Phone tone
Before my current job I'd never used computer integrated telephony. Yes, Skype and other VoIP systems but not CIT proper.
It's interesting to see the results of the system trying to understand the tones it is 'hearing' it really isn't very good at it. What I hear as a slight 'blip' in one network's ring tone (I think it's O2) the computer obviously hears as the ring tone stopping, so it serves up the next page ready for an answered call to be logged/coded, even though ring tone is continuing.
Of course these tones were originally intended for human ears/brains and with the legacy public switched telephone network holding out this kind of lumpy system will continue.
In the old analogue days the phone system worked by setting up a metallic speech path from caller to called party. The callers exchange (IIRC) would send ringing current down this path to the called party's phone toring the bell, and the called party's exchange would put ring tone back the other way.
With digital exchanges this protocol changed. No speech path would be set up until the called party answered. The calling exchange would, as it were, tell the called exchange to ring out the number and let the calling exchange know when and if it had been answered. [And here is some irony. I spend a lot of time listening to ring tone and voicemail outogoing messages, where the obvious thing to do would be only to connect the call to me once it has been answered. This is doable, but how accurately I don't know. given the need for automatic 'listening' to tones.]
Dialling tone is another matter. It was first provided as part of connecting the caller to the switching apparatus, but as technology developed it was only really there for backwards compatability. I worked in internal voice (Mitel SX 2000s mainly) in the 1980s and I knew that the system could assign an MF decoder (to hear what digits were being keyed in) even if it couldn't lay on dial tone. But such was the folk memory of how to use phones that my colleagues upon not hearing dial tone would rattle the switch hook to try to get it. You can't dial if you don't have dial tone is the received yet untrue wisdom. The system would interpret each "rattle" as another call attempt and would try to assign dialling tone and an MF decoder.
The other thing these brave SX 2000s would do is allocate a 1 way speech path. A two-way speech path seems to be a minimum requirement for most if not all phone calls, which otherwise comprise both parties saying "hello?" a few times and then clearing down. I'm still getting calls with one way speech in my current job.
It's interesting to see the results of the system trying to understand the tones it is 'hearing' it really isn't very good at it. What I hear as a slight 'blip' in one network's ring tone (I think it's O2) the computer obviously hears as the ring tone stopping, so it serves up the next page ready for an answered call to be logged/coded, even though ring tone is continuing.
Of course these tones were originally intended for human ears/brains and with the legacy public switched telephone network holding out this kind of lumpy system will continue.
In the old analogue days the phone system worked by setting up a metallic speech path from caller to called party. The callers exchange (IIRC) would send ringing current down this path to the called party's phone toring the bell, and the called party's exchange would put ring tone back the other way.
With digital exchanges this protocol changed. No speech path would be set up until the called party answered. The calling exchange would, as it were, tell the called exchange to ring out the number and let the calling exchange know when and if it had been answered. [And here is some irony. I spend a lot of time listening to ring tone and voicemail outogoing messages, where the obvious thing to do would be only to connect the call to me once it has been answered. This is doable, but how accurately I don't know. given the need for automatic 'listening' to tones.]
Dialling tone is another matter. It was first provided as part of connecting the caller to the switching apparatus, but as technology developed it was only really there for backwards compatability. I worked in internal voice (Mitel SX 2000s mainly) in the 1980s and I knew that the system could assign an MF decoder (to hear what digits were being keyed in) even if it couldn't lay on dial tone. But such was the folk memory of how to use phones that my colleagues upon not hearing dial tone would rattle the switch hook to try to get it. You can't dial if you don't have dial tone is the received yet untrue wisdom. The system would interpret each "rattle" as another call attempt and would try to assign dialling tone and an MF decoder.
The other thing these brave SX 2000s would do is allocate a 1 way speech path. A two-way speech path seems to be a minimum requirement for most if not all phone calls, which otherwise comprise both parties saying "hello?" a few times and then clearing down. I'm still getting calls with one way speech in my current job.
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