bendsley

Actually, the DOCSIS framework allows cable companies to monitor anything on the cable modem they want to. The are also able to monitor bandwidth from specific IP addresses via MAC address.

When a cable modem comes online, it talks to a Universal Broadband Router (UBR) and the UBR tells the modem to download a certain file from a server. The first process involves getting this information. The config file is stored on a TFTP Server. Once your modem downloads this config, it processes it and if the CMTS (Cable Modem Termination System) is successful, your modem will become online.

Anyone who tells you that your ISP cannot track your bandwidth is lying.

As for DSL, this usually is detected right at the DSLAM, where the DSL lines come together before heading to the main CO.

DSLAM: A digital subscriber line access multiplexer (DSLAM) delivers exceptionally high-speed data transmission over existing copper telephone lines. A DSLAM separates the voice-frequency signals from the high-speed data traffic and controls and routes digital subscriber line (xDSL) traffic between the subscriber's end-user equipment (router, modem, or network interface card [NIC]) and the network service provider's network.

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