Securing VoIP networks using graded protection levels

Abstract

This contribution evaluates the security of VoIP networks. Potential threats to VoIP networks lead to unbearable risks which need to be eliminated by suitable countermeasures. However, cost and complexity of countermeasures should be adapted to the practical situation. Therefore the protection requirements are assessed. In this contribution the range of possible protection requirements is divided into three graded protection levels to allow for an adaptation of the cost of the countermeasures to the required protection level. VoIP-specific threats, countermeasures and implementation problems are disussed. It is derived at which protection level encryption of VoIP is necessary and which problems currently have to be considered with VoIP encryption.