Control software for virtual-circuit switches: Call processing

Roy Campbell, Sean Dorward, Anand Iyengar, Chuck Kalmanek, Gary Murakami, Ravi Sethi, Ce Kuen Shieh, See Mong Tan

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


The software architecture in this paper has evolved through a sequence of research projects at AT&T Bell Laboratories. We review the architecture and describe an experimental reimplementation. Calls from each device attached to a virtual-circuit switch are managed by a software process, called a line process; the line process translates call requests from the device into a uniform device-independent internal protocol. Host computers and trunks can have numerous lines multiplexed over a single physical link. This process-per-line architecture leads to a profusion of specialized processes, most of them idle, with very simple contexts. Previous implementations used machinedependent code to manage tile processes. The experimental implementation does basic call processing and was completed largely by three people in three months. It is portable. The architecture was reused, but the code was not. The relatively small effort supports the belief that the architecture is suited to call processing and dispels the myth that the complexity of control software prevents limited experiments.

Original languageEnglish (US)
Title of host publicationFuture Tendencies in Computer Science, Control and Applied Mathematics - International Conference on the Occasion of the 25th Anniversary of INRIA, Proceedings
EditorsAlain Bensoussan, Jean-Pierre Verjus
Number of pages12
ISBN (Print)9783540563204
StatePublished - 1992
EventInternational Conference on Research in Computer Science and Control, 1992 - Paris, France
Duration: Dec 8 1992Dec 11 1992

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume653 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


OtherInternational Conference on Research in Computer Science and Control, 1992

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science


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