A Distributed Approach to Real-Time Payments-Processing in a Partially-Connected Network of Banks: Modeling and Simulation

Abstract

The payment-processing system in the banking industry consists of deposits, withdrawals, and transfers of monies through the use of cash, checks, magnetic tapes, and electronic transactions. Of these, nearly all of the check processing through the United States Federal Reserve System, most of the check processing in the private networks, and a part of the electronic transactions are realized through the utilization of the principles of batch- mode processing. Batch-mode processing suffers from many limitations, the principal ones being that (i) users are denied real-time access to their money and that (ii) a user's banking privileges cannot be extended anywhere in the USA — a facility that is increasingly being demanded by users.

This paper observes that the banking process may be mathematically mapped to a discrete-event simulation system with feedback loops wherein deposits, withdrawals, and transfers may be modeled as events that are introduced into the system asynchronously i.e., at irregular intervals of time. It proposes a new, distributed architecture for payments processing within a network of major banks as an alternative to the Federal Reserve System. This approach distributes the processing operations to multiple, concurrent, cooperating geographically distributed computers i.e., at many sites, to achieve real-time transaction processing. It utilizes the principles of asynchronous, distributed, discrete-event simulation algorithm utilizing pseudo- transaction (timestamps), and mathematically guarantees the accrcracy of every transaction. Given that the major banks are geographically distributed throughout the entire country, the distributed nature of the algorithm, proposed in this paper, is extremely appropriate. It offers the hope of a banking system that is available, transparently, to a user anywhere within the coverage area of the network. While the balances of accorents at each of the major banks are owned exclusively by the respective banks, thereby implying privacy and security, any transaction inserted anywhere in the system is guaranteed to be correctly routed to the target bank for execution. This architecture assumes that the banking nodes are partially connected through a broadband-ISDN Network. The choice of B-ISDN is timely given the importance of global, electronic banking in the world economy and CCITT's desire to standardize B-ISDN for all telecommunications in the world. This paper also reports on an implementation of a model of a network of major banking nodes on a network of SUN workstations, configrcred as a loosely-coupled parallel processor system, at Brown University. Performance analysis indicates that this approach achieves a very high throughput for transaction processing.