I called the number of a restaurant from within side the restaurant from my Verizon-based cel phone. It was to play a joke on a friend who worked there but ended up stumbling upon an odd happenstance. The restaurant phone rang, but I never heard the "ring" on my cel phone, I couldn't hear their voice, they couldn't hear me. Tried it several times.
Called the same number with the same cel phone from a different location a distance from the restaurant and the above symptoms vanished. Heard it ring, they heard me, I heard them.
I encountered something like this once before, a friend in a different city called my land line from his cel - my phone rang but neither of us could hear the other. Yet, I could call his cel from my land line with no problem.
So what caused this? It also gave me cause for concern, wondering if this same phenomenon could prevent you from reaching emergency services from a cel phone.
The restaurant was a standard telephone, right (i.e., not a cell phone) -- connected to the public switched telephone network (PTSN)? Most likely, a trunk was down at the serving cell site (the site you used when you called from the restaurant). Note: This may or may not have anything to do with the supervisory ring tones you usually hear on your end (of called phone ringing), but it probably is related to a busted trunk line.
Move to a different location, different serving cell, and obviously you'll get a different trunk, and in your case, one that worked. The sitaution you describe has nothing to do with your proximity to the called destination. If you had been patient long enough, you might have even eventually got a trunk that worked at the cell nearest the restaurant. But, it's possible a whole bunch of them were out (typical, when they break), or you kept getting the same one all the time.
Likewise, you could have experienced the reverse of the whole situation: i.e., Calls not going through away from restaurant (cell B), but working at restaurant (cell A) with cell A actually serving the restaurant. And actually it doesn't really matter where you are or who you are calling. If the trunk is busted, the call processing may not function correctly. The phone could ring, but no audio. Any maybe no supervisory audio either. (Note: Often, the called phone won't even ring - it depends on the nature of the problem with the PTSN.) Hope this makes sense to you.
I've simplified the discussion tremendously, to avoid fiber-to-T1, packet switching, and a host of other issues you'll encounter at a typical cell site. The takeaway is the cell site was talking to the PTSN, which wasn't actually completing the call properly. The cell site didn't know it. That's why your call went through, instead of automatically dropping.
The restaurant might have had a cell phone damping field, so the obnoxious cell phone addicts don't disturb the other customers' peaceful dining experience.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.