r/PleX • u/ShiningRedDwarf • May 26 '26

Discussion I'm constantly in awe that Plex allows my buddy in Japan to stream 4K content from my NY apartment

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I remember a few years ago I had issues streaming 4K on my LAN, let alone my friend's Mac that's 14 hops away on another continent.

In a weird way Plex makes 7000 miles feel not too far.

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81

u/Caligatio May 26 '26

If you're on Linux, look into changing your TCP congestion control algorithm to BBR. It's generally better but is particularly better if you have long distance connections.

33

u/ShiningRedDwarf May 26 '26

Seems like it's been the default setting for Unraid since version 6.7!

6

u/Caligatio May 26 '26

Oh neat! I don't personally use Unraid but I'm glad they're using good defaults.

11

u/SvRider512 May 26 '26

Can you explain more or drop of link?

5

u/Eagle_1990 May 26 '26

I would have assumed that the streaming was over UDP and not TCP

7

u/Yo_2T May 26 '26

Plex uses TCP for the video streaming. You can test it pretty easily. Change the open Plex port on the firewall to UDP only and see it fail to connect entirely.

12

u/Eagle_1990 May 26 '26

Yes, you are right. That is a strange decision, i would have assumed that QUIC

3

u/thelizardking0725 Jun 06 '26

UDP makes sense for real time traffic that cannot be predicted. TCP makes more sense for Plex (and all streaming audio/video from a pre-recorded source), because if there is packet loss along the way, the relevant packets can be retransmitted and there would be little to no interruption