VoIP Can Be Vulnerable To Hackers, Too: Page 2 of 2

It's also relatively easy to launch an attack against a VoIP network because the software tools available to hackers and others bent on invading a network are more available and easier-to-use. "And the exposure levels have gone up because there are so many nets," he said.

What's the solution? "You need strong encryption over VoIP servers and VoIP client devices," Nagiel said. He observed that extensive encryption can slow down efficiency of networks, but encryption is a small price to pay to avoid denial-of-service and invasions of networks. Another useful defense tactic is to use VLANs "whenever possible to separate traffic," according to Nagiel. In this way, transmitted data can be segregated into unique VLANs for data and voice transmission.

Nagiel cautioned, however, that security managers should resist using shared Ethernet network segments for voice.

One seemingly benign issue--the growing use of softphones on laptops--can easily be violated, Nagiel said, suggesting that softphones be encrypted, too.