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#21 ThoughtPhreaker

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Posted 01 April 2013 - 02:48 PM

That's interesting, have you tried asking the operator what the word is? In ex-Embarq territory, it's not special, it's "visually handicapped" or something just as politically correct sounding. The way I do it is to say something like "Hi, I just moved here from Verizon territory, and when a blind person needs help dialing a number, they tell the operator they're special. Is there a word like that here we can use to get help making a call?"

 

That being said, I do make my way to the ex-GTE part of Frontier territory pretty frequently, and 'special' most certainly is the word they use.



#22 skywanter

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Posted 02 April 2013 - 01:39 PM

I just asked the operator and she said I'd have to call the disability office to get a tag put on my line, which I then did. The lady I spoke to was gonna send some forms to my house for me to fill out which I'd imagine require me to provide some documentation proving my 'disability' so I just told her to not bother.   :'(



#23 ThoughtPhreaker

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Posted 03 April 2013 - 02:03 AM

It sounds like they're pretty serious about this then. Geez, lighten up, AT&T!



#24 Partyline4

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Posted 10 April 2013 - 12:16 AM

Something interesting that I noticed:

Many people today use these 2.4ghz digital phone systems with electret mics and such, right?


I, however, use the old style model 500's and noticed that a yelp, at a certain pitch, causes a break in the line. 

This is the in-band signaling still used on the POTS local lines.  A recorded sound file of your phone number played into the microphone will cause the line to actually dial out!

This does not work for these digital phones, at least for my experience.

I just wanted to post this because I figured it out myself. I'm sure many of you have know this for decades. 

So if long distance was switched, why did they leave the local calling with in band? 



#25 systems_glitch

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Posted 10 April 2013 - 10:51 AM

So if long distance was switched, why did they leave the local calling with in band? 

 

I would suspect this is to allow legacy hardware to continue functioning. Plus, there's little harm you can do in sending IBS that was intended to originate from the customer's equipment.

 

Presumably wireless handsets for cordless phones don't send DTMF to the base station, but rather some sort of signalling that gets the base station to generate DTMF. I'm sure it's integrated in modern cordless base stations, but I remember scavenging DTMF generator ICs from old ones!



#26 ThoughtPhreaker

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Posted 11 April 2013 - 05:26 AM

This is the in-band signaling still used on the POTS local lines.  A recorded sound file of your phone number played into the microphone will cause the line to actually dial out!

This does not work for these digital phones, at least for my experience.

 

It could be the mic in the phone. I remember trying this with a cordless phone way back and having trouble. Some cordless phones also use really obnoxious processing such as compression and a noise gate. If the volume of your touchtones are low and your phone has some degree of gating or downward expansion, it could be suppressing it. The codec digital cordless phones use back to the base (g.726 in most cases) should be more then capable of transporting touchtones.

 

As systems_glitch mentioned, this isn't new, though; the base generally transmits touchtones for you. If you're listening to the line itself, you can hear analog cordless phones make some strange data noise as they send touchtones or flash and whatnot.

 

So if long distance was switched, why did they leave the local calling with in band?

I'm not sure I understand your question, but local interoffice signalling is all done out of band with SS7. For the sake of redundancy, though, most offices are equipped with a couple trunks back to the access tandem that accept MF.

 

If you're talking about local dialing, part of the reason is probably because ISDN never caught on. Especially considering we need touchtones for things like IVRs anyway, I guess the answer was "why not?" No need to fix something that works.



#27 systems_glitch

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Posted 11 April 2013 - 08:14 AM

 

I guess the answer was "why not?" No need to fix something that works.

 

Indeed, it's a very robust system! It's hard to run into a situation where DTMF signaling becomes a limitation for dialing.






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