If your router’s cpu is locked 100% because of an upload it can’t handle additional download, probably. This could be improved with a more powerful cpu or a more efficient process of sorting out up- and downloads. At least that’s what I got from the original comment. I’m not a networking expert (far from it) so take this with a big grain of salt.
Comment on oh no
andrewrgross@slrpnk.net 3 weeks agoDoes uploading slow down downloading? I thought the two processes were totally decoupled. How does this work?
dabaldeagul@feddit.nl 3 weeks ago
Natanael@infosec.pub 3 weeks ago
On the ISP end sometimes non symmetrical equipment is used, especially on copper coaxial which are used much like “wired wifi” in that data is transported by encoding it into frequency bands. Each frequency band can only be used up OR down per cable, so ISPs tend to dedicate more frequency bands to the downlink than to the uplink.
And as others mentioned, the commonly used TCP protocol will slowly ramp up bandwidth by having the server send a burst of packets, the client acknowledges, then the server sends more packets faster and the client acknowledges again, and once the client and server starts noticing packet losses it backs down and resend the lost packets a bit slower, until the connection bandwidth is stable.
BorgDrone@feddit.nl 3 weeks ago
Yes, it can slow down downloading.
(The explanation below is simplified quite a bit)
When you download the server that is sending you the file doesn’t just dump all the data onto the network in one go. They don’t know how fast you can receive and it’s not like the routers along the way will buffer large amounts of data. It needs to figure out how fast it can send.
So how does it do this? The sender sends a few packets of data and then waits for the receiver to acknowledge reception before it sends more data. Now the acknowledgment message isn’t that big so when downloading the amount of data sent back (uploaded) is just a tiny fraction of the amount downloaded, so that usually doesn’t matter.
The problem occurs when your local network is much faster than your internet upload and your router isn’t smart about which packets to send first. A good router will not allocate all the spots in the outgoing queue to the connection doing the large upload and instead will make sure the connection with smaller amounts of outgoing data will get a fair turn.
If your router isn’t smart like that the ‘data received, please send more’ packets may be delayed and thus slow down the download.