> Those 2 asymmetries are A) clients have lower bandwidth than servers and B) IPv4 address exhaustion and the need/insistence on NAT. There's a third asymmetry

> Those 2 asymmetries are A) clients have lower bandwidth than servers and B) IPv4 address exhaustion and the need/insistence on NAT. There's a third asymmetry: C) power-constrained clients which are asleep most of the time. And this applies not only to battery-powered phones/tablets and laptops, but also to modern desktops which are configured by default to suspend on inactivity.