1. SIP: session initiation protocol, RFC 3261;Rosenberg;Internet Engineering Task Force,2002
2. RTP: a transport protocol for real-time applications;Schulzrinne;RFC 3550,2003
3. Voice Pharming Attack and the Trust of VoIP;Wang;SecureComm,2008
4. Billing attacks on SIP-based VoIP Systems;Zhang;WOOT,2007
5. A scalable content-addressable network;Ratnasamy,2001