Security experts believe Voice over Internet Protocol (VOIP) technology can be the next major target for various attacks. VOIP is a category of hardware and software that enables its users to utilize the Internet as the transmission medium for telephone calls. Voice data is sent in packets rather than by traditional POTS (plain old telephone system) circuits. Experts recommend the use of such security appliances as firewalls that are specifically designed to filter VOIP traffic for suspicious patterns and drop those connections. The technology is still pretty much a closed structure since almost no company exposes their VOIP system to the Internet.”]
Source: https://www.csoonline.com/article/2119211/experts–future-security-threats-to-target-voip.html