A:AnswerI don’t know if your old phones are compatible with the CS 5129–26. I would direct that question to the VTEC website. That said, I know you can add additional headsets for this particular model; anywhere from 1 to 5 more phones could be added.
A:AnswerHi - The VTech CS5129-26 has a call block feature that will enable you to block unknown calls and certain undesired calls. The call block list can store up to 20 entries.
Thank you,
-VTech Support