Seedorf, Jand'Heureuse, NicoNiccolini, SaverioEwald, ThiloAlkassar, AmmarSiekmann, Jörg2019-04-032019-04-032008978-3-88579-222-2https://dl.gi.de/handle/20.500.12116/21509While deployment of Voice-over-IP (VoIP) systems is gaining momentum, security remains a major challenge for this new technology. Due to the inherited flaws of IP-networks, lacking authentication mechanisms, and complexity in termi- nals (among others) many threats to VoIP systems exist. Thus, there is a need for protecting VoIP systems and its users against attacks. To address these challenges, we present a modular protection framework for VoIP networks and a corresponding pro- totype implementation. Our solution, VoIP SEAL, can protect against various kinds of VoIP threats at different stages of a call-setup process. Using a modular approach, different protection mechanism can be combined and interact with each other. This allows for flexible protection against diverse types of VoIP attacks. We describe our overall architecture as well as some recent enhancements in detail.enText/Conference Paper1617-5468