We have developed the NWS for use by dynamic schedulers and to provide statistical Quality-of-Service readings in a networked computational environment. The AppLeS scheduling methodology makes extensive use of its facilities and we have developed prototype implementations for Globus and the Global Grid Forum (GGF) Grid Information System (GIS) architecture.

Currently, the system includes sensors for end-to-end TCP/IP performance (bandwidth and latency), available CPU percentage, and available non-paged memory. The sensor interface, however, allows new internal sensors to be configured into the system. This particular interface is not what it should be -- we are working on it.

The current set of supported forecasting methods treat successive measurements from each monitor as a time series. Our initial methods fall into three categories:

• mean-based methods that use some estimate of the sample mean as a forecast,
• median-based methods that use a median estimator, and
• autoregressive methods.