Processor controlled system and method for operating a processor controlled system

p0001The invention relates to a method for operating a processor-controlled system according to the preamble of claim 1, in particular a network management system, and a processor-controlled system according to the preamble of claim fifth

p0002Systems are controlled by one or more processors for many applications by running them a control program such as an operating system. For the control program, a structure consisting of several hierarchical layers arranged program is often selected, each program layer provides various services and at least building a part of the service of a higher layer to a lower services program layer. Especially for network management systems, the multilayer structure is used.

p0003The patent <patcit id="pcit0001" dnum="US5572727A"><text>US 5,572,727</text></patcit> entitled "Software Structure For Telecommunication Switching Systems" discloses a multilayer software architecture for use in switching centers (so-called switches) of telecommunications systems.

p0004From the article "A Multilayered Operating System for Microcomputers" F. <nplcit id="ncit0001" npl-type="s"><text>Eliassen et al, Micro Processing and Micro Programming 14 (1984) S.45-55</text></nplcit>, A program comprising several layers operating system for microcomputers is known to build up in the service of a higher program layer on services of a lower channel layer.

p0005The conference article "<nplcit id="ncit0002" npl-type="s"><text>Asynchronous Remote Operation Execution in Distributed Systems "by E. Walker et al, Proceedings of the International Conference on Distributed Computing System 1990 S.253-259</text></nplcit>, Describes a method of asynchronous interprocess communication that enables a calling process while continue working editing a remote call (RPC). For this, the remote call is divided into two parts which can be processed separately. A first portion initiates the remote call and generates a future designated as return value, which is then used by the second part to retrieve the result. Both RPC-parts have to be processed by the calling process.

p0006In the article "<nplcit id="ncit0003" npl-type="s"><text>Management of SDH network elements:. An application of information modeling, "MP Bosse et al, Electrical Communication Q4 1993 S.329-338</text></nplcit>, The structure of a control program for a network management system of a synchronous digital transmission system for SDH is described. The control program consists of various hierarchical layers program. These program layers include a network layer and a layer element. The article also mentioned that the network management system has database functions. Communication between the program layers via a fixed, called Q3 interface.

p0007According to the article "<nplcit id="ncit0004" npl-type="s"><text>Technology of SDH network elements. The software platform "of S. Colombo et al, Electrical Communication Q4 1993 S.322-328</text></nplcit>, The element layer is also structured by the multi-layer structure control program: In the first program, the layer network element functions in the form of managed objects are located. This program layer is based on features that are offered by the program layer designated as a virtual hardware module. Among them is the on-board controller software, which ultimately accesses the SDH hardware. The first program layer has a non-volatile memory for storage of configuration parameters (managed objects) in a database called persistency.

p0008With the stated multilayer structure communication between adjacent layers program is required: A higher program layer must forward requests to a lower program layer, the lower layer program must return a confirmation of the execution of the request and optionally a result. Usually waits a higher program layer on the confirmation and the lower layer program sends the acknowledgment only after successful execution of the request.

p0009In this procedure, the difficulty that in a multi-layer structure, the whole system can be blocked if a higher program layer waits for an acknowledgment from a lower program layer, the lower program layer, however busy and for processing the data received from the higher program layer requirement is not comes. The flow through such a multi-layer control program is therefore limited by the Working speed of the slowest layer. Also a decoupling of program layers by queues here brings no fundamental improvement since queues can overflow, eg if one program layer due to an error that occurred.

p0010The object of the invention is to provide a method for operating a processor-controlled network management system, and a processor-controlled network management system, in which blocking due to a busy or failed program layer can not occur.

p0011The object is solved as to the method by the features of claim 1 and with regard to the system by the features of claim fifth Advantageous embodiments are disclosed in the dependent claims.

p0012An advantage of the invention is that the availability and robustness and survivability in the event of a failure of a system according to the invention is improved.

p0013Another advantage is that the performance of a system according to the invention is improved as summarized multiple requests in a program layer and can be processed together. In addition, the flow rate through the various programming layers is not limited by the processing speed of the slowest program layer.

p0014A further advantage is found that the present system remains toward operated even with total loss of a middle or lower program layer, at least outwardly. As a special case of a total failure is to cite here that a part of the system is turned off or not connected. The invention thus enables a transparent off-line configuration of inventive systems. A preferred application of the invention lies in the field of network management as Network Management System of a telecommunication network, or as control means of a network element of a telecommunications network.

p0015The invention will in the following with reference to the <figref idrefs="f0001 f0002">Figures 1 to 3</figref> described in more detail in an exemplary embodiment. It shows:<dl id="dl0001" compact="compact"><dt>figure 1</dt><dd>the schematic structure of a system according to the invention,</dd><dt>figure 2</dt><dd>the flow of data through a program layer of an inventive system and</dd><dt>figure 3</dt><dd>a flow chart of the inventive method.</dd></dl>

p0016to entkopeln To individual program layers of a control program in timing an asynchronous approach is chosen according to the invention. Here is a basic idea of ​​the invention is first to process a request in a higher program layer locally and return a confirmation and then forward the request to a lower program layer for further processing. The statement confirming receives the character of a promise to take care of the execution of the request. You therefore no longer have the significance that the request was processed successfully, but acknowledge receipt of the request and promises work through this. Through these measures, an effective, complete decoupling of program layers is achieved.

p0017A user receives according to the invention to a request to confirm an "OK" back before the request was actually executed. It is particularly advantageous if the request is checked logically and semantically in a current program layer. It is then ensured that the requirement is at least in principle be executed and the confirmation will then offer an assurance of implementation.

p0018Thus a local processing of the request can be carried out, have the program layers its own memory in which the current configuration parameters of each layer are stored and secured. Under configuration parameters be understood in this context, event and state information of each program layer. The storage of program layers are logically separate storage, which can be physically contained within the same storage device, such as a RAM, an EEPROM, a hard disk or other media, however. Preferably, the memory is structured into a database in which the configuration parameters are stored. The control program may also be a complex control software that consists of several program modules, which are executed as a distributed application on different processors.

p0019In which, in <figref idrefs="f0001">figure 1</figref> illustrated embodiment, the inventive system SYS of four program layers LAYER1 to Layer4. The program layers each have a database DB1 to DB4. In the database configuration parameters of the corresponding program stored layer. Access to the system SYS expires so that a request REQ is delivered to the highest program layer Layer4. There occurs a local processing of requests REQ by those concerned in the request configuration parameters in the database DB4 are updated according to the requirement. Once this is done, then it is sent back in response to the request REQ confirmation CONF.

p0020If a processing of the request REQ in the next lower program layer LAYER3 required, the request will be forwarded to the program layer LAYER3. There happen again the same steps: Local processing of requests by the affected configuration parameters in the database DB3 are updated and then send back a confirmation.

p0021The forwarding to the respective next lower program layer is repeated until the lowest necessary for the execution of the request program layer is reached.

p0022Using the example of a network management system that is easy to understand: The program layer Layer4 is an application layer in a central network management facility. The next lower program layer LAYER3 is called MIB (<i>Management Information Base</i>As described in ITU-T X.720 standardized) together with a software framework (framework) in a control device of a network element, such as a digital cross-connects. The turn next lower program layer LAYER2 is a virtual hardware module VHM, which performs the translation between the MIB and the hardware. The lowermost layer program LAYER1 is the firmware that is on the individual circuit boards (boards) of the cross-connects and controls the so-called on-board controller (OBC).

p0023A user's request to change a certain connection parameters of an existing connection must be processed by all four layers program to execute the request. On the other hand can be fulfilled by the first or second layer program a request to read a connection parameters of an existing connection already, depending on the type of the parameter.

p0024A particular advantage of the invention is that several requirements summarized in a program layer and can be processed together. For example, if the top layer program multiple requests received, which want to change all a certain parameter directly or indirectly, the specific parameter is actually repeatedly set to a new value in the top program layer. However, this is done only locally. When forwarding the plurality of requests can be combined into a single, so that in the underlying layers jeweil only must be a single change of the relevant parameter. This approach is particularly important in the case of an off-line configuration of the system according to the invention advantageously, so if the lower layers are not available program. In this case, all changes to the local database may be made to pass the necessary by the carried out off-line configuration changes in a single request to the lower layers program after commissioning of the entire system.

p0025Event reports can trigger follow-up actions to the next lower layer. It follows as a further advantage of the invention that a request to perform the follow-up action can be sent to the next lower layer, even if the next higher layer to which the event report is to be forwarded, can not currently process or receive these event reports. Several event reports can be summarized as the higher program layer to which they are forwarded, a long time can not accept any reports. This means that only the current state is forwarded respectively. Events are so processed locally and summarized in forwarding if possible. It is adaptive to the event rejection.

p0026In <figref idrefs="f0001">figure 2</figref> is schematically shown in a program layer of data flow. The program layer LAYERS receives requests REQ from the next higher program layer, satisfies the request locally and sends a response back a confirmation CONF. Thereafter, the request REQ to the next lower program layer is passed. In the opposite direction the program layer LAYERS receives from the next lower channel layer event reports EVE (English: event reports). Certain events may require follow-up actions, so that in the program layer LAYERS processing of the event report is carried out in the form that a request REQ is sent to the underlying program layer to carry out the follow-up action. Due to the event reports the internal database is updated if necessary also. Then, the event report EVE is forwarded to the overlying layer program.

p0027In <figref idrefs="f0002">figure 3</figref> is shown a flow chart of the inventive method. The method includes the steps of:<dl id="dl0002" compact="compact"><dt>Step S1:</dt><dd>In the system is accessed by a request is sent to the highest program layer. The highest layer is characterized program for current program layer.</dd><dt>Step S2:</dt><dd>The request is executed in the current program layer.</dd><dt>Step S3:</dt><dd>The configuration data in the memory, preferably the database are changed according to the requirement.</dd><dt>Step S4:</dt><dd>It is returned in response confirmation.</dd><dt>Step S5:</dt><dd>If the lowest layer program required for execution of the request has not been reached, the request for further processing to the next lower program layer is passed. The next lower program layer is characterized for the current program layer. Then, steps S2 to S5 are repeated.</dd></dl>

p0028As current program layer, the program layer is referred to in this context is always that satisfies the request locally known.