The default `talk` and talk service were trash, and often there were protocol errors that would cause you to hang forever, vainly waiting for an answer (classic talk used UDP only.)

https://en.wikipedia.org/wiki/Talk_(software)

Eventually, a few competing offerings sprang up, in the form of `ntalk`, `xtalk` and `ytalk`. These were superior in every way, and sometimes required swapping out the service attached to inetd. Once you did that, it was a fantastic way to chat live and direct on Unix. Way better than the `write` we started with!