ldm-server - 2:2.18.06-1+deb10u1 main

ldm is an X11 display manager similar to xdm, gdm and kdm, but unlike
those it wraps the X11 traffic within an SSH tunnel to provide a
secure login mechanism for remote X sessions.
.
This package includes the server components used by ldm to discover
available sessions and locales on the server. It also recommends
packages relevant for local device access, a login session, and remote
sound.
.
LTSP stands for 'Linux Terminal Server Project'.