I am using PuTTY as my ssh client (which is probably what most people use) and ascii line drawing has never worked. Some time had enough of it and one search and 10 minutes later I found the solution.

The tip on this open suse page did the trick for me. In the Settings under Window/Translation set Received data assumed to be in which character set to UTF-8 and make sure that the option Handling of line drawing characters is set to Use Unicode line drawing code points. Obviously the Font that is configured under Window/Appearance/Font settings needs to have the unicode line drawing characters. I have tried it with the fonts Lucidia Console and Courier New which both work fine and are standard windows fonts.