Terminal Server Bandwidth Requirements Hardware and bandwidth requirements depend on many factors: which
OS is running on your Terminal Server, which applications your
users are running on the TS (16-bit applications are CPU killers,
graphics intensive applications like CAD programs are bandwidth
killers), how much printing is done, etc.

Minimum bandwidth for a useable RDP Session = 26.4Kbps
800x600 @16 bit color - 26.4Kbps per

https://www.hakanuzuner.com/terminal-server-bandwidth-requirements/