Evolution of Fault Tolerant Switching Systems in AT&amp;T

Clement, George F.; Giloth, P. K.

doi:10.1007/978-3-7091-8871-2_2

Cited by 13 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Of the six faults that may have contributed to the 1200-900 cal years B.P. cluster (each >5% of the total rate), two (the Seattle main thrust and Boulder Creek faults) have had previous earthquakes within the 16,000 year record apparently without any on the other four. Thus, the relevance of this type of synchronization model to this study remains unclear.…”

Section: Discussionmentioning

confidence: 99%

Crustal earthquake triggering by pre-historic great earthquakes on subduction zone thrusts

Sherrod

Gomberg

2014

J. Geophys. Res. Solid Earth

View full text Add to dashboard Cite

Triggering of earthquakes on upper plate faults during and shortly after recent great (M > 8.0) subduction thrust earthquakes raises concerns about earthquake triggering following Cascadia subduction zone earthquakes. Of particular regard to Cascadia was the previously noted, but only qualitatively identified, clustering of M >~6.5 crustal earthquakes in the Puget Sound region between about 1200-900 cal years B.P. and the possibility that this was triggered by a great Cascadia thrust subduction thrust earthquake, and therefore portends future such clusters. We confirm quantitatively the extraordinary nature of the Puget Sound region crustal earthquake clustering between 1200-900 cal years B.P., at least over the last 16,000. We conclude that this cluster was not triggered by the penultimate, and possibly full-margin, great Cascadia subduction thrust earthquake. However, we also show that the paleoseismic record for Cascadia is consistent with conclusions of our companion study of the global modern record outside Cascadia, that M > 8.6 subduction thrust events have a high probability of triggering at least one or more M >~6.5 crustal earthquakes.

show abstract

Section: Discussionmentioning

confidence: 99%

Crustal earthquake triggering by pre-historic great earthquakes on subduction zone thrusts

Sherrod

Gomberg

2014

J. Geophys. Res. Solid Earth

View full text Add to dashboard Cite

show abstract

“…For instance, the 4ESS switches achieved observed downtime (from all causes) of less than 2 hours per 40 years, or about 5.7 . 10 -6 unavailability [4]; a recent analysis [15] indicates that software failure accounts for only 2% of telephone service outage time experienced by customers.…”

Section: What Levels Of Reliability Are Currently Achievable?mentioning

confidence: 99%

Software reliability and dependability

Littlewood¹,

Strigini²

2000

Proceedings of the Conference on the Future of Software Engineering

104

View full text Add to dashboard Cite

Software's increasing role creates both requirements for being able to trust it more than before, and for more people to know how much they can trust their software. A sound engineering approach requires both techniques for producing reliability and sound assessment of the achieved results. Different parts of industry and society face different challenges: the need for education and cultural changes in some areas, the adaptation of known scientific results to practical use in others, and in others still the need to confront inherently hard problems of prediction and decision-making, both to clarify the limits of current understanding and to push them back.We outline the specific difficulties in applying a sound engineering approach to software reliability engineering, some of the current trends and problems and a set of issues that we therefore see as important in an agenda for research in software dependability.

show abstract

“…The establishment and the maintenance of a telephone communication path is largely the result of a hardware solution built into specialized and expensive equipment. In addition, the dependable execution of services is determined by an array of software techniques embedded in the central office switches [1]. This approach to dependability is the cornerstone of the guaranteed delivery of service quality.…”

Section: I) Who Pays For What?mentioning

confidence: 99%

“…For instance, the average down time of central office switching equipment is expected, as a de facto standard, not to exceed three hours in forty years of operation. This high equipment availability is achieved by relying on different mechanisms: hardware redundancy with built-in fault detection and correction, speedy hardware based switch-over of stand-by units, and software-based mechanisms for data integrity and correction, and for recovery escalation [1]. Due to the need to satisfy stringent real-time system performance requirements, this array of techniques yields hardware which is highly specialized, produced at low volumes and costly.…”

Section: Introduction: the Clash Of The Titansmentioning

confidence: 99%