Here is an article and several Youtube videos describing an attack on the UK MI6 organization (their equivalent of the CIA). The article uses the term "phone bombing", where the attacker uses automation to flood the target with calls, thereby preventing legitimate callers from getting in. This is just another term for Telephony Denial of Service (TDoS).
The video's narrate the attacker calling in themself and taunting the MI6. If this weren't such as serious type of attack, it would be humorous.
The PSTN is not what it used to be, closed and somewhat safe. It has so much VoIP/SIP in it, that it is starting to look like the Internet in terms of threat level. We will see more and more harassing calls, TDoS/phone bombing, voice SPAM, voice phishing (vishing), etc.
http://www.msnbc.msn.com/id/47032601/ns/technology_and_science-security/#.T4hJ4VGDTcM
http://www.youtube.com/watch?v=wtoOo-e5mNY&feature=channel&list=UL
http://www.youtube.com/watch?v=SAFf-9ohNJo
http://www.youtube.com/watch?v=PEBQoxHh1uU&feature=channel&list=UL
Unfortunately, these kinds of calls remain a problem with any kind of phone. The only thing that can be done at the moment is limit the number of people who know the phone's number.
Posted by: business voip solution | July 17, 2012 at 03:09 AM
Unfortunately, a lot of enterprises can't do this. They have to publish their 1-800 numbers, fax lines, retail numbers, government offices, and of course, everyone knows 911/311.
Posted by: Mark Collier | July 30, 2012 at 10:31 AM
Those things sometimes made by telemarketing and now a days there are still harassing in Finland country now a days call center and other customer services give a good services rather than to those telemarketers which only annoy people,i am glad to tell it to us.
Posted by: Ronja Jyrkiäinen | September 04, 2012 at 04:55 AM