Home Networking

11 readers

1 users here now

A community to help people learn, install, set up or troubleshoot their home network equipment and solutions.

Rules

Please stay on topic.
Please use the search function to look for keywords related to what you want to ask before posting since most common issues have been answered.
No Ads. This community is for support and discussion. Ads and self promotion are not welcome here.
No product reviews or announcements. If you have a question about a product, be specific about what you want to know.
Be civil. Don't be a jerk. Not being a jerk is surprisingly easy.
No URL shorteners. URL shorteners tend to hide the real use of a link. For this reason, please use normal links, even if they're long.
No affiliate links.
No gatekeeping. With profession shall come professionalism. Extend help without judging others for their ignorance. The same goes for downvoting of comments or posts for "stupid questions" or not being as knowledgeable as others.

founded 1 year ago

MODERATORS

communick@selfhosted.forum

rglullis@communick.news

How the f*ck does a modem work? (alien.top)

submitted 11 months ago by EgoPoweredDreams@alien.top to c/homenetworking@selfhosted.forum

25 comments fedilink hide all child comments

Google searches have only yielded 5th grade level examples (“the modem talks between your ISP and your home network!”) or articles I would need a degree to understand. Can anyone provide an explanation that’s somewhere in between the two? I understand the fundamentals of how the Internet works, and how LAN works regarding a router and individual devices, but I’m curious to know more about the link between those.

you are viewing a single comment's thread
view the rest of the comments

[–] LRS_David@alien.top 2 points 11 months ago

As others have noted a modem is a modulator / demodulator.

Most modems are designed into other things. Like cable coax modem/router/switch/wi-fi access point. Or other things. Or in a cell phone it converts bits internal to the phone into radio signals or back the other way. Many things people call a modem is really a more complicated box with a modem built into it.

In the basic definition of the term it is bits <-> analog wave forms. Back in the day it was land line modems and the wave forms could be heard by most people if they listened "in". Actual FAX machines (not email pretending to be a FAX) still do this. Connected to the "bits" side of a modem is usually a circuit that takes those bits and organizes them in agreement with the other end of the connection. Mostly these days Ethernet.

Most Fiber setups do NOT have a modem as they have networking bits already in the light in the fiber. They do "media conversion" between fiber and copper.

And if you want to dig deeper look into how DSP (Digital Signal Processing) works, Fourier Transforms, and how Wi-Fi radios encode things, and so on.