I've gotten a report from a couple of our field techs we're seeing an issue where apparently older residential call boxes (not ancient ones, some only 4 or 5 years old), appear to no longer be able to process the button press to let people in from cell phone users. One of the products is from Linear, and according to them the recent upgrades by cell phone carriers means the button tone, DTMF, is no longer being passed through.
With Linear it sucks because apparently they don't have a module to do any conversion to be compatible with the carrier upgrades, instead the just want you to buy the newer call boxes.
****** **** *** **** ****, ** know ** *** ************* ********** ******* on *** ******?
**** ***** *** ********** ** ******* sending ***** ***** ******* *** ******* tones ******* *** ** **** ********* (i.e. ***** * *** **** *******)?