Fascinating! I would have thought most people didn't have land lines in Taiwan. Are they dialing in using mobile phones?
AFAIK most Taiwanese BBSes established in the 90's already run on Telnet over TCP/IP. PTT has SSH support, smartphone clients are available as well.
BBS with Internet today serves as a high-performance forum, loading boards/articles takes a single RTT. Storage is still file-based and relies on filesystem and kernel caching.
For those interested, their codebase is available on GitHub [1].
[0] https://en.wikipedia.org/wiki/PTT_Bulletin_Board_System
[1] https://github.com/ptt/pttbbs