

Ask HN: I just heard someone else's call on Skype - crixlet

This legitimately freaked me out.<p>I use Skype to frequently make calls to cells.  I just fired up Skype this morning, dialed a cell number and hit &quot;call&quot;.  Then, without ringing or any delay I was suddenly on a call between 2 other callers.  It sounded like a business meeting (talking about agendas, deliverables, etc) and the audio was a bit garbled with some type of distortion, but I could with some effort make out what they were saying.<p>Then they hung up and my call ended.<p>What happened here?  Does this happen frequently?
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ycskyspeak
I have had this happen to me once. I am from India and we used to have this
quite often when cell phones were just starting out, we even had a name for
them - "cross connection". I could hear conversations but it happened only
once. For what its worth, Skype tends to act up for me whenever there are
rains in the location where I am calling to.

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xyzzy123
This is called "crosstalk". It used to happen in POTS reasonably often, and I
have experienced it in mobile to mobile calls a few times as well.

Classical crosstalk on POTs is fairly easy to get your head around - signals
from one circuit leaking out onto another circuit through EMI, e.g. wires near
each other, faulty amplifiers etc.

I never came up with a good explanation for crosstalk in mobile (GSM, CDMA,
..)[1] etc as audible crosstalk doesn't seem to be possible at the radio
level. In fact I would be surprised if the actual voice baseband signal is
analog at any point on the network.

Nevertheless, it happens.

Most likely, you experienced crosstalk at the cellular end of your Skype call.
In theory, barring some pretty severe software errors, VOIP or Skype crosstalk
should be impossible.

[1] AMPS networks, sure, but the newer digital systems, no.

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Casseres
I had this happen to me 6 years ago in the U.S. on a cell phone. The only
thing out of the ordinary was I was in a ship (not a cruise liner) at the dock
with a bad cell signal at the time. I'm not exactly sure what happened then,
but it was probably a "perfect storm" scenario for that to happen.

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collyw
I noticed a load of icons downloaded to my Android Gallery application. They
were not pictures I had taken, and didn't seem to be cached from something
else I had looked at.

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ag-lobal
Maybe is an "IP conflict / IP duplication", and the VoIP packets go to both IP
addresses.

IP duplication can be caused by some type of "monitoring/spy" at their (or
your) computer, and a dynamic IP address.

it's not usual.

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golergka
Still very strange. Shouldn't the calls be encrypted? If the other call was
started before, and the OP's client wasn't there for the handshake, how could
it decrypt the call content?

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pmelendez
>"Shouldn't the calls be encrypted?"

Calls Skype to Skype are encripted, but as far as I know you lose that when
you make calls to landlines or mobiles.

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JoeAltmaier
Not gonna happen with Sococo Teamspace. It uses unique encryption keys for
every conversation, every pair of participants.

