1152 Ieee Transactions on Systems, Man, and Cybernetics—Part C: Applications and Reviews, Vol. 37, No. 6, November 2007

1152 IEEE TRANSACTIONS ON SYSTEMS, MAN, AND CYBERNETICS—PART C: APPLICATIONS AND REVIEWS, VOL. 37, NO. 6, NOVEMBER 2007
Security Challenge and Defense
in VoIP Infrastructures
David Butcher, Member, IEEE, Xiangyang Li, Member, IEEE, and Jinhua Guo, Member, IEEE
Abstract—Voice over Internet Protocol (VoIP) has become a popular
alternative to traditional public-switched telephone network
(PSTN) networks that provides advantages of low cost and flexible
advanced “digital” features. The flexibility of the VoIP system and
the convergence of voice and data networks brings with it additional
security risks. These are in addition to the common security
concerns faced by the underlying IP data network facilities that
a VoIP system relies on. The result being that the VoIP network
further complicates the security assurance mission faced by enterprises
employing this technology. It is time to document various
security issues that a VoIP infrastructuremay face and analyze the
challenges and solutions that may guide future research and development
efforts. In this paper, we examine and investigate the concerns
and requirements of VoIP security. After a thorough review
of security issues and defense mechanisms, we focus on attacks
and countermeasures unique to VoIP systems that are essential
for current and future VoIP implantations. Then, we analyze two
popular industry best practices for securing VoIP networks and
conclude this paper with further discussion on future research directions.
This paper aims to direct future research efforts and to
offer helpful guidelines for practitioners.
Index Terms—Computer attacks, network security, voice over
Internet Protocol (VoIP).
I. INTRODUCTION OF VOIP TECHNOLOGY
VOICE over Internet Protocol (VoIP) is a technology that
allows users to make telephone calls using a broadband
Internet connection instead of an analog phone line. VoIP holds
great promise for lowering the cost of telecommunications and... [continues]

Read full essay