Since I am an adjunct with only a cell phone, when I call a student, they learn my home phone.
Of the sixty calls that I have made to students, I have never encountered a problem with a student who knows my home phone number.
I do resolve most issues by email.
We have live chats available in our LMS but we do not have efficient two way audio. I use the live chat to show a visual and talk concurrently by phone.
