The number porting process was completed in just 5 days for my old phone number. The Ooma site indicates porting an existing phone number can be up to three or four weeks. Much of the porting time depends on the old carrier. The device itself resembles an answering machine, and indeed, basic voicemail review buttons are included on the base unit.

https://www.amazon.com/Smart-Service-Wireless-Bluetooth-Connectivity/dp/B078Z4HBFG