[asterisk-users] Asterisk and TDD

[John Millican]

Hello all,
I was just asked a question from a client that I have in regards to
TTY/TDD "telecommunications device for the deaf".  I have read on
voipinfo at http://www.voip-info.org/wiki/view/tdd+mode that back in Dec
2006 this was in alpha stage in Asterisk. There does not (in my limited
searching) seam to be any other documentation. Is this in 1.4/1.6? Is
anyone using it? How well does it work?
TIA
-- 
JohnM