I recall a lot of my peers hosting mail and web servers
I don’t think that’s representative of the global population. There’s more people streaming movies than hosting private blogs.
Comment on ISPs seem designed to funnel people to capitalist cloud services
hobbsc@lemmy.sdf.org 4 weeks agois that because asymmetry is the norm due to these ISPs’ practices or because people just don’t upload things often as a common behavior?
i recall a lot of my peers hosting mail and web servers among other things when broadband started to become more common, before they started blocking common ports as “security” and “antivirus” measures designed to extract more money from you.
milicent_bystandr@lemm.ee 4 weeks ago
greyfox@lemmy.world 4 weeks ago
For shared lines like cable and wireless it is often asymmetrical so that everyone gets better speeds, not so they can hold you back.
For wireless service providers for instance let’s say you have 20 customers on a single access point. Like a walkie-talkie you can’t both transmit and receive at the same time, and no two customers can be transmitting at the same time either.
So to get around this problem TDMA (time division multiple access) is used. Basically time is split into slices and each user is given a certain percentage of those slices.
Since the AP is transmitting to everyone it usually gets the bulk of the slices like 60+%. This is the shared download speed for everyone in the network.
Most users don’t really upload much so giving the user radios equal slices to the AP would be a massive waste of air time, and since there are 20 customers on this theoretical AP every 1mbit cut off of each users upload speed is 20mbit added to the total download capability for anyone downloading on that AP.
So let’s say we have APs/clients capable of 1000mbit. With 20 users and 1AP if we wanted symmetrical speeds we need 40 equal slots, 20 slots on the AP one for each user to download and 1 slot for each user to upload back. Every user gets 25mbit download and 25mbit upload.
Contrast that to asymmetrical. Let’s say we do a 80/20 AP/client airtime split. We end up with 800mbit shared amongst everyone and 10mbit upload per user. Realistically 10mbit upload is more than the average user will need and we gained %33 more download speed which users do need.
In the worst case scenario every user is downloading at the same time meaning you get about 40mbit of that 800, still quite the improvement over 25mbit and if some of those people aren’t home or aren’t active at the time that means that much more for those who are active.
I think the size of the slices is a little more dynamic on more modern systems where AP adjusts the user radios slices on the fly so that idle clients don’t have a bunch of dead air but they still need to have a little time allocated to them for when data does start to flow.
A quick Google seems to show that DOCSIS cable modems use TDMA as well so this all likely applies to cable users as well.