You say that the static files being served are not of a big size
. The smaller they are, the more you'll be worried about packets per second instead of overall bandwidth on the network.
As with bandwidth, AWS doesn't publish any concrete numbers, only "Low", "Moderate", "High", etc. I ran into some problems with PPS limitations, and it was even less published than bandwidth numbers, so I ran some tests.
Here's what I found for various instance sizes:
t1.micro 8,473
t2.nano 9,807
t2.micro 19,391
t2.small 28,296
t2.medium 47,214
t2.large 49,512
c1.medium 110,575
m3.large 142,839
m1.large 157,557
m4.large 222,280
c4.large 233,450
r3.large 412,315
c3.large 475,996
i3.large 529,558
r4.large 544,981
c5.large 823,806
There was a lot more that I found, too, around guaranteed throughput and best effort PPS (packets per second). I put it into a blog on monitoring packets per second on EC2 where I show graphs and tables better than I can show in a comment.
To tie it back to Amazon's Network Performance Designation ("Low", "Moderate", "High"), you'd probably be shocked to know there's little correlation between actual bandwidth and actual PPS to those designations. They are worthless - only rely on test results, not published categories from AWS.