<p>SIP is receiving much attention these days and it seems to be the most promising candidate as a signaling protocol for the current and future IP telephony services. Realizing this, there is the obvious need to provide a certain level of quality comparable to the traditional telephone service signalling system. Thus, we identified the major costs of SIP, which were found to be delay and security. This thesis discusses the costs of SIP, the solutions for the major costs, and the development of a low cost SIP application. The literature review of the components used to develop such a service is discussed, the networks in which the SIP is used are outlined, and some SIP applications and services previously designed are discussed. A simulation environment is then designed and implemented for the instant messaging service for wireless devices. This environment simulates the average delay in LAN and WLAN in different scenarios, to analyze in which scenario the system has the lowest costs and delay constraints.</p>

According to current development of internet technology, remote control over the internet becomes a heated discussed topic. Some recent technologies such as Service-Oriented Architecture (SOA), web service and ontology offer great opportunity for remote control over the internet and a lot of research has been done into this topic. However, there are still many challenges in architecture design and dynamic user interface generation. Architectures in this research field lack clear description of controlled machine model as well as related knowledge support. Also, there is little system support further control service development. There is little research on web user interface design for remote control system over the internet. The design of web user interface has the challenge of overcoming the limitations of web technology to satisfactorily support different machines, users and control process requirements. This work overcomes the limitations on architecture by offering a SOA based design which allows both multiple users and distributed machine access. The system applies a machine model for the description of the machine structure and functions, which help the system to reason about machine components and their relationships with instructions. With a web service based design, different machines can be connected via the system and execute user commands. Using semantic description and ontology based methods the system can automatically retrieve machine information and generate the structure and function descriptions for different machines. Moreover, the system provides services which can support further development in remote control services. The proposed architecture improves on former designs, and offers a flexible architecture for remote control services over the internet. An intelligent web user interface is also introduced in this work. The design separates the interface data structure from the data representation. Supported by the remote control service development environment, the user interface could adapt to the control sessions. Semantic descriptions are used to describe the page data structure, session context as well as control command. Therefore, control page content can be adapted by the computer to real time control session. At the same time, a session dependent navigation is designed to resolve the problem of changeable requirements for multiple-machine web user interface. With a message driven model and a session dependent semantic data structure, the required machine data can be analysed by the system and categorised according to user s requirements. Compare with other designs, this service offers a method for web user interface generation for different machines, users and can adapt to different control processes. The design is demonstrated in five evaluation scenarios aimed at testing different aspects of the system. Evaluation demonstrates the design proposed in this thesis is feasible. It also shows the design can be applied to different areas and adapted to different control related requirements well.

Resumé Information duty of municipalities in selected countries In this thesis I have concentrated on the topic of transparency and openness of municipality bodies in the Czech republic, the Slovak republic and the Free State of Bavaria. The legislations in these countries have historically similar grounds, nevertheless, nowadays they show up many distinctions. My concentration was focused on the Czech legislation and legislative proposals, since the topics of open (digital) society, transparent politics and elements of direct democracy are being held as popular key words in the election struggles. The attempts of last three governments were heading almost to the same goals, showing that there is a need to adjust the processes of municipality bodies in terms of enabling citizens to participate and control easily the work of their representatives. These measures were meant to have the effect of decreasing the possibility of corruption at the municipal level. I have oriented on the following topics in comparing of the relevant legislations: the possibility of public to be present during sessions of municipal bodies; processes of preparation and invitations of citizens to these sessions and legal consequences in case the procedure would not be abided by; releasing of written and multimedia records of the...

Esta dissertação de mestrado aborda a introdução de reconhecimento de sessões http em um modelo de servidor web com serviços diferenciados (SWDS). Algumas técnicas foram desenvolvidas com o objetivo de produzir diferenciação de serviços junto com garantias de que novas sessões poderiam ser aceitas no sistema. Esses objetivos constituem requisitos essenciais na Internet atual, especialmente para aplicações web modernas. Um novo esquema para controle de admissão de sessões foi desenvolvido e introduzido no modelo SWDS, considerando dois mecanismos para aceitar novas sessões, com garantia de nalização. O mecanismo que estima a capacidade do sistema de aceitar novas sessões, baseado em um modelo de sessão construído dinamicamente a partir da carga do sistema, é destacado. A proposta global deste trabalho também considera um controle de admissão de requisições, baseado em sessões, onde a nova política de atendimento criada mantém o sistema livre de sobrecargas e oferece atendimento diferenciado para as sessões. As políticas de negociação desenvolvidas para o controle de admissão de requisições tiveram um papel importante neste trabalho, contribuindo para a priorização do atendimento das sessões. Os resultados obtidos mostram que os controles propostos constituem estruturas fundamentais para a estabilidade do desempenho do sistema, tanto quanto os mecanismos desenvolvidos têm grande importância no atendimento das sessões e, portanto de seus clientes, através de uma abordagem baseada em diferenciação. / This MSc dissertation approaches the introduction of the HTTP sessions recognition in a web server model with diferentiated services (SWDS). Some techniques have been developed aiming at issuing diferentiation of services together with guarantees that new sessions could be accepted in the system. These aims constitute essential requirements for the current Internet, especially for modern web applications. A new scheme for the admission control system has been developed and introduced in the SWDS model, considering two mechanisms for accepting new sessions, with guarantee of their nalizations. The mechanism that estimates the system capacity of acceptance of a new session, based on a session model built dynamically from system workload information, is highlighted. The global propose of this work also considers a request admission control, based on sessions, where the new attendance polices created keep the system free from overloads and over diferentiated attendance for the sessions. The negotiation polices developed for request admission control had an important place in this work, contributing for the session attendance prioritization. The results reached show that the controls proposed comprise fundamental structures for system performance stability, as well as the mechanisms developed have great importance in attending sessions and, therefore, their clients by means of a diferentiation-based approach.

This thesis looks in depth at telephony server clusters, the modern switchboards at the core of a packet-based telephony service. The most widely used de facto standard protocols for telecommunications are the Session Initiation Protocol (SIP) and the Real Time Protocol (RTP). SIP is a signaling protocol used to establish, maintain, and tear down communication channel between two or more parties. RTP is a media delivery protocol that allows packets to carry digitized voice, video, or text. SIP telephony server clusters that provide communications services, such as an emergency calling service, must be scalable and highly available. We evaluate existing commercial and open source telephony server clusters to see how they differ in scalability and high availability. We also investigate how a scalable SIP server cluster can be built on a cloud computing platform. Elasticity of resources is an attractive property for SIP server clusters because it allows the cluster to grow or shrink organically based on traffic load. However, simply deploying existing clusters to cloud computing platforms is not good enough to take full advantage of elasticity. We explore the design and implementation of clusters that scale in real-time. The database tier of our cluster was modified to use a scalable key-value store so that both the SIP proxy tier and the database tier can scale separately. Load monitoring and reactive threshold-based scaling logic is presented and evaluated. Server clusters also need to reduce processing latency. Otherwise, subscribers experience low quality of service such as delayed call establishment, dropped calls, and inadequate media quality. Cloud computing platforms do not guarantee latency on virtual machines due to resource contention on the same physical host. These extra latencies from resource contention are temporary in nature. Therefore, we propose and evaluate a mechanism that temporarily distributes more incoming calls to responsive SIP proxies, based on measurements of the processing delay in proxies. Availability of SIP server clusters is also a challenge on platforms where a node may fail anytime. We investigated how single component failures in a cluster can lead to a complete system outage. We found that for single component failures, simply having redundant components of the same type are enough to mask those failures. However, for client-facing components, smarter clients and DNS resolvers are necessary. Throughout the thesis, a prototype SIP proxy cluster is re-used, with variations in the architecture or configuration, to demonstrate and address issues mentioned above. This allows us to tie all of our approaches for different issues into one coherent system that is dynamically scalable, is responsive despite latency varations of virtual machines, and is tolerant of single component failures in cloud platforms.

The purpose of this dissertation was to determine if a there was a dose-response relationship across an NCAA Division I men’s soccer season. Specifically, this dissertation serves to: 1.) assess the validity of duration measurements that have previously been used to calculate session RPE during competitive matches, 2.) determine the degree and magnitude of change in intermittent endurance performance across a season and to observe how change in endurance relates with training load, 3.) determine the degree and magnitude of change in strength and explosiveness across a season, and to see how these strength changes relate to training load. 1.) Minutes played were found to be the most accurate duration for calculating session RPE during men’s NCAA Division I soccer matches. 2.) Endurance performance, measured using the Yo-Yo IR1, increased by an average of 14 percent from pre to post season. Furthermore, a large, negative relationship was observed between training load and change endurance performance. These relationships suggest that excessive accumulation of training load can impair endurance performance. The congested NCAA DI match schedule may make it difficult to prevent excessive training loads. 3.) When players were grouped by amount of college soccer experience (upper and underclassmen), upperclassmen jumped significantly higher than underclassmen during the preseason. Moreover, the upperclassmen maintained or increased jump height from pre to post season, while underclassmen experienced a general decrease in jump height from pre to post season. Moderate relationships indicate a positive relationship between training load from resistance training and changes in strength. Likewise, these same relationships strengthened in the players who received more playing time during matches. Taken together, the high numbers of moderate relationships indicate a high level of individual variability. Dose-response relationships with strength variables were not sufficiently established. The overall findings of this dissertation provide evidence that subjectively and objectively monitoring training load and soccer-related performance variables can assist coaches in making decisions that will promote the welfare of their team.

abstract: Temporal bisection is a common procedure for the study of interval timing in humans and non-human animals, in which participants are trained to discriminate between a “short” and a “long” interval of time. Following stable and accurate discrimination, unreinforced probe intervals between the two values are tested. In temporal bisection studies, intermediate non-reinforced probe intervals are typically arithmetically- or geometrically- spaced, yielding point of subjective equality at the arithmetic and geometric mean of the trained anchor intervals. Brown et al. (2005) suggest that judgement of the length of an interval, even when not reinforced, is influenced by its subjective length in comparison to that of other intervals. This hypothesis predicts that skewing the distribution of probe intervals shifts the psychophysical function relating interval length to the probability of reporting that interval as “long.” Data from the present temporal bisection study, using rats, suggest that there may be a within-session shift in temporal bisection responding which accounts for observed shifts in the psychophysical functions, and that this may also influence how rats categorize ambiguous intervals. / Dissertation/Thesis / Masters Thesis Psychology 2019

Software defects caused by inadequate software testing can cost billions of dollars. Further, web application defects can be costly due to the fact that most web applications handle constant user interaction. However, software testing is often under time and budget constraints. By improving the time efficiency of software testing, many of the costs associated with defects can be saved. Current methods for web application testing can take too long to generate test suites. In addition, studies have shown that user-session-based test suites often find faults missed by other testing techniques. This project addresses this problem by utilizing existing user sessions for web application testing. The software testing method provided within this project utilizes previous knowledge about combinatorial coverage testing and improves time and computer memory efficiency by only considering test cases that exist in a user-session based test suite. The method takes the existing test suite and prioritizes the test cases based on a specific combinatorial criterion. In addition, this project presents an empirical study examining the application of the newly proposed combinatorial prioritization algorithm on an existing web application.

<p>Session Initiation Protocol (SIP) arises as a new standard of establishing and releasing connections for vast variety of multimedia applications. The protocol may be used for voice calls, video calls, video conferencing, gaming and many more.</p><p>The 3GPP (3^rd Generation Partnership Project) suggests SIP as the signalling solution for 3^rd generation telephony. Thereby, this purely IP-centric protocol appears as a promising alternative to older signalling systems such as H.323, SS7 or analog signals in PSTN. In contrast to them, SIP does not focus on communication with PSTN network. It is more similar to HTTP than to any of the mentioned protocols. </p><p>The main standardisation body behind Session Initiation Protocol is The Internet Engineering Task Force (IETF). The most recent paper published on SIP is RFC 3261 [5]. Moreover, there are working groups within IETF that publish suggestions and extensions to the main standard. One of those extensions is “Caller Preferences for the Session Initiation Protocol (SIP)” [1]. </p><p>This document describes a set of new rules that allow a caller to express preferences about request handling in servers. They give ability to select which Uniform Resource Identifiers (URI) a request gets routed to, and to specify certain request handling directives in proxies and redirect servers. It does so by defining three new request header fields, Accept-Contact, Reject-Contact, and Request-Disposition, which specify the caller preferences. [1]. </p><p>The aim of this project is to extend the existing software with caller preferences and evaluate the new functionality.</p>

The purpose of this project is to update the tool of Network Traffic Recognition System (NTRS) which is proprietary software of Ericsson AB and Tsinghua University, and to implement the updated tool to finish SIP/VoIP traffic recognition. Basing on the original NTRS, I analyze the traffic recognition principal of NTRS, and redesign the structure and module of the tool according to characteristics of SIP/VoIP traffic, and then finally I program to achieve the upgrade. After the final test with our SIP data trace files in the updated system, a satisfactory result is derived. The result presents that our updated system holds a rate of recognition on a confident level in the SIP session recognition as well as the VoIP call recognition. In the comparison with the software of Wireshark, our updated system has a result which is extremely close to Wireshark’s output, and the working time is much less than Wireshark. In the aspect of practicability, the memory overflow problem is avoided, and the updated system can output the specific information of SIP/VoIP traffic recognition, such as SIP type, SIP state, VoIP state, etc. The upgrade fulfills the demand of this project.