In this paper we present a wide area distributed sys-
tem using a content-based publish/subscribe communica-
tion middleware which can deterministically detect and re-
port failures with respect to timely message delivery. Our
approach does not require external clock synchronization
nor does it impose any constraints on the publish/subscribe
middleware. We show that our system performs better and
is safer than when using NTP for external clock synchro-
nization.