Alright fella,
Read this "This product is designed for telephone/voice signals only, and is not ADSL compatible."
I think the idea of this product is so you can connect 2 phones and a fax machine, or does a fax machine use a telephone port?
But from that it deffo sounds like it wont work with ADSL internet. Where do you put the ADSL filter, i have never used one before, is it after or before that adapter?
EDIT: after reading it again this "Ideal for PC’s, Laptops and fax connection from one telephone point " makes it sound like it should work.
Are you plugging a modem into it, or a cable directly into it? maybe you forgot to put the modem on if thats even possible with ADSL