I found the manufacturer of my modem.
They call it TDSL(Time division duplex Digital Subscriber Line), my ISP called it TS-DSL though. Sorry about that.
You can get some information from here.
http://www.gigalink.co.kr/english/02...pro_02tdsl.php
My modem is 'T-LAN SU-400'.
Hope you can find some clue.