While transmitting a phone call from one mobile phone to another across several carriers, I assume it may be necessary to buffer the audio data for a few seconds.

My questions:

  • a) Is it true, that the contents are cached by the provider for very short periods of time or are missing frames just being dropped?
  • b) If they are cached, how long is this information stored and where?

Why I ask this: Today, I made a call from one european country to another and I got a replay of what was said on the phone about five minutes ago. This means, the call was established for about 8 minutes when suddenly I heard what the person I called said five minutes ago. It was clearly a recording, as even the background noises where distinctly the same. I listened for about 30 seconds before I hung up. The person I spoke to was unable to hear a thing from what I said during this replay. I know that there are at least three different providers involved: the provider that provides the local network where I currently stay and two providers from the country the two contracts are made in. My provider denies that any recording is happening (no surprise) - not even temporary. I know that this is anecdotal evidence, but it made me curious.

closed as off-topic by Philipp, RoraΖ, user45139, Stephane, Rory Alsop Sep 8 '15 at 14:20

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "This question does not appear to be about Information security within the scope defined in the help center." – Philipp, RoraΖ, Community, Stephane, Rory Alsop
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 3
    How is this question related to security? – Philipp Sep 8 '15 at 12:40
  • eluskemi - This question is not a security question. It sounds like someone was recording it - not sure how you'd find out who. – Rory Alsop Sep 8 '15 at 14:21

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