Abstract:
A new architecture for deploying network management and service provisioning solutions is provided. The new architecture includes the provision of a framework implementing a software development methodology for coding complex software applications relating to network management and service provisioning. The software development methodology results in software application code that is easy to: understand, debug, extend, test, and deploy while still being efficient when used in real time. The methodology includes the coding, compiling and linking of a single managed object class. The managed object class is used to model and represent different data network entities in accordance with attributes held therein. The methodology further makes use of a network management and service provisioning specific grammar used by a parser associated with the framework to read a body of attribute files associated with the data network entities. The interpretation of the contents of the attribute files is performed by hierarchical lexical analyzer which when encountering an enabling technology specific directive, the directive is interpreted by a corresponding enabling technology specific lexical analyzer stub. Provisions are made for the run-time definition of methods implementing polymorphic characteristics although using a statically typed implementation. The advantages provided by the software development methodology are derived from application code that is easy to: understand, debug, extend, test, and deploy while still being efficient when used in real time.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to management and provisioning of data networks, and in particular to methods of implementing data network management and provisioning solutions.  
         BACKGROUND OF THE INVENTION  
         [0002]    In the field of data network management, data transport networks are made up of a collection of managed data transport equipment. Data services are provisioned over the managed data transport equipment.  
           [0003]    In a competitive market place, due to a recent explosive technological development, the network management and service provisioning task is complicated by many factors including: multiple data network equipment vendors having multiple approaches in implementing the data network equipment; a multitude of data transport technologies, with each vendor specializing in a sub-group of the multitude of data transport technologies; a multitude of network management and service provisioning protocols, with each vendor implementing only a sub-group of the multitude of network management and service provisioning protocols; a multitude of auxiliary network management and service provisioning equipment employing yet another multitude of network management and service provisioning technologies; etc.  
           [0004]    Data transport equipment includes, but is not limited to: data switching equipment, routers, bridges, access nodes providing a multiplexing function, Remote Access Servers (RAS), distribution nodes providing a demultiplexing function, Customer Premise Equipment (CPE), etc. with next generation data transport equipment in development.  
           [0005]    With regards to data network equipment, for example data switching nodes schematically shown in FIG. 1, a vendor may chose to implement an integral device  110  having a data switching processor and a group of ports  112 , while another vendor may chose a customizable implementation of a data switching node  120  including: a switching fabric, an equipment rack divided into shelves, each shelf  122  having slot connectors for connection to interface cards, each interface card  124  having at least one port  112 . Although conceptually the two the data switching nodes  110  and  120  provide the same data switching function, each implementation is adapted for a different environment: the former data switching node  110  is more adapted to enterprise solutions as a private data network node, perhaps further adapted to enable access to public data services; while the latter data switching node  120  is better adapted for high data throughput in the core of public data transport networks. Typically the former ( 110 ) implements a small number of data transport protocols while for the latter ( 120 ), data transport protocols are implemented on interface cards  124  and/or ports  112 —providing for a flexible deployment thereof.  
           [0006]    Data transport technologies include: electrical transmission of data via copper pairs, coaxial cable, etc: optical transmission of data via optical cables; free space optical interconnects, etc.; wireless transmission of data via radio modems, microwave links, wireless Local Area Networking (LAN), etc.; with next generation data transport technologies under development.  
           [0007]    Data transport protocols used to convey data between data transport equipment includes: Internet Protocol (IP), Ethernet technologies, Token-Ring technologies, Fiber Distributed Data Interface (FDDI), Asynchronous Transmission Mode (ATM), Synchronous Optical NETwork (SONET) transmission protocol, Frame Relay (FR), X-25, Time Division Multiplexing (TDM) transmission protocol, Packet-Over-SONET (POS), Multi-Protocol Label Switching (MPLS), etc. with next generation data transport protocols in development.  
           [0008]    The physical data network equipment alluded to above is part of larger body of managed data network entities enabling the provision of data services. The data network entities also include, but are not limited to: logical ports, logical interfaces, end-to-end data links, paths, virtual circuits, virtual paths, etc.  
           [0009]    Network management and service provisioning enabling technologies include, but are not limited to: Simple Network Management Protocol (SNMP), Common Management Information Protocol (CMIP) etc.; as well as devices: special function servers, centralized databases, distributed databases, relational databases, directories, network management systems (NMS), etc. with next generation devices and technologies under development.  
           [0010]    Network management and service provisioning solutions include Network Management Systems (NMS) enabled via special purpose software applications coded to configure and control the above mentioned data network entities. Such software applications include, but are not limited to: inventory reporting, configuration management, statistics gathering, performance reporting, fault management, network surveillance, service provisioning, billing &amp; accounting, security enforcement, etc.  
           [0011]    It is a daunting task to provide network management and service provisioning solutions taking into account the permutations and combinations of the elements presented above. Prior art approaches to providing network management and service provisioning solutions includes the coding of hundreds of software applications with knowledge of hundreds of data networking entities using tens of data transmission and network management protocols.  
           [0012]    Coding, deploying, maintaining, and extending such software applications for network management and service provisioning has been and continues to be an enormous undertaking as well as an extremely complex procedure. Such software applications require a large number of man-hours to create, frequently are delivered with numerous problems, and are difficult to modify and/or support. The difficulty in creating and supporting large applications is primarily due to the inability of existing software development paradigms to provide a simplification of the software development process. In accordance with current coding paradigms, the complexity of the software applications has been shown to increase as an exponential function of the number of different operations that are expected to be performed. Large programming efforts suffer in terms of reasonable performance, reliability, cost of development, and reasonably long development cycles.  
           [0013]    Object Oriented Programming (OOP) attempts to improve productivity whenever a problem can be simplified by decomposing it into a set of black-box objects. Object oriented programming depends heavily upon the benefits of data hiding, inheritance, and polymorphism to simplify software design. If a network management and service provisioning solution cannot be subdivided into objects, object oriented programming does not offer significant productivity improvements. Moreover, heavy reliance on object oriented programming to achieve compact code intending to reduce the size of software applications and perhaps development time, suffers from deeply nested function calls which creates a processing overhead leading to inefficient code. Deep nesting of function calls obscures the implementation paradigms used; thereby negatively impacting code debugging, code maintenance, and further development thereof. As applied to the implementation of network management and service provisioning solutions, object-oriented techniques call for the use of a large number of base classes from which hundreds of sub-classes are derived in a pre-compiled linked-in monolithic class hierarchy to code knowledge of hundreds of data networking entities. Changes to any part of such implemented solution involves re-compiling and re-linking the monolithic class hierarchy.  
           [0014]    Prior art efforts including: Preside™ by Nortel Networks Corp., IP Manager™ by Cisco Systems Inc., OneVision Management System™ by Lucent Technologies Inc., NetProvision Activator by Syndesis Limited, Resolve 2.1 by Orchestream Holdings Plc., and others, capture the properties, associations, relationships, functionality and management of data network entities in class definitions, as well as methods of interaction with network management and service provisioning devices using specific network management and service provisioning technologies. These efforts are all laudable but at the same time are subject to all of the above mentioned factors making it difficult to improve productivity in the development and maintenance of such complex software applications for network management and service provisioning.  
           [0015]    A prior art U.S. Pat. No. 5,491,796 entitled “APPARATUS FOR REMOTELY MANAGING DIVERSE INFORMATION NETWORK RESOURCES” which issued on Feb. 13, 1996 to Wanderer et al. describes a method of coding and organizing software application code into compilable device specification files to map an object oriented software application architecture to a relational database which only provides a very specific implementation for a specific remote management system. Although inventive, the coded routines in the device specification files, just as the prior art methods described above, capture the properties, associations, relationships, functionality and management of data network entities in class definitions, as well as methods of interaction with network management and service provisioning devices using specific network management and service provisioning technologies. The resulting solution is still provided via large monolithic software applications without support for persistent storage.  
           [0016]    There therefore is a need to devise improved methods of software application code development and maintenance taking into account the above mentioned complexities.  
         SUMMARY OF THE INVENTION  
         [0017]    In accordance with an aspect of the invention, a network management and service provisioning environment comprising a framework is provided. The framework includes: an implementation of a single managed entity object class, a plug-in registry, a parser, a generic lexical analyzer, and an interpreter. The single managed entity object class is run-time derivable an interpreter via type derivation into a hierarchy of managed entity object types minimizing the need to re-code and re-compile framework software application code in support of new managed entity object types. The registry registers at run-time of at least one plug-in brokering access to network management and service provisioning enabling technologies. A dictionary holds a roster of function names, the functions defining methods associated with derived managed entity object types. The parser processes at least one managed data network entity specification. The generic lexical analyzer interprets at least one directive. The interpreter processes messages received from at least one network management and service provisioning software application. A separation is provided between managed entities, enabling technologies and software applications. The separation enables independent development, maintenance and troubleshooting in providing network management and service provisioning solutions.  
           [0018]    In accordance with another aspect of the invention a network management and service provisioning apparatus using the framework is also provided.  
           [0019]    In accordance with yet another aspect of the invention, a method of providing a network management and service provisioning solution is presented. The method comprises a sequence of steps. At least one plug-in brokering access to at least one network management and service provisioning enabling technology is registering with a framework providing the network management and service provisioning solution. At least one managed data network entity specification loaded by the framework is parsed. A single managed entity object class is derived into a managed entity object type hierarchy of managed entity object types via type derivation. And, at least one message received by the framework from at least one network management and service provisioning software application is processed. The framework acts as an enabler separating managed data network entities, enabling technologies and software applications, as well as a facilitator therebetween in providing the network management and service provisioning solution.  
           [0020]    The advantages are derived from an improved ability to add new functionality in support of improved network management and service provisioning solutions to support new data network entities as well as from an ability to define, at run-time, methods implementing polymorphic characteristics although using a statically typed implementation. This improved ability comes from a reduction in the development effort required to achieve these objectives. The development effort is reduced because the work required in developing and/or updating part of the network management and service provisioning solution is isolated. This provides improved ability for developers to work independently, simplifying verification efforts and reducing regression testing efforts. The independent maintenance and development of code provides an improved ability to develop and troubleshoot new functionality in parallel.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    The features and advantages of the invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached diagrams wherein:  
         [0022]    [0022]FIG. 1 is a schematic diagram showing data network elements implementing connected data transport networks;  
         [0023]    [0023]FIG. 2 is a schematic diagram showing elements implementing a network management and service provisioning solution in accordance with a preferred embodiment of the invention;  
         [0024]    [0024]FIG. 3 is a schematic diagram showing a managed entity object hierarchy used in providing the network management and service provisioning solution in accordance with the preferred embodiment of the invention;  
         [0025]    [0025]FIG. 4 is a flow diagram showing steps of an interworking process facilitated in accordance with an exemplary implementation of the invention;  
         [0026]    [0026]FIG. 5 is a schematic diagram showing an managed entity containment hierarchy used in providing the network management and service provisioning solution in accordance with the preferred embodiment of the invention; and  
         [0027]    [0027]FIG. 6 is a schematic diagram showing the framework facilitating the interaction between interworking software applications and managed object type instances in accordance with the preferred embodiment of the invention. 
     
    
       [0028]    It will be noted that in the attached diagrams like features bear similar labels.  
       DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0029]    [0029]FIG. 1 is a schematic diagram showing data network elements implementing connected data transport networks.  
         [0030]    Data network nodes  102 ,  110 ,  120  are physically interconnected in the data transport network  100  via physical links  108 . Data transport networks  100  may be bridged via bridge data network nodes  104  to enable data exchange therebetween. Connected data transport networks  100  can be grouped defining areas of focus and influence for the purposes of network management and service provisioning, known as network partitions  106 .  
         [0031]    Physical links  108  provide Open Systems Interconnection (OSI) Layer- 1  connectivity between data network nodes  102 / 104 / 110 / 120  physically conveying data for OSI Layer- 2  data links between nodes  102 / 110 / 120  end-to-end. A Layer- 2  data link may be provisioned over at least one physical data link  108 —the sequence of physical data links  108  used representing an OSI Layer- 3  path  128 .  
         [0032]    Network management and service provisioning is typically performed with the aid of at least one Network Management System (NMS)  130  connected to at least one node  102  associated with a data transport network  100 .  
         [0033]    [0033]FIG. 2 is a schematic diagram showing elements implementing a network management and service provisioning solution.  
         [0034]    In accordance with a preferred embodiment of the invention, a framework  200  is provided. The framework  200  may include a combination of hardware and software application code. The framework  200  facilitates the implementation of a software development methodology for coding complex software applications  210  relating to network management and service provisioning.  
         [0035]    The framework  200  implements a new architecture for providing network management and service provisioning solutions. The new architecture categorizes the above presented elements into:  
         [0036]    Manageable data network entities  220  representative of field installed managed data network entities to be configured and controlled in providing network management and service provisioning solutions. The managed entities include:  
         [0037]    i. Physical data network equipment installed in the field such as: nodes  102 / 104 , routers, switches, hubs, OC-3 links  108 , etc., and  
         [0038]    ii. Logical data network entities associated with data network equipment installed in the field such as: network partitions  106 , paths  128 , virtual circuits, virtual routers etc.;  
         [0039]    Network management and service provisioning software applications  210  used to configure and control the manageable data network entities  220 . The software applications  210  include as mentioned above: inventory reporting  214 , configuration management, statistics gathering, performance reporting, fault management, network surveillance  212 , service provisioning, billing &amp; accounting  216 , security enforcement, etc.;  
         [0040]    Network management enabling technologies  230  providing interaction between the manageable entities  220  and, logical as well as field installed physical managed data network entities. Enabling technologies  230  include:  
         [0041]    i. Data network management and service provisioning protocols: SNMP, CMIP, CLI, DNS, etc., and  
         [0042]    ii. Data network management and service provisioning devices: databases, DNS servers, etc.  
         [0043]    The interaction may be command driven as specified by the software application  210 , as well as event driven as a current state of the managed data transport network(s) in the realm of management changes.  
         [0044]    The enabling technologies  230  include support for a concept known as “persistence”. Each data network entity including data network equipment has an associated group of parameters. These parameters either have an effect on the operation of the data network entity or label the data network entity. The persistence concept encompasses the storage of, access to, reading, writing, modifying, synchronization/reconciliation, etc. of persistence parameters to control the operation of data network entities.  
         [0045]    The persistence parameters can be stored in a network management and service provisioning database  132 , as well as in registers associated with the managed physical data network equipment installed in the field. The persistence access to, reading of, writing of, modification of these parameters is provided via the data network management and service provisioning protocols mentioned above. Persistence reconciliation and synchronization is performed between a persistence database and a persistence value held in a volatile register ensuring a correct record keeping thereof, fast access to the persisted information and backup thereof. Distributed storage of persistence information is also used in reconfiguring data network equipment subsequent to network failures.  
         [0046]    The persistence concept also encompasses special persistence types such as: constant persistence which can only be initialized but not modified or written to subsequently; as well as derived persistence which is not stored but rather calculated from other persistence values when needed.  
         [0047]    Further information regarding persistence entity support is provided in co-pending U.S. patent application bearing Attorney Docket Number 11922-US filed on even date entitled “NETWORK MANAGEMENT SYSTEM ARCHITECTURE” which is incorporated herein by reference.  
         [0048]    Coding techniques are used in support of the preferred software development methodology enable on-demand loading of enabling technology specific object code. These coding techniques implement what are known in the art as software application plug-ins such as, but not limited to: SNMP plug-ins, CMIP plug-ins, CLI plug-ins, database plug-ins, etc. The plug-ins are provided as shared object code library (.so) files  232  which register  234  with the framework  200  for on-demand loading thereof. The plug-ins  232  capture data and methods necessary to interact with actual enabling technology entities (databases, registers, etc.) Each plug-in shared library (.so) file  232  contains a coded description of the functionality it is capable to provide.  
         [0049]    In accordance with the preferred embodiment of the invention, a single abstract managed entity class is implemented in the framework  200  to model all manageable data network entities  220 . The single managed entity class implementation includes generic methods to all manageable data network entities such as, but not limited to: set (attribute) value, get (attribute) value, etc. as well as a generic “invoke” method to perform operations on instantiated objects  206 .  
         [0050]    The single managed entity class is used, via type derivation, to define a single-class type derivation hierarchy  300  of (concrete) manageable object types. FIG. 3 is a schematic diagram showing an exemplary managed entity object hierarchy used in providing a network management and service provisioning solution. The single-class modeling of the manageable entities  220  provides for a flexible implementation of network management and service provisioning solutions without the need to re-code and re-compile the framework  200  application code and the software applications  210  to support newly added manageable data network entities  220 —as these are developed.  
         [0051]    In accordance with the preferred embodiment of the invention, the derivation of the abstract single managed entity class into the single-class type derivation hierarchy  300  is preferably enabled by coding the abstract single managed entity class to be defined by a group of associated attributes. A human-readable attribute file  222  is provided for each manageable data network entity type  220 . An additional dynamically linked library (.dll) file  226  corresponding to each manageable data network entity type  220  provides an implementation of methods to be used in interacting therewith. The software development methodology provides a reduction in some files used in implementing the presented network management and service provisioning solution from six files used by prior art methods to two files.  
         [0052]    In accordance with the invention, each human-readable attribute file  222  gathers the particulars of a corresponding managed entity object type including the managed entity object type inheritance specifications thereof in a self-contained manner. Each attribute file  222  further specifies data and relationships. Directives defining a grammar are used in the attribute files  222  to specify particulars of the corresponding managed entity object type. The corresponding .dll file  226 , when used, gathers all methods that can be invoked on the associated managed entity object type in a self contained manner. Each .dll file  226  is a stub of loadable object code implementing managed entity object type specific methods.  
         [0053]    In deriving a managed entity object type from the single managed entity class, each attribute file  222  makes use of an “entity” directive specifying the inheritance. For example the human-readable directive:  
         [0054]    entity [abstract|concrete]derivedType: parentType 1  [parentType 2 , . . . ] 
         [0055]    is used, where the “derivedType” managed entity object type is derived from the “parentType” managed entity object type described perhaps in another attribute file  222 . Multiple inheritance is enabled via the specification of additional parentTypes. A facility may be provided for specifying whether the derived managed entity object type represents an abstract or concrete object type.  
         [0056]    In setting attributes the following directive is used:  
         [0057]    attr[constant]dataType attributeName[=&lt;initial value&gt;] 
         [0058]    specifying the specific “attributeName” and the attribute&#39;s “dataType” “integer”. A facility may be provided for initializing the attribute to an initial value. Another facility may be provided for specifying whether the attribute is constant or not.  
         [0059]    In accordance with the invention, specifying managed object entity type functionality in the corresponding attribute file  222  may include the declaration of at least one operation to be invoked. The declaration of each operation is a logical interface (signature) of the corresponding method. The declaration of the operation specifies parameter types, a return type and errors that the operation may report. An “operation” directive is used for registering, with the framework  200 , methods implementing functionality to be provided by the managed entity object type instances  206 . The operation directive has the following grammar:  
         [0060]    operation[private protected|public]operationName ([in|out|inout]argumentType 1  argumentName 1 , . . . ): returnType { implementor=functionName }.  
         [0061]    A visibility of the operation can be specified as, but not limited to: “private”, “protected”, “public”. The operation having a name specified by “operationName” as well as a group of arguments “argumentNameX” each having a specified “argumentType”. The arguments are preferably passed by value. The specification of argument types enables argument type-checking on the arguments prior to as well as after the execution of the corresponding method. The passing of arguments by value provides for implementation between software applications  210  and the manageable entities  220 . Further, the implementation of side-effects call for the specification of a direction for each attribute in the invocation of the operation at run time. A reduction of processing overheads in invoking methods is attained by not sending “out” attributes on invocation as well as not returning “in” attributes after the execution of the method. The method, after the execution thereof, may return a value having a “returnType”. Return values used by methods having pass-by-value arguments typically report on the success attained by the method invocation. Each declared operation is implemented by a function in the corresponding .dll file  226 . The function is specified as the “implementor” and the specified “functionName” corresponds to a function implementation in the .dll file  226  having the same name specified in a symbol table of the .dll file  226 . More than one operation may be declared in the attribute file  222 .  
         [0062]    Operations declared for a particular managed entity object type are inherited by managed entity object types derived therefrom. Preferably all operations are implemented as free functions having a global scope. Name spaces are used in specifying the function name implementing the operation. The declared operations corresponding to derived managed entity object types are tallied up in a dictionary of operations which is made available to the software applications  210 .  
         [0063]    In accordance with the invention, the same subsequent operation may be declared more than once, in the managed entity object type hierarchy, overriding previously declared operations with respect to an ancestor managed entity object type. The subsequent operation is inherited only in an inheritance tree derived from the managed entity object type for which the subsequent operation was declared. Polymorphism is implemented by looking-up each operation as it is invoked in the dictionary of operations. An example of a dictionary having polymorphic OnLine and OffLine operations is shown at  330  in FIG. 3.  
         [0064]    In accordance with the preferred embodiment of the invention, the coding of the functions implementing the declared operations includes the use of a generic function declaration to ensure a standard signature in the symbol table of the corresponding .dll file. In order to support the generic function declaration, a variant data type is provided. All other concrete data types are derived from the variant data type. An exemplary data type derivation hierarchy  360  is presented in FIG. 3 which includes, but is not limited to derived data types such as: integer, float, double, long, char, etc. The data types derivation hierarchy  360  may be extended via directives specified in the attribute files  222  or via software application  210  directives.  
         [0065]    The following represents an exemplary generic function declaration:  
         [0066]    attributeValue functionName (managedEntityInstance, vector attributeValue arguments [,context])  
         [0067]    where the generic “attributeValue” variant data type is used for the arguments of the function declaration as well as for any return values. The arguments are passed as a packed data structure such as a “vector”. Other packed data structures may be used such as but not limited to: arrays, etc. A “managedEntityInstance” is provided and specifies the managed entity object type instance on which the operation is to be performed, (“this”). Optionally a “context” specifies the invocation context of the operation.  
         [0068]    In accordance with the preferred embodiment of the invention, the software applications  210  are also coded in a general fashion implementing the functionality provided while only making reference to manageable data network entities  220  at high level abstract implementation. Specific information regarding manageable data network entities  220  is held by the framework  200  which instantiates  202 , at run-time, and provides interaction  204  with, instances of managed object entities  206 . The software applications  210  register  218  with the framework  200  which augments the functionality thereof in providing interaction with the instances  206  of specific manageable entities  220  and the methods associated therewith.  
         [0069]    In accordance with the preferred embodiment of the invention, the facilities provided by the framework  200  are extended to other software applications developed employing other software coding methodologies via a Managed Object Server (MOS)  240  associated with a Common Object Request Broker Architecture (CORBA) bus  250 . The specific implementation of the MOS  240  used, parallels that of a software application  210 . Just like a software application  210  the MOS  240  registers with the framework  200 .  
         [0070]    [0070]FIG. 4 is a flow diagram showing, in accordance with an exemplary implementation of the invention, steps of an interworking process  400  facilitated by the framework  200 .  
         [0071]    On start-up  402 , the framework  200  loads-up the shared library (.so) files  232  registering  234  the enabling technology plug-ins  230 . The attribute files  222  are also loaded-up  404  and processed  406  by the framework  200 . In processing  406  an attribute file  222 , a corresponding managed entity object type ( 300 ) is derived  408 , optionally, the methods associated with the managed entity object type, parsed from the attribute file  222 , are registered  410  and the corresponding .dll file  226  is loaded by the framework  200 .  
         [0072]    The attribute files  222 , .dll files  226  and the so files  232  may be stored in pre-specified locations known to the framework  200 . Facilities may be provided for run-time loading  404  and processing  406  of a group ( 426 ) of the attribute files  222  as well as the loading and registration  234  of a group ( 428 ) of shared library (.so) files  232 .  
         [0073]    When all of the attribute files  222  have been loaded-up  404  and processed  406 , the framework  200  is in a state  430  ready to provide the interworking function for the software applications  210 .  
         [0074]    Each software application  210 , upon start-up  440  thereof, registers  218  with the framework  200  to participate in a distributed computing environment.  
         [0075]    In accordance with the preferred embodiment of the invention, the framework  200  makes available the dictionary of operations and publishes a standard interface for the software applications  210  to interact with instances  206  of managed entity object types.  
         [0076]    In accordance with the preferred embodiment of the invention, the single managed entity object class implements an “invoke” method used by each derived managed entity object type instance  206  to perform operations thereon. For example:  
         [0077]    attributeValue invoke (operationName, vector attributeValue parameters [,context]).  
         [0078]    The “operationName” will be mapped to the corresponding functionName at run-time. Alternatively the invoke method need not be a method of the single managed entity object class but rather a free public function.  
         [0079]    Each software application  210  preferably sends request messages  444  to the framework  200 . Typically, the request messages  444  are used to invoke  442  an operation on at least one managed entity object type instance  206 . The parameters needed are packaged in a prior step  441 .  
         [0080]    The framework  200 , receiving the messages  444 , extracts the name of the operation invoked and determines ( 431 ) whether the operation is implemented by the managed entity object type instance  206  on which the operation was invoked, by looking up the operationName in the dictionary of operations  330 . In accordance with the invention, in looking the operation up in the dictionary  330 , a most derived operation is considered, to provide the above mentioned polymorphic behavior.  
         [0081]    The parameters are unpacked in step  432 . The parameter unpacking includes consistency checks  433 . The framework  200  determines whether the vector is of the correct size, whether the parameters are of the correct data types, etc. The “in” and “inout” parameter data type checks are the most relevant. Failing any of these checks, errors are reported and the invocation is terminated.  
         [0082]    The operation is performed in step  434  by using the corresponding implementor function. The performed operation may return a value as well as “out” and “inout” parameters. Consistency checks  435  are performed on the return value, and the parameters. Errors are reported on finding any discrepancies. Else the parameters are packaged in step  436  and a response message  437  is sent back to the software application  210 .  
         [0083]    In accordance with the preferred embodiment of the invention, the interaction between the software applications  210  and the managed object type instances  206 , changes the data network state and/or provides an update of the data network state by making use of the enabling technologies  230 . The instantiation of the managed object types ( 300 ) is performed subsequent to the discovery of physical managed entities in the realm of influence of the network management and service provisioning solution. The discovery of physical managed entities is provided via software applications  210  such as the inventory reporting software application  214 . The instantiation of managed entity object types may also be a result of the interaction of an analyst with the NMS  130  via the software applications  210 . The instantiated manageable entity object types define a managed object type containment hierarchy  500  presented in FIG. 5.  
         [0084]    The interaction between the software applications  210  and the managed object type instances  206 , changes the data network state and/or provides an update of the data network state by making use of the enabling technologies  230 .  
         [0085]    [0085]FIG. 6 is a schematic diagram showing, in accordance with the preferred embodiment of the invention, the framework  200  facilitating the interaction between interworking software applications  210  and managed object type instances  206 .  
         [0086]    In accordance with the preferred embodiment of the invention, the attribute files  222  are parsed to lexically analyze directives specified therein. The framework  200  is provided with a generic lexicon analyzer  620  for interpreting directives. Besides deriving  408  manageable entity object types and specifying attributes, the directives are also used for specifying methods to be implemented by the managed entity object types in the hierarchy  300 . A parser  610  is used for processing  406  attribute files  222 .  
         [0087]    In accordance with the preferred embodiment of the invention, a new grammar is introduced. The grammar enables the description in a corresponding attribute file  222  of: managed entity object types, their data members (e.g. attributes), relationships (inheritance et al.) and methods. The grammar is interpreted by the generic lexical analyzer  620  associated with the framework  200 .  
         [0088]    Further, the grammar enables access to the capabilities provided in a enabling technology plug-in  230 . Special purpose lexical analyzer stubs  630  specific to each particular enabling technology plug-in  232  are also provided to implement multilevel language. Depending on an implementation used, each special purpose lexical analyzer  630  may be coded in the corresponding enabling technology plug-in shared library (.so) file  232  or coded separately and registered with the framework  200  via a separated shared library (.so) file  232 . With the lexical analyzer stub  630  provided separately, the initial registration of each enabling technology plug-in  230  may include only the loading-up of the lexical analyzer stub  630 ; the remainder of the enabling technology plug-in  230  being only loaded-up on a need to use basis. Future information regarding the access to enabling technologies  230  capabilities is presented in the above mentioned co-pending patent application.  
         [0089]    In accordance with the invention, the request messages  444  exchanged between the software applications  210  and the framework  200  are interpreted by an interpreter  640  associated with the framework  200  rather than making specific reference to manageable data network entities  220  or enabling technology plug-ins  230 .  
         [0090]    In accordance with the preferred embodiment of the invention, validation is performed in invoking methods of managed entity object types as mentioned above with respect to FIG. 4.  
         [0091]    In accordance with the preferred embodiment of the invention, the network management and service provisioning solution is componetized to enable independent development, maintenance and troubleshooting of the software application  210  code, code associated with enabling technologies, as well as independent development, management, troubleshooting and deployment of new manageable data network entities  220 .  
         [0092]    The framework  200  therefore performs a facilitation function: each managed entity object type is loaded-up by the framework  200 , parsed and its methods registered independently. The independence between manageable data network entities  220  and software applications  210  eliminates code interdependency therebetween and provides a run-time adaptable and extensible network management and service provisioning solution. There is no necessity to re-link and/or re-compile the framework  200  and/or software application  210  code to support new manageable data network entities  220  while streamlining software application implementation, deployment and maintenance. Therefore, the process of coding complex software applications is greatly simplified and streamlined, resulting in an increased productivity.  
         [0093]    The software development methodology described herein provides for a dynamic addition of manageable data network entities  220  via human-readable attribute files  222  and optionally corresponding dynamically linked libraries .dll files  226 . The attribute files  222  and the corresponding .dll files  226  may be modified or augmented, in parallel, to modify and/or augment the operation of the software applications  210 . The software development methodology results in software application code that is easy to: understand, debug, extend, test, and deploy while still being efficient when used in real time.  
         [0094]    The software development methodology described herein further provides a mechanism to enable dynamic invocation of methods in a statically typed coding language thereby enabling a simplified single managed entity object class architecture to be used.  
         [0095]    The embodiments presented are exemplary only and persons skilled in the art would appreciate that variations to the above described embodiments may be made without departing from the spirit of the invention. The scope of the invention is solely defined by the appended claims.