Check this out:  blogger Oona Räisänen (windytan on Google+) recently diagrammed the old-school handshake that telephone modems make when connecting.

For those of you who have never used a telephone modem, the link includes a sound file of two modems connecting and negotiating protocols – a process that is known as the handshake.  For those of us that have been around the proverbial internet block, this may bring back some memories.