Patent Publication Number: US-8984145-B2

Title: Network management interface for heterogeneous data network and system using the same

Description:
BACKGROUND 
     1. Field 
     Apparatuses, devices and systems consistent with exemplary embodiments relate to management of computer networks and, more specifically, to network management apparatuses, management protocols and systems using the same. 
     2. Description of the Related Art 
     Computer networks in enterprise and industrial environments include multiple network objects.  FIG. 1  illustrates a generic example of a computer network. The network  100  includes various network objects. For example, the network objects may include infrastructure devices such as router/firewall  140 ; switches  120 ,  130 ,  150 ; access points  132 ,  134 ,  136 ; and wireless LAN controllers (WLC)  125 . The network objects may also include various computing devices, such as servers  110 ; workstations (PCs)  170 ,  180 ; printers  160 ; and portable computing devices  133 ,  135  such as personal data assistants (PDAs) and mobile terminals. The network objects shown in  FIG. 1  are not exhaustive, and new network objects capable of interacting over a network are constantly being developed by various manufacturers. 
     A network  100  typically does not include network objects from only one manufacture or running only one system. Rather, it is common to have network objects from many manufacturers and having different network management protocols together on one network. A network including these disparate elements is called a heterogeneous network. 
     One example of a heterogeneous network is in the industrial automation context. In an industrial network, field devices that include various sensors and control equipment used for monitoring a process may be provided by one or more manufacturers. These field devices may be connected to a switch that is purchased or otherwise provided from another manufacturer, and the switch may, in turn, be connected to a monitoring device made by another different manufacturer. Another example of a heterogeneous network may be a network found in an office networking environment which has several printers made by different manufacturers, one or more servers provided by another manufacturer, several network switches made by another manufacturer that provide connections to various workstations, which are perhaps manufactured by the same manufacturer of the servers or perhaps by a different manufacturer. 
     Additionally, particularly in an industrial automation setting, often legacy network objects, which have been in place for some time, and it is advantageous to add new network objects from different manufacturers to the network in order to provide for increased functionality. 
     As more and more network objects are added to the network, network related conflicts between network objects can develop and communication quality can degrade as new network objects add to the traffic on the network, create security issues, and communications quality issues, etc. Network management operations are performed with respect to the network objects in order to ensure that the network is properly configured and provisioned to maintain acceptable communication quality and security in the network. 
     In order to efficiently carry out network management, it is convenient if the network administrator can carry out the network management operations from a centralized location using a workstation. In such a case, the network administrator manages the network objects remotely using a single program. This program allows the network administrator to monitor the communication status of the network objects and to update network configuration information in the network objects to alter various network properties such as the network topology, quality of service parameters, and so on. 
     Thus, it is advantageous if the network administrator can be able to easily communicate with the network objects. Most network objects have a network management protocol that allows a network administrator to communicate with the network object from the management server to monitor and configure the network object so that the network administrators can carry out network management operations. Using the network management protocols, a network administrator can remotely monitor communication status and configure and update network configuration information in network objects. However, as discussed above, these network management protocols are typically different for different manufacturers, and one manufacturer or vendor may even provide different products that use different network management protocols. Additionally, as new network objects are added to increase functionality, legacy network objects and legacy network management protocols present challenges. 
     Thus, network management becomes difficult in the case of managing heterogeneous networks in which network objects are from different manufactures and use different network management protocols. 
     SUMMARY 
     According to an aspect of an exemplary embodiment, there is provided an apparatus for managing a plurality of network objects in a heterogeneous network, the apparatus comprising a central processing unit that receives, using a first protocol communicated using a communications protocol, a network management request to manage a network object in the heterogeneous network, and that transmits, according to a second protocol that is different than the first protocol, the network management request to the network object. 
     According to another aspect of an exemplary embodiment, there is provided a network management apparatus for managing a plurality of network objects in a heterogeneous network, the network management apparatus comprising a memory that stores a network object list comprising network management information associated with the plurality of network objects, the network management information comprising, for each of the network objects, a network management protocol associated with the network object; a central processing unit that receives a network management request using a management information. exchange protocol communicated over a communications protocol, and that transmits the network management request to a network object of the plurality of network objects specified in the network management request using the network management protocol associated with the network object in the network object list, wherein the network management protocol each are different than the management information exchange protocol. 
     According to another aspect of an exemplary embodiment, there is provided a network management system for managing a heterogeneous network, the network management system comprising a first network manager; and a first network management interface that is coupled to the network manager and to a first network object, and that is configured to communicate with the network manager using a first network management protocol transmitted over a communications protocol, and to communicate with the first network object according to a second network management protocol that is different from the first network management protocol. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects will be more apparent by describing in detail exemplary embodiments, with reference to the accompanying drawings, in which: 
         FIG. 1  is a diagram illustrating an example of network devices; 
         FIG. 2  is a view illustrating a schematic configuration of a network management system according to an exemplary embodiment; 
         FIG. 3  is a view illustrating a schematic configuration of a network management system according to another exemplary embodiment; 
         FIG. 4  is a view illustrating a schematic configuration of a network management system according to another exemplary embodiment; 
         FIG. 5  is a view illustrating a structural configuration of a network management interface (NMI) according to an exemplary embodiment; 
         FIG. 6  is a view illustration a configuration of an NMI with network devices according to an exemplary embodiment; 
         FIG. 7  is a functional block diagram of a network management system according to an exemplary embodiment; 
         FIGS. 8 and 9  are an example of a network object list of a network management interface (NMI) shown in  FIG. 7 ; 
         FIG. 10  is an example of a flowchart showing the operation of an NMI according to an exemplary embodiment; 
         FIG. 11  is an example of an activity diagram showing messaging operations in a network management system according to an exemplary embodiment; and 
         FIG. 12  is an example showing a network management interface in a network management system according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments are directed to computer networks, network management software, and network management systems which provide centralized access to network configuration and monitoring information in managed computer networks. Exemplary embodiments allow for exchanging network management information between centralized network management programs and managed network objects in heterogeneous networks. 
     There are two approaches to network management. The first approach is a two-tier approach in which a manager directly communicates with each of the network objects relying on pre-existing remote management protocols supported by the network objects on the network in order to configure and manage the network objects. 
     However, the two-tier approach has disadvantages such as increased firewall management overhead and increased vulnerability to security issues. When a manager directly exchanges network management information with network objects using different management protocols, several firewall rules need to be maintained in different firewalls to allow the corresponding data traffic to pass through. The maintenance of such firewall rules can become cumbersome for the network administrator using the manager. Moreover, in cases in which the pre-existing network management protocols supported by the network objects do not provide adequate confidentiality and integrity of communications, the manager and the network objects become exposed to network security threats. 
     The two-tier approach also have disadvantages in that the two-tier approach results in interruptions when adding new network objects and have difficulty with scalability, particularly in a heterogeneous network environment. For example, when a network object that uses a new network management protocol is added to the network, the manager needs to be altered to support the new protocol. As a result, the manager must be taken offline in order to test and perform the update. Moreover, as the number of network objects increases, performance issues arise at the manager responsible for communications with the network objects, as memory and storage must be used for maintaining a larger number of data exchange and communication contexts. 
     A second approach is a three-tiered approach in which an intermediary component is provided between the manager and the network objects being managed. Use of the intermediary component addresses some of the disadvantages of the two-tier approach. However, the intermediary components use a vendor specific network management protocol to communicate with network objects that are provided by the same vendor. For example, a manager may be used with Cisco wireless LAN controllers and Cisco Access Points. Accordingly, a management component is installed on each of the network objects being managed. This management component is the same for each network object. The intermediary component receives requests from the manager and sends the requests to the management component of the network objects. 
     However, in a heterogeneous network environment in which network objects are manufactured by different manufacturers and use different network management protocols, it is not possible to install a common management component on each of the network objects, because the internal structure and software of the network objects are not known and/or not accessible. For example, a network object may have a proprietary structure and software scheme. Thus, compatibility becomes a disadvantage of the three-tier approach in the heterogeneous network environment. 
     Exemplary embodiments address the above disadvantages. However, exemplary embodiments are not required to address the disadvantages, and a particular exemplary embodiment might not address any of the disadvantages discussed above. 
     Hereinafter, exemplary embodiments will be described in greater detail with reference to the accompanying drawings. 
       FIG. 2  is a view illustrating a configuration of a network management system according to an exemplary embodiment. As shown in  FIG. 2 , the network management system  200  includes a manager  210 , a network management interface (NMI)  220 , and network objects  230 ,  240 . Although two network objects  230 ,  240  are shown in  FIG. 2 , this is only for convenience of description, and one of ordinary skill in the art will understand that one network object or more than two network objects may be coupled to the NMI  220 . That is, any number of network objects may be provided. 
     The manager  210  may be coupled to the NMI  220  using either a wired or wireless connection. Examples of a wired connection include Ethernet, universal serial bus (USB), firewire, serial connection, etc. Examples of a wireless connection include WiFi, Bluetooth, IEEE standards-based connections, etc. The manager  210  communicates with the NMI  220  using a communications protocol (not shown in  FIG. 2 ) such as TCP/IP, Novell Network, or similar low level communications protocol. Similarly, the NMI  220  may be coupled to the network objects  230 ,  240  using either a wired or wireless connection. Any combination of connection configurations between the manager  210  and the NMI  220 , and between the NMI  220  and network objects  230 ,  240  may be used. For example, the manager  210  may be coupled to the NMI  220  using an Ethernet connection over the internet, and the network object  230  may also be coupled to the NMI  220  over an Ethernet connection while the network object  240  may be coupled to the NMI  220  using a serial connection. However, one of ordinary skill in the art will understand that this is only an example and many different connection configurations are possible. 
     The manager  210 , NMI  220 , and network objects  230 ,  240  may be provided as part of the same local area network (LAN) or as part of a wide area network (WAN). Thus, the manager  210 , the NMI  220  and the network objects  230 ,  240  may be located locally, such as in one industrial plant or within one office building. Alternatively, the NMI  220  and the network objects  230 ,  240  may be located locally with a same industrial plant or office, and the manager  210  may be provided remotely at an off-site location so as to provide remote network management of the NMI  220  and network objects  230 ,  240 . 
     The network objects  230 ,  240  may be any network object that is capable of being managed on the network. For example, the network objects  230 ,  240  may be any of the types of network objects shown in  FIG. 1 . Thus, the network objects  230 ,  240  may be infrastructure devices such as routers  140 ; switches  120 ,  130 ,  150 ; access points  132 ,  134 ,  136 ; and wireless LAN controllers  125 . The network objects  230 ,  240  may also be various computing devices, such as servers  110 ; workstations  170 ,  180 ; printers  160 ; and portable computing devices  133 ,  135  such as personal data assistants (PDAs) and mobile terminals. As discussed above with respect to  FIG. 1 , new network objects capable of interacting over a network are constantly being developed by various manufacturers. Thus, the network objects  230 ,  240  are not particularly limited, and may be any network object that is capable of being provisioned and configured on the network. 
     As discussed above, it is common that the network objects are not all the same. In other words, a given network will usually include network objects that are manufactured by one or more different vendors and/or manufacturers, and operate according to one or more network management protocols. Some examples of legacy network management protocols are SNMP (rfc1157), NetConf (rfc4741), IOS (Cisco), TiMOS (Alcatel-Lucent), JunOS (Juniper), and Diameter (rfc3588). Additionally, manufacturers often have their own proprietary network object structures, configurations, and network management protocols, which also may be legacy protocols. 
     The manager  210  may be, for example, a personal computer, workstation, or handheld computing device that is capable of being coupled to the network. The manager  210  runs a computer program that provides a user interface by which a network administrator can perform centralized network management functions. Thus, a network administrator (not shown) operating the manager  210  is able to perform functions to provision and configure the NMI  220  and also the network objects  230 ,  240  on the network. 
     The NMI  220  is a personal computer, workstation, or server that acts as an interface between the manager  210  and the network objects  230 ,  240  to which the NMI  220  is coupled. The NMI  220  is provided separately from the manager  210 . 
     As discussed above, the manager  210  runs a network management computer program. The network management computer program is configured to communicate with the NMI  220  using a first protocol  215 . The first protocol  215  is a network management protocol and, in certain exemplary embodiments, may be a management information exchange protocol, which will be described in more detail below. One of ordinary skill in the art will understand that the first protocol  215  is a higher level protocol than a communications protocol such as TCP/IP, Novell Network, and the like. Network management information is formatted using the first protocol  215  and is packetized and sent to the NMI  220  using the communications protocol. 
     The NMI  220  also runs a computer program that is configured to communicate with the manager  210  using the first protocol  215 . The NMI  220  is also configured to communicate with the network objects  230 ,  240  using a second protocol  225 . The second protocol  225  is also a network management protocol and is different than the first protocol  215 . The second protocol  225  is a network management protocol of the network objects  230 ,  240  and thus allows communication of network management information between the NMI  220  and the network objects  230 ,  240 . In other words, the NMI  220  is programmed with a module or modules for implementing the network management protocol of the network objects  230 ,  240  to which the NMI  220  is coupled. In  FIG. 2 , the network objects  230 ,  240  are shown as both communicating using the second protocol  225 . However, this is only an example, and one of ordinary skill in the art will understand that the second protocol  225  may actually be separate protocols, one unique to the network object  230  and one unique to the network object  240 . Such a situation may arise where the network objects  230 ,  240  are manufactured by different manufacturers, or by a same manufacturer but using different network management protocols. 
       FIG. 3  is a view illustrating a schematic configuration of a network management system according to another exemplary embodiment. As shown in  FIG. 3 , the network management system  300  according to this exemplary embodiment includes a manager  310 , a first NMI  320 , and network objects  330 ,  340 . The manager  310  and first NMI  320  are each configured to communicate network management information with each other using a first protocol  315 , and the first NMI  320  configured to communicate network management information with the network objects  330 ,  340  according to a second protocol  325 . The manager  310 , first NMI  320 , first protocol  315 , second protocol  325 , and network objects  330 ,  340  are the same as those in  FIG. 2 , and thus repeated description will be omitted. 
     The network management system  300  further includes a second NMI  350 . The second NMI  350  is coupled to network objects  360 ,  370 , and  380 . Similar to the first NMI  320 , the second NMI  350  is configured to communicate network management information with the manager  310  using the first protocol  315 . However, in this exemplary embodiment, the second NMI  350  is also configured to communicate using a third protocol  355  and a fourth protocol  357 . The NMI  350  uses the third protocol  355  to communicate with network objects  360  and  370 , and uses the fourth protocol  357  to communicate with network object  380 . In this configuration, the third protocol  355  is unique to the network objects  360 ,  370 , which may, for example, be provided by a same manufacturer. The fourth protocol  357  is unique to the network object  380 , which may be provided by a different manufacturer than the network objects  330 ,  340 ,  360 ,  370 . One of ordinary skill in the art will understand that alternatively the network object  380  may be coupled to an additional NMI such that the additional NMI handles the network object  380  which is provided by a different manufacturer and/or uses a different network control protocol. In other words, the additional NMI would be configured to communicate network management information using the fourth protocol. 
     Thus, according to the exemplary embodiment shown in  FIG. 3 , the first NMI  320  is provided to handle network objects  330 ,  340  from one manufacturer, and the second NMI  350  is provided to handle network objects  360 ,  370 ,  380  from manufacturers different than the manufacturer of the network objects  330 ,  340 . Accordingly, flexibility in configuration is increased. Additionally, when a network object that is from a new, different manufacturer and/or that uses a new, different network management protocol is added to the network, a network administrator can either modify one of the existing NMI on the network, or can add an additional NMI in order to handle the new network management protocol. Thus, additional network objects may be added to the network and configured without taking existing NMIs offline, and scalability may similarly be increased. 
     In the exemplary embodiment shown in  FIG. 3 , the second NMI  350  includes the third protocol  355  and the fourth protocol  357 . However, alternatively, according to another exemplary embodiment, the second NMI  350  may include the second protocol  325  of the first NMI  320  instead of the third and fourth protocols. Such a case may be advantageous, for example, where network objects  330 ,  340 ,  360 ,  370 , and  380  are provided by a same manufacturer and use the same network management protocol, but where the network objects  330  and  340  are physically separated from network objects  360 ,  370 ,  380  by a large distance. In such a case, the first NMI  320  and second NMI  350  may each be placed in closer proximity to their respective network objects. In other words, the number of network management interfaces does not necessarily depend on the number of network management protocols. 
       FIG. 4  is a view illustrating a schematic configuration of a network management system according to another exemplary embodiment. As shown in  FIG. 4 , the network management system  400  according to this exemplary embodiment includes a first manager  410 , a first protocol  415 , a first NMI  420 , a second protocol  425 , a second NMI  440 , a third protocol  445 , and network objects  430 ,  435 ,  450 , and  455 . These elements are substantially the same as the manager  310 , first protocol  315 , first NMI  320 , second protocol  325 , second NMI  350 , third protocol  355 , and network objects  330 ,  340 ,  360 ,  370  shown in  FIG. 3 . Accordingly, repeated description of these elements will be omitted. 
     The network management system  400  of  FIG. 4  further includes a third NMI  470  which is coupled to network objects  480 ,  485 , and  490 . In this exemplary embodiment, the third NMI  470  includes the fourth protocol  475 , which is substantially the same as the fourth protocol  357  of  FIG. 3 . However, the third NMI  470  is coupled to a second manager  460 . The second manager  460  also is configured to use the first protocol  415  to communicate network management information with the third NMI  470 . Thus, according to this exemplary embodiment, both the first manager  410  and the second manager  460  are provided, which provides additional scalability and flexibility. 
       FIG. 5  is a view illustrating a structural configuration of a network management interface (NMI) according to an exemplary embodiment. As shown in  FIG. 5 , the NMI  500  includes a central processing unit (CPU)  510 , a storage  520 , a memory  530 , and a communications interface  540 . The communications interface  540  includes an Ethernet interface  550 , a serial interface  560 , a USB interface  570 , a wireless interface  580  and an other communications interface  590 . The CPU  510  is connected to and controls the operation of the storage  520 , the memory  530 , and the communications interface  540 . A computer program that is configured to communicate network management information to the manager using the first protocol, and to one or more network objects using one or more additional protocols (i.e., one or more of the second, third, fourth protocols discussed above) is stored in the storage  520  and/or the memory  530 . Upon running the computer program, the CPU  510  operates to format the network management information according to one or more network management protocols and to control communication of the formatted information through the communications interfaces  540 . 
       FIG. 6  shows an example of connections to the NMI  500 . The NMI  500  may be connected to a manager  670  and network objects  650 ,  660  through Internet  680  and the Ethernet interface  550 . The NMI  500  may be connected to network object  640  using the wireless interface  580 , network object  630  using the other communication interface  590 , network object  620  using USB interface  570 , and network object  610  using serial interface  560 . The network objects  610 ,  620 ,  630 ,  640 ,  650 , and  660  may correspond to any of the network objects described above, and the manager  670  may correspond to any of the managers described above. 
       FIG. 7  is a functional block diagram of a network management system according to an exemplary embodiment. As shown in  7 , the network management system  700  includes a manager  701 , one or more NMIs  702 , and one or more network objects  703 . However, the one or more NMIs will be collectively referred to by NMI  702 , and the one or more network objects will be referred to by network object  703 . 
     The manager  701  includes a network management program that runs on the manager  701  and provides a user interface by which the network administrator may manage the network. The network management program includes a management information controller module  710  for exchanging network management information with the NMI  702  according to a management information exchange protocol  720 . The NMI  702  includes a network management interface program that provides a management information service module  730  for communicating directly with the manager  701  using a management information exchange protocol  720 , and for creating data exchange processes  750  for communicating directly with the network objects  703  to communicate network management information with the network objects  703 . 
     The network management program of the manager  701  uses the management information controller module  710  to send requests to the NMI  702  to read and write network management information from and to the network objects  703 . The management information exchange protocol  720  is used to format and transport the requests and the responses between the management information controller module  710  of the manager  701  and the network management interface  702 . 
     The management information controller module  710  provides two functions. The first function is to exchange information with the network objects  703  through the NMI  702 . The management information controller module  710  creates request messages and sends the request messages to the NMI  702  over the network using the management information exchange protocol  720 . The management information controller module  710  is also responsible for receiving and processing response messages from the NMI  702 . The management information controller module  710  thus forward network management information received from the NMI  702  to the network management program of the manager  701 . 
     The second function of the management information controller module  710  is to manage the NMI  702 . The management information controller module  710  thus allows the network administrator using the manager  701  to remotely configure the NMI  702  by sending management messages to the NMI  702 . Such management messages are formatted according to the management information exchange protocol  720  and sent to the NMI  702  over the network. 
     A single management information controller module  710  may communicate with one or more NMIs  702 . 
     The management information exchange protocol  720  specifies two categories of messages. The first category of messages is related to reading and writing network management information from and to network objects  703 . The second category of messages is related to the maintenance and configuration of the NMI  702 . 
     The network management interface program of the NMI  702  includes a management information service module  730 , a network object list  740 , and one or more data exchange processes  750 . 
     Network object list  740  includes information and parameters related to the network objects  703  with which the NMI  702  can communicate. The information and parameters may include, for example, specification of the network management protocols of the network objects  703  and parameters for reading and writing network management information to each network object  703 , identification of what network management information can be read or written to each network object  703 , and specific commands used for reading and writing the information. 
       FIGS. 8 and 9  show an example of a network object list  740 . As shown in  FIG. 8 , the network object list  740  includes object records  810 ,  820 ,  830 , etc. Each object record, for example object record  820 , includes an object identifier (ID)  830 , one or more object-properties  840 ,  850 ,  860 , etc. and one or more object-data  845 ,  855 ,  865 , etc. 
       FIG. 9  shows a non-limiting example of an object record. The object record has an object-ID  910  of “DEV-123456789022366”, and includes object-properties  920 ,  930  of an “IP address” and a “Management Protocol”, respectively, and object-data  940 ,  950  of a “Radio channel” and an “Uptime”, respectively. The object-property  920  has fields including a Property-ID  921 , a Property Name  922 , an IP Version  923 , and an IP-Address  924  with corresponding value fields  925 - 928  with values of “POP-00001”, “Device IP address”, “6”, and “3ffe:1900:4545:20:56cf:f8ff:76cf:00f3”, respectively. The object-property  930  has fields including a Property-ID  931 , a Property Name  932 , a Protocol Name  933 , and a Protocol Version  934  with corresponding value fields  935 - 938  having values of “POP-00002”, “Management Protocol”, “SNMP”, and “2”, respectively. The object-data  940  has fields including Data-ID  941 , Data Name  942 , Type 943, and SNMP OID  944  with value fields  945 - 948  having values of “DAT-00001”, “Radio channel”, “Integer”, and “1.3.6.1.3.6.2.6.2”, respectively. The object-data  950  has fields including Data-ID  951 , Data Name  952 , Type 953, and SNMP OID  954  with corresponding value fields  955 - 958  having values of “DAT-00002”, “Uptime”, “String”, and “1.3.6.1.2.1.25.1.1.0”, respectively. It is to be noted that these fields are only examples, and more or fewer fields may provided. Additionally, it should be noted that these are only examples, and any properties and data may be specified in the network object list  740 . 
     Turning back now to  FIG. 7 , the management information service module  730  receives, sends, and processes messages from the management information controller modules  710  of one or more managers  701 . When a request message is received by the management information service module  730 , the request is processed according to the type of network management information contained in the message. 
     The data exchange processes  750  are created by the management information service module  730  for reading or writing network management information to and from a given network object  703 . Each data exchange process  750  when created is provided with information related to the tasks assigned to the process. The data exchange process refers to the network object list  740  to obtain detailed information on how to perform the read or write operations. The data exchange processes  750  may also be used to perform periodic communication with the network objects  703 . 
     The processing performed by the management information service module  730  will be described below in more detail with reference to the flowchart shown in  FIG. 10 , which shows an example of the process according to an exemplary embodiment. 
     The process  1000  begins by the management information service module  730  receiving a message in operation S 1010 . In operation S 1020 , it is then determined whether the message is a request for communicating network management information with a network object. 
     If the message is a request for communicating network management information with a network object (S 1020 : YES), the message is forwarded to a data exchange process in operation S 1030 , and it is determined whether the message is a request for reading network management information in operation S 1040 . 
     If the message is not a request for reading network management information (S 1040 : NO), the message is a request for writing network management information. The network management information is then written to the network object and verified in operation S 1045 , and an acknowledgement is sent to the requestor to notify the requestor of the success or failure of the write operation in operation S 1090 . 
     If the message is a request for reading network management information (S 1040 : YES), the network management information is read from the network object in operation S 1050 , and a message is sent to the requestor containing the read information in operation S 1080 . 
     Returning to operation S 1020 , if the message is not a request for communicating network management information with a network object (S 1020 : NO), then it is determined whether the message is a request for reading information from the network object list in operation S 1060 . If the message is a request for reading information (S 1060 : YES), then the requested information is read from the network object list in operation S 1070 , and a message is sent to the requestor with the read information in operation S 1080 . 
     If the request is not for reading information from the network object list (S 1060 : NO), then the request is for writing information to the network object list. The information is written to the network object list and verified in operation S 1065 . Then, an acknowledgement is sent to the requestor to notify the requestor of the success or failure of the write operation in operation S 1090 . After sending the acknowledgement, the process ends. It is noted that the acknowledgement operation is optional and may be omitted in some cases. 
       FIG. 11  is an example of an activity diagram showing messaging operations in a network management system according to an exemplary embodiment. With reference to  FIGS. 7 and 11 , a non-limiting example of a management information exchange protocol will be described. 
     For example, the management information exchange protocol  720  (see  FIG. 7 ) may specify at least two categories of messages communicated between the centralized network management program of the manager  701  and the network management interface program of the NMI  702 . The first category of messages is I/O messages for reading and writing management information to and from the network objects  703  through the NMI  702 . The second category of messages is management messages for managing the NMI  702 . 
     I/O messages  1110  (see activity chart in  FIG. 11 ) are used to remotely read and write network management information to and from the network objects  703  through the NMI  702 . The I/O messages may include I/O request (IOREQ) messages and I/O response (IORESP) messages. 
     The following is an example of a specification for an I/O Request message (IOREQ) message:
         IOREQ=MSG-TYPE, sequence-of IO-JOB   IO-JOB=ACCESS-MODE, OBJECT-ID, DATA-ID, (DATA), (READ-INTERVAL)       

     When the network management program of the manager  710  performs communications, such as reading and/or writing operations, with a given network object  703 , the management information controller module  710  of the network management program of the manager  701  sends an IOREQ message ( 1115 ) that contains one or more read and write jobs (Sequence of IO-JOB structures) to the management information service module  730  of the appropriate NMI  702  associated with the given network object  703 . 
     Each read or write job specifies a type of the operations (ACCESS-MODE is used to specify whether reading or writing), a unique identifier of the corresponding object (OBJECT-ID) and an identifier of the data (DATA-ID). The OBJECT-ID and DATA-ID include values that correspond, respectively, to an Object-Record and Object-Data record in the network object list of the NMI. The request may also include a parameter to specify a read frequency (READ-INTERVAL) in the case that the centralized network management program, for example, periodically monitors status information in the network object  703 . In case of a write request, the data to be written is included in the job request (DATA). The management information service  703  of the NMI  702  creates a data exchange process  750  and forwards the I/O job specifications (IO-JOB) ( 1120 ) to the data exchange process. The data exchange process  750  then carries out the read or write request according to the job ( 1125 ) with the network object  703 , and receives either data or acknowledgement ( 1130 ) from the network object  703  as the case may be. The data exchange process  750  then forwards the data or acknowledgement ( 1135 ) to the management information service module  730 . 
     The following is an example of a specification for an I/O Request message (IORESP) message:
         IORESP=MSG-TYPE, sequence-of IO-RESPONSE   IO-RESPONSE=ACCESS-MODE, OBJECT-ID, DATA-ID, (DATA), (READ-INTERVAL), STATUS       

     When a read or write operation is completed, an IORESP response message ( 1140 ) is sent by the management information service module  730  of the NMI  702  to the management information controller module  710  of the manager  701 . The response message includes one or more outcomes (Sequence of IO-RESPONSE structures) from the read and write jobs that were requested by the management information controller module  710 . Each outcome includes information about the requested job operation (ACCESS-MODE, OBJECT-ID, DATA-ID and READ-INTERVAL) and information about the success or failure of the read or write operation (STATUS). In the case of a requested read operation, the information that was requested to be read from the network object  703  is included in the response (DATA). 
     As described above, the second category of messages is management messages for managing the NMI  702 . Management messages  1150  (see activity chart in  FIG. 11 ) are used to maintain the network object list  740  of the NMI  702 . The management messages may include object management request (OMREQ) messages and an object management response (OMRESP) messages. 
     The following is an example of a specification for an object management request (OMREQ) message:
         OMREQ=MSG-TYPE, sequence-of OM-JOB   OM-JOB=OPERATION, OBJECT-ID, (PROPERTY-ID), (DATA)       

     The operations that may be performed on the network object list  740  include, for example, creating and deleting object-record entries and reading and modifying object-properties and object-data. 
     When the network management program of the manager  701  performs managing operations, such as creating, deleting, reading or modifying, of the network object list  740  of a given NMI  702 , the management information controller module  710  of the network management program of the manager  701  sends an OMREQ message ( 1155 ) to the management information service module  730  of the NMI  702  specifying the type of operation to be carried out (using the OPERATION field) and the relevant information for carrying out the operation (OBJECT-ID, PROPERTY-ID, DATA, READ-INTERVAL). The OBJECT-ID and PROPERTY-ID include values that correspond, respectively, to an Object-Record and Object. Property record in the network object list of the NMI. 
     When deleting or creating an empty Object-Record, the identifier of the object (OBJECT-ID) alone may be indicated. However, when writing or reading object properties, the identifier of the property to be read or modified is specified (PROPERTY-ID) in addition to the object (OBJECT-ID). For writing operations, the data to be written is also provided (DATA). The management information service module  730  then creates, deletes, reads, or writes an object record ( 1160 ) according to the request, and data or an acknowledgement ( 1165 ) may be returned to the management information service module  730 . 
     The following is an example of a specification for an object management response (OMRESP) message:
         OMRESP=MSG-TYPE, sequence-of OM-RESPONSE   IO-RESPONSE=OPERATION, OBJECT-ID, (PROPERTY-ID), (DATA), STATUS       

     When the management operation (create, delete, read or write) is completed, an OMRESP response ( 1170 ) message is sent by the management information service module  730  of the NMI  702  to the management information controller module  710  of the manager  701 . The response message includes one or more outcomes (Sequence of OM-RESPONSE structures) resulting from the management jobs that were requested by the management information controller module  710 . Each outcome contains information about the requested job operation (OPERATION, OBJECT-ID and PROPERTY-ID) and information about the success or failure of the operation (STATUS). In the case of a read operation, the information that was read from the network object list  740  is included (DATA). 
       FIG. 12  illustrates a non-limiting example showing a network management interface in a network management system according to an exemplary embodiment. As shown in the network  1200  in  FIG. 12 , two communication technologies, i.e., WiFi/IEEE 802.11 and ISA100.11a, are provided. Each of the communications technologies are used by various network objects, including infrastructure objects (e.g., WiFi Access Points (AP)  1274 ,  1272 ; switch  1270 ; ISA100.11a routing devices  1262 ,  1264 ; and switch  1260 ), end node objects (e.g., WiFi devices  1275  and ISA100.11a I/O devices  1265 ), and management objects (e.g., WiFi Controller  1250  and ISA100.11a manager  1245 ). These infrastructure objects, end node objects, and management objects constitute the set of network objects that are managed by the centralized network management program running on host server  1220 . 
     A serial interface connection may be used to connect the NMI  1240  to the ISA100.11a manager  1245 , and a TCP/IP connection over an Ethernet network may be used to communicate with the WiFi controller  1250 . A network administrator  1210  connects at terminal  1215  to the centralized network management application running on the host server  1220  to monitor and control the network objects being managed. Messages exchanged between the centralized network management application running on the host server  1220  and the NMI  1240  using the management information exchange protocol are formatted according to the management information exchange protocol and relayed using a communication protocol to a router/firewall  1235 . Once received by the NMI  1240 , the messages are read and formatted according to the network management protocol for WiFi/IEEE 802.11 or ISA100.11a and sent using the appreciate TCP/IP or serial communication protocol to the network object. Alternatively or additionally to network administrator  1210 , a remote network administrator  1211  may access host server  1220  through terminal  1216  through the Internet. In other words, multiple network administrators may access host server  1220  through terminals and use the host server  1220  to run the network management program to interact with the NMI  1240 . 
     The foregoing exemplary embodiments and advantages are merely exemplary and are not to be construed as limiting the present inventive concept. The exemplary embodiments can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.