Can't play games online while uploading

[dec1992]

Hopefully somebody can help me with this, I know very little about internet stuff!

Basically whenever I am uploading something to YouTube or streaming on twitch, no other devices on my internet are able to play multiplayer online games (not even basic phone games)

Let me know if there's any information I need to add, I'm on Vodafone broadband using the router they gave me and it doesn't seem to matter whether I'm using WiFi or Ethernet straight into the router.

[BandOfBrothers]

Can you see what your download speeds are ?

Ookla Speedtest.net is a good speed checker and then post a screenshot of your results so we can see what your achieving.

🌈 Stay Safe  🌈 

[dec1992]

Thanks for the reply, I've tested it a few times and get between 25-30mbps down and 7-10mbps upload

[Anonymous]

There are reasons to do with handshakes that can cause downloads to be affected by uploads, though commonly it's more noticeable the other way around.  In any case, while it can substantially slow things down it shouldn't normally make things unplayable.

The key here is probably once again it shouldn't be that bad, but if you are using the VF supplied router, then I have no doubt that it is that bad.  There are a few issues that keep showing up on these boards that kind of suggests the router firmware has somewhere been borked.

[dec1992]

Yeah, it hasn't been a case of it being crap performance, I literally get a connection error on all of my other devices if something is uploading

[TJ]

Hey @dec1992 - that certainly doesn't sound right and we'd need to take a closer look into your account to help figure out what's causing the connection issues. Your router should be perfectly capable of preforming both tasks, so it may need replacing. 

We'll need to access your account to help get you up and running - please contact our team via Facebook, or get in touch on Twitter. You can find more information on doing this here.

[Alex882 · Accepted solution]

This is a well known problem on asymmetric lines. The TCP protocol uses ACK packets to let the sender know the data has been received. If ACK packets are not received in a timely manner, the connection stalls. When you are uploading and downloading at the same time, your ACK packets have to share the limited upload bandwidth with the data you are uploading. A good router will prioritise ACK packets over ordinary data packets, so your ACK packets will be sent without delay. Cheap routers don't do that - they queue everything first-in-first-out and there lies the problem. The ACK packets have to wait for everything else that has come before and buffered to be sent first, thus causing the download to slow down or even stop (connection timeout).

The best solution is to upgrade your router. Failing that, you can artificially restrict the bandwidth used by your upload process, e.g. see https://thegeekpage.com/limit-your-upload-speed-in-google-chrome/  on how it is done on Google Chrome.

[dec1992]

Seems like upgrading my router is the best option, I k is nothing about them though. Is there something I need to be looking for when choosing?

[Alex882]

Look for Quality of Service (QoS) support and ACK prioritisation. Routers running the dd-wrt or tomato open firmwares will certainly have the feature:

https://wiki.dd-wrt.com/wiki/index.php/Quality_of_Service 

https://learntomato.flashrouters.com/setup-quality-service-qos-rules-tomato-firmware/ 

Some if not all Asus routers support it and I am sure there are many others too:

https://www.asus.com/uk/support/FAQ/1010951/