+ 0 Votes modem CG IT 6 years ago if you ISP provided your ZyXEL gateway, then its setup to use your ISP line. The netgear ADSL modem might not put out the correct digital signal that your ISP will recognize. only those modems and DSL combination modem/routers that your ISP provides will put out the correct digital signal that their equipment will recognize. Think of a DSL modem as something similar to your cable tuner box. Without the correct cable tuner box you can't see the cable TV channels. Not all cable tuner boxes will work with all cable TV providers. Without the correct DSL modem you can't connect to your DSL line. Not all DSL modems will work with all ISP DSL providers. + 0 Votes Thank you elenaholmes 6 years ago Now thinking about what you mention, I agree with you. shame. I really like Netgear for VPN settings and easy setup. will go for DSL modem for that particular IPS provider which is Zyxel.