Generic snmp information collection

Abstract

The present invention provides a technique to define objects and object instances in a dynamically modifiable table within the confines of a management information base definition. With the invention, new objects and object instances may be added to the table without changing the management information base definition at a managed device or network management system. The managed device can change the table, yet allow the network management system to access the table using an associated object identifier. The network management system can systematically step through the various objects or object instances, which may correspond to rows and columns of the table, to detect additions or modifications to the table. The various objects and object instances in the table may be individually accessed, once identified, using a unique object identifier.

What is claimed is: 
     
         1 . A method of operating a network management system for a network implementing a simple network management protocol environment, the network comprising a network management system controller and a managed device coupled to the network management system controller by the network, the method comprising:
 providing a managed information base definition, the managed information base definition associating a unique identifier with a table located at the managed device and associating a respective unique object identifier with each object in the table, the managed information base definition being known to the network management system controller and to the managed device;   sending a request to obtain information for objects and associated object instances in the table from the network management system controller to the managed object, the objects and object instances not being included in the managed information base definition;   receiving the request at the managed device;   responsive to the received request, sending the requested information from the managed device to the network management system controller; and   receiving the requested information at the network management system controller.   
     
     
         2 . The method of  claim 1 , wherein, when the managed device adds additional information associated with additional objects or associated object instances to the table, the additional information is accessible without modifying the managed information base definition at the managed device or the network management system. 
     
     
         3 . The method of  claim 2 , comprising sequentially sending, from the network management system controller to the managed device, requests for selected information corresponding to objects or associated object instances from the table, and sending the selected information from the managed device to the network management system controller until an end of a row or column in the table is reached, such that the table is fully accessible without modifying the managed information base definition. 
     
     
         4 . The method of  claim 3 , wherein sequentially sending the requests from the network management system controller to the managed device comprises sending a request for information for a first object and then repetitively sending requests for information for a next object in sequence until the end of the row or column in the table is reached. 
     
     
         5 . The method of  claim 3 , wherein, when the network management system controller receives information for an object or object instance not already in a table at the network management system controller, the network management system controller adds the object or object instance to the table at the network management system controller. 
     
     
         6 . The method of  claim 1 , wherein each object and associated object instance in the table is associated with an object identifier which is dependent on the object identifier for the table. 
     
     
         7 . The method of  claim 1 , wherein each object instance in the table which is associated with a particular object is associated with an object identifier which is dependent on the object identifier for the particular object. 
     
     
         8 . The method of  claim 1 , wherein each object in the table is associated with an object identifier which comprises the object identifier of the table and an identifier element associated with the object that makes the object identifier unique to the object. 
     
     
         9 . The method of  claim 1 , wherein each object instance in the table is associated with an object instance identifier which comprises the object identifier of the object and an identifier element associated with the object instance that makes the object instance identifier unique to the object instance. 
     
     
         10 . The method of  claim 1 , comprising creating the table at the managed device to comprise information for objects and associated object instances which are not included in the managed information base definition. 
     
     
         11 . The method of  claim 1 , comprising adding additional information associated with additional objects or associated object instances to the table at the managed device and providing access to the additional information by the network management system controller without modifying the managed information base definition at the managed device or the network management system. 
     
     
         12 . The method of  claim 1 , wherein multiple tables are associated with one another to provide historical information for the objects and object instances. 
     
     
         13 . The method of  claim 1 , wherein the object instances are metrics obtained from the managed device. 
     
     
         14 . The method of  claim 1 , wherein the network comprises a plurality of managed objects coupled to the network management system controller by the network, and the managed information base definition associates a respective unique identifier with a respective table located at each managed device and associates a respective unique object identifier with each object in each table, the managed information base definition being known to the network management system controller and to each managed device.