System for centralized captioned telephone service

A system for centralized captioned telephone service (“C-CTS”), the system comprising:

• a C-CTS system (“C-CTSS”) for providing a transcription service to a user subscribed to the C-CTS during a phone call with a peer;
• a mobile communications device of the user which includes a first phone number assigned from a carrier of the user;
• a communications device of the peer which includes a second phone number;
• and
• a plurality of caption providers that communicate with the C-CTSS, wherein each of the caption providers provide a captioned telephone service,
• wherein the carrier of the first phone number includes a voice network, a data network, and a database that stores the first phone number of the user who is subscribed to the C-CTS, wherein the C-CTSS includes a database that stores the first phone number of the user,
• wherein the carrier of the first phone number is configured to route a call, which originated from the first phone number and is directed to the second phone number, to the C-CTSS,
• wherein the call includes a call setup message from the carrier, and
• wherein the C-CTSS is configured to:
• receive the call setup message from the carrier;
• add or modify a parameter of the call setup message to a predetermined value during a call setup procedure of the call to prevent the carrier from re-routing the call to the C-CTSS;
• and
• route the call to the carrier of the first phone number, upon receiving the call from the C-CTSS and checking the added or modified parameter, the carrier of the first phone number routes the call to the communications device of the second phone number.