Abstract:
In accordance with one embodiment of the present invention, a network element comprises a first subsystem operable to receive management transactions in a first management protocol and to map the transactions to a common management protocol. A second subsystem is operable to receive management transactions in a second management protocol and to map the transactions to the common management protocol. A common management information base (MIB) includes a dataset and a common interface to the dataset. The common interface is operable to access the dataset to process transactions received from the first and second subsystems in the common management protocol.

Description:
RELATED APPLICATION 
     This application is related to copending U.S. application Ser. No. 09/325,690, entitled “COMMON MANAGEMENT INFORMATION BASE (MIB).” 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates generally to telecommunications systems, and more particularly to a method and system for managing multiple management protocols in a network element. 
     BACKGROUND OF THE INVENTION 
     Telecommunications systems include customer premise equipment (CPE), local loops connecting each customer premise to a central office (CO) or other node, nodes providing switching and signaling for the system, and internode trunks connecting the various nodes. The customer premise equipment (CPE) includes telephones, modems for communicating data over phone lines, computer and other devices that can directly communicate video, audio, and other data over a datalink. The network nodes include traditional circuit-switch nodes, which have transmission pass dedicated to specific users for the duration of a call and employ continuous, fixed-bandwidth transmission as well as packet-switch nodes that allow dynamic bandwidth, dependent on the application. The transmission media between the nodes may be wireline, wireless, or a combination of these or other transmission medias. 
     In a telecommunication system, the nodes are managed by standardized management protocols such as Transaction Language One (TL-1), simple network management protocol (SNMP), Common Management Information Service Element (CMISE), and the like. Generally speaking, each of these management protocols includes a protocol agent and object model. The agent is responsible for parsing the external management commands and maintaining communication sessions with external management stations or users. The object model is a management information base (MIB). The MIB is a data structure built for a specific management protocol to exchange the management information between a node and external management stations. 
     Multiple protocol nodes that handle disparate types of traffic are typically required to support multiple management protocols such as TL-1, SNMP, and/or CMISE. Provision of multiple databases to support the different protocols requires large amounts of resources to implement the databases and maintain data integrity across the databases. One attempt to use a single database for multiple protocols configured the database in accordance with one protocol and used a protocol adapter for a second protocol. The protocol adapter translates protocol messages from the second protocol to the first protocol and responses back to the second protocol. Due to the incompatibility between management protocols, however, the adapter is a complex component that is expensive to implement. In addition, the adapter is inefficient due to the protocol translations, which slow down response time. Other attempts to support multiple management protocols with a single database provided only limited functionality for one of the protocols while creating special commands for the other. This solution is expensive to implement and provides only a partial solution. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method and system for managing multiple management protocols in a network element that substantially eliminates or reduces problems associated with previous methods and systems. In particular, the common MIB provides a layer of abstraction to isolate internal data representations from data representations made externally to a network element. This allows a network element to have a single, consistent internal representation of data, and at the same time, support multiple different external interfaces for management. 
     In accordance with one embodiment of the present invention, a network element comprises a first subsystem operable to receive management transactions in a first management protocol and to map the transactions to a common management protocol. A second subsystem is operable to receive management transactions in a second management protocol and to map the transactions to the common management protocol. A common management information base (MIB) includes a dataset and a common interface to the dataset. The common interface is operable to access the dataset to process transactions received from the first and second subsystems in the common management protocol. 
     Technical advantages of the present invention include providing a protocol independent MIB for managing multi-protocol network elements within a telecommunications network. In particular, the common MIB provides a layer of abstraction to isolate data representations internal to the network element from data representations made externally to the network element. This allows the network element to have a single, consistent internal representation of data and at the same time support multiple different external interfaces for management. As a result, data integrity and consistency is guaranteed as only a single database is maintained. 
     To support multiple external data representations, the network element performs transformations to convert the data between the internal representation and the required external representation format. Thus, adaptation functions between management protocols is eliminated and each management protocol is capable to support complete management of the network element. Moreover, the modular design of the common MIB allows for time and cost efficient testing, integration and packaging of the system. 
     Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, description, and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of the present invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts, in which: 
     FIG. 1 is a block diagram illustrating a common management information base (MIB) in accordance with one embodiment of the present invention; 
     FIG. 2 is a block diagram illustrating relationships between interface, base and managed entities (ME) classes in the common MIB of FIG. 1 in accordance with one embodiment of the present invention; 
     FIG. 3 is a block diagram illustrating the ME command object of FIG. 1 in accordance with one embodiment of the present invention; and 
     FIG. 4 is a flow diagram illustrating a method for performing a management transaction with the common MIB of FIG. 1 in accordance with one embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates management components of a multi-protocol network element (NE)  10  in accordance with one embodiment of the present invention. In this embodiment, the NE  10  includes Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and Synchronous Optical Network (SONET) layers and functionality and can communicate over local area networks (LANs) as well as transmission line trunks. IP and other suitable traffic from the LAN is converted to ATM traffic for transmission by the SONET layer which forms the physical interface for the transmission line trunks. 
     The NE  10  supports Common Management Information Service Element (CMISE), simple network management protocol (SNMP), and Transaction Language One (TL-1) management protocols. A CMISE management station  14 , SNMP management station  16 , and TL-1 management station  18  are coupled to the NE  10  by a local area network (LAN), wide area network (WAN), or other communication link  20 . Accordingly, the management stations  14 ,  16 , and  18  may be local or remote from the NE  10 . 
     Referring to FIG. 1, the NE  10  includes a plurality of protocol-specific subsystems  30 , a common management information base (MIB)  32 , and a set of low level software drivers  34 . Each subsystem  30  includes a protocol-specific agent  40  and a data model  42 . The protocol-specific agent  40  parses external management commands and maintains communication sessions with external management stations or users. The data model  42  maps protocol-specific management transactions received from a management station to a common management protocol for processing by the common MIB  32 . Accordingly, all protocol-specific processing is local to the subsystems  30 , allowing the common MIB  32  to be protocol independent. 
     For the embodiment of FIG. 1, the subsystems  30  include a CMISE subsystem  50  for supporting the CMISE management station  14 , a SNMP subsystem  52  for supporting the SNMP management station  16 , and a TL-1 subsystem  54  for supporting the TL-1 management station  18 . The CMISE protocol is an OSI defined management service containing an interface with a user, specifying the service provided, and a protocol, specifying the protocol data unit format and the associated procedures. In the CMISE subsystem  50 , the data model  42  is a Guideline for Definition of Managed Object (GDMO) which is an OSI specification for defining a management information structure used in the CMISE environment. SNMP is an IETF defined network management protocol including definitions of a database and associated concepts. In the SNMP subsystem  52 , the data model  42  is an entity-relationship model in accordance with SNMP standards. TL-1 is an ASCII or man-machine management protocol defined by Bellcore and typically used to manage broadband and access equipment in North America. In the TL-1 subsystem  54 , the data model  42  includes a data dictionary for access identifiers (AIDs) and commands in accordance with TL-1 standards. In this way, the data models  42  only occupy a small amount of memory resources in the network element  10  and keep protocol-specific processing local to each subsystem  50 ,  52 , or  54 . 
     The common MIB  32  includes an application interface (API)  60 , a transaction queue  62 , a set of response queues  64 , and a database  66 . The API  60  provides generic management functionality to the CMISE, SNMP, and TL-1 subsystems  50 ,  52 , and  54 . As described in more detail below, the common MIB  32  provides an efficient and flexible component to allow a telecommunications device to be controlled and monitored by external interfaces using specific management protocols. 
     The API  60  includes an interface object  70  for each subsystem  30  registered with the API  60 , one or more command objects  72  for each registered subsystem  30 , and a set of managed entity (ME) classes  74  to which protocol-specific transactions are mapped by the subsystems  30 . As described in more detail below, by applying object-oriented modeling techniques, the information of the hardware and/or software resource is encapsulated into the class definition, which then provides service interfaces to other software components. 
     The interface objects  70  are each accessed by a corresponding subsystem  30  to communicate with the API  60 . The interface object  70  for a subsystem  30  is created by the API  60  upon registration by the subsystem  30 . At that time, the subsystem  30  requests a number of command objects  72  that can be simultaneously used by the subsystem  30 , which are generated and allocated by the API  60 . 
     The command objects  72  each encapsulate a base class  76  for the ME classes  74 . The ME classes  74  each include specific functionality for an ME type. The base class  76  includes function calls, methods, parameters, behaviors, and other attributes shared by all or at least some of the ME classes  74 . Accordingly, each command object  72  includes base functionality that is used by the ME classes  74  to access the database  66  or perform functions within the common MIB  32 , such as communicating with the low level software driver  34  in order to determine or change the state of hardware in the NE  10 . As described in more detail below, portions of the base class  76  may be overloaded by specific ME classes  74  when forming an ME command object  78 . The ME command object  78  forms an interface for accessing ME attributes and functions in the database  66  and the low level software driver  34 . In this way, each ME class  74  may select functionality from the base class  76  to be used in accessing the corresponding ME. 
     The transaction queue  62  stores ME command objects  78  generated by the API  60  in conjunction with the subsystems  30  for processing by the common MIB  32 . In one embodiment, the transaction queue  32  is a first-in-first-out (FIFO) buffer that serializes processing in the common MIB  32  to prevent multiple operations from being performed at the same time, and thus prevent corruption of data, data contention, and race conditions within the common MIB  32 . 
     In the database  66 , attributes for each of the ME types are stored in ME data structures  80 . Preferably, the data structures are non-volatile structures to ensure data integrity. In one embodiment, the database  66  is a relational database and the ME data structures  80  are relational database tables. It will be understood that the ME attributes may be otherwise suitably stored without departing from the scope of the present invention. 
     The response queues  64  store responses to transactions processed by the common MIB  32 . In one embodiment, the response queues  64  include a discrete queue for each subsystem  30 . In this embodiment, each subsystem  30  reads responses in its corresponding queue  64  and extracts data for generating a protocol-specific response for transmission to the management station originating the transaction. It will be understood that responses to transactions may be otherwise made available by the common MIB  32  to the subsystems  30 . 
     FIG. 2 illustrates details of the object interfaces  70 , command objects  72 , and ME class objects  74  in accordance with one embodiment of the present invention. In this embodiment, the objects  70 ,  72 , and  74  are each fully instantiated objects encapsulating both data and behavior and inheriting data and behavior from parent classes. 
     Referring to FIG. 2, the interface object  70  includes client callback, client quality of service (QoS), client command objects, and client interface parameters. The interface object  70  calls an associated command object  72  in the API  60 . 
     The command objects  72  include command methods, command correlation, command errors, and command parameters. The command object  72  further inherits attributes of the base class  76 . As previously described, the base class  76  includes common ME attributes and common ME methods. 
     The ME class objects  74  each include functionality associated with a particular ME type. Such functionality includes ME attributes, methods, parameters, and behavior for the ME type. Attributes of an ME class  74  are inherited by the command objects  72  through the base class  76  to generate the ME command object  78 . As previously described, the ME command object  78  provides an interface for accessing data and functionality in the common MIB  32 . 
     FIG. 3 illustrates details of an ME command object  78  in accordance with one embodiment of the present invention. In this embodiment, the ME command object  78  is self contained. Any system resources obtained, such as memory or buffers are “owned” by the object  78  and released when the object  78  is destructed. It will be understood that the ME command object  78  may be otherwise suitably implemented for accessing data and attributes and common MIB  32 . 
     Referring to FIG. 3, the ME command object  78  includes a public data section  100  and a private data section  102 . The public data section  100  of the ME command object  78  is accessible by the client subsystem  30 . The public data section  100  includes method functions that hide the structure, data manipulation, and allocation details from the client subsystem  30 . In addition, the methods in the public data section  100  respond to affects of the methods chosen and perform any command integrity checks required. 
     In one embodiment, the methods may include inline functions, particularly those used for setting and retrieving small (typically integer) attribute values. Attribute methods, for example, will be available to populate get/set/create commands, and to retrieve values resulting from the same. Constructor, invoker, and releasor methods will be used to create, execute, and destroy ME command objects  78 . Behavior methods are used by common MIB  32  to execute the commands. 
     The private data section  102  of the ME command object  78  includes data to complete the command. The response data for successful or error return will also be contained in the private data section  102 . In one embodiment, any miscellaneous system resources dynamically allocated for the command are retained in the private data section  102 . This type of allocation is preferably minimized. 
     FIG. 4 is a flow diagram illustrating a method for performing a management transaction in accordance with one embodiment of the present invention. In this embodiment, the transaction may be received from any one of the plurality of management stations in a management protocol supported by the NE  10 . 
     Referring to FIG. 4, the method begins at step  110  in which subsystem  30  receives a transaction in a specific management protocol. Next, at step  112 , the subsystem  30  maps the protocol specific transaction to a protocol independent ME class  74  which will be used by the common MIB  32  to perform the transaction. Mapping may include any suitable type of transaction, conversion, or associations. Accordingly, protocol specific processing is retained at the subsystem level. 
     At step  114 , the subsystem  30  opens a communications session with the API  60 . As previously described, the session may be opened by calling an interface object  70  in the API  60  corresponding to the subsystem  30 . Proceeding to step  116 , the subsystem  30  requests a command object  72  from the API  60 . The subsystem  30  may use any number of command object  72  at a time up to the number allocated to the subsystem  30  in the API  60 . 
     At step  118 , the subsystem  30  identifies the protocol independent ME class  74  to which the protocol specific transaction was mapped. Next, at step  120 , the API  60  generates and returns an ME command object  70  to the subsystem  30 . As previously described, the ME command object  78  includes attributes of the base class  76  and the ME class  74 . Portions of the ME class  74  may overload portions of the base class  76  to provide specific functionality in place of base functionality. At step  122 , the subsystem  30  populates the ME command object  78  based on the transaction by calling command functions stored in the ME command object  78 . 
     Proceeding to step  124 , the populated ME command object  78  is transferred to the transaction queue  62  in common MIB  32  for processing. The transaction queue  32  serializes processing in common MIB  32  to prevent data contention between co-pending ME command objects  78 . At step  126 , the ME command object  78  is removed from the transaction queue  62  and executed by the common MIB  32 . During execution, the ME command object  78  accesses the corresponding ME table  80  and/or performs functions in accordance with functions, behaviors, and parameters in the ME command object  78  which are based on the transaction. 
     Next, at step  128 , the common MIB  32  generates a response in accordance with the function calls in the ME command object  78 . At step  130 , the response is transferred to the response queue  64  for the subsystem  30  that generated the ME command object  78 . Next, at step  132 , the subsystem  30  extracts data from the response and generates a protocol specific response for transfer back to the requesting management station. At step  134 , the subsystem  30  releases the command object  72  back to the API  60 . In this way, the common MIB  32  provides a layer of abstraction to isolate data representations internal to the network element  10  from data representations made externally to the network element  10 . Data integrity and consistency is guaranteed as only a single database is maintained. 
     Although the present invention has been described with several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims.