Possibilities of Voice Resource DoS Attacks Based on H.323 Protocol in Softswitch Network

The essence of the voice resource DoS attacks, which are unusual in telecom networks, is the malicious occupation of called party link resource. Softswitch technology achieves the inter-communication between Internet and telecom networks. Voice over Internet Protocol (VoIP) describes the transmission of voice using packet switched networks. And H.323 is one of the standards used in VoIP. The H.323 soft phone achieves the voice and video communication between Internet and telecom networks. In this paper, based on the analysis of softswitch architecture, H.225.0 calling signals and programmable property of H.323 terminal, we propose a hypothesis that in softswitch, hackers may launch voice resource DoS attacks against the telecom network users. Based on this hypothesis, traditional telecom networks may confront a new threat from Internet. At the same time, some solutions can be employed for voice resource DoS attacks in order to deal with this threat.