OnSIP is fully functional with TTY. TTY machines are analog phone devices, and require the use of an ATA, or analog to digital converter, for use with OnSIP.
Our testing was with the Ameriphone q90D with the Grandstream HT503.
Configure the Grandstream HT503 for use on our boot server per our instructions, and then connect the q90D into the phone jack of the HT503 and use as normal.
We have tested inbound and outbound capabilities with the Ameriphone q90D and HT503 using our general boot server configuration and have found no issues.
For use with a relay service, read about 711 integration here.
Created June 2015