Alternative specification and verification of a periodic state exchange protocol

The formal analysis of a data-transfer protocol based on the novel idea of periodic state exchange has been presented by Gouda et al. (see IEEE Trans. Commun., vol.43, no.9, p.2475-84, 1995). In certain environments, such as the Internet, the requirements for the correctness of the protocol may impose impractical constraints. We present an alternative specification of the periodic state-exchange protocol based on the discovery that the protocol can be treated as a special sliding-window protocol. Although our protocol behaves better in an Internet-like environment it has other shortcomings with respect to the original. The comparison of the alternatives reveals the trade-offs in their design.