V.90 modem handshake diagram

[pne]

The Sound of the Dialup: an Example Handshake by Oona Räisänen (2500×1301px JPEG, cc-by-sa 3.0)

via dotaturls

A fascinating, annotated image of what a modem handshake (V.90, apparently) looks like when split up into frequences (is that called a spectrogram?), and what the individual bits mean.

A pity that my modem days were so long ago that I don’t really recall what the handshake sounded like; it would have been even more fun to correlate the sound I heard with the visual description in that image.

Comments

[steorra]

I'd guess that it's possible to find recordings of a modem handshake somewhere online, though I don't have time to look right now.

[sophie]

I just came across this post and thought you might like to know that the original sound that the image (which yes, is a spectrogram) used is https://en.wikipedia.org/wiki/File:Dial_up_modem_noises.ogg . The image itself cuts off after the scrambled data starts, but the OGG itself is longer.

[pne]

Thank you!

It was interesting to compare the sound file with the image.