This paper examines current approaches to signalling and service interworki
ng between Internet and public switched telephone network (PSTN). It notes
that until now convergence between the two networks has for the most part t
aken place in the transport and signalling layers. Signalling interworking
architectures cater for the specific class of telephony-like services and a
lthough they can accommodate the extension of the intelligent network's (IN
) realm of control in the Internet, they do not provide a generic platform
for service interworking. Through the adoption of the Parlay APIs, a way is
foreseen for (a) consolidation of telephone service over both Internet and
PSTN through the imposition of a uniform call control API while allowing t
he installed IN infrastructure to be used also for Internet telephony servi
ces and (b) for service interworking between telephony-like services and op
en distributed services in the Internet. The paper proposes a service archi
tecture that can be used as a platform for Parlay-based service interworkin
g while offsetting some drawbacks that the Parlay approach incurs. (C) 2001
Elsevier Science B.V. All rights reserved.