Telcordia Technologies

About: Telcordia Technologies is a based out in . It is known for research contribution in the topics: Network packet & Node (networking). The organization has 3097 authors who have published 4737 publications receiving 237882 citations.

When Should One Stop Testing Software

Abstract: We derive an optimal rule for stopping the testing of a module of software prior to release, based on the trade-off between the cost of continued testing and the expected losses due to any bugs that remain in the released code. Our economic assumptions are that testing costs are perfectly predictable, but of arbitrary form f(t), and that the costs of fixing a bug, both during testing and subsequent to release, are known constants. Our stochastic assumptions are as follows: (a) The total number of bugs in the module (N) is unknown; (b) N has a Poisson distribution with a mean λ that is distributed randomly (across modules) according to a known gamma distribution; (c) given a particular bug, the time it takes to find it during testing is random, with a known distribution G of arbitrary form; and (d) the lifetimes of different bugs are independent. With these assumptions, we find conditions on f and G that ensure that the optimal stopping rule has a simple form, which can be found by a dynamic progr...

Prime: Byzantine Replication under Attack

Abstract: Existing Byzantine-resilient replication protocols satisfy two standard correctness criteria, safety and liveness, even in the presence of Byzantine faults. The runtime performance of these protocols is most commonly assessed in the absence of processor faults and is usually good in that case. However, faulty processors can significantly degrade the performance of some protocols, limiting their practical utility in adversarial environments. This paper demonstrates the extent of performance degradation possible in some existing protocols that do satisfy liveness and that do perform well absent Byzantine faults. We propose a new performance-oriented correctness criterion that requires a consistent level of performance, even with Byzantine faults. We present a new Byzantine fault-tolerant replication protocol that meets the new correctness criterion and evaluate its performance in fault-free executions and when under attack.

Polarization dispersion and principal states in a 147-km undersea lightwave cable

Abstract: The authors describe measurements of polarization dispersion in a 147-km undersea lightwave cable at 1.56 mu m. The wavelength dependence of the transmitted state of polarization was measured and interpreted in terms of the principal states description of polarization dispersion to determine the difference in the propagation delay time between the two principal states of polarization. Measured differential propagation delay times ranged between 2.5 and 10 ps among the four fibers tested. Significant wavelength dependence in both the principal states and the propagation delay times was observed over a 12-AA interval. >

TeleMIP: telecommunications-enhanced mobile IP architecture for fast intradomain mobility

Abstract: This article first surveys existing protocols for supporting IP mobility and then proposes an extension to the mobile IP architecture, called TeleMIP. Our architecture attempts to achieve smaller handoff latency by localizing the scope of most location update messages within an administrative domain or a geographical region. TeleMIP is intended for use in evolving third-generation wireless networks, and introduces a new logical entity, called the mobility agent, which provides a mobile node with a stable point of attachment in a foreign network. While the MA is functionally similar to conventional foreign agents, it is located at a higher level in the network hierarchy than the subnet-specific FAs. Location updates for intradomain mobility are localized only up to the MA; transmission of global location updates are necessary only when the mobile changes administrative domains and/or geographical regions. By permitting the use of private or locally scoped addresses for handling intradomain mobility, TeleMIP allows efficient use of public address space. Also, by reducing the frequency of global update messages, our architecture overcomes several drawbacks of existing protocols, such as large latencies in location updates, higher likelihood of loss of binding update messages, and loss of inflight packets, and thus provides better mobility support for real-time services and applications. The dynamic creation of mobility agents (in TeleMLP) permits the use of load balancing schemes for the efficient management of network resources.

Glasses as Nonlinear Photonic Materials

Abstract: The success of photonic switching depends on the development of the materials and devices that are capable of processing light signals without converting them to electronic forms. Glasses are promising materials for these all-optical devices because of their fast-responding nonlinearities and low absorption. The aim of this paper is to apprise the ceramic community of the development of nonlinear optics research. The relative merits and trade-offs of glasses as nonlinear photonic material are discussed.