Sometime, probably close to 20 years ago, but perhaps more recently, you heard a dial tone for the last time and you didn’t even realize it would be.
Sometime, probably close to 20 years ago, but perhaps more recently, you heard a dial tone for the last time and you didn’t even realize it would be.
Well, it’s generated in the same way as modern tones are in a telephone exchange, not a played sample. You can usually configure the tone frequencies (never tried on cisco ip phone, but asterisk allows it for its own generated tones and I had a cisco ATA that let you configure them).
So, unless we’re limiting ourselves to the original mechanically generated dial-tones. I’ll consider them for all intents and purposes to be one and the same.
E.g. for the UK on cisco/sipura ATAs you would use the configuration found here https://teamhelp.sipgate.co.uk/hc/en-gb/articles/208200875-UK-Regional-Settings-Cisco-Linksys-Sipura-Adaptors and as an example (dial tone)
Dial Tone: 350@-19,440@-22;10(*/0/1+2)
The comfort noise is also generally only added when there’s no other noise on the call. This is to prevent you thinking you were disconnected when no-one is talking.