Jürgen M. Schneider

The role of ontologies in autonomic computing systems

The goal of IBMs autonomic computing strategy is to deliver information technology environments with improved self-management capabilities, such as self-healing, self-protection, self-optimization, and self-configuration. Data correlation and inference technologies can be used as core components to build autonomic computing systems. They can also be used to perform automated and continuous analysis of enterprise-wide event data based upon user-defined configurable rules, such as those intended for detecting threats or system failures. Furthermore, they may trigger corrective actions for protecting or healing the system. In this paper, we discuss the use of ontologies as a high-level, expressive, conceptual modeling approach for describing the knowledge upon which the processing of a correlation engine is based. The introduction of explicit models of state-based information technology resources into the correlation technology approach allows the construction of autonomic computing systems that are capable of dealing with policy-based goals on a higher abstraction level. We demonstrate some of the benefits of this approach by applying it to a particular IBM implementation, the eAutomation correlation engine.

Management of virtual private networks for integrated broadband communication

Management of Virtual Private Networks (VPNs) is becoming an increasingly important issue in the context of integrated broadband communication (IBC). In the near future corporate customers may want to subscribe to broadband VPN services offered by globally operating service providers to replace most of their leased line services that are used today to build their corporate networks. The concepts historically known as characterizing VPNs, such as the concept of closed user groups, will still be valid, but the importance of VPN service features and, in particular, the set of VPN management services offered to VPN customers will become dominant. In this paper we present a detailed technical approach to the management of broadband VPNs based on current technology and common standards. In particular, we discuss architectural solutions, management interfaces and management services provided at these interfaces, as well as managed objects.

Detection of dynamic execution errors in IBM system automation's rule-based expert system

We formally verify aspects of the rule-based expert system of IBM’s System Automation software for IBM’s zSeries mainframes. Starting with a formalization of the expert system in Propositional Dynamic Logic (PDL), we encode termination and determinism properties in PDL and its extension PDL. We then translate our decision problems to propositional logic and apply advanced SAT techniques for automated proofs. In order to locate real program bugs for each failed proof attempt, we apply extra formalization steps and represent propositional error formulae in concise normal form as Binary Decision Diagrams (BDDs). In our experiments, we revealed residual non-termination bugs in a tested program version close to shipment, and, after correcting them, we formally verified the absence of this class of bugs in the production code.

End-to-End Service Management with Multiple Providers

For end-to-end service management reaching from end-user to end-user we need cooperation of management systems from private and public service providers. In a liberalized telecommunications market there will be multiple providers of bearer services and value-added services competing and cooperating to meet customer requirements. Within this paper we describe how the TMN standards serve as a useful framework for end-to-end service management in an open service environment with multiple providers. We use the results, experiences and plans from the PREPARE1 project to illustrate the possible options and solutions discussed.

A Test Derivation Method Based on Exploiting Structure Information

Abstract The development of conformance test suites for testing of protocol implementations requires methodological assistance and efficient tools. Existing development approaches aim at full automation of the test derivation process, and often, the number of tests generated is too large to be useful in practice. Rather than aiming at complete automation, test derivation methods are needed which include parameters that can be adjusted by a test designer. In this paper, we present such a parametrized method, which is based on exploiting the structure of formal specifications.

Automated Validation of TTCN Test Suites

Protocol conformance testing within ISO aims at increasing the probability that communication systems of different vendors are able to interwork. A first step towards establishing worldwide conformance testing services was the development of international standards providing a common framework and a test notation (TTCN). With the publication of the 5 part standard ISO 9646, which is expected in early 1992, this task has been successfully finished. In a second step, test suites have to be standardized in order to have common references for the certification of implementations. These test suites are still being developed manually and due to their immense size and the lack of appropriate tool support they may contain errors. In order to achieve the goals of conformance testing it is of utmost importance that the correctness of test suites can be assured. In this paper, we clarify the meaning of correctness of test suites and propose methods for test suite validation. The design and implementation status of a prototype tool for automatic test suite validation, based on formal protocol descriptions and FDT simulators, is described.

An integrated environment for developing communication protocols

Abstract Due to technological advances and the international trends to open interoperable systems, development of communication protocols for computer networks and distributed systems is becoming increasingly complex and cost sensitive. Protocol engineers require an improved methodology, supported by powerful tools over the whole development process. In this paper, we introduce a development life-cycle based on formal methods. It is used to identify the different activities, from requirements definition to specification, implementation, and testing, together with the set of tools that apply to each phase. We then describe the architecture of an integrated tools environment for protocol engineering and report on a realization of the basic components.

End-to-end communications management using TMN “X” interfaces

The ongoing integration of LANs and WANs to support global communications and businesses and the emergence of integrated broadband communication services has created an increased demand for cooperation between customers, network and service providers to achieve end-to-end service management. Such a cooperation between autonomous authorities, each defining their own administrative management domains, requires the application of an open standardized framework to facilitate and regulate interworking. Such a framework is given by the ITU-T recommendations on “TMN”, where the so-called “X” interface is of particular importance for inter-domain management. In this paper, we explain the role of the TMN “X” interface within an inter-domain TMN architecture supporting end-to-end communications management. We identify the important issues that need to be addressed for the definition and realization of TMN “X” interfaces and report about our practical experiences with the implementation of TMN “X” interfaces in the PREPARE project.

ATM Public Network Management in PREPARE

The Asynchronous Transfer Mode (ATM) technology is the basis for the Integrated Broadband Communications (IBC) environment of the envisaged information society. In this paper we present results from the application of the ITU-T TMN framework and associated ETSI standards for ATM management within the PREPARE project. In particular, we describe the design of the TMN architecture for the public ATM network part of the PREPARE 1995 Demonstrator testbed and the design and implementation of the ATM network management layer operations system (OS).