Notes from bench-testing the Quectel RM500U-EA on tower, bought to
eventually replace stream's Virgin Media WAN. Like the switches and
APs, the module is configured out-of-band and is not referenced by
the flake.
Records what it takes to connect at all: the module must be switched
from its stock NCM composition to MBIM, since under NCM the PDP
context activates but the cdc_ncm link never raises carrier; and the
connect only succeeds with the network-expanded APN read off the
default-attach bearer, as IPv4.
Also flags the two consequences for stream: the SIM is CGNAT so it
cannot carry the public lease stream's WAN currently publishes, and
the bearer reports a /8 that would cover Tailscale's 100.64.0.0/10
if configured literally.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
jackos1998