This paper deals with ways and means of testing SIP or IAX2 based equipment and protocols itselfs. I analyse terminology and methodology for benchmarking of proxy and registrar servers as it was described in documents RFC 7501 and RFC 7502 from organization IETF. In the practical part is described the tester realization programmed in PHP programming language witch will use described methodology. Aplication is available in web based interface.

This dissertation examines the effect of the Earned Income Tax Credit (EITC) on labor force participation of single mothers by controlling for child care costs. Based on a simple model of utility maximizing households that jointly determine hours worked and hours of non-maternal child care demanded, I estimate the change in the labor force participation rate of single mothers following the EITC expansions of the 1990s. In order to investigate the usage of different modes of childcare services, a multinomial logit model has been estimated. The data source for the study is topical module panels of the Survey of Income and Program Participation (SIPP) for the years 1992, 1993, 1996 and 2001. These panels were selected to reflect the time horizon during which the policy changes of the 1990s took place. The empirical estimation strategy is designed to deal with the problems of both selection bias and simultaneity in choosing hours worked and hours of non-maternal child care demanded. Due attention has been paid to the issue of identification of the empirical equations to be estimated in this paper.

Made available in DSpace on 2014-06-12T15:50:15Z (GMT). No. of bitstreams: 4 arquivo5275_1.pdf: 9010552 bytes, checksum: 780f36f6e5f2e1a2206d1872ab9c36c8 (MD5) arquivo5275_2.pdf: 4473381 bytes, checksum: de78ef453ff96f6587a112a96e73ea19 (MD5) arquivo5275_3.pdf: 836886 bytes, checksum: 5889fd1cb28a787bdf5d1142e100a667 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2007 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Todo processo industrial gera resíduos, muitas vezes tóxicos e perigosos, não sendo possível simplesmente descartar esses materiais na natureza sem provocar danos à saúde e ao meio ambiente. Na busca da minimização dos problemas ambientais a utilização de rejeitos em processos industriais tem uma grande importância, haja visto que diminui o volume dos depósitos e contribui significativamente para a redução na extração de matéria-prima. Alguns desses rejeitos vêm sendo reciclados, gerando novos produtos. Esse trabalho teve como objetivo caracterizar o subproduto de polimento de porcelanato (SIPP) de uma indústria local e desenvolver novos materiais a partir do mesmo. Foram inicialmente preparados blocos sinterizados a partir do SIPP. A composição mineralógica do SIPP mostrou a possibilidade do uso do mesmo como produto de partida na preparação de vidros (SIPPBORAX). A partir desses vidros foram obtidas fritas. Finalmente, o SIPP foi usado para formação de um compósito com gesso. O SIPP e os produtos derivados do mesmo foram caracterizados por difração de raios-X, por análise térmica diferencial (DTA), por fluorescência de raios-X (EDX) e microscopia eletrônica de varredura (MEV)

In recent times, the usage of Voice and Video over Internet Protocol (VoIP) services has increased tremendously. There are many signaling protocols such as Bearer Independent Call Control (BICC), H.323, Media Gateway Control Protocol (MGCP), Session Initiation protocol (SIP) etc., that are used for establishment of sessions and to carry out voice and video data services. SIP has become popular because of its easy implementation, flexibility and good scalability. Choice of Open Source SIP server software (OS-SIP Server Software) is important when deploying in a VoIP based network. So we need to evaluate the performance of OS-SIP Server Softwares in an ideal condition before it is deployed to real environment. This document evaluates and compares the performance of three OS-SIP Server Softwares which are quite popular. A SIPp traffic generator tool is used to generate scenarios namely Registration with authentication, Registration without authentication, Session establishment, and Session establishment with response delay at User Agent Server (UAS) side. Using these scenarios, the performance of OS-SIP Server Softwares is evaluated with respect to parameters such as Registrations per second, Calls per second, Response delay, and Percentage of successful calls and registrations. From the experimental results, we observed that there is a significant performance difference among the SIP server softwares. OpenSIPS is the best OS-SIP Server Software for the scenarios Registration with authentication, Registration without authentication and Session establishment with response delay. Asterisk server is the best OS-SIP Server Software when compared with the other two (OpenIMSCore and OpenSIPS) servers for the scenario Session establishment.

This diploma thesis focuses on attacks on PBX Asterisk, FreeSWITCH and Yate in LTS versions. In this work was carried out two types of attacks, including an attack DoS and the attack Teardown. These attacks were carried out using two different protocols, SIP and IAX. During the denial of service attack was monitored CPU usage and detected if its possible to establish call and whether if call can be processed. The Security of PBX was build on two levels. As a first level of security there was used linux based firewall netfilter. The second level of security was ensured with protocols TLS and SRTP.

This master project focuses on the possibilities of protecting the most common free software PBX Asterisk, FreeSWITCH and YATE. In practice, it was verified the behavior of PBX in the attacks and suggested protection against them on one of the most popular distributions of Linux server on CentOS. Tool was created to simulate several types of attacks targeting denial of service. Both protective options PBX themselves and operating system capabilities are used in this work. Comparison was also the possibility of protection of individual PBX with each other. It also includes a brief description of the protocol, topology attacks and recommendation for the operation of softswitches.