If you do the math, 4.6gb over 6 hours:
4823449.6kb / 21600 seconds = 223kb/sec
4.6gb x 4 x 30 days = 552gb per month
That would be about half your allocated bandwidth as a Comcast customer.
But since we're being optimistic, I was thinking that it was downloading updates to keep it and your network safe. But that's upload.
Okay, my last guess would be it's using spare compute and sending up calculations to determine if there is life.
I give up.
For what it's worth, it was basically saturating my upload (which is about 2mbit—I was approximating—so ~200kb/sec).
I had a friend suggest compute too. But considering the board and chip cost $10, I can't imagine what it could compute with its tiny, tiny ARM CPU :-)
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