Divide and Conquer Technique for Network Fault Management
Kohei Ohta, Takumi Mori, Nei Kato, Hideaki Sone, Glenn Mansfield, Yoshiaki Nemoto · 1997
From the perspective of fault management, traffic characteristics contain symptoms of faults in the network. Symptoms of faults aggregate and are manifested in the aggregate traffic characteristics generally observed by a traffic monitor. It is very difficult for a manager or an NMS to isolate the symptoms manifested in the aggregate traffic characteristics. Symptoms get obscured by other symptoms. At times there are too many symptoms clouding the symptom space, making the task of symptom isolation practically impossible. In this work we present a powerful technique, the divide and conquer technique, wherein symptoms are iteratively isolated from the aggregate observable. This provides a tractable mechanism for symptom isolation, fault detection and analysis. The symptom isolation technique makes it possible to use a simple thresholding mechanism for detecting abnormalities. We have implemented the system using the popular SNMP-based RMON technology. Using dynamically constructed filters to suppress already detected symptoms in the observed aggregate, fresh symptoms are isolated. Experimental results show a significant improvement in the fault management capability and accuracy.