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When I dial using wvdial, sometimes it prints some garbage text into the terminal. This is not happening every time, but in the garbage text I can see some readable strings which is often irc logs(from xchat) or GET requests from the browser.

One of my friend told me that this is probably something it's reading from /dev/random for Random entropy, but I couldn't find any supporting information.

What is this text, and why is it being printed to the terminal?

See the below picture for an example: enter image description here

Excellll
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Hrishi
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1 Answers1

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This is data sent by modem via serial port. As you see - initially it looks normal and there are is AT communication. Modem is working in 'command mode'.

After connection is initialized - your modem enters 'data mode'.

wvdial cannot recognize when modem switches to 'data mode' and prints everything that came to serial port.

This is quite common in USB cellular modems. These modems are not standarized.

More information:

  1. Command and Data_modes (modem) on Wikipedia - about modem modes

  2. Hayes command set on Wikipedia - how Hayes-compatibile and other modems indicate mode switching

Kamil
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