Line tones
取自E.182這個doc
E.182定義了標準會用到的Tones如下:
Dial tone: The exchange is ready to receive address information.
PABX internal dial tone: The PABX is ready to receive address information.
Special dial tone: Same as dial tone, but the caller’s line is subject to a specific condition, such as call diversion or a voice mail is available (e.g., "stutter dial tone").
Second dial tone: The network has accepted the address information, but additional information is required.
Ring: This named signal event causes the recipient to generate an alerting signal ("ring"). The actual tone or other indication used to render this named event is left up to the receiver. (This differs from the ringing tone, below, heard by the caller
Ringing tone: The call has been placed to the callee and a calling signal (ringing) is being transmitted to the callee. This tone is also called "ringback".
Special ringing tone: A special service, such as call forwarding or call waiting, is active at the called number.
Busy tone: The called telephone number is busy.
Congestion tone: Facilities necessary for the call are temporarily unavailable.
Calling card service tone: The calling card service tone consists of 60 ms of the sum of 941 Hz and 1477 Hz tones (DTMF ’#’), followed by 940 ms of 350 Hz and 440 Hz (U.S. dial tone), decaying exponentially with a time constant of 200 ms.
Special information tone: The callee cannot be reached, but the reason is neither "busy" nor "congestion". This tone should be used before all call failure announcements, for the benefit of automatic equipment.
Comfort tone: The call is being processed. This tone may be used during long post-dial delays, e.g., in international connections.
Hold tone: The caller has been placed on hold.
Record tone: The caller has been connected to an automatic answering device and is requested to begin speaking.
Caller waiting tone: The called station is busy, but has call waiting service.
Pay tone: The caller, at a payphone, is reminded to deposit additional coins.
Positive indication tone: The supplementary service has been activated.
Negative indication tone: The supplementary service could not be activated.
Off-hook warning tone: The caller has left the instrument off-hook for an extended period of time.
Call waiting tone: Another party wants to reach the subscriber.
Warning tone: The call is being recorded. This tone is not required in all jurisdictions.
Intrusion tone: The call is being monitored, e.g., by an operator.
CPE alerting signal: A tone used to alert a device to an arriving in-band FSK data transmission. A CPE alerting signal is a combined 2130 and 2750 Hz tone, both with tolerances of 0.5% and a duration of 80 to. 80 ms. The CPE alerting signal is used with ADSI services and Call Waiting ID services [14].
Payphone recognition tone: The person making the call or being called is using a payphone (and thus it is ill-advised to allow collect calls to such a person).
另外也定義Event與其encode
Event encoding (decimal) _____________________________________________ Off Hook 64 On Hook 65 Dial tone 66 PABX internal dial tone 67 Special dial tone 68 Second dial tone 69 Ringing tone 70 Special ringing tone 71 Busy tone 72 Congestion tone 73 Special information tone 74 Comfort tone 75 Hold tone 76 Record tone 77 Caller waiting tone 78 Call waiting tone 79 Pay tone 80 Positive indication tone 81 Negative indication tone 82 Warning tone 83 Intrusion tone 84 Calling card service tone 85 Payphone recognition tone 86 CPE alerting signal (CAS) 87 Off-hook warning tone 88 Ring 89
後續會做說明補充...
