Real-Time Support on Top of Ethernet

Ethernet is a widely used low-cost networking technology. It however lacks the determinism and resource management features needed to meet realtime requirements of multimedia applications, for instance. This paper presents the BEAT communication service that adds basic real-time mechanisms on top of Ethernet to the Linux operating system while supporting the use of conventional applications and protocols such as TCP and UDP. To avoid the indeterminism of the CSMA/CD network access control a token mechanism has been employed. Priorities can be attached to packets and are taken into account in allocating bandwidth locally, for the messages on the node, as well as globally, among the nodes on the network. Moreover, shares of network bandwidth can be reserved by tasks, controlled by a utilization-based admission test. In addition, a global notion of time is needed for time constraints to be meaningful in a distributed real-time system. BEAT therefore integrates a clock synchronization algo...

• Type: Conference
• Year: 2001
• Where: KIVS
• Authors: Rainer Koster, Thorsten Kramp
• Keywords: Basic Real-time Mechanisms, BEAT Communication Service, Computer Networks, KIVS 2001, Network Bandwidth