ISP
Short for Internet Service Provider. Provides internet access to the users 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.