Securing VoIP Systems: A QoS-Oriented Approach

Voice over IP (VoIP) is a communication technology allowing voice traffic transmission as data packets over a private or a public IP network. VoIP allows significant benefits for customers and service providers including cost savings, services integration, and systems extensibility. Nevertheless, the VoIP technology suffers from many hurdles such as architecture complexity, interoperability problems, security issues, and QoS concerns. The main challenging matter encountering the deployment of VoIP systems is the mutual interaction between the QoS and the security issues. Actually, the strict performance requirements of voice traffic have significant implications for VoIP system security, particularly in terms of service availability. On the other hand, the use of IP network security standards (firewalls, NATs, IPSec) to overcome security issues results into a degraded VoIP QoS. In this paper, we focus on the effects of the security measures on the VoIP QoS, and we aim to propose a QoS-oriented system allowing the deployment of secured VoIP networks without adversely affecting the provided QoS.