Assertional verification of a connection management protocol

Abstract

This paper deals with the verification of a connection management protocol which uses timestamps and network-wide synchronized clocks for the reliable opening and closing of connections. We prove the correctness of the protocol over an unreliable, bounded-delay network for the cases when (i) timestamps are unbounded; (ii) timestamps are from a finite modulo-N space. We determine the minimal safe value of N as a function of real-time parameters such as maximum packet lifetime, clock skew and maximum connection duration. The protocol is modeled as a state-transition system and we argue about the properties of the system using an assertional technique based on temporal logic. Apart from handling safety and progress properties, this framework is also suitable to describe real-time aspects of the system