To those who played online multiplayer via the Sega Dreamcast -- how was it?

I recently found out that the Dreamcast could play online multiplayer games. I had a Dreamcast back in the day, but as a young kid with no access to the internet I never knew it was an option.

Now I'm totally fascinated with the concept and am curious; for those who got to play it, how was it? Was it laggy? Were there a lot of disconnections? How was the online interface? Was there a friends system?

I need to know! 😁