I have had this problem for a couple of months now and first suspected my ISP as the culprit (which turned out not to be true):
All remote users, regardless of client, version, media type and client/server settings, experience massive buffering. If a client is set to auto-convert, it stabilizes at around 2 mbit SD quality. Anything above that is problematic.
Things I have ruled out as being the culprit:
Server CPU, hardware transcoding (all good)
Internet uplink (40 mbit upstream, zero packet loss, clients on same ISP)
local network setup (even attached server directly to cable modem to bypass any firewalls, NAT etc.)
Noteworthy:
This happens regardless of server version (has been going on for months with multiple updates), client device type and media type (all video files, regardless of format and size have the issue, no exception).
This only happens on remote connections. On the local LAN, everything works fine (direct play, transcoding, etc.).
I am not sure what else to look for, other than suspecting an issue with Plex itself. Note that remote streaming worked perfectly before, without any changes in my setup (other than upgrading Plex versions). It started out of the blue.
Remote Access: Regularly check that the green “fully accessible” light remains on. For best results, in your router, turn off UPnP and manually forward the Plex port (32400).
Upload Bandwidth: If your router does not support Quality of Service (QoS), ensure all upload-heavy services are paused eg., torrent clients.
Disk Speed: Prefer internal instead of external HDDs for faster transfer speeds to better support multiple streams simultaneously.
Client Side:
Client App: At time of writing, there is still a bug on Plex for Mac that makes direct play/stream buffer constantly and also requires higher bitrates for each session. Use Plex HTPC for PCs.
Remote Quality: Ensure each user caps their remote quality to be slightly under your ISP’s upload limit or their own download limit, whichever is lower.
Force a Transcode: If direct play still fails after all the above, ask users to set playback quality one level below “original.” This forces a transcode which seems to smooth out any hiccups in the stream like bitrate spikes.
All of this has already been checked, to no avail. My server is very powerful, I have 10 Gbit Ethernet at home, the NAS uses a 16 disk Raid array and as such, is very fast, upload bandwidth is available plentiful, and as mentioned, this happens regardless of client settings (force transcode, direct stream, direct play, capped BW etc. pp - makes no difference). Remote port is always green, and it doesn’t work even if I connect the server straight to the internet (modem - no router, no NAT, no firewall).
I’ve had huge buffering issues with Plex web app and now avoid it at all costs.
Those other clients you’re testing are pretty reliable normally. Presume they’ve all been updated with latest versions?
I can’t offer much more other than to say at least you’ve isolated that the issue is not in your local network. You’ll have to keep ruling out which houses it happens in, times of day, speed check your friends connections etc.
I had an issue where a friend thought he had a 50mbps ISP plan but it would randomly drop to 4mbps. We didn’t realize it was dropping until we ran live speed tests and lowered remote quality to match. The fact you said stabilizes at 2mbps made me think of this.
Yep, as @ChuckPa mentioned, we did some troubleshooting together and the issue is clearly on my ISP’s side. Thanks everyone for chiming in. And thanks Chuck for the joint troubleshooting session. If you ever come to Europe/Germany, hit me up for a couple of cold beers
When I next come to Germany, I have a list of “to do” which includes much more than a few Biers. There are certain foods which I cannot get here – and I miss them dearly. (Rippchen mit Kraut und Kartoffeln being top of the list – haha)
@cryptochrome do you mind sharing the ISP either here or in a direct message? I have a similar issue with one remote location and I have a hard time tracking it down… It looks like playing files in original quality always buffers, but automatic quality may settle on something like 10 MBit/s.
