1. A method for determining a probable root cause of congestion within a network, comprising: collecting data representing a network performance metric; computing for the collected data an associated value r pm that represents a difference between a first correlation coefficient r 1 computed for a baseline set of the collected data and a second correlation coefficient r 2 computed for a second set of the collected data that includes the baseline set and other data points classified as duration outliers, the first and second correlation coefficients representing correlations between the network performance metric and durations of network connections; generating a value representing statistical significance of the value r pm by comparing r pm to a statistical property of a set of Bayesian correlation coefficients computed using the baseline set of the collected data; eliminating the network performance metric from further consideration if the value r pm is less than the statistical property of the set of Bayesian correlation coefficients, or otherwise retaining the network performance metric for further consideration; repeating the computing and eliminating or retaining processes for other network performance metrics to develop a set of retained network performance metrics and associated r pm values for each retained network performance metric; and determining the probable root cause of congestion within the network based on selecting that retained network performance metric that has a largest associated r pm value of all r pm values associated with the retained network performance metrics, wherein the largest r pm value indicates congestion based on anomalous deviations in the durations of network connections.