Based on some learnings from the networking course I did three years ago in IITM. Was one hell with a slave driver of a prof. Had a good assignment group though, so had some fun also.
The three way protocol is used to keep in touch with long-lost friends/relatives. It goes like this:
1. I send him/her a mail saying “hi i’m skimpy, hope you remember me” and all that
2. He/she replies with “yeah of course i remember you, hope you’re fine. i’m working at XXX. what are you upto?”
3. I reply to that mail, with more fundaes about my life.
I don’t get a reply to that mail.
Has happened multiple times, with multiple people. Sometimes it does get extended and you have enuff material to rebuild the friendship rather than just “keep in touch”.
But on most occasions, it ends in three. After all, both messages have been acknowledged. And this can’t go on for ever (remember the red army – white army problem in Tanenbaum?). And the minimum number of messages to ensure both is three. Simple, isn’t it?
And not so long ago I used to be extremely pissed if people didn’t reply a second time. Until I started doing so myself!!