VoIP may deliver great savings over traditional telephony, but with call-jacking over unsecured lines costing UK businesses not the telephony providers. VoIP is not just a new, lower cost telephone system; it using the Internet data connection to provide a voice service and should be treated as such in terms of security and usage policies. With the cost and simplicity of the latest generation of VoIP security the voice firewall removing any barrier to adoption, Paul German, CTO & Founder, VoipSec, calls on companies to wake up to the security implications of Vo IP before it is too late.”]
Source: https://informationsecuritybuzz.com/articles/unsecured-voice-calls-leave-the-door-wide-open/