Assessing the Impact of DoS Attacks on the Performance of Asterisk-Based VoIP Platforms

In this work, a hypothesis is studied as to whether different DoS attacks affect the parameters of voice and video streams, as well as performance, on three different VoIP platforms. This research is a continuation of a previous work, which studied the same hypothesis on the Asterisk FreePBX platform. The studied VoIP platforms are VitalPBX, Issabela, and CompletePBX 5, which are based on Asterisk Free PBX. For the purpose of this research, a simple model of an IP network was developed in the GNS3 IP network modeling platform. The experimental part of this work is conventionally divided into two parts. In the first part, only voice/video streams are exchanged in the network, and the studied VoIP server is not under DoS attacks. In the second part, the studied VoIP server is subjected to DoS attacks. The results obtained confirm the results of the previous research—the performance of the three studied platforms is not affected by DoS attacks. The attacks do not affect the parameters of the VoIP flows—the mean jitter value is below the permissible value of 30 ms; for the three servers, it is around 4 ms. The percentage of lost packets is again below the permissible value of 1%; for the three servers, it is around 0.5%. Despite sustained packet flooding, all three servers remained operational, and VoIP calls were maintained without significant degradation.