| 单词 | dial tone |
| 释义 | dial tone 1. An audible signal indicating that a telephone set is connected to a telephone switching system that is available to process an outgoing call. 2. Central office (CO) dial tone, sometimes referred to as hard dial tone, is provided by the CO switch to a terminal device. When the dial tone is seized, the user is free to dial a telephone number. See also CO. 3. PBX dial tone, sometimes referred to as internal dial tone or soft dial tone, is provided to a PBX station indicating that the PBX switch is available.The user is then free to dial an internal PBX station number. If the target telephone number is an external number, the user must dial an access code in order to gain access to an external trunk connected to the public switched telephone network (PSTN). See also PBX and PSTN.The conventional access code is nine (9) in the United States and Canada, and zero (0) in most other countries. 4. Stutter, or stuttered, dial tone is dial tone interrupted by short, regular periods of silence, and is used by some centrex and PBX systems as a message indicator, typically indicating that a voice message has been deposited in a voice mailbox either integrated with or interfaced directly to the system. Stuttered dial tone also is often used to confirm that a feature, such as call forwarding, has been activated or deactivated. See also call forwarding, centrex, and PBX. 5. Video dial tone, or visual dial tone, refers to the notion of a broadband network that provides videoconferencing capability on demand. See also broadband. |
| 随便看 |
|
科学参考收录了5291条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。