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Risk assessment
Voice is a perennial cash cow for traditional telephony service providers, a lucrative emerging market for VoIP vendors and
a mission-critical service for businesses. Thus, the most serious risk public (carrier) and private (enterprise) VoIP operators
must manage is service disruption.
VoIP users will expect no less than the high availability they are accustomed to receive from the public switched telephone
network (PSTN). Accordingly, a thoughtful VoIP deployment plan for all would-be VoIP operators must include measures for reducing
the threat of DoS attacks.
Other priority risks include identity theft and toll fraud. Public operators face a greater challenge than do PSTN and cellular
carriers with identity and endpoint verification in VoIP deployment because endpoint IP addresses are generally not validated
at Internet ingress points, and unlike public telephone numbers, there are as yet no widely adopted methods for VoIP operators
to certify or assert cooperatively that a SIP identity is valid.
VoIP operators must manage trust relationships with other VoIP operators carefully and should avoid service arrangements unless
they have some confidence that the other providers are using equivalent identity and endpoint verification methods. This might
be arranged contractually across an extended enterprise or business-to-business VoIP deployment.
In general, insider attacks are more frequent than outsider attacks, so enterprise VoIP network operators must consider impersonation
a threat even if they operate in isolation. Enterprise VoIP managers then must consider methods to detect and block impersonation
attacks, and should maintain accounting and auditing tools to help detect abuse and identify perpetrators.
While public VoIP infrastructures may be more frequently targeted for politically motivated attacks and terrorism, private
VoIP networks increasingly are at risk of electronic industrial espionage and eavesdropping attacks (for example, employees
intercepting privileged calls).
Enterprise customers also must consider help desk and customer care. Service disruption, subscriber impersonation and toll
fraud are serious support matters. Resolving disputes and restoring service to employees who are victims of such attacks sap
resources and adversely affect productivity. The effects that security incidents may have on consumer, user, management and
even shareholder confidence can be lasting.
Click to see: Anatomy of a DDoS attack
