On Thu, 04 Jun 2015 10:32:58 -0400, micky
wrote:

If I can call in and out and the mother can call in and out,
why can't we call each other?

Venues like Madison Square Garden can go through periods of hardly
anyone using a cell phone followed by periods with hundreds or even
thousands of calls. Cell sites and interconnecting system can and do
get overloaded. All sorts of strange things can happen including
calls just being dumped or sent to voicemail for no reason apparent to
the user. I can imagine 90% of those graduating students texting,
calling relatives, and calling each other before during and after the
ceremony.

Pat