Security analysis: Where the real threat of internet telephony comes from

With the popularization of VoIP technology, the security of VoIP voice communication has aroused more and more widespread concern in the industry. But where the security threats of VoIP originate, this should be the first step in the industry to systematically address VoIP security issues.

In October of this year, VOIPSA (Voice over IP Security Alliance) VoIP Safety Alliance released a classification of VoIP security threats, a more detailed classification and description of the security threats faced by IP telephony, taking the first step in the industry to systematically address VoIP security issues.

Who let the voice infect the virus?

It is different from the traditional PSTN public switched telephone network without virus and Dos attack. In VoIP system, VoIP voice traffic as a special traffic in the IP network hosting voice services, and other types of data traffic is not essential difference, the same will face the IP data network common viruses and attacks and other security threats.

Matthias Machowinski, head of corporate voice and data at Infonetics, a market research firm, said VoIP users must have a clear understanding of the IP infrastructure that this technology relies on. "Threats to IP networks, such as viruses, fall within the context of data security, but this threat also affects the quality and reliability of VoIP voice services." "In fact, compared to conventional data traffic, including VoIP voice, the various real-time traffic is more sensitive to network anomalies, the bottom line of VoIP security is the security of data network first." As Machowinski said, "full monitoring of overall security is important, and VoIP security must be overall security, including voice and data." ”

"VoIP not only inherits all the security flaws of the IP network, but also has no immunity to specific protocol Dos attacks," said Jonathan Zar, a senior executive at the SonicWALL company, a VoIP security alliance secretary. "Therefore, VoIP security is first and foremost the security of the underlying IP network architecture."

Who tapped your call?

Of course, VoIP's security threat does not come from IP networks alone. Many security threats also focus on the transition from a closed PSTN public switched telephone network to an open Internet network.

The transmission and security mechanisms of VoIP voice services are quite different from traditional telephony services. Because the IP protocol itself does not have the ability to protect against attacks, unencrypted voice data traffic is easily intercepted or listened to during transmission. While packet listening is not a high proportion of VoIP security incidents, because of the difficulty of this kind of interception, voice packet listening may become a major security threat to VoIP after VoIP becomes the mainstream of voice services.

According to the VoIP Security Alliance survey, some hackers now have mastered how to attack specific targets and specific network voice traffic technology, so that VoIP face security threats further increase. The only thing to be thankful for is that most of the current VoIP applications in large and medium-sized enterprises take branch offices, headquarters from the network, and then unified traffic into the central IP PBX system mode, remote office VoIP traffic through the VPN network connection for VoIP voice traffic provides a degree of security protection.

Who moved your ID?

In the VoIP security threat classification issued by the VoIP Security Alliance, there is a particular concern about the security threats that are unique to VoIP, namely the illegal bypass threat. Such threats include multiple types of fraudulent calls from VoIP-based harassment calls, spam calls, and other identity theft.

In the traditional PSTN network, the caller ID can not be changed, but in the VoIP system, the forgery of the caller ID is not difficult, which provides all kinds of fraudulent calls to facilitate. VoIP fraud calls disguised as corporate IT departments or service provider IDs can easily leave listeners with a loss of vigilance.

Like spam e-mail, voip spam calls, in addition to the potential for indirect illegal bypass threats, can cause network performance to plummet and network congestion. But such threats are far from being taken seriously, Machinowski that the main reason for this is "the current VoIP system, which is connected to remote sites, still has good VPN protection." As corporate VoIP applications really turn to open-end VoIP, the severity of such threats cannot be overlooked. He believes that the best way to reduce VoIP risk now is to ensure consistency in corporate security policies while maintaining existing network security. In addition, deploying security software and hardware products specifically for VoIP applications is a viable strategy.