Wow. It’s been at least 20 years since I had to set up a dial-up line. My concern is why the DSL is failing that often that you are considering a dial-up line. They are SLOW….I have sporadic issues with my DSL (Verizon) but the most I have been down is 5 to 10 minutes. Usually a reset of the router and modem resolves the issue. I’d contact you DSL provider, you may have some faulty equipment on interference on the line. They can run some tests. For me they found a line issue 2 blocks away, patched the line and have had no further issues.