I've always wondered whether network interfaces that have these flashing lights flash as a gimmick or do they actually indicate the flow of traffic? Perhaps one flash per packet in or out? I wish I could remember what my call up modem looked like to make a historical comparison too.
TL-SG105E
An Ethernet frame's payload can't exceed 1500 bytes without using jumbo frames. So every internet routable packet is actually less than or equal to 1.5kB.