USENIX Technical Program - Abstract - 7th Tcl/Tk Conference - February 2000
Introducing QoS awareness in Tcl programming: QTcl
Roberto Canonico, Maurizio D'Arienzo, Simon Pietro Romano, and Giorgio Ventre, Dipartimento di Informatica e Sistemistica, Universitą di Napoli "Federico II", Napoli, Italy
A number of distributed applications
require communication services with Quality of Service (QoS) guarantees.
Among the actions undertaken by the Internet Engineering Task Force (IETF)
with regard to the end-to-end QoS provisioning issue in the Internet, the
definition of the Integrated Services (IntServ) framework plays
a major role. According to this model, applications need to interact with
network routers by means of a signalling protocol, RSVP. Even though special-purpose
APIs have been defined to let applications negotiate QoS parameters across
RSVP-capable networks, the integration of QoS negotiation mechanisms in
the applications still remains an open issue. In modern programming, the
Tcl scripting language plays a significant role, as it enables fast system
prototyping by gluing basic components to build complex applications. In
this paper we present QTcl, an extension of Tcl-DP which provides programmers
with a new set of primitives, fully compliant with the SCRAPI programming
interface for RSVP. We also present how QTcl has been used in an advanced
VoD application to setup reservations in an IntServ network.
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