TERENA Networking Conference 2000    

QoS Management Scheme Based on OAM Performance Management

Zhao Yang and Wang GuangXing, Northeastern University, Shenyang, China

Monitoring the change of network performance parameters is a key to realising QoS management in ATM networks. The OAM performance management function defined by the ITU-T, however, simply monitors network performance and reports status information. It cannot give QoS management enough support. In terms of the relationship between QoS and network performance parameter, an ATM layered QoS management model is proposed and defined. In this model, an improvement in OAM performance management functions is also made. Some new functions, which are necessary to QoS management, are defined in reserved field of activation/deactivation OAM cell and forward monitoring/backward reporting OAM cell.

At present, a generally accepted concept of QoS architecture is layered QoS structure, in which each layer guarantees the requested QoS to its next-higher layer and demands a (possibly different) QoS from its next-lower layer. The QoS layered structure we use is modelled on this concept. The architecture consists of four horizontal protocol layers and three vertical control planes. On the basis of this discussion, we consider the following two principles to define the QoS management model for ATM layer:

  1. Protocol machines in user and control planes execute their own functions intelligently with autonomy.
  2. The functions of upper planes should do more abstract and integrated functions that lower planes can not control. The function of upper plane reacts to solve a request, when the function of lower plane issues it as an event.
This model is separated into three levels including protocol machine, layer management, and plane management. To realise the model, we emphasise the QoS management on the extended OAM performance management. Some new added fields defined in reserved field separate the boundaries of end-to-end monitoring and segment-to-segment monitoring in whole switch system. According to the difference of management goal, the former is called general management mode, and the latter is used for concrete segment problem monitoring when problem is detected in general management mode. Our study shows that the improvement is feasible and efficient in QoS management mechanism.

Full Paper (PDF 3.4MB) (Word 119KB)



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