Providing secure communication has become an essential requirement for VoIP networks. To meet this requirement in a VoIP environment is more complex than in conventional data networks due to the implementation of realtime applications. Network traffic can be encrypted by many solutions. One of them is a widely used and standardized IPSec. During the experiments we have consequently tested the impact of the IPSec encryption on the router CPU utilization, bandwidth required and voice quality. All of these parameters are functions of the number of performed calls. Setting the appropriate Voice Payload Period (VPP) can change the number of simultaneously transmitted and processed packets. The tests were carried out on Integrated Services Cisco 2811 routers that are suitable for small companies. Measurements were carried out for two types of codecs. The outcomes proved a significant effect of VPP on the CPU utilization and also on bandwidth. If the VPP is chosen properly, up to 40 to 60 % of bandwidth can be saved. The call quality, expressed by MOS scales, remains almost constant up to the moment when the utilization is close to 80 %.

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The article contributes to the research field on the development of speaking in a foreign language. It presents the results of a survey conducted at the University of Defence in Brno. The survey was designed to identify differences between two groups of fifty students with different levels of their speaking sklil in English, corresponding to A1 and B1 levels in terms of the CEFR. The participants were interviewed in Czech about their previous language achievements, motivation to learn English and their experience of learning English. The interviews were audio recorded, transcribed and analysed using inferential and descriptive statistics. The outcomes have shown that the groups differed significantly in the type of school the students had studied at prior to the university, the grades they had achieved in their secondary school leaving examinations in English Language and Czech Language and Literature, and the degree of their motivation to learn English. Furthermore, the analysis of students’ opinions on the development of their speaking skill in English has revealed that successful foreign language speakers actively seek opportunities to speak in the foreign language, and attribute their success to factors within their control, which is not the case of the unsuccessful ones. The author proposes that undergraduates with low foreign language skills should be detected and interviewed in their native language when they enter university to reflect on their language learning experience, and encouraged to resume responsibility for their language skills development.

Background. There are many factors that affect the development of speaking in a foreign language. Drawing on the theories that state that competencies established in a native language will transfer across foreign languages, this study examines whether there is a relationship between native and foreign language speaking proficiency. Purpose. Although literature research indicates that native and foreign language acquisition processes are interrelated, there is a lack of studies comparing proficiency levels of native and foreign language speaking skills in adult learners. The purpose of this study was to examine the relationship between speaking competences in English as a Foreign Language and Czech as a Native Language in university students.  Methods. A between-group design was used to compare two groups of fifty university students at two different levels of their speaking proficiency in English. Both groups were tested in speaking in Czech. Each test was assessed by an analytical rating scale examining four speaking sub-skills: accuracy, discourse, content and paralinguistics. The scores were analyzed using the F-Test for Equality of Variances and T-Test for the Differences between the Means. Results. The results showed that the group with the lower level of speaking proficiency in English achieved significantly worse scores for their speaking sub-skills in Czech than the group with the higher level of speaking proficiency in English. Implications. The study offers another piece of empirical evidence in support of the theories that state that competencies established in a native language will transfer across foreign languages and suggests the importance of the development of native language competence with regard to later proficiency in a foreign language.

Research background: The development of listening comprehension in a foreign language is a complex process, interrelated with the progress in other language skills, and could be affected by numerous variables, including age. This study responds to middle-aged adults’ complaints about their difficulties in listening comprehension in English as a Foreign Language (EFL) by examining the relationship between the success in listening comprehension in EFL and age.Gap in knowledge and Purpose of the study: Although age is considered a crucial factor in language acquisition, there is a lack of studies providing evidence on the relationship between age and listening comprehension achievement in a foreign language in adult learners. This study aimed to find out whether age is one of the significant factors affecting listening comprehension in relation to other language skills.Methods: Quantitative data analysis was used to determine the relationship between the success in listening comprehension in EFL and age in 1,323 Czech adults. Analysis of variance (ANOVA) was used to compare the success in listening in three age groups, tested within five academic years. Then a generalized linear model was used to assess the relationship between the success in listening and age.Findings and Value added: The analysis of variance has shown that the age group 21—30 achieved significantly better results in listening than the age group 41—60 at p < .05. The logistic regression curve has illustrated a gradual increase in the percentage of ‘unsuccessful listeners’ aged 25 to 52 in relation to age. Thus, the study offers empirical evidence that there is a negative correlation between the success in listening comprehension in a foreign language and age. Educators should assist adult learners in developing knowledge, skills and strategies to overcome listening comprehension difficulties with respect to increasing age.