MRT: A tool developed for predicting the mean message response time of communication channels in sizeable networks exemplified by the Internet

In this paper an algorithm M²RT for predicting the mean message response time (MMRT) of a communication channel is proposed with emphasis on Internet applications. The M²RT development went through four major phases. They include:

(a) Formulating the theoretical foundation with the central limit theorem.

(b) Determining the parameters of the algorithm by simulations.

(c) Performing off-line verification tests for the algorithm with local Internet/Intranet nodes and well-known middleware (MPI and CORBA).

(d) Performing on-line validation of the M²RT over the Internet involving both local and international sites.

The acceptance criteria for the algorithm include:

(a) It must perform efficiently for different conditions of workload, geography, and traffic.

(b) It must perform consistently with the same software entities (e.g., MPI) for similar operations.

(c) It must be able to exist both as an off-line tool and an on-line program object (to be invoked on a real-time basis).

(d) Its computation time should be sufficiently small so that the result actually reflects the current physical conditions.

All the results from simulations, verification tests, and validation experiments have confirmed that the M²RT algorithm indeed meets all the acceptance criteria. In these tests, we also discovered that the algorithm could be developed into a powerful tool for measuring the relative performance between firmware products. This development will be explored in the near future.