While registering yourself in a router.asus.com account, you need to choose the registration method with which you want to register your ASUS router. From the Signup page, if you choose the “Register with email” option, you need to assign a mail id which you are going to utilize for the registration process. If you select the “Register with mobile number” option you have to mention a phone number that will be responsible for the registration of your ASUS router in an ASUS account. Usually, users are recommended to register their router through a phone number as it is more secured and protective than a mail id.