Basic HTML version of Foils prepared 21 October 1995

Foil 25 Circuit Switched Networks

From New CPS615 Foils-- B 28 August 95 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox


1 Rather than have messages travel single hop at a time, sometimes circuit is first established from sender to receiver, and then data transmitted along circuit.
2 Similar to establishing phone connection
3 Can result in significantly lower communication overhead as latency deterministic once circuit established
4 If circuit blocked, many options possible, including
  • Retry, perhaps with alternative circuit or random delay
  • Wormhole routing: message travel like a wagon-train along path, stops when blocked but stays in circuit.
  • Virtual cut-through: message dumps into memory where forward progress blocked, then retries. Blend of pure circuit-switching and store-and-forward.
5 At high levels of message traffic, performance sometimes severely degraded.

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© on Tue Oct 7 1997