Unable to hear the person's phone ringing on outgoing calls

The “sidetone” ring that you hear when making a call is actually provided by the carrier for the number you are calling, so if you don’t hear it they are not providing it; this has nothing to do with the iPhone itself. I’ve tried calling a variety of different numbers, and some I hear the sidetone and others I don’t. Generally, calling another person I hear it ringing, but calling a business I don’t.