About CAS Channel Associated Signaling for openovice or hoot or always on channel

Have you heard a type hoot or openvoice or always on
channel. Those channel is always on after start up and never stop if no
issue .end user can always talk and listen through it . It use Channel
Associated Signaling .
Do you have those ABCD bit pattern ?? I heard
some one tell me there is only one pattern 1101 and that is all . Do you
have any idea and spec for this ??
Please advise