An Approach to QoS Monitoring in ATM Networks

Forthcoming applications, especially in the multimedia area, require communication services with guaranteed quality of service (QoS). In order to guarantee a certain quality of service, supporting mechanisms must be applied inside the communication system. Additionally, due to dynamic changes in the network, it is crucial to monitor continuously the achieved quality of service during data transmission. Based on the monitoring results, supporting mechanisms can be adjusted accordingly. However, QoS monitoring in end systems is not sufficient in order to locate a QoS violation inside an ATM network. A QoS monitor operating at the network interface of end systems is able to measure the achieved end-to-end QoS continuously and to detect QoS violations, but only additional monitoring of each involved ATM switch allows to detect the network component causing the QoS degradation. Therefore, this paper focuses on monitoring of switches inside an ATM network. Firstly, an architecture for management of ATM networks is described. Monitoring agents, currently realized by proxy agents, are proposed for providing a well defined management interface to ATM switches within a network. Moreover, the ATM Network Monitor ANEMON, an entity for the collection of information on topology and connection-related QoS within an ATM network, is presented.