This section provides information about how the Attendant Vectoring feature behaves in certain circumstances. Use this information to ensure that you receive the maximum benefits of Attendant Vectoring under all conditions. The following considerations apply to Attendant Vectoring:

• Teletypewriter device (TTY) for the hearing impaired

  Unlike fax machines and modems, a TTY has no handshake tone and no carrier tone. A TTY is silent when not transmitting. Systems cannot automatically identify TTY callers.

  However, the absence of these special tones also means that voice and TTY tones can be intermixed in prerecorded announcements. The ability to provide a hybrid voice-and-TTY announcement, when combined with the Attendant Vectoring capability, can permit a single telephone number to accommodate both voice and TTY callers.