Modeling of the D0 data acquisition system

A queuing theory model was used in the initial design of the D0 data acquisition system. It was mainly used for the front-end electronic systems. Since then the model has been extended to include the entire data path for the tracking system. The tracking system generates the most data; so this system is expected to determine the overall transfer rate. The model was developed using both analytical and simulation methods for solving a series of single server queues. The authors describe the model and the methods used to develop it. They also present results from the original models, updated calculations representing the system as built, and comparisons with measurements made with the hardware in place for the cosmic ray test run.<>