A:Answer I realize this is 6 months after the question was asked but I had a similar conversation with Spectrum today and wanted to share. I have been currently renting an all-in-one device which served as modem, router, and phone. I found out that even if I replace the all-in-one unit that, I will still need to use their unit for the phone, I just wont be charged the rental fee since I"m not using it for the internet. WTH? Not a typo. Anyway, I am going to now have 3 devices instead of the one (pros and cons to that setup but I digress). TBH though, I have my land line phone forwarded to my mobile so I may not use the ISP provided equipment anyway.