Class-pinning: A Novel Approach for Hop-by-Hop QoS Routing

M. Curado, O. Reis, J. Brito, G. Quadros, and E. Monteiro (Portugal)


QoS routing, Differentiated Services, Stability


The need for Quality of Service (QoS) on the Internet is increasing everyday due to the wide dissemination of new communication services with more stringent demands from the network. There have been several proposals for QoS provisioning, particularly, the Integrated Services and Differentiated Services frameworks developed on the Internet Engineering Task Force (IETF). As the deployment of Differentiated Services on the Internet becomes a reality, it urges for its combination with QoS aware routing protocols. Among other proposals, at the Laboratory of Communications and Telematics of the University of Coimbra is being developed an intra-domain QoS routing protocol (UC QoSR). In this paper a mechanism of class-pinning to integrate the UC-QoSR strategy is proposed and evaluated. This mechanism addresses the stability problem associated with congestion based routing by controlling the instant when a traffic class shifts to a new path. A traffic class is moved to a new path only if it is considerably better than the current path. Results show that with the use of class pinning it is possible to maintain a adequate path for each traffic class and to avoid the instability due to frequent path shifts.

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