Zhone 6212-a2 ユーザーズマニュアル

1.  Make sure you have DSL service. You should get some kind of information from your ISP which states that 

DSL service is installed. You can usually tell if the service is installed by listening to the phone line; you will 
hear a high-pitched noise. If you do not hear a high-pitched noise, contact your ISP. 

2.  Verify that the phone line is connected directly to the wall and to the Line input on the router. If the phone line 

is connected to the phone side of the router or you have a splitter installed on the phone line, the DSL light will 
not come on.