[nandhp]

This is an amazing article; I expect I'll get a lot out of it next time I have to debug a Cable modem problem.

> Some cable modems (often based on the Broadcom chipset) expose a 'Spectrum Analyzer' interface on port 8080.

I had no idea this was a thing, but it turns out to exist on the SB6183 (http://192.168.100.1:8080/), though doesn't support Firefox for some reason.

[icelancer]

Huh. On my SB8200 this interface is up but doesn't send any data (Chrome normal and incognito).

[bscphil]

If it's like my SB8600 model you can access the spectrum analyzer as a tab in the main interface, no need for a separate port.

[coretx]

Pssshst... That model supports custom firmware...