In-band signaling

In-band signaling is kind of like the secret codes that friends use to talk to each other without anyone else understanding. When people talk on the phone, the sounds that they make are sent through something called a phone line. But sometimes, instead of just talking normally, they might press certain buttons on their phone or make specific sounds, which is called in-band signaling.

These special sounds and buttons tell the phone system to do different things. For example, if you press the numbers 9-1-1 on your phone, it tells the phone system to call the emergency services like the police or an ambulance. Or if you hear a certain sound when you're on a call, it might mean that the other person wants you to hang up.

In-band signaling can be very helpful because it allows people to access different services or features on their phone simply by pressing a few buttons or making specific sounds. But it's important to use in-band signaling with care and only for its intended purposes, to ensure that the phone system works properly and everyone stays safe.