SEGA'S ONLINE HISTORY & NETLINK PLAY OVER VOIP
Official Saturn NetLink over VoIP Thread: https://www.dreamcast-talk.com/forum/viewtopic.php?f=2&t=8453
 
Official Video Setup Guide: https://www.youtube.com/watch?v=PKNOhWgMCMY
SEGA RPG FAN (at Dreamcast-Talk): https://www.dreamcast-talk.com/forum/memberlist.php?mode=viewprofile&u=58ItsStillThinking (at Dreamcast-Talk): https://www.dreamcast-talk.com/forum/memberlist.php?mode=viewprofile&u=5587 Xiden (at Dreamcast-Talk): https://www.dreamcast-talk.com/forum/memberlist.php?mode=viewprofile&u=7828
 
OPENING Obscure game of the cast: Gundam Side Stories
MAIN TOPIC:
Sega, ahead of their time...
Sega network based service started on the mega drive in 1990
Sega Channel
offered games for download
X-Band
modem was built in to later sega channel adapters
for the most part, matchmaking came about by reverse engineering the game code, then develop a hack to intercept 2 player activity.
Multi player Online MMO
Dragon's Dream
Phantasy Star Online
Technical Aspects
Hardware
Japanese Hardware
Sega Saturn Modem (XBand)
14.4kbps
Saturn media card requiring credits
required the XBand server for matchmaking
US Hardware
Netlink (Some XBand Technology)
28.8kbps
Direct dial only (no central server)Taisen Cable (DirectLink Cable)
Postby rush6432 » Wed Nov 03, 2010 5:52 pm
i did a ton of research on this a while back and ive got a copy of the euro version of doom and a few others. 
i even got the pinouts for the cable and made an adaptor to allow the serial cable to link a console to a computer serial port and had a program tunneling the serial connection over the internet for internet play seemed to work but i only tested it on a LAN and not actually the internet. worked fine. internet play might work but im not sure how much if any lag there will be.
http://www.saturnleague.com/phpBB3/viewtopic.php?f=7&t=654&sid=a5f80701ca4f5a4c8cdb134952e4a484&start=15
Software
Japanese
Sega Saturn Modem
Daytona USA Circuit Edition
Decathlete
Dennou Senki Virtual-On
Dennou Senki Virtual-On Media Card Pack
Habitat II
Pad Nifty
Pad Nifty 1.1 & Habitat II
Puyo Puyo Sun
Puzzle Bobble 3
Saturn Bomberman
Sega Rally Championship Plus
Sega Saturn Internet 2
Sega Saturn Internet Vol. 1
Sega Worldwide Soccer '98
Shadows of the Tusk
Special Disc with Sega Saturn Internet 2
Virtua Fighter Remix
Dragon's Dream (a demo that is said to be the first online console RPG)
Taisen Cable
Daytona USA Circuit Edition
Doom
Gungriffon 2
Hexen (accessed through debug menu, very buggy)
Hyper 3D Taisen Battle Gebockers
Hyper Reverthion
Steeldom
Daytona USA demo (U)
Doom (U) (U has it, but E version seems to not have system link. J may have it, code is listed (unlike U or E).)
Independence Day (U)(present but nonfunctional)
Hexen (U) (U has it, but E verion seems to not have system link) (buggy)
Virtual-On: Cyber Troopers - Netlink Edition (U)
Dennou Senki: Virtual-On for SegaNet (J)
Wipeout (JUE) (this listing is probably wrong, can someone confirm? Not listed in code and no reviews mention it.)
Wipeout XL/2097 (JE) (as above, this game probably does NOT have system link. Not listed in code, etc.)
Duke Nukem 3D (U) (U version is listed as having DirectLink support in its code and does have it; E version does not have it (neither code nor support))
Daytona USA: Circuit Edition (J)
Gun Griffon 2 (J)
Steeldom (J) 
Shadows of the Tusk (J) (unconfirmed, listed as having it in code)
Saturn Bomberman (U) (unconfirmed, listed as having it in code)
Sega Rally Championship Plus (J) (unconfirmed, listed as having it in code)
Puyo Puyo Sun for SegaNet (J)
Hyper 3D Taisen Battle Gebockers (J)
Sega Touring Car Championship (JUE) (unconfirmed, listed as having it in code)
Densetsu no Ogre Battle (J) (unconfirmed, listed as having it in code)
Netlink Browser (PlanetWeb Internet Browser V. 1.135) (unconfirmed, listed as having it in code)
Decathalete for SegaNet (J)
Dragon's Dream
https://forum.digitpress.com/forum/showthread.php?136448-Saturn-system-link-questi