NEC has warned businesses that telephony spam levels are about to soar.
Telephony spam could soon comprise over half of all phone calls, the networking vendor says, potentially causing worker productivity to plummet.
While junk messages are already prevalent in the data world, they have largely failed to affect telephony because it would be too costly, as senders would have to pay for each call. But as telephony is starting to be delivered over IP networks, the volumes of spam aimed at telephony users is likely to explode, according to NEC.
"Now the telephony world is migrating to Internet telephony, 'botnet' platforms can be used to create spam phone calls as well as e-mail," Juergen Quittek, senior manager at NEC Network Labs, told ZDNet UK. Quittek cited statistics saying that the percentage of phone calls that are spam will soon rise to between 40 percent and 70 percent.
NEC has developed a software add-on to its PBXs, which it says will stop up to 99 percent of spam phone calls. Its software, called VoIP Seal, uses a variety of techniques to detect spam calls. For example, if too many calls originate from one IP address, those calls can be sent to voicemail or rejected. The software also includes a policy tool to whitelist or blacklist callers by caller ID or IP address. Another approach "answers" incoming calls with a fake ringing tone. This will trigger a spam message to start playing, while a human caller won't detect any change and will remain silent. Spam calls will then be rejected by the PBX without the recipient's phone ringing.
Several other companies are also developing techniques for blocking telephony spam.
Security products vendor Check Point has developed a framework for detecting telephony spam, which it refers to as SPIT (spam over Internet telephony). Eyeball Networks, a Canadian company, has developed a server specifically designed to stop SPIT. And several individuals within the IETF international standards body have written drafts suggesting ways to limit its spread.
But Cisco Systems, the vendor which has sold the most IP telephony systems, is less convinced about the threat. "We have not seen activity [of this nature] that has put people on the back foot," said Mick Stevens, U.K. security market manager at Cisco. "We have nothing along the lines of what NEC has developed."