Hi @liangwang0414 ,
Welcome to the community!
We're sad to know that you're having issues with the service. We're able to locate your account using your community details and ran an initial test to the service. What modem/router are you using?
We did an article that will guide you on how to setup your ADSL2+ modem/router. Feel free to visit
the link below.
Let us know how it will go.