Summary: Verifying Programs with Unreliable
Channels
Parosh Abdulla and Bengt Jonsson
Uppsala University
Dept. of Computer Systems
P.O. Box 325, 751 05 Uppsala, Sweden
E--mail:fparosh,bengtg@docs.uu.se \Lambda
Abstract
We consider the verification of a particular class of infinite­state systems,
namely systems consisting of finite­state processes that communicate via un­
bounded lossy FIFO channels. This class is able to model e.g. link protocols
such as the Alternating Bit Protocol and HDLC. For this class of systems,
we show that several interesting verification problems are decidable by giv­
ing algorithms for verifying (1) the reachability problem: is a finite set of
global states reachable from some other global state of the system, (2) safety
properties over traces formulated as regular sets of allowed finite traces, and
(3) eventuality properties: do all computations of a system eventually reach
a given set of states. We have used the algorithms to verify some idealized
sliding­window protocols with reasonable time and space resources. Our re­
sults should be contrasted with the well­known fact that these problems are

Source: Abdulla, Parosh Aziz - Department of Information Technology, Uppsala Universitet

Collections: Computer Technologies and Information Sciences