Definition given by Wikipedia:

A modulator-demodulator, commonly referred to as a modem, is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more carrier wave signals to encode digital information, while the receiver demodulates the signal to recreate the original digital information.

So fiber optics are not analog, but then again, neither are modern phone lines that use VoIP. No analog (as in analogous to sound waves) signal goes over them, both ends are permanently connected to modems. Yet it’s still called a modem.

I think that turning a laser on and off can technically be described as modulating a carrier wave, so that part of the definition fits.

The ONT is fulfilling the same function as a modem, except the medium is a fiber optic cable instead of a copper one, so that makes me want to call it a modem by analogy. An electric burner doesn’t burn anything either.

Thoughts?

  • trompete [he/him]@hexbear.netOP
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    1 month ago

    It used to be FTTB (DSL from there), only installed a couple of years ago, but recently they ran fiber into all the apartments. There’s a new thin plastic cabinet, about 40x40 cm, in the bike cellar (server room lol) with a laser warning sign on it. All done in cooperation with the ISP it seems. In fact the landlord seemed utterly uninvolved.

    Also why would it be called a modem in one situation, but not the other? Like what’s the difference here.

    • invalidusernamelol [he/him]@hexbear.net
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      1 month ago

      ONTs generally do less work than modems from my understanding. I deal primarily with PON so to me it’s all physical fusion splices. We have done some work with older Coax networks, and those have a lot more active mux/demux equipment (as well as powered signal repeaters, which don’t really exist on a PON) all over the place to cram as much bandwidth as possible into a single copper cable. That’s not really a problem with fiber until you hit an OLT cabinet.

      I would also like to add that the terminology in telecom is absolutely insane. It’s up there with the oil industry when it comes to acronyms and multiple names for the same thing. We also frequently use “Transmedia” to refer to the cables and we call enclosures “closures”.