Abstract Gazer-Theta is a software model checking toolchain including various analyses for state reachability. The frontend, namely Gazer, supports C programs through an LLVM-based transformation and optimization pipeline. Gazer includes an integrated bounded model checker (BMC) and can also employ the Theta backend, a generic verification framework based on abstraction-refinement (CEGAR). On SV-COMP 2021, a portfolio of BMC, explicit-value analysis, and predicate abstraction is applied sequentially in this order.

The rate of deployment and adoption issues of new network technologies, IPv6 in particular, have recently been hotly debated in the research community. However, the question of how protocols migrate, especially the dynamics of migration, to new paradigms is still largely open. In this paper, we address the issue from a game theoretic point of view. We model and analyze the profit maximizing strategies of Autonomous Systems (ASes); both the properties of ASes and the topology of the Internet is considered. The contribution of our work is threefold. First, we propose an economic model of the ASes and their relations from the IPv4-IPv6 migration viewpoint. Second, we apply the findings of evolutionary dynamics on the problem of migration by incorporating Internet-specific properties to the evolutionary model, namely the size of the ASes and the cost of migration. The analyses show that even if IPv6 has higher payoff than IPv4, the whole migration does not happen always fast. Finally, extensive simulations are carried out based on the proposed models to illustrate the impacts of different parameters on the IPv6 migration dynamics in realistic scenarios.

Recent Internet access speeds have made it possible even for home users to reach and use previously unavailable bandwidth consuming (e.g. video on demand) services. However, the rapid spread of these applications is hindered by the lack of QoS guarantees in packet networks. In this article a QoS architecture is presented which have been designed for access networks and applies a logical overlay network to make network management tasks easier. The novelty of the architecture lies in the application of two key procedures adopted for dimensioning logical channels between edge nodes and mapping them to the physical routes. The upper load thresholds of the applied logical channels are also determined, which may form the basis of a more sophisticated call admission control policy.

The paper reviews the current state and the development strategies of telecommunications in Hungary. Telephone systems are predominantly analog, with a relatively low main-line penetration ratio (14.5% by the end of 1993) and several years waiting time. Advanced telecommunications services are scarcely established. However, the significance of telecommunications has been recognized, therefore intensive development and modernization plans were formed, the legislative environment has been liberalized, the state-owned network operator has been partly privatized, and the full restructuring of the telecommunication sector is in process. Over the last several years, Hungary focused on the basic network infrastructure and fixed telephone service, but mobile telephony was also urgently required for the rapid satisfaction of business needs. The need to join Europe accelerates the pace of digitalization and the introduction of new telecommunication services, as well as the establishment of international cooperation to harmonize the expansion of international links. The paper summarizes the general features and development goals for this decade.>