Abstract: A node on a collision detection protocol based network forces collisions to gain control of the network when it has real time data that needs to be transferred to another node on the network, and then begins transmitting the real time data prior to other nodes gaining control of the network. Each node which has real time data to transfer keeps track of a maximum wait time parameter to determine when the real time data must be transferred to ensure it arrives at a destination on time. As the maximum wait time is approached, the node forces a collision by transmitting even though it senses another node is already transmitting to force the network into a quiet mode. It then starts transmitting the real time data prior to other nodes beginning transmission.

Abstract: The present invention discloses a method for securely adding a new end station to a local area network (LAN) segmented into a number of virtual local area networks (VLANs). The invention is applicable to various types of LANs such as Ethernet and token ring. The LAN comprises an authentication server (AS) which interacts with each new end station before connection to a VLAN is allowed. The method involves the AS administering a test to the new end station, which may involve prompting the new end station for a password or asking it to encrypt a given number using a secret algorithm known only to the new end station and to the AS. The AS examines the results of this test and determines whether the new end station is permitted to join the VLAN.

Abstract: A programming language system in a high level language should comprise language means that enable a reliable and purely logical programming of a locally transparent communication between programs sequencing parallel. This is enabled by the introduction of a specific data type, that is referred to as the service type, that combines references to components (objects) of a service to form a service interface that is announced to the operating system.

Abstract: A control system for a switching system that is optimally flexible. In order to achieve this goal, the operating system of the control system contains a services management system that makes it possible for service processes to utilize other service processes for the implementation of their services without knowing their location in the control system.

Abstract: In order to save development costs, a real time control system should offer the possibility of being upgraded or of growing by replacing software during operation. This ability is achieved in that every message for communication contains a version identifier in addition to containing a designation of the addressed software unit that is unambiguous system-wide. This version identifier indicates the version of the addressed software unit to the operating system.