packet as a flow that should be under traffic control and performs a traffic control action, referring to information that is set in association with the flow for information elements of the transmission control information  390 . 
     The maintenance personnel specify a mobile terminal type as information on a flow that should be under traffic control and gives a command to implement traffic control. The traffic management unit  310  holds information mapping between mobile terminal type information that is specified by the maintenance personnel and a terminal type and converts the mobile terminal type information specified by the maintenance personnel to its corresponding “terminal type”. The traffic management unit  310  sets the “terminal type” information as one information element in the flow information  331 . Upon receiving a packet, the traffic control apparatus  105  analyzes the packet and compares terminal type information included in the received packet with terminal type information which is set in the flow information  331  according to information of an information element set in the flow information  331 . If there is a match between both terminal types, the apparatus sorts the packet as a flow that should be under traffic control and performs a traffic control action, referring to information that is set in association with the flow for information elements of the transmission control information  390 .