@Doris: Nein, dial tone = Wählton ist völlig richtig. Im IT-Slang wird "wählen" (der Vorgang der Rufnummernübermittlung) nicht als "dialing" sondern als "signalling" bezeichnet, die vom Einsender angesprochenen "Wähltöne" die man hört, wenn man eine Ziffentaste drückt heißen "DTMF (dual tone multi frequency) signalling characters" oder "DTMF digits".
Als Beleg noch ein Auszug aus ETSI TBR 021 ed.1 (1998-01) "Terminal Equipment (TE);Attachment requirements for pan-European approval for connection to the analogue Public Switched Telephone Networks (PSTNs) of TE (excluding TE supporting the voice telephony service) in which network addressing, if provided, is by means of Dual Tone Multi Frequency (DTMF) signalling"
220.127.116.11 Dialling with dial tone detection
Justification: 91/263/EEC, Article 4(f); Interworking with the PSTN is assured by requiring a TE with
automatic dialling to start sending its digits during the time period when the network is ready to receive
Requirement: If the TE is intended for automatic dialling with an automatic dial tone detection, and this
facility is enabled in accordance with the supplier's instruction, it shall start dialling within 8 s of the start of
the application of:
- a continuous dial tone; and
- a cadenced dial tone whose cadence comprises a repeated sequence of:
200 ms ON, followed by 200 ms OFF, followed by 600 ms ON, followed by 1 000 ms OFF.
For the purposes of this requirement, the dial tone is defined as a single tone signal, delivered from a
generator with a source impedance equal to ZR, in the frequency range 300 Hz to 500 Hz, whose level is
between -35,7 dBV and -0,7 dBV when measured across the reference impedance ZR which substitutes
Test: The test shall be conducted according to annex A, subclause A.18.104.22.168.