Network DL Traffic Causing Kodi Buffering?

[newoski]

Hi Guys,

I'm experiencing heavy Kodi buffering -- but only when I have heavy download activity occurring on my network (other computers, not via my Unraid server). I'm not sure what to make of this. I'm on a gigabit network. I'm currently downloading from Google Drive, via rclone, at about 60MB/s on one computer. My Odroid N2 running COREELEC buffers consistently while these transfers are active. The second I kill the download, the buffering stops. 

I'm confused... Could someone help me understand how these two are related and what I can do to solve?

(No logs attached, as this is really a larger network/Unraid question vs a Tower optimization, but happy to provide any logs or diagnostics, if helpful)

[Frank1940]

First thing to do is to reboot everything on the physical network--- switches, router and modem.  (These things are basically small dedicated computers and sometimes suffer from things like memory leaks, etc.)  

 

Are you using a router as a switch?   You might consider employing a switch and use the router just for routing.  Any decent switch will setup a dedicated paths (running at Gb speed) between its ports so the speed between any two ports is at Gb speed regardless of the total network traffic.  (Thus, the total traffic on a 16 port switch could hit 8Gb per second.)  There should only be one cable between your router and your primary switch.  

 

Second thing.  Avoid using WiFi as much as possible.  Use it only for things that actually move.  Hard wire everything else.  (I have a Gb switch at each of my remote media setups-- mini home theaters -- so that I only have to had to run one CAT5 cable to these locations.  Since these are on separate floors in my residence, I also have a intermediary Gb switch on that floor so that I only need one cable between floors.) 

[newoski]

33 minutes ago, Frank1940 said:

First thing to do is to reboot everything on the physical network--- switches, router and modem.  (These things are basically small dedicated computers and sometimes suffer from things like memory leaks, etc.)  

 

Are you using a router as a switch?   You might consider employing a switch and use the router just for routing.  Any decent switch will setup a dedicated paths (running at Gb speed) between its ports so the speed between any two ports is at Gb speed regardless of the total network traffic.  (Thus, the total traffic on a 16 port switch could hit 8Gb per second.)  There should only be one cable between your router and your primary switch.  

 

Second thing.  Avoid using WiFi as much as possible.  Use it only for things that actually move.  Hard wire everything else.  (I have a Gb switch at each of my remote media setups-- mini home theaters -- so that I only have to had to run one CAT5 cable to these locations.  Since these are on separate floors in my residence, I also have a intermediary Gb switch on that floor so that I only need one cable between floors.) 

Hi Frank,

 

I have a Linksys EA9500, which is a beast of a router, with 8 ports. Most devices are plugged in, directly, via Cat6 to the EA9500. However, I do have a few more devices connected via a switch, GS105E. Based on the number of Cat6 cables I have run through walls, I'm going to end up with a Switch in my basement, expanding one Cat6 run into 5 more.

 

Taking into consideration my existing Router, what would the best combination of switches be to get the fastest possible connection? 

[Frank1940]

I would be looking at a 16 port switch (at least)   and plug everything into that absolutely has to have Gb speed.  (Note:  Most video streaming can get by with 100Mb speed.  I am not completely sure if this is true for 4K content as I have not even considered setting up for that yet.)  Make sure you have a few spare ports on this switch as you will probably need a few more one of these days.  That will be your primary switch.  Single CAT6 cable from the EA9000 to this primary switch.  Now connect up each secondary switch to the primary switch.  The number of ports on each secondary switch will be determine by the  number of connections required.

 

What do you get by doing this.  First, the expensive EA9500 will run much cooler.  Cooler electronics is always a good thing!  Second, you have offloaded a lot of CPU cycles to the switch, so the router will now run faster, doing the things you want the router to do.  Of course, at this point, the EA9500 will still be doing the routing for WiFi. 

 

At this point, take a deep breath.  If the number of connections is large or cable running problems present themselves, consider tertiary switches if the devices are located in a clusters.  Remember that usually by the time you get to these devices, each one will not require continuous Gb service from upstream.  Often only one device at a location will be in usage at a time.  Plus, if two devices on that tertiary switch are 'talking' to each other, the primary and secondary switches never see the traffic.

 

WiFi is a subject unto itself.  Those connection speeds that you see listed in the ads for your EA9500, all say 'up to...'!  The old adage," Your mileage may vary" is very applicable here.  What needs to be done is to minimize the traffic (this you are doing by moving as much equipment as possible to the wired network) and locate the Hub so that you have excellent RF signal strength where you need it.  Plus, the client must also provide an adequate RF signal back to the Hub.  Folks with big houses often have two or more Access Points (AP) to provide adequate coverage.  (Getting the faster 5G signals though walls is a big issue!)   If you decide to go down this route, have a look at MikroTik and/or Ubitiqui.  They provide prosumer grade access points at reasonably affordable prices.   (You will become a junior IT pro before you are finished.)

 

EDIT: Disclosure---  I know just enough about larger networking issues and solutions to make me really, really dangerous...

[newoski]

3 hours ago, Frank1940 said:

I would be looking at a 16 port switch (at least)   and plug everything into that absolutely has to have Gb speed.  (Note:  Most video streaming can get by with 100Mb speed.  I am not completely sure if this is true for 4K content as I have not even considered setting up for that yet.)  Make sure you have a few spare ports on this switch as you will probably need a few more one of these days.  That will be your primary switch.  Single CAT6 cable from the EA9000 to this primary switch.  Now connect up each secondary switch to the primary switch.  The number of ports on each secondary switch will be determine by the  number of connections required.

 

What do you get by doing this.  First, the expensive EA9500 will run much cooler.  Cooler electronics is always a good thing!  Second, you have offloaded a lot of CPU cycles to the switch, so the router will now run faster, doing the things you want the router to do.  Of course, at this point, the EA9500 will still be doing the routing for WiFi. 

 

At this point, take a deep breath.  If the number of connections is large or cable running problems present themselves, consider tertiary switches if the devices are located in a clusters.  Remember that usually by the time you get to these devices, each one will not require continuous Gb service from upstream.  Often only one device at a location will be in usage at a time.  Plus, if two devices on that tertiary switch are 'talking' to each other, the primary and secondary switches never see the traffic.

 

WiFi is a subject unto itself.  Those connection speeds that you see listed in the ads for your EA9500, all say 'up to...'!  The old adage," Your mileage may vary" is very applicable here.  What needs to be done is to minimize the traffic (this you are doing by moving as much equipment as possible to the wired network) and locate the Hub so that you have excellent RF signal strength where you need it.  Plus, the client must also provide an adequate RF signal back to the Hub.  Folks with big houses often have two or more Access Points (AP) to provide adequate coverage.  (Getting the faster 5G signals though walls is a big issue!)   If you decide to go down this route, have a look at MikroTik and/or Ubitiqui.  They provide prosumer grade access points at reasonably affordable prices.   (You will become a junior IT pro before you are finished.)

 

EDIT: Disclosure---  I know just enough about larger networking issues and solutions to make me really, really dangerous...

Sadly, upgrading to dual TL-SG108E 8 Port Gigabit switches had no impact on the buffering issue. When internet DL is high, Kodi buffers, which I still don't understand as it's internet vs LAN and the Gigabit switches aresupposed to have 16gb total bandwidth and 1GB per port...

[Frank1940]

9 hours ago, newoski said:

My Odroid N2 running COREELEC buffers consistently while these transfers are active. The second I kill the download, the buffering stops. 

I'm confused... Could someone help me understand how these two are related and what I can do to solve?

What is the source of the data for the N2?  Is the N2 connected via CAT5/6 or WiFi? What is the video resolution when buffering occurs?  (You must have really hi-speed internet to be getting 60MB/s!)

[newoski]

Cat6

Using Jellyfish test vids. 1080p. I can go to 140MB/s when not downloading. Get buffering on most nitrate test files when heavy downloading

[Frank1940]

OK.  First thing.  MB/s  is Megabytes  per second.  Mb/s  is Megabits per second.  Network speed are usually measured on Mb/s.  Transfer speed of files between hard disks is usually measured in MB/s.  The difference is a factor of approximately eight times.   I am attaching a section of the Jellyfish download catalog for info for anyone else following this thread.    From http://jell.yfish.us/

 

 

So which switches are the N2 and its source plugged into?   And which switches are the Internet connection from the router and receiving download computer?  This is important because you have two switches, the connection between the two switches is limited to 1Gb/s and the connection between the router and the switch has the same restriction. What you have set up is a primary switch and a secondary switch because you have one switch plugged into the second switch.  (You do realize that 60MB/s download is approximate 500 Mb/s on the Network.)   The connections between levels are limited to 1Gb/s --- router to primary switch, and primary switch to secondary switch.  As I said, network design is an art.   That is why I suggested  a 16 port switch so that everything is on the primary level as much as possible.  When large enterprise LAN's are being set up the intent is to minimize data transfer between switches.   (This often proves difficult, which is why so many commercial switches will use 10Gb/s fiber between switches.)  

 

 

[newoski]

16 hours ago, Frank1940 said:

OK.  First thing.  MB/s  is Megabytes  per second.  Mb/s  is Megabits per second.  Network speed are usually measured on Mb/s.  Transfer speed of files between hard disks is usually measured in MB/s.  The difference is a factor of approximately eight times.   I am attaching a section of the Jellyfish download catalog for info for anyone else following this thread.    From http://jell.yfish.us/

 

 

So which switches are the N2 and its source plugged into?   And which switches are the Internet connection from the router and receiving download computer?  This is important because you have two switches, the connection between the two switches is limited to 1Gb/s and the connection between the router and the switch has the same restriction. What you have set up is a primary switch and a secondary switch because you have one switch plugged into the second switch.  (You do realize that 60MB/s download is approximate 500 Mb/s on the Network.)   The connections between levels are limited to 1Gb/s --- router to primary switch, and primary switch to secondary switch.  As I said, network design is an art.   That is why I suggested  a 16 port switch so that everything is on the primary level as much as possible.  When large enterprise LAN's are being set up the intent is to minimize data transfer between switches.   (This often proves difficult, which is why so many commercial switches will use 10Gb/s fiber between switches.)  

 

 

While I won't pretend to know much about iperf, I ran a few tests and confirmed that when there are NOT heavy downloads, there is 900+ Mbits/sec between my Unraid server and the Kodi clients. I've also confirmed that when there is heavy downloading on the network, the iperf test results drop accordingly to about 60Mbit/sec, so clearly it is having an impact.

I've attached an image of my network. I was under the impression that using Gigabit switches would enable 1Gbit/sec across each ethernet port -- which is to say, I could have a computer pulling 900+ MBits directly from the internet, while the Kodi devices also pulled a combined total of 900+ MBits from the NAS.

Any help would be greatly, greatly appreciated!

https://i.ibb.co/ccCmBQN/Capture.png

[Frank1940]

Which computer(s) is the Internet download going to on your chart?

 

Are both of N2's buffering and does it occur at the same time.? 

 

There are firmware updates for the TL-SG108E.  Have you applied them?   (I normally do NOT like to do firmware updates on devices like switches unless I have a big problem.  But you have a problem and a firmware update could be the solution. ) 

 

Is this a continuous download that is running for hours on end?   The reason I am asking is that this is about a 100GB of data in twenty to thirty minutes.  In approximately two and half hours, you would download a TB of data.  (In the time, we have been discussing this, you should have downloaded more than 10TB of data.)

 

EDIT:  They are up to version 5 of the hardware.  What version(5) are your TL-SG108E's?

Edited October 1, 2020 by Frank1940

[newoski]

Bartop Arcade is the device downloading

 

Both are buffering, yes. They are on separate floors so I can't test at same time, but if one is, the other would be. I've never found that it to be random. 

 

Yes, continuous download that is running for hours. 

 

Version 4.6

 

Quick aside question... For 4K playback, what is actually required? I keep seeing from Kodi wiki that you want to be able to play up to 140Mb/sec for stable 4K, but looking at Remuxes, I have yet to find anything over 80Mb/sec

[Frank1940]

There is one experiment that might be worth conducting.  First, look at these couplers:

 

      https://www.amazon.com/Coupler-Ethernet-Wenter-Extender-Adapter/dp/B07R5XBWY7

 

I see you have a 'spare' CAT6 run between the living room and the basement.  Plug the living room end of that spare cable into an EA9500 port.   Now use coupler(s) (and other CAT5/6 cables as required) to connect that spare cable so you have a direct connection between the EA9500 and the Bartop Arcade. Test and see what happens now. 

[newoski]

On 10/1/2020 at 4:22 PM, Frank1940 said:

There is one experiment that might be worth conducting.  First, look at these couplers:

 

      https://www.amazon.com/Coupler-Ethernet-Wenter-Extender-Adapter/dp/B07R5XBWY7

 

I see you have a 'spare' CAT6 run between the living room and the basement.  Plug the living room end of that spare cable into an EA9500 port.   Now use coupler(s) (and other CAT5/6 cables as required) to connect that spare cable so you have a direct connection between the EA9500 and the Bartop Arcade. Test and see what happens now. 

UPDATE: Happy to report that replacing my Linksys EA9500 router with an ASUS RT-AX88U AX6000, turning on Adaptive QOS and prioritizing Streaming Media fixes the problem so effectively that I am now able to watch two simultaneous NAS to Kodi box streams of Lucy (4K Remux), WITH 100MB/s download going on. In real-time, the router essentially deprioritizes the 100MB/s download to about 80MB/s and the streams both are 100% stable. I'm shocked. Not to mention, with WIFI 6 speeds, I'm getting over 500mbps from the router to my computer which is in the same room.