I create this for the bug on Bugzilla ([1234438] (https://bugzilla.mozilla.org/show_bug.cgi?id=1234438)).
The scenario is that if the patient who is in emergency, she/he just need to click the button on the device, it would call her/his doctor or family. To reach the requirement, I want to implement WebRTC to communicate among patients, doctors and maybe nurses. I decide to use id number to recognize everyone who uses this app. The id number just like the telephone number. So, if the patient want to call his doctor, she/he just call his doctor's id number. Actuall, I don't want the patients have to dial the number because dial may be a big problem for the elderly. I hope they just click the button, and I would automatically dial to her/his doctor(s).