Nearly all states currently rely on a single vendor to provide TRS services. However, the Commission has recognized that its rules allow multiple carriers to provide TRS services within a state, and has supported multi-vendoring in the belief that it will reduce the costs and improve the quality of TRS services. 5 Text service can be accessed using a variety of protocols. Under a simple 711 system the TRS system cannot distinguish a request for text service from voice service. In the event that the caller desired a voice call, the voice user will be required to listen to several TTY tones, then wait for the CA to recognize that the caller is waiting for a voice greeting.
Similar problems occur with text calls.
In the event the caller were connecting using another protocol, the user would again have to wait for the CA to recognize that the caller desires either a different text protocol or a voice call. Finally, a simple 711 system would not permit the TRS customer to choose which vendor will carry the call. One could assign calls to competing TRS providers, randomly, proportionately or according to some other algorithm. Many of the problems have already been identified. For example, randomly assigning calls could overwhelm small carriers.