When you call someone, they are supposed to say "hello" or a greeting?

[Nicolette12764m]

I was calling my friend and he answered because my phone said so and he said nothing. I hung up on him! And when I conforted him about it in text, he said he was saying hello in silence. I tried calling again to see what he would do and he figured he would answer but hung up on me, because he said I didn't answer when I called??? He first of all should have said something the first and second time. And I'm mad at that and he thinks it no big deal and I think he is being dum. Who is right or wrong? No trolls, thanks!!!
I said a greeting not greeting.

As in he could have said hey or hi.

I know lol, but thanks for the answer.
Thanks Samantha!!!