1. VOIPSA, VoIP Security and Privacy Threat Taxonomy, October 2005. .
2. D. Sisalem, S. Ehlert, D. Geneiatakis, G. Kambourakis, T. Dagiuklas, J. Markl, M. Rokos, O. Botron, J. Rodriguez, J. Liu, Towards a Secure and Reliable VoIP, Deliverable 2.1, May 2005. .
3. Asterisk SIP Implementation Issue, August 2003. .
4. CERT® Advisory CA-2004-01, Multiple H.323 Message Vulnerabilities, April 2004. .
5. CERT® Advisory CA-2003-06, Multiple Vulnerabilities in Implementations of the Session Initiation Protocol (SIP), February 2003. .