yt-dlp with MultiWAN

[doctorm]

I've been toying with a dual WAN configuration and was surprised when I tried a yt-dlp download with --live-from-start. Although lots of individual segments are download and merged, I was surprised that they all passed through the same WAN.

Don't know if it's just my setup or the way yt-dlp was written. Since current and past segments are downloaded individually, is it possible to take full advantage of the extra bandwidth?

[doctorm]

Just to follow this up, yt-dlp has the switch --concurrent-fragments (-N). Default is 1, but you can select how many fragments to download simultaneously.
It works in theory, but I can't get it to use both WANs, it just does multiple fragments across the same one. It doesn't works as well as I'd like.

[Karoolus]

I think a lot dependa on how your dual-WAN is setup. Do you have two breakouts? Are they load balancing? Is one a failover for the other?

Try running

curl ifconfig.io

in a loop and see if it actually switches the WAN gateways.

[Quint]

Maybe the load balancing works in a way that the line is selected (maybe amongst other criteria) by file size, or maybe the load balancing even happens ONLY for bigger files at all... And ALL chunks are relatively small single files...

[Karoolus]

Exactly, it all depends on how it was setup initially and the configuration

[doctorm]

I'm using OpenWRT's mwan3 setup on my router to load balance two ISPs. Beyond that, I dunno much.

@Karoolus - How does someone run curl? Sounds linux-y.

[ElCap]

https://openwrt.org/docs/guide-user/network/wan/multiwan/mwan3#how_mwan3_load-balancing_works

How mwan3 load-balancing works
- mwan3 uses normal Linux policy routing to balance outgoing traffic over multiple WAN connections
- Linux outgoing network traffic load-balancing is performed on a per-IP connection basis -- it is not channel-bonding, where a single connection (e.g. a single download) will use multiple WAN connections simultaneously
- As such load-balancing will help speed multiple separate downloads or traffic generated from a group of source PCs all accessing different sites but it will not speed up a single download from one PC (unless the download is spread across multiple IP streams such as by using a download manager)

it sounds like it wont work for load sharing the one yt-dlp command over multiple WANs - even with --concurrent-fragments enabled.

how fast are your WAN connections?

If you have version 1803 or later of Windows 10, curl is installed by default.

open up a cmd prompt and run the curl command multiple times and see if the external ip address response changes
(but if the above mwan3 info is true, it will only return the same external ip address each time)

[doctorm]

Rebooted router, access point router and modems and now it works fine.

It's strange since failover worked fine. Different devices used different wans, but I couldn't get single programs to use more than one wan on my PC.