https://gitlab.synchro.net/main/sbbs/-/issues/713#note_5471

Seems we can close this issue now then (?).
--- SBBSecho 3.20-Linux
* Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)

https://gitlab.synchro.net/main/sbbs/-/issues/713#note_5493

I'm not sure the underlying issue ever got resolved in that a user can be disconnected but the socket stays open until it times out but very difficult to replicate.
--- SBBSecho 3.20-Linux
* Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)

https://gitlab.synchro.net/main/sbbs/-/issues/713#note_5499

Most likely, this: https://superuser.com/questions/298919/what-is-tcp-half-open-connection-and-tcp -half-closed-connection

The socket inactivity detection feature can be used to successfully detect this condition.
--- SBBSecho 3.20-Linux
* Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)