Slashdot Mirror
Strange Numbers on Caller ID?
boohiss asks: "I've been getting a lot of calls on my cell phone from '+001819'. I haven't answered them, of course. But what is this number? I've found some various explanations here and there, but nothing conclusive. There's also the story on Snopes about the famed 809 long distance scam, which may or may not be what this is. Could it be some form of cell phone spam that isn't compatible with my phone? Does anyone else get these calls, and has anyone figured out what they are?" If anyone is unfortunate enough to fall for one of these, what options do they have in terms of damage control?
When my sister was working at the district attorney office, if she called out house from there, the caller ID showed up as "out of area", but if she called our cell phones it showed up as ( I think ) 0393.
Always the same number, so we knew who it was, but it was odd.
Perhaps your carrier isn't receiving the caller ID info, and your carrier is just sticking some number on there to indicate that.
What you are experiencing is someone calling you through a carrier that does not properly populate the CLI and ANI fields in the SS7 (or ISDN) message to the terminating carrier.
This isn't anything scamy at all, and nothing for you to worry about. All this means is that someone is using some cheap ass long distance to call you... maybe from a prepaid phone card or a VoIP-to-POTS service. Its very easy to not set this up correctly if you are using some crap switching platform like NACT STX, and if the carrier is small enough to be under the radar, they probably aren't filing the PIU forms anyway so they don't give a shit about the tax penalities for not sending ANI.
Your cell phone provider will treat this call the same way it treats all incoming calls. Most likely that means it will just charge you at your normal airtime rate.
According to http://decoder.americom.com/cgi-bin/decoder.cgi it might be:
Spoofing ANI and CLI only requires that you have an oob signaling link to your upstream carrier. Every upstream carrier is going to populate whatever the one before them had in the message for ANI and CLI. You can probably do that with any old ISDN or T1 without much trouble.
If you just have a regular DS0 land line, its a bit different. ANI and CLI are transmitted out of band, so you can't reall effect that. The terminating switch will have the same ANI and CLI that your originating switch trasmitted in the SS7 message. However, the "caller id" information (taken from the CLI field) is transmitted in band from the terminating switch to the receiving party's handset... and this is very easy to spoof. Once you are connected, you can send your own in band "caller id" signal which will be picked up by the receiving part's handset. You can probably do it with sound card.
In-band = information transmitted the same way your data (or voice in this case) is. In an analog phone network, in-band signalling and control is done with things like audible tones and voltage changes.
Out-of-band = signalling and control that happens by some other means outside your data (voice) link. For instance with an ISDN line, the out-of-band signalling is on the D channel, whereas the voice/data are on the B channels.
CLI/ANI info, posted from the first hit of a google search:
CLI , ANI
Calling Line Identification , Automatic Number Identification
CLI = ANI
A service available on digital phone networks that tells the person being called which number is calling them.
The central office equipment identifies the phone number of the caller, enabling information about the caller to be sent along with the call itself. (Osicom)
The providing of the Directory Number from which a terminating call has originated ( NI )
A service available on digital phone networks that tells the person being called which number is calling them.
The central office equipment identifies the phone number of the caller, enabling information about the caller to be sent along with the call itself. ( WorldCom )
At a minimum, the calling line identification includes a single calling party number; it may also include a second calling party number, a calling party subaddress, and redirecting number information.
Calling line identification may not include any calling party number due to interworking, or because of an interaction with the CLIR supplementary service. ( TG )
11*43+456^2