Anyone have any experience with having TDD/TTY telephone servies setup? I have a need to have that service available for several of our toll free numbers.

First off, there's a very good definition of the service at:

"https://www.pcmag.com/encyclopedia_term/0,2542,t=TDDTTY&i=52627,00.asp"

Basically, it's a Single Line (basic T&R Service) with a rather low speed modem or Teletype device connected to it.

I would doubt that VOIP would support this type of connection considering I have had problems with modem connections over VOIP.

dial 711 from any phone in the US to access a tty relay operator (free).

Really! I wonder if that could be a resolution for us. I will have to see if that is good enough to satisfy the auditors. thanks for your help!