Abstract:
It provides a network management system in which the expandability of a network management device is increased, and the cost for expanding the function is suppressed. A gateway is provided between an SNMP network and the internet, making it possible to operate an MIB using an HTTP and receive a Trap. The network management device is provided as a Web service for a Web browser, making it possible to cooperate with the other various Web services and easily expand the function by adding the Web service to the network management device.

Description:
CLAIM OF PRIORITY 
       [0001]    The present application claims priority from Japanese patent application JP 2010-125558 filed on Jun. 1, 2010, the contents of which are hereby incorporated by reference into this application. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a network system, a network management device and a gateway device, and more particularly to a network system using an SNMP-Web gateway in the Web technology, and a network management device and a gateway device for use in the network system. 
         [0004]    2. Description of the Related Art 
         [0005]    A current network management technology depends on an Simple Network Management Protocol (SNMP). 
         [0006]      FIG. 2  shows an example of a network management system using the general SNMP. A plurality of SNMP agents  114  and  115  are connected on an SNMP network  109 , and an SNMP manager  201  collectively manages them. 
         [0007]    In patent document JP-A-9-73423, it is disclosed that if a Common Management Information Protocol (SNMP-CMIP) gateway  110  is installed, the SNMP manager  201  could also manage CMIP agents  112  and  113  connected to a CMIP network  111 . 
         [0008]    A general internal configuration of the SNMP manager  201  is made up of a TCP/IP processing part  188  for processing a TCP/IP protocol, an SNMP processing part  187  for processing an SNMP protocol, a Management Information Base (MIB) Data Base (DB)  189 , and an MIB compiler  190  for adding the MIB for new management, as the base, and a management application group  202  including a plurality of applications  203  to  206  for management on that base. 
         [0009]    Also, on the other hand, every time a new protocol or new network device is produced, the MIB on the protocol or MIB intrinsic to the network device is created, so that an enormous amount of MIB is defined at present. 
         [0010]    Herein, the MIB is abstraction of the statistical information (send or receive packet number and so on) or management information (sort of device, name, configuration, administrator, installation place and so on) held by the SNMP agent, and can be uniquely identified by an Object IDentifier (OID). 
         [0011]    In patent document JP-A-2008-269092, it is disclosed that any network device not supporting the SNMP could be also managed in the SNMP by using an SNMP mediator. 
       SUMMARY OF THE INVENTION 
       [0012]    While an enormous amount of MIB or SNMP agent comes into existence, the technology for expandability of the SNMP manager, namely, easily adding the application group has made little advancement. Therefore, there are two options of using the expensive and perfunctory SNMP manager and using the SNMP manager of its own provided by a network device vendor. 
         [0013]    If the expensive and perfunctory SNMP manager is used, the usage is almost fixed, whereby there is a problem that the cost of making the original expansion to suit the network for management is too much. 
         [0014]    Also, if the SNMP manager of its own provided by the network device vendor is used, it is required that the SNMP manager is properly used for each network device in the network in the multi-vendor environments, whereby there is a problem that the management becomes complicated. 
         [0015]    A primary cause of poor expandability may be that the SNMP protocol involves sending or receiving the messages binary encoded by an encoding method of an Abstract Syntax Notation One (ASN.1) Basic Encoding Rules (BER), which is less expandable than a data sending or receiving method in a text form of an eXtensible Markup Language (XML) base by the Web technology in the mainstream at present. 
         [0016]    In patent document JP-A-2002-101098, it is disclosed that an application group is created as a CORBA module, using a Common Object Request Broker Architecture (CORBA) technique, and the communication is made via a CORBA-SNMP gateway to improve the expandability and reusability of the application group, though the cost of creating the CORBA module itself occurred to make the expansion. Also, in a wide area network environment, there is a problem that the CORBA communication cannot be made through a FireWall (FW). 
         [0017]    In the light of the above-mentioned problems, an object of the invention is to provide a network system, a network management device and a gateway device in which the expandability of the network management device is increased, and the cost for expanding the function is suppressed. 
         [0018]    In order to accomplish the above object, an application example 1 of the invention is a gateway device having an HTTP processing part for receiving a HyperText Transfer Protocol (HTTP) request message and sending an HTTP response message, and an SNMP processing part for sending an SNMP request message and receiving an SNMP response message, wherein the gateway device includes an SNMP request processing part for creating the SNMP request message from the HTTP request message received by the HTTP processing part and passing it to the SNMP processing part, and an HTTP response processing part for creating the HTTP response message from the SNMP response message received by the SNMP processing part and passing it to the HTTP processing part. 
         [0019]    Also, an application example 2 of the invention is a gateway device having an SNMP processing part for receiving an SNMP Trap message, wherein the gateway device includes an SNMP Trap processing part for inputting the received SNMP Trap message into an SNMP Trap queue. 
         [0020]    Also, an application example 3 of the invention is a gateway device having an HTTP processing part for receiving an HTTP request message of requesting an SNMP Trap message, wherein the gateway device includes an SNMP Trap processing part for taking out the SNMP Trap message, creating an HTTP response message including the contents of the SNMP Trap message, and passing it to the HTTP processing part, if the SNMP Trap message is inputted in the SNMP Trap queue. 
         [0021]    Also, an application example 4 of the invention is a gateway device having an HTTP processing part for receiving an HTTP request message of requesting an SNMP Trap message, wherein the gateway device includes an SNMP Trap processing part for waiting for the SNMP Trap message to be inputted for a certain long period of time, if the SNMP Trap message is not inputted in the SNMP Trap queue, in which if the SNMP Trap message is inputted, the SNMP Trap processing part takes out the SNMP Trap message, creates an HTTP response message including the contents of the SNMP Trap message, and passes it to the HTTP processing part, while if the SNMP Trap message is not inputted, the SNMP Trap processing part creates an HTTP response message indicating that there is no SNMP Trap message, and passes it to the HTTP processing part. 
         [0022]    Since the gateway device enables the operation of the MIB in the SNMP agent and the acquisition of the SNMP Trap message to be performed on the HTTP, it is possible to transparently manage the SNMP agents distributed over the internet partitioned by the FW (common effect to the application examples 1 to 4). 
         [0023]    Also, an application example 5 of the invention is a network management device having an HTTP processing part for sending an HTTP request message to the gateway device and receiving a corresponding HTTP response message, wherein the network management device includes an OID table for holding the Object name of the MIB and the OID associated therewith, and an MIB operation part for searching the OID table, acquiring the corresponding OID from the Object name of the MIB, adding it as the parameter to the HTTP request, and passing it to the HTTP processing part. 
         [0024]    Also, an application example 6 of the invention is a network management device having a statistical information table for holding the statistical information including the send Byte number, receive Byte number, send IP packet number, and receive IP packet number of each SNMP agent at each time, and including a statistical information processing part for periodically acquiring the statistical information of the SNMP agent via the MIB operation part and the gateway device, and updating the statistical information table. 
         [0025]    Also, an application example 7 of the invention is a network management device having an HTTP processing part for sending an HTTP request message to the gateway device and receiving a corresponding HTTP response message from the gateway device, wherein the network management device has a Trap table for holding the contents of the SNMP Trap message, and includes a Trap processing part for creating the HTTP request message of requesting the SNMP Trap message, receiving the HTTP response message via the HTTP processing part, and updating the Trap table if the contents of the SNMP Trap message are included. 
         [0026]    Also, an application example 8 of the invention is a network management device having an HTTP processing part for receiving an HTTP request message from the Web browser and sending a corresponding HTTP response message, wherein the network management device includes a network information processing part for receiving the HTTP request message of requesting the MIB of the SNMP agent from the Web browser via the HTTP processing part, acquiring the MIB via the MIB operation part and the gateway device, creating the HTTP response message including the MIB, and responding to the Web browser via the HTTP processing part. 
         [0027]    Also, an application example 9 of the invention is a network management device having an HTTP processing part for receiving an HTTP request message from the Web browser and sending a corresponding HTTP response message, wherein the network management device includes a network information processing part for receiving the HTTP request message of requesting the statistical information of the SNMP agent from the Web browser via the HTTP processing part, acquiring the statistical information of the SNMP agent from the statistical information table, creating the HTTP response message including the statistical information, and responding to the Web browser via the HTTP processing part. 
         [0028]    Also, an application example 10 of the invention is a network management device having an HTTP processing part for receiving an HTTP request message from the Web browser and sending a corresponding HTTP response message, wherein the network management device includes a network information processing part for receiving the HTTP request message of requesting the Trap information from the Web browser via the HTTP processing part, acquiring the Trap information from the Trap table, creating the HTTP response message including the Trap information, and responding to the Web browser via the HTTP processing part. 
         [0029]    Also, the network management device makes it possible to provide the operation of acquiring the MIB, acquiring the statistical information, or acquiring the Trap information as a Web service (common effect to the application examples 5 to 10). 
         [0030]    Also, an application example 11 of the invention is a network management device including a Web service processing part for receiving an HTTP request message of requesting the use of a Web service on the internet from the Web browser via the HTTP processing part, taking out an input parameter of the Web service from the received HTTP request message, making access to the Web service via the HTTP processing part, creating an HTTP response including the result, and responding to the Web browser via the HTTP processing part. 
         [0031]    Also, an application example 12 of the invention is a network management device including a Web service processing part corresponding to each of a plurality of Web services on the internet. 
         [0032]    Also, the network management device enables the Web service of network management to easily cooperate with the other various Web services (common effect to the application examples 11 and 12). 
         [0033]    Also, an application example 13 of the invention is a network management system composed of the Web browser, the gateway device and the network management device, in which the network management system can acquire the MIB or statistical information or Trap information via the network management device and the gateway device, make access to the Web service via the network management device based on the acquired information, and display the result integrated with the MIB on the Web browser. 
         [0034]    Also, since the network management system enables the Web service to be simply added, it is possible to construct the network management system with excellent expandability at a lower cost (effect corresponding to application example 13). 
         [0035]    According to the first solving means of this invention, there is provided a network system comprising: 
         [0036]    a gateway device for creating an SNMP request message from a first HTTP request message and sending it to an SNMP agent, and creating and sending a first HTTP response message from an SNMP response message to the SNMP request message; and 
         [0037]    a network management device for communicating with the gateway device; 
         [0038]    wherein the network management device includes: 
         [0039]    an HTTP processing part for sending and receiving an HTTP request message and an HTTP response message corresponding thereto; 
         [0040]    a network information processing part for receiving a second HTTP request message for requesting a desired Management Information Base (MIB) of the SNMP agent via the HTTP processing part from a Web browser; and 
         [0041]    an MIB operation part for creating the first HTTP request message including an object identifier of the desired MIB and outputting it via the HTTP processing part to the gateway device; 
         [0042]    wherein the network information processing part receives the first HTTP response message to the first HTTP request message from the gateway device, the first HTTP response message including the MIB of the SNMP agent, creates a second HTTP response message including the MIB and sends it via the HTTP processing part to the Web browser. 
         [0043]    According to the second solving means of this invention, there is provided a network system comprising: 
         [0044]    a gateway device for storing a received SNMP Trap message; and 
         [0045]    a network management device for communicating with the gateway device; 
         [0046]    wherein the network management device includes: 
         [0047]    an HTTP processing part for sending and receiving an HTTP request message and an HTTP response message corresponding thereto; 
         [0048]    a Trap table for holding contents of the SNMP Trap message received from the gateway device; 
         [0049]    a Trap processing part for creating a first HTTP request message for requesting the SNMP Trap message, sending it via the HTTP processing part to the gateway device, receiving a first HTTP response message including the contents of the SNMP Trap message from the gateway device via the HTTP processing part, and storing the contents of the SNMP Trap message in the Trap table; and 
         [0050]    a network information processing part for receiving a second HTTP request message for requesting Trap information from the Web browser via the HTTP processing part, acquiring the contents of the SNMP Trap message from the Trap table, creating a second HTTP response message including the contents of the SNMP Trap message, and sending it via the HTTP processing part to the Web browser. 
         [0051]    According to the third solving means of this invention, there is provided a network management device in a network system which comprises a gateway device for creating an SNMP request message from a first HTTP request message and sending it to an SNMP agent, and creating and sending a first HTTP response message from an SNMP response message to the SNMP request message and, the network management device for communicating with the gateway device, the network management device comprising: 
         [0052]    an HTTP processing part for sending and receiving an HTTP request message and an HTTP response message corresponding thereto; 
         [0053]    a network information processing part for receiving a second HTTP request message for requesting a desired Management Information Base (MIB) of the SNMP agent via the HTTP processing part from a Web browser; and 
         [0054]    an MIB operation part for creating the first HTTP request message including an object identifier of the desired BIB and outputting it via the HTTP processing part to the gateway device; 
         [0055]    wherein the network information processing part receives the first HTTP response message to the first HTTP request message from the gateway device, the first HTTP response message including the MIB of the SNMP agent, creates a second HTTP response message including the BIB and sends it via the HTTP processing part to the Web browser. 
         [0056]    According to the fourth solving means of this invention, there is provided a gateway device comprising: 
         [0057]    an HTTP processing part for receiving an HTTP request message from a network management device and sending an HTTP response message to the network management device; 
         [0058]    an SNMP processing part for sending an SNMP request message to an SNMP agent and receiving an SNMP response message from the SNMP agent; 
         [0059]    a request processing part for creating the SNMP request message from the HTTP request message received by the HTTP processing part and outputting it to the SNMP processing part; and 
         [0060]    a response processing part for creating the HTTP response message from the SNMP response message received by the SNMP processing part and outputting it to the HTTP processing part, 
         [0061]    wherein the request processing part creates the SNMP request message by adding request type information included in received HTTP request message and an object identifier for specifying information of object to the SNMP request message, and 
         [0062]    wherein the response processing part creates the HTTP response message including the object identifier and value information, based on a pair of the object identifier and the value information indicating the information of the object that are included in the SNMP response message sent in response to the SNMP request message. 
         [0063]    According to the invention, it is possible to provide a network system, a network management device and a gateway device in which the expandability of the network management device is increased, and the cost for expanding the function is suppressed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0064]      FIG. 1  is a block diagram of an SNMP-Web gateway according to an embodiment of the invention. 
           [0065]      FIG. 2  is a block diagram of an SNMP manager in the related art. 
           [0066]      FIG. 3  shows a request message sequence. 
           [0067]      FIG. 4  shows an example of an HTTP request message (Get Request). 
           [0068]      FIG. 5  shows an example of an HTTP request message (Set Request). 
           [0069]      FIG. 6  is an organization view of an SNMP request message. 
           [0070]      FIG. 7  is a flowchart showing the operation of an SNMP request processing part. 
           [0071]      FIG. 8  is an organization view of an SNMP response message. 
           [0072]      FIG. 9  shows an example of an HTTP response message. 
           [0073]      FIG. 10  is a flowchart showing the operation of an HTTP response processing part. 
           [0074]      FIG. 11  shows a Trap message sequence  1 . 
           [0075]      FIG. 12  shows a Trap message sequence  2 . 
           [0076]      FIG. 13  shows an example of an HTTP request message (Trap). 
           [0077]      FIG. 14  is an organization view of an SNMP Trap message. 
           [0078]      FIG. 15  shows an example of an HTTP response message (Trap). 
           [0079]      FIG. 16  is a flowchart  1  showing the operation of an SNMP Trap processing part. 
           [0080]      FIG. 17  is a flowchart  2  showing the operation of the SNMP Trap processing part. 
           [0081]      FIG. 18  is a block diagram of a Web network management device according to one embodiment of the invention. 
           [0082]      FIG. 19  is a table organization view of an OID table. 
           [0083]      FIG. 20  is a flowchart  1  showing the operation of an MIB operation part. 
           [0084]      FIG. 21  is a flowchart  2  showing the operation of the MIB operation part. 
           [0085]      FIG. 22  is a table organization view of a statistical information table. 
           [0086]      FIG. 23  is a flowchart showing the operation of a statistical information processing part. 
           [0087]      FIG. 24  is a table organization view of a Trap table. 
           [0088]      FIG. 25  is a flowchart showing the operation of a Trap processing part. 
           [0089]      FIG. 26  is a flowchart showing the operation of a network information processing part. 
           [0090]      FIG. 27  is a flowchart showing the operation of a Web service processing part. 
           [0091]      FIG. 28  shows a message sequence in a network management system using this device. 
           [0092]      FIG. 29  shows a display example of a Web browser. 
           [0093]      FIG. 30  is an organization view of an MIB DB. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0094]    The embodiments of the present invention will be described below with reference to the drawings. 
       First Embodiment 
       [0095]      FIG. 1  is a block diagram of a gateway device  108  and a network system according to a first embodiment of the invention. 
         [0096]    The gateway device (SNMP-Web gateway)  108  includes TCP/IP processing parts  181  and  188  for performing the processing of a TCP/IP protocol, an HTTP processing part  182  for performing the processing of an HTTP protocol, an SNMP processing part  187  for performing the processing of an SNMP protocol, an MIB DB  189  for holding an MIB for management, an MIB compiler  190  for adding a new MIB for management, an SNMP request processing part  183  for converting an HTTP request into an SNMP request, an HTTP response processing part  184  for converting an SNMP response into an HTTP response, an SNMP Trap queue  186  for accumulating an SNMP Trap message, and an SNMP Trap processing part  185  for accumulating the SNMP Trap message in the SNMP Trap queue  186  and making a response to an HTTP request message of requesting the SNMP Trap. 
         [0097]    The gateway device  108  of this embodiment is connected to an SNMP network  109 , with a plurality of SNMP agents (SNMP agent devices)  114  and  115  connected on the SNMP network  109 . Also, an SNMP-CMIP gateway  110  is installed between a CMIP network  111  and the SNMP network, with the CMIP agents  112  and  113  connected on the CMIP network  111 . 
         [0098]    Also, the gateway device  108  of this embodiment is connected via a firewall (FW)  107  to an internet  106 . A network management device (web network management device)  103  of this embodiment is connected via an FW  104  to the internet  106 , and a Web browser  101  is connected via a web proxy  102  to the internet  106 . Further, a various kinds of Web service group  105  is connected to the internet  106 . The Web browser  101  may be realized by an appropriate device such as a server or terminal. 
         [0099]      FIG. 3  is a chart showing a request and response message sequence between the gateway device  108 , the network management device  103  and the SNMP agent  114  according to this embodiment. 
         [0100]    An HTTP request message  301  issued from the network management device  103  is converted into an SNMP request message  302  in the gateway device  108 , and sent to the SNMP agent  114 . An SNMP response message  303  issued from the SNMP agent  114  is converted into an HTTP response message  304  in the gateway device  108 , and sent to the network management device  103 . 
         [0101]    An HTTP request may be periodically sent from the network management device  108  to collect the statistical information, for example. Also, it may be sent from the network management device  108  to make an appropriate request or notification with the user&#39;s operation as a moment. 
         [0102]    Practically, a plurality of FWs may exist between the gateway device  108  and the network management device  103 , but they are omitted from the drawing, because the HTTP is transmittable. Also, the SNMP agent  114  can become a CMIP agent that exists ahead of the SNMP-CMIP gateway  110 . The SNMP request message  302  may be sent to an appropriate agent device such as the CMIP agent  112 , other than the SNMP agent  114 , via an appropriate gateway such as the SNMP-CMIP gateway  110 . In this embodiment, all of them are unified and explained as the SNMP agent. 
         [0103]    First of all, the conversion from the HTTP request message to the SNMP request message will be described below. 
         [0104]      FIG. 4  is a view showing an example of the HTTP request message before conversion into a Get Request message of the SNMP. 
         [0105]    Get Request is a message for acquiring the MIB of the agent. The parameter required for conversion is URL encoded and sent. In this drawing, a host  401  designates the host name of the SNMP agent at the sending destination. An opr  402  is a request type, indicating the Get Request message herein. An oid  403  designates the OID for identifying the MIB of object. 
         [0106]      FIG. 5  is a view showing an example of the HTTP request message before conversion into a Set Request message of the SNMP. 
         [0107]    Set Request is a message for setting the MIB of the agent. The parameter required for conversion is URL encoded and sent. In this drawing, a host  501  designates the host name of the SNMP agent at the sending destination. An opr  502  is a request type, indicating the Set Request message herein. An oid  503  designates the OID for identifying the MIB of object. A value  504  designates a setting value. 
         [0108]    In conversion into the other SNMP request message, the necessary parameter is URL encoded and sent in the same way. 
         [0109]      FIG. 6  is an organization view of the SNMP request message after conversion. 
         [0110]    A Version  601  and a Community  602  are acquired and set from a predetermined setting file. A PDU type  603  is set in accordance with the assortment of the SNMP request message. 
         [0000]    A request ID  604  is set to a value unique in the request message. An error status  605  and an error index  606  are unnecessary in the request message, and set to an adequate value (e.g., 0). A Variable Bindings (VB)  607  is set to a parameter value of URL encode in accordance with the assortment of the request message. 
         [0111]      FIG. 7  is a flowchart showing the operation of the SNMP request processing part  183 . 
         [0112]    First of all, the SNMP request processing part  183  receives an HTTP request message from the network management device  103  ( 701 ), and specifies the PDU type  603  from the values of the parameters opr  402  and  502  of the URL encode ( 702 ). The SPUR request processing part  183  determines whether or not the PDU type  603  is Set Request ( 703 ). If YES, the SNMP request processing part sets the values of the parameters old  503  and value  504  of the URL encode in the VB  607  ( 704 ). On the other hand, if NO (in the case of Get Request), the SNMP request processing part  183  sets the value of the parameter oid  403  of the URL encode in the VB  607 . Then, the SNMP request processing part  183  creates an SNMP request message ( 706 ). The values set at the above steps  702 ,  704  and  705  are used for the PDU type  602  and the VB  607  of the SNMP request message. The other fields are appropriately set as described above in  FIG. 6 . The SNMP request processing part  183  sends the created SNMP request message to the SNMP agent  114  ( 707 ). Though the process for the PDU type of Set Request and Get Request is only shown herein, the necessary parameter may be acquired from the URL encode and set to the VB in the case of the other types. 
         [0113]    Next, the conversion from the SNMP response message to the HTTP response message will be described below. 
         [0114]      FIG. 8  is an organization view of the SNMP response message. 
         [0115]    Though the organization is the same as in  FIG. 6 , whether there is an error or not is determined by referring to an error status  801 . In the case of the response to the request of the type of acquiring the MIB, the acquired MID data is set in a VB  802 . For example, a pair of oid and value is set. Two or more pairs may exist. 
         [0116]      FIG. 9  is a view showing an example of the HTTP response message to Get Request. 
         [0117]    The message is an XML base, and has an XML tree structure corresponding to an MIB tree structure. An Object name of each MIB is an element name of the XML, and oid is set as an attribute of each element. The acquired value of MIB is set as an element value  901 . 
         [0118]    In the example of the drawing, information of sys Location MIB is acquired, and as a result, the address of the device is returned. 
         [0119]      FIG. 30  is an organization view of an MIB DB. 
         [0120]    The MIB DB  189  is composed of a pair of an OID  3001  and an Object name  3002 , in which the Object name  3002  can be retrieved from the OID  3001 . It is supposed that each MIB held by the SNMP agent of management object is registered in the MIB DB  189 . 
         [0121]      FIG. 10  is a flowchart showing the operation of the HTTP response processing part  184 . 
         [0122]    First of all, the HTTP response processing part  184  receives an SNMP response message ( 1001 ), and determines whether or not the error status  801  is 0 (value indicating an error) ( 1002 ). If YES, the HTTP response processing part creates an HTTP response message indicating the error ( 1004 ), and sends it ( 1010 ). On the other hand, if NO, the HTTP response processing part  184  firstly creates an empty HTTP response message ( 1003 ). And the HTTP response processing part  184  determines whether or not there is untreated VB within the VB  802  of the received SNMP response message ( 1005 ). If NO (there is no untreated VB), the HTTP response message is directly sent ( 1010 ). If YES, the HTTP response processing part  184  takes out one VB  802  ( 1006 ), and searches the MID DB  189  for the taken-out oid ( 1007 ). The object name (Object name) of the MIB is obtained as a search result, and the HTTP response processing part  184  creates a corresponding XML tree from the search result and the value of the VB  802  ( 1008 ). The HTTP response processing part  184  adds the created XML tree to the HTTP response message ( 1009 ). The above cycle is repeated until there is no untreated VB, and finally the HTTP response message is sent, for example, to the network management device  103  ( 1010 ). 
         [0123]    Next, a process for an SNMP Trap message will be described below. 
         [0124]      FIG. 11  is a chart showing a first message sequence of the Trap message. 
         [0125]    The network management device  103  of this embodiment sends an HTTP request message of requesting the Trap information ( 1101 ). The gateway device  108  of this embodiment having received the HTTP request message monitors the SNMP Trap message to be accumulated in the SNMP Trap queue  186  for a relatively long, certain period of time such as five minutes from receiving. If the time out finally occurs, the gateway device  108  responds with an HTTP response message indicating no Trap ( 1102 ). 
         [0126]    The gateway device  108  receives an HTTP request message ( 1103 ), and an SNMP Trap message from the SNMP agent  114  is accumulated in the SNMP Trap queue  186  ( 1104 ). Then, the gateway device  108  takes out the SNMP Trap message, stores it in an HTTP response, and sends the HTTP response to the network management device  103  ( 1105 ). 
         [0127]      FIG. 12  is a chart showing a second message sequence of the Trap message. 
         [0128]    The gateway device  108  of this embodiment receives an HTTP request message  1201 , and receives a large number (plurality) of SNMP Trap messages from the SNMP agent  114  ( 1202 ) that are accumulated in the SNMP Trap queue  186 . The gateway device  108  takes out the SNMP Trap messages one by one, stores each SNMP Trap message in the HTTP response and responds to the network management device  103  ( 1203 ). The network management device  103  receiving the HTTP response sends the HTTP request message at once ( 1204 ). The above cycle is repeated until the SNMP Trap queue  186  becomes empty. 
         [0129]      FIG. 13  is a view showing an example of the HTTP request message in requesting the Trap information. 
         [0130]    When the Trap information is requested, the URL of request may be changed to the URL dedicated to Trap ( 1301 ). 
         [0131]      FIG. 14  is a message organization view of an SNMP Trap message. 
         [0132]    The SNMP Trap message includes a PDU type, an enterprise ID  1401 , an agent address  1402 , a general Trap number  1403 , an extended Trap number  1404 , and a Time Stamp  1405 , and thereafter a VB  1406 , if necessary. 
         [0133]    The enterprise ID  1401  is the ID for identifying the trap. For example, it designates an enterprise of the agent vendor. The agent address  1402  designates the address of an SNMP agent of the sender. The general Trap number  1403  is a predetermined number. The extended Trap number  1404  is the number unique to the vendor. The Time Stamp  1405  designates the occurrence time of Trap. 
         [0134]      FIG. 15  is a view showing an example of an HTTP response message including the Trap information. 
         [0135]    The HTTP response message includes an enterprise ID  1501 , an agent address  1502 , a general Trap number  1503 , an extended Trap number  1504 , and a Time Stamp  1505  as the element values of each XML. 
         [0136]    Though an SNMP Pv1 Trap is described in this example, the same configuration may be taken for the Trap message in the other versions. 
         [0137]      FIG. 16  is a flowchart  1  showing a first operation of the SNMP Trap processing part  185 . 
         [0138]    First of all, the SNMP Trap processing part  185  receives an SNMP Trap message ( 1601 ), and adds it to the SNMP Trap queue  186  ( 1602 ). 
         [0139]      FIG. 17  is a flowchart  2  showing a second operation of the SNMP Trap processing part  185 . 
         [0140]    First of all, the SNMP Trap processing part  185  receives an HTTP request message ( 1701 ), and sets a timer (e.g., to 5 minutes) ( 1702 ). Then, the SNMP Trap processing part  185  creates an empty HTTP response message ( 1703 ). The SNMP Trap processing part  185  determines whether or not there is Trap in the SNMP Trap queue ( 1704 ). If NO, a determination is made whether the timer times out ( 1705 ). If the timer does not yet time out, the operation returns to the determination  1704  for the SNMP Trap queue again. On the other hand, if the timer times out ( 1705 ), an empty response message is sent ( 1712 ). 
         [0141]    If there is Trap in the SNMP Trap queue at step  1704 , the SNMP Trap processing part  185  takes out one Trap from the SNMP Trap queue ( 1706 ). And the SNMP Trap processing part  185  takes out the enterprise ID  1401 , the agent address  1402 , the general Trap number  1403 , the extended Trap number  1404 , and the Time Stamp  1405  from the Trap, and adds them to the HTTP response message created at step  1703 . The SNMP Trap processing part  185  determines whether there is untreated VB  1406  ( 1708 ). If YES, the operation goes to step  1709 . The SNMP Trap processing part  185  takes out the aid and the value from the VB  1406 , and searches the MID DB  189  for the taken-out oid of the VB  1406  ( 1709 ). The SNMP Trap processing part  185  creates a corresponding XML tree from the search result and the value of the VB ( 1710 ), and adds the created XML tree to the HTTP response message ( 1711 ). This cycle is repeated until there is no untreated VB  1406 . If there is no untreated VB  1406 , the SNMP Trap processing part  185  sends the created HTTP response message to the network management device  103  ( 1712 ). 
       Second Embodiment 
       [0142]    Ina second embodiment, a function of acquiring the MIB using the first embodiment and using a Web service by making access to the Web service based on the information of MIB is provided. 
         [0143]      FIG. 18  is a block diagram showing one example of the network management device  103  according to the second embodiment. 
         [0144]    The network management device  103  includes a TCP/IP processing part  1811  for performing the processing of a TCP/IP protocol, an HTTP processing part  1810  for performing the processing of an HTTP protocol, an OID table  1804  for holding the OID associated with the Object name, an MIB operation part  1803  for searching the OID table  1804  and adding an oid parameter to the HTTP request message, a statistical information table  1801  for holding the statistical information, a statistical information processing part  1802  for periodically acquiring the statistical information in the HTTP and updating the statistical information table, a Trap table  1806  for holding the Trap information, a Trap processing part  1807  for acquiring the Trap information and adding it to the Trap table, a network information processing part  1805  for acquiring the MIB, statistical information or Trap information in accordance with a request from the Web browser  101  to respond to the Web browser  101 , and Web service processing parts  1808  and  1809  for processing each Web service. 
         [0145]    The network management device  103  is connected via the FW  104  to the internet  106 . The other components are the same as in  FIG. 1 . 
         [0146]      FIG. 19  is a table organization view of the OID table  1804 . 
         [0147]    The OID table  1804  has a pair of Object name  1901  and OID  1902  in the MIB. For example, the OID table is used to retrieve the corresponding OID from the Object name. 
         [0148]      FIG. 20  is a flowchart showing a first operation of the MIB operation part  1803 . 
         [0149]    First of all, the MIP operation part  1803  receives the URL encode part and the Object name of the HTTP request message except for the oid parameter from the statistical information processing part  1802  or the network information processing part  1805  ( 2001 ). 
         [0150]    The URL encode part received herein includes the host  401 / 501 , the opr  402 / 502 , or the value  504 , for example, in accordance with the kind of the request. And the MIB operation part  1803  searches the OID table  1804  with the passed Object name as the key, and acquires the OID corresponding to the Object name ( 2002 ). The MIB operation part  1803  adds the acquired OID as the oid parameter  403 / 503  to the URL encode part of the HTTP request message received at step  2001  ( 2003 ). The MIB operation part  1803  creates the HTTP request message using the URL encode part, and sends it to the gateway device  108  ( 2004 ). 
         [0151]      FIG. 21  is a flowchart showing a second operation of the MIB operation part  1803 . 
         [0152]    First of all, the MIB operation part  1803  receives an HTTP response message from the gateway device  108  ( 2101 ). For example, the same process of the first embodiment is performed for the HTTP request message sent at step  2004 , and the HTTP response message sent from the gateway device  108  is received. The received HTTP response message is received in the same connection as the HTTP request message, whereby to which request the response is can be identified. The MIB operation part  1803  passes the HTTP response message to the statistical information processing part  1802  or the network information processing part  1805  receiving the corresponding HTTP request message at step  2001  ( 2102 ). 
         [0153]      FIG. 22  is a table organization view of the statistical information table  1801 . 
         [0154]    The statistical information table  1801  includes an agent name  2201 , a time  2202 , a send Byte number  2203 , a receive Byte number  2204 , a send IP packet number  2205 , and a receive IP packet number  2206 . The agent name is an identifier such as the SNMP agent  114  or  115 , for example, and may be pre-stored. 
         [0155]    The other items than the agent name  2201  and the time  2202  are required to be statistical information that can be acquired as the MIB, though the other items are not shown in this drawing (e.g., send or receive UDP packet number or send or receive ICMP packet number). 
         [0156]      FIG. 23  is a flowchart showing the operation of the statistical information operation part  1802 . 
         [0157]    First of all, the statistical information processing part  1802  takes out the agent name  2201  of the statistical information table  1801 , and creates a URL encode part. The request type  402  is set to opr=get, for example. And the statistical information processing part  1802  passes the URL encode part and the Object name, with the send Byte number as the Object name, to the MIB operation part  1803  ( 2301 ). The MIB operation part  1803  performs the above process, and passes an HTTP response message to the statistical information processing part  1802 . 
         [0158]    Next, the statistical information processing part  1802  receives the HTTP response message from the MIB operation part  1803 . The HTTP response message received herein includes the information on the send Byte number designated in the Object name, for example. The statistical information processing part  1802  updates the corresponding item of the statistical information table  1801 . 
         [0159]    The above operation is performed by the number of items in the statistical information table  1801 . For example, the information of each item in the statistical information table  1801  is acquired by changing the Object name successively, and the statistical information table  1801  is updated. The time  2202  may appropriately include the updated time or the time included in the HTTP response message. 
         [0160]      FIG. 24  is a table organization view of the Trap table  1806 . 
         [0161]    The Trap table  1806  includes a number  2401  for uniquely identifying the Trap, an enterprise ID  2402 , an agent address  2403 , a general Trap number  2404 , an extended Trap number  2405 , a Time Stamp  2406  and a VB  2407 . Since more than one VB  2407  may be possibly included in one Trap, the VB is stored in another table, associated with the number  2401 , as shown in the drawing. 
         [0162]      FIG. 25  is a flowchart showing the operation of the Trap operation part  1807 . 
         [0163]    First of all, the Trap processing part  1807  sends an HTTP request message of requesting the Trap information to the gateway device  108  ( 2501 ). The Trap processing part  1807  receives an HTTP response message from the gateway device  108  ( 2502 ). The Trap processing part  1807  determines whether or not the HTTP response message is empty ( 2503 ). If YES (in the case of empty), the Trap processing part  1807  cancels the HTTP response message ( 2504 ), and returns to the top. On the other hand, if NO (in the case of not empty), the Trap processing part  1807  registers each parameter (e.g.,  1501  to  1505  of  FIG. 15 ) of the received HTTP response message in each corresponding item of the Trap table  1806  ( 2505 ). The number  2401  of the Trap table  1806  may be appropriately assigned. Thereafter, the Trap processing part  1807  cancels the HTTP response message ( 2504 ), and returns to the top. 
         [0164]      FIG. 26  is a flowchart showing the operation of the network information processing part  1805 . 
         [0165]    First of all, the network information processing part  1805  receives an HTTP request message from the Web browser  101  ( 2601 ). The HTTP request is sent with the user&#39;s operation as a moment, for example. The network information processing part  1805  determines whether the received HTTP request message indicates a request for statistical information ( 2602 ). If YES at step  2602 , the network information processing part  1805  collects data from the statistical information table  1801 , processes it in an XML form ( 2603 ), and creates an HTTP response message and sends it to the Web browser  101  ( 2611 ). 
         [0166]    If NO at step  2602 , the network information processing part  1805  determines whether the received HTTP request message indicates a request for Trap information ( 2604 ). If YES at step  2604 , the network information processing part  1805  collects data from the Trap table  1806 , processes it in the XML form ( 2605 ), and creates an HTTP response message and sends it to the Web browser  101  ( 2611 ). 
         [0167]    If NO at step  2604 , the network information processing part  1805  determines whether the received HTTP request message indicates a request for MIB information ( 2606 ). If NO at step  2606 , the network information processing part  1805  processes the information indicating an error in the XML form ( 2607 ), and creates an HTTP response message and sends it to the Web browser  101  ( 2611 ). On the other hand, if YES at step  2606 , the network information processing part  1805  passes the Object name and the object agent of the concerned MIB that are URL encoded to the MIB operation part  1803  ( 2608 ). The Object name and the object agent of the concerned MIB can be designated by the HTTP request message received at step  2601 . The network information processing part  1805  receives an HTTP response message from the MIB operation part  1803  acquiring the information via the gateway device  108  at the above step ( 2609 ). And the network information processing part  1805  takes out XML data of the HTTP response message ( 2610 ), and creates an HTTP response message and sends it to the Web browser  101  ( 2611 ). 
         [0168]      FIG. 27  is a flowchart showing the operation of the Web service processing parts  1808  and  1809 . 
         [0169]    First of all, the Web service processing parts  1808 ,  1809  send an HTTP request to the corresponding Web service, using the parameter in the URL encode part of the HTTP request message received from the Web browser  101  ( 2701 ). For example, the parameter of the URL encode part and the Web service are associated beforehand with each other, whereby the identification information or address information of the Web service can be pre-stored, associated with the parameter of the URL encode part. The Web service processing parts  1808 ,  1809  receive an HTTP response including XML data from the corresponding Web service ( 2702 ). And the Web service processing parts  1808 ,  1809  send the HTTP response including the XML data to the Web browser  101  ( 2703 ). 
         [0170]    Though the required parameter and the XML data format are different depending on the Web service, it is required that the process is changed according to an Application Program Interface (API) as publicized. 
         [0171]      FIG. 28  is a chart showing an example of a message sequence in the network management system according to this embodiment. 
         [0172]    For example, a message sequence of acquiring an address as the MIB information, and acquiring a peripheral map from the acquired address and a weather situation at the address from the Web service is exemplified. 
         [0173]    First of all, an HTTP request message of requesting the MIB information of sys Location is sent from the Web browser  101  ( 2801 ). The network management device  103  receiving the HTTP request message transfers it to the gateway device  108  ( 2802 ). The gateway device  108  converts the received HTTP request message into an SNMP request, and sends it to the SNMP agent  114  of object ( 2803 ). 
         [0174]    The SNMP agent  114  sends an SNMP response message including the sys Location information to the gateway device  108  ( 2804 ). The gateway device  108  converts the received SNMP response message into an HTTP response message, and sends it to the network management device  103  ( 2805 ). The network management device  103  transfers the received HTTP response message to the Web browser  101  ( 2806 ). 
         [0175]    The Web browser  101  receiving the sys Location information sends an HTTP request message of requesting the map information based on that information to the network management device  103  ( 2807 ). The network management device  103  receives the message in the Web service processing part  1808  or  1809  corresponding to a map information service, and transfers it to a map information service (device such as a server providing the map information service)  2815  ( 2808 ). The map information service  2815  responds with the peripheral map information as an HTTP response based on the received information ( 2809 ). The Web service processing part  1808  or  1809  corresponding to the map information service of the network management device  103  transfers the received map information to the Web browser  101  ( 2810 ). 
         [0176]    Also, the Web browser  101  receiving the sys Location information sends an HTTP request message of requesting the weather information to the network management device  103  based on that information ( 2811 ). The network management device  103  receives the message in the Web service processing part  1808  or  1809  corresponding to a weather information service, and transfers it to a weather information service (device such as a server providing the weather information service)  2816  ( 2812 ). The weather information service  2816  responds with the peripheral weather information as an HTTP response based on the received information ( 2813 ). The Web service processing part  1808  or  1809  corresponding to the weather information service of the network management device  103  transfers the received weather information to the Web browser  101  ( 2814 ). 
         [0177]    The Web browser  101  properly displays the received sys Location information, map information and weather information on the display part. 
         [0178]      FIG. 29  is a view showing a Web browser display example in the network management system according to this embodiment. 
         [0179]    In this drawing, an agent  1   2901 , a host name  2902 , outline information  2903 , address  2904 , map  2905 , and weather information  2906  are displayed. In these items, the host name is acquired from the sys Name information of the MIB, the outline information is acquired from the sys Descr information of the MIB, the address is acquired from the sys Location information of the MIB, the map is acquired from the map information Web service based on the sys Location information, and the weather information is acquired from the weather information Web service based on the sys Location information. 
         [0180]    The invention is applicable to the SNMP network using the Web technology, for example.