Out of curiosity, what's the use case for ringconnectd? Just to find out what your IP is? What would you need that for back in the day?
replyDialup systems typically spent most of their time offline. If you wanted to connect to one over IP you'd need some way to get it to dial back up to the ISP, and then some way to get the new address it'd ended up on.
replyYup, and phoning a number wouldn't incur charges unless the other side picked up.
replyringconnectd never answered a call, but rather listened for a ring pattern that you could specify. So what I'd typically do is go to a payphone, dial my line at home, let it ring twice, hang up, get my money back, dial again letting it ring twice again, hang up, get my money back again, then go to the computer lab to wait. My system at home was configured to connect after the ring pattern [ring, ring, delay, ring, ring]. It would then wait 30s, connect to its ISP, and email me its current IP address.
I did it this way because I was already using the terminal for pretty much everything, and we didn't get dedicated machines on campus. So it was better to just hold my work on my Linux machine at home and connect to it from the lab.