Ulf Hollberg

Joint inter domain management: CORBA, CMIP and SNMP

In this paper, we present an overview on the work of a joint activity of the X/Open and the Network Management Forum known as “Joint Inter Domain Management (JIDM) ”. The activity of this group has been split into two phases, called “Specification Translation” and “Interaction Translation”. In this paper, we present the basic concepts of the Specification Translation, which has been defined to allow for the migration of information models between different domains of management technology. We will also present in short the problems to be solved during the ongoing Interaction Translation phase, which aims at enabling the inter-working between management software across the different domains: CMIP, CORBA and SNMP. The Specification Translation document is currently in final review as X/Open preliminary specification. The Interaction Translation document is expected to be released in the second Quarter of 1997.

An architecture for the cooperation of heterogeneous operating systems

The DAC Network Operating System (DACNOS) was designed to support resource sharing in a world of interconnected heterogeneous computing systems. The prototype implementation demonstrates that it is feasible to add powerful and flexible means for distributed cooperation to an operating system without affecting its existing individual interfaces and applications. The authors describe the important design issues of DACNOS and their experiences with the implementation and performance of a prototype. Particular emphasis is put on the portability of the NOS software and on the design of the interface to the NOS kernel that provides the facilities for distributed cooperation. It is shown by an example how this set of facilities eases the implementation of distributed applications by taking most of the burden of distribution, access protection, resource management and data representation away from the programmer.<<ETX>>

Retrospective on DACNOS

Heterogeneity of hardware and software is a fact in most distributed computing environments. The DACNOS prototype is a network operating system that enables resource sharing in such environments. It extends the local operating systems without interfering with existing programs. It provides comprehensive system level support for distributed applications.

TMN/C++: an object-oriented API for GDMO, CMIS, and ASN.1

The TMN/C++ API offers a standardized object-oriented application programming interface (API) for telecommunications management applications. The architecture comprises three modular, layered APIs. The ASN.1/C++ API provides a role-independent interface to the data itself and its encoding. The CMIS/C++ API provides a service-oriented interface for the basic management information model (MIM) services—creating and deleting objects, getting and setting their attributes—in an agent or manager role. The GDMO/C++ API provides a MINI-oriented framework for accessing and implementing managed objects in a containment tree and accessing CMIS services in an agent or manager role. The API set supports two distinct application types: “specific” applications which efficiently implement a static MIB specification, and “generic” applications which can dynamically interpret new MIBs. By the end of 1997, these standards documents are expected to be published as X/Open preliminary specifications and adopted by the NMF.

Remote File Access

This report describes the Remote File Access (RFA) component of the network operating system, which is being implemented in the joint project “Distributed Academic Computing” (DAC) of the University of Karlsruhe and IBM’s European Networking Center at Heidelberg. The DAC project and the RFA component put major emphasis on the bridging of the boundaries of heterogeneity and of remoteness transparent to the user. Accordingly, this report investigates common concepts of the file systems of VM/CMS, VAX VMS, PC DOS and Unix.

DACNOS - Ein Betriebssystem für heterogene Netze

Die heutige Situation an Universitaten und groseren Unternehmen ist durch ein Nebeneinander verschiedenartiger Rechensysteme gekennzeichnet. Diese Heterogenitat ist in der Regel durch die Beschaffung von Rechnern fur spezifische Zwecken, wie z.B. Prozessteuerung, Datenbanken, umfangreichen Berechnungen oder individuelle Programmierausbildung entstanden. Benutzer mussen sich mit den Gegebenheiten der jeweiligen Rechner vertraut machen, wenn sie deren Dienste nutzen wollen. Verbindungen der Rechner untereinander und Dienste wie „Remote Login“ oder Dateitransfer erleichtern den physischen Zugang bzw. den Informationsaustausch, losen aber nicht das Problem der Heterogenitat. Verschiedene Ansatze sind bekannt, um diese Situation zu verbessern. Im HECTOR-Projekt zwischen der Universitat Karlsruhe und der IBM wurde ein systematischer Ansatz entwickelt, das Nebeneinander der verschiedenen Rechner in einen „Informationsverarbeitungsverbund“ zu verwandeln, in dem die Benutzer jedes Rechners transparent Dienste der anderen Rechner benutzen konnen, ohne ihre gewohnte Umgebung zu verlassen.

Distributed academic computing

The main objective of the DAC project is to contribute to the development of a systematic approach to resource sharing in a heterogeneous network of autonomous computers. Ideally, users should have access to remote resources from their own environment independent of the location of the resource. Owners of resources should maintain full control over the use of their resources and resource allocation should be accomplished according to their objectives. Users should be protected from misbehavior or malice of other users. Important additional design objectives are compatibility and portability: the native user interfaces of local operating systems should remain unchanged, and access to remote resources, wherever possible, should be provided through the native user interfaces; further, it should be easy to port the solution to different types of operating systems, network architectures and computer architectures.