[p1mrx]

> I wonder how many customers can realistically hide behind a single IPv4 (CGNAT), given that there are 65535 TCP/UDP ports.

In theory, one IPv4 address can maintain 65535 connections with every HTTPS server (TCP port 443) on the Internet simultaneously. The main cause of port depletion would be when lots of users connect to the same server.

A reasonable number is 1000 users with 64 ports each, but you could probably squeeze in another 10X.

[MayeulC]

Ah, right, the mapping can be per server IP, thanks for pointing this out.

If Facebook started throwing persistent connections left and right, it imagine it could cause a problem, but short of that, it should be fine.