Abstract: A network monitoring architecture and methodology enabling performance detection and diagnostics in storage area networks or other networks. The network monitoring is performed using a three-tiered distributed computing system architecture, including a data source tier, a portal tier and a client tier. The data source tier monitors the physical data on the network medium using multiple data collection sources, or data probes, connected to the network. The probes analyze network data and generate metrics that describe attributes of the network data. The metrics are used by the data portal tier, which is the second tier of the system. The portal tier encapsulates the metrics into data containers. The data containers may be requested by the client tier, which is the third tier in the network monitoring system. The client tier provides a user interface for displaying various types of network information derived from the contents of data containers.