Inventors:
Monty M. Denneau - Brewster NY
Bruce D. Gavril - Chappaqua NY
Peter H. Hochschild - New York NY
Craig B. Stunkel - Bethel CT
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
H04J 116
Abstract:
For use by a particular node within a digital data communications network having a plurality of counter-synchronized nodes including the particular node, called the central service node (CSN), and at least one remote node, all nodes being clocked at a common frequency, each node being synchronized by its own nodal time counter and connected to at least one other node by at least one transmission segment that completes a transmission path from the CSN, method and apparatus for: (a) establishing any value of virtual transmission delay (vtd) at individual transmission segments; (b) non-destructively determining the existing vtd at individual transmission segments; and (c) establishing basal distributions of vtd throughout the network and determining the elements thereof, (a), (b), and (c) being achieved without the central service node knowing real transmission delay (rtd) and inter-nodal asynchrony anywhere within the network and without requiring the active participation of any remote node. Virtual transmission delay for a transmission segment is the algebraic difference between rtd and the asynchrony between its source and destination nodes. It is the fundamental parameter governing the synchronization of nodal counters and inter-nodal information transfer.