Alternative Multiple Spanning Tree Protocol (AMSTP) for Optical Ethernet Backbones

The availability and affordable cost of Gigabit and 10 Gigabit Ethernet switches has impacted the deployment of metropolitan area networks (MAN) and campus networks. This paper presents a new protocol, the alternative multiple spanning tree protocol (AMSTP), that uses multiple source based spanning trees for backbones using Ethernet switches. It provides minimum paths and more efficient usage of optical backbone infrastructure than currently proposed protocols such as resilient packet ring and rapid spanning tree. The protocol exhibits features similar to MAC routing protocols like Link State Over MAC (LSOM) such as optimum path and effective infrastructure usage, without requiring MAC routing due to the use of the spanning tree protocol paradigm. AMSTP is not restricted to specific topologies such as ring or tree, but performs efficiently in arbitrary topologies. Among the application areas are optical backbones of campus and MANs.Publicad

Spreadsheet as a didactic tool to teach and learn financial math

In this document we propose a methodology to teach financial mathematics, using a spreadsheet as a didactic tool. We describe the traditional education process in a specific topic of mathematics, “debt restructuring and modeling with equivalent-equation” from the theoretical explanation to design a financial simulator programmed in a spreadsheet. After this, the result will be verified and validated by the designed software.TIC, Financial mathematics, teaching-learning process, financial tools.

Fault Tolerant Scalable Support for Network Portability and Traffic Engineering

The P-SHIM6 architecture provides ISP independence to IPv6 sites without compromising scalability. This architecture is based on a middle-box, the P-SHIM6, which manages the SHIM6 protocol exchange on behalf of the nodes of a site, which are configured with provider independent addresses. Incoming and outgoing packets are processed by the P-SHIM6 box, which can assign different locators to a given communication, either when it is started, or dynamically after the communication has been established. As a consequence, changes required for provider portability are minimized, and fine-grained Traffic Engineering can be enforced at the P-SHIM6 box, in addition to the fault tolerance support provided by SHIM6.This project has been supported by the RiNG project IST-2005-035167 and by the IMPROVISA project TSI2005-07384-C03-02.Publicad

BGP-like TE Capabilities for SHIM6

In this paper we present a comprehensive set of mechanisms that restore to the site administrator the capacity of enforcing traffic engineering (TE) policies in a multiaddressed IPv6 scenario. The mechanisms rely on the ability of SHIM6 to securely perform locator changes in a transparent fashion to transport and application layers. Once an outgoing path has been selected for a communication by proper routing configuration in the site, the source prefix of SHIM6 data packets is rewritten by the site routers to avoid packet discarding due to ingress filtering. The SHIM6 locator preferences exchanged in the context establishment phase are modified by the site routers to influence in the path used for receiving traffic. Scalable deployment is ensured by the stateless nature of these mechanisms.Publicad

Credit cards in Mexico: Correct use of plastic money

Abstract It can be said that the use of credit cards is on the rise and one of the studied markets is that of college students, the greater part of them being first-time users of credit cards. Card usage tendencies are mentioned throughout the study, as well as the description of their general good or bad use. Also, causes are identified as to why they are incorrectly used sometimes, which results in risks to their users. In addition, the study mentions some points to be considered for a better credit card management in order to obtain the best possible benefit from this purchase resource, which can also be a financing resource if it is known how to properly use it. The conclusion is that we must be aware of our own financial situation and know how to distinguish when we are able to acquire a certain good and when we are not; besides, we need to be patient and try not to be someone else through superfluous possessions that lead us into debt in an irresponsible way

Mimesis y verosimilitud en el cuento fantástico hispanoamericano.

Sin resume

Estado del conocimiento de los morteros de cemento reforzados con fibras de acero, vidrio, polipropileno, basalto y acrílicas

La presente investigación presenta una breve revisión del estado del arte de los morteros de cemento reforzados con fibras de acero, polipropileno, vidrio, basalto y acrílicas, ademas de mezclas de fibras

La presencia del tiempo en el pensamiento de Nimio de Anquín

Fil: García Astrada, Arturo

Simulación numérica del flujo de aire no estacionario alrededor de la sección rectangular de un cilindro

Flows around varied barriers are involved in many practical areas such as bridges, flow meters, towers, cables... The prediction of both the efforts exerted on the structure and main frequencies is of great importance in terms of engineering, especially in aeroacoustics. Development and validation of flexible numerical tools allowing an easy evaluation of different geometries can be very useful.La interacción entre una corriente de aire y un obstáculo está presente en muchos aspectos de la vida cotidiana, como pueden ser puentes, torres, rascacielos, cables… La predicción tanto de los esfuerzos que soporta la estructura como de las frecuencias principales, es de gran importancia en términos ingenieriles, especialmente en aeroacústica. El desarrollo y validación de herramientas numéricas que permitan evaluar diferentes geometrías de forma sencilla podría ser muy útil.Ingeniería Industria