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With a normal telephone connection you can't call two people separately and simultaneously. You can have a conference call where the signal is shared by all participants. With my DSL line I can call and use the internet at the same time. This means that a phone call is essentially a conference call with me, the person, and my ISP, just in different frequency bands. If the person did not just listen to the audio frequency band but also the DSL one, it seems that they could listen to my internet traffic.

Is this true?

nebuch
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  • DSL is digital. The concept of "listening to it" is I'll defined without a translation process designed for the encoding. – Neil Smithline Mar 24 '16 at 04:21
  • Why listen to your internet, when they simply could [listen to your {old} monitor](https://en.wikipedia.org/wiki/Van_Eck_phreaking)? – hamena314 Mar 24 '16 at 08:44
  • Although you are concerned about security, what you are really asking is for technical details on how DSL frequency work, which is off topic here. I also think that you are making some logical leaps that are putting you astray in your thinking. – schroeder Mar 24 '16 at 14:44

1 Answers1

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The DSL signal only exists between your house and the DSLAM on your street.

Voice is separated out and transmitted on a TDM digital channel with only 8kHz bandwidth.

So, no, nobody in a multi-party conference call will get more than that 8kHz voice channel connected to them, and therefore have no idea whether you have DSL or not.

Fiasco Labs
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  • Furthermore, on modern systems, the voice signal is digitised at 64kbps before being sent on over optical fibre. Even if some DSL signal did leak past the filters and into the analogue voice signal, it would be completely scrambled by the digitisation. – Simon B Mar 24 '16 at 12:04