Do modems have public address? [closed]
No, per definition. The Modem is classically NOT PART OF THE IP SPACE. It is a modulator/demodulator working on some lower level transforming a bitstream into a wire level format.
Whatever is behind a modem will be assigned the IP address. If the modem also works as router, then it obviously get an IP Address + does NAT (normally) for the home, but it is not the "modem" part that gets the IP address, but the router functionality.
As example, say voice recording. You basically ask "does the microphone do recording" - no, it translates audio into electrical signals, the recording happens behind. The recorder does not know how the recording is done, all it sees is the incoming line.
A modem is a device that convert digital signal to an analog signal. It doesn't have an IP. If you have a xDSL line, on your end, you likely have
- A modem, converting the analog signal transmitted over the DSL line to something digital (binary data)
- A router, a device that forward IP packets between your internal network and the provider network. This device has an IP.
The modem function and router function, can be on the same device.
In a SOHO environnement, the router will likely hide your internal private IP network by a public IP that is hosted on the router.