Cable Access Network

ISP

Short for Internet Service Provider. Provides access to the internet through cable networks.

CMTS

Short for Cable Modem Termination System. Main device at ISP side. Handles downstream and upstream traffic.

Downstream

Signals transmitted from the ISP to the user’s device. Multiple 40Mbps broadcast channels. Data, TV, control signals are sent at different frequencies.

Upstream

Signals transmitted from the user’s device to the ISP. Multiple 30Mbps shared channels. Users must share the data channel, managed by time slots. Collisions are possible.

Cable Modem

Device at user side. Handles downstream and upstream traffic. Filters downstream broadcast and sends them to the user’s device. Sends upstream traffic in the assigned time slots and frequency.

Connected via a splitter, which splits the internet and TV.