A Framework for Rapid Development and Portable Execution of Packet-Handling Applications

This paper presents a framework that enables the execution of packet-handling applications (such as sniffers, firewalls, intrusion detectors, etc.) on different hardware platforms. This framework is centered on the NetVM - a novel, portable, and efficient virtual processor targeted for packet-based processing - and the NetPDL - a language dissociating applications from protocol specifications. In addition, a high-level programming language that enables rapid development of packet-based applications is presented

Comparing the Efficiency of IP and ATM Telephony

Circuit switching, suited to providing real-time services due to the low and fixed switching delay, is not cost effective for building integrated services networks bursty data traffic because it is based on static allocation of resources which is not efficient with bursty data traffic. Moreover, since current circuit switching technologies handle flows at rates which are integer multiples of 64 kb/s, low bit rate voice encoding cannot be taken advantage of without aggregating multiple phone calls on a single channel. This work explores the real-time efficiency of IP telephony, i.e. the volume of voice traffic with deterministically guaranteed quality related to the amount of network resources used. IP and ATM are taken into consideration as packet switching technology for carrying compressed voice and it is compared to circuit switching carrying PCM (64 Kb/s) encoded voice. ADPCM32 is the voice encoding scheme used throughout most of the paper. The impact of several network parameters, among which the number of hops traversed by a call, on the real-time efficiency is studie

Modularità applicata all'elaborazione di pacchetti di rete: il linguaggio NetPDL

Questo articolo presenta NetPDL, un linguaggio basato su XML che permette di descrivere il formato delle intestazioni e l'imbustamento dei protocolli di rete e la sua implementazione nella libreria NetBe

Human ascariasis, an evolutionary complex relationship between host and parasite

La ascariasis es una enfermedad parasitaria que diezma la salud de cientos de miles de seres humanos, especialmente en los países en desarrollo. Sin embargo, la falta de profilaxis adecuada del parásito, asociado con un mayor riesgo de sufrir enfermedades inmunes, es un problema principalmente en los países desarrollados donde la prevalencia del parásito es muy baja. La relación evolutiva y los mecanismos por los cuales el parásito fue capaz de colonizar y establecerse en el huésped humano aún no se han descifrado. Del mismo modo, los mecanismos inmunes (proximales) de respuesta del huésped para eliminar o controlar el parásito no se entienden completamente. La comprensión de estos mecanismos nos permitirá establecer mejores tratamientos médicos, evitando efectos indeseables y más enfocados en el control de la parasitosis, así como para la terapia de estas enfermedades inmunológicas asociadas con la relación huésped-ascárido.Ascariasis is a debilitating parasitic disease that has decimated the health of hundreds of thousands of human beings, especially in developing countries. The lack of adequate prophylaxis of the parasite associated with an increased risk of immunological disease is a challenge mainly in developed countries where the prevalence of this parasite is very low. The evolutionary relationship and mechanisms by which the parasite was able to colonize and establish itself in human hosts have not yet been unraveled. In addition, the host immune response mechanisms to eliminate or control the parasite are not fully understood. Understanding these immunological mechanisms (proximates) will allow establishing better medical treatments for diseases related to the positive effects of parasitosis, thus also avoiding the undesirable effects of the parasitosis itselfUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Centro de Investigaciones Antropológicas (CIAN)UCR::Vicerrectoría de Docencia::Ciencias Sociales::Facultad de Ciencias Sociales::Escuela de Antropologí

ALEX: Improving SIP Support in Systems with Multiple Network Addresses

The successful and increasingly adopted session initiation protocol (SIP) does not adequately support hosts with multiple network addresses, such as dual-stack (IPv4-IPv6) or IPv6 multi-homed devices. This paper presents the Address List Extension (ALEX) to SIP that adds effective support to systems with multiple addresses, such as dual-stack hosts or multi-homed IPv6 hosts. ALEX enables IPv6 transport to be used for SIP messages, as well as for communication sessions between SIP user agents (UAs), whenever possible and without compromising compatibility with ALEX-unaware UAs and SIP servers