if your TTY attaches to one of the IP phones currently
on the Cisco SW \ HW Compatibility Guide matrix, the IP phone and the
TTY should function fine. If it is utilizing a device that is not on
the Compatibility guide, then it is not supported. Here is the URL link to the Cisco SW \ HW Compatibility Guide, which
lists all the supported HW and SW. Just navigate to your current CRS
version for info.