Freezing, losing Connection, sporadic stops

    Hi :)

    In May I installed Libreelec 10.0.2 with Kodi v19.4 on a Raspberry Pi 3, Model B. This is connected via WIFI with my Fritz!Box. Everything worked fine since then and did so on older versions of Libreelec, too. Since a few weeks I have randomly problems with freezing of the video stream (videos are on my good working Synology Diskstation, connected via cable to the Fritz!Box), the Kodi-GUI says "No route to host" or it loses connection without any message. Then only a reboot helps.

    On http://ix.io/46eD you find the latest log. There are more log in the /log-directory, which are probably more expressiv, but I hope you can help me with this already.

    Thanks for any advice!

    The log shows several wifi disconnects and reconnects. Got a new neighbor or one of them switching APs maybe? Unfortunately these things are kind of normal with WIFI, best solution is you switch to ethernet LAN or powerline (the latter can be a bit unreliable, too though, but is in general far more reliable than wifi).

    so long,

    Hias

    I also would suggest LAN.

    what in wifi works today isn't meant: it will work tomorrow too !

    But you maybe could play with the Wifi setting somewhat:

    use your Wifi always with fixed channel, NOT auto channel

    why ?

    well, auto channeling seems to be un-reliable on fritzboxes ( I own a 7590)

    why else ?

    given that your your neighbours also own a fritzbox and most of the owner let the boxes run with the defaults, what is "auto channel"

    why not use this ?

    setting your WLAN channels fixed and let your neigbours channels move when their channel collide with yours. :P

    I bet (if your neigbours run auto channeling): in 1-2 days your mostly alone on your fixed channel !

    I would suggest

    for 2.4 : channel 13

    why ?

    AFAIK this channel is OFF per default in the fritzbox settings and if my above assumption is valide: OFF on your neigbours FB's too

    if so: nice, a free channel !, but ...

    for 5: channel 100

    why ?

    beginninig with channel 100 the FB sends with 1000 mW (all other channels with lesser, see your FB manual, page 267)

    seeing a strong channel and your neighbours move again ...

    BUT, with channel 100 and what I've read so far about FB's also on lesser channels, FB's are scanning for radar from time to time, means: there is a "buildin" and highly discussed shortcoming in FB's (with release firmware; beta FW should have fixed it) regarding stable connections

    so channel 100 needs testing in your environment !

    ===

    that said and somewhat contrary:

    the best channel setting I found here with ~40x 2.4 and ~8x 5 GHz neigbour WLANs, is the *same* fixed channel I strongestly see from my neigbours WLAN.

    sounds stupid, but ...think of physics "amplitude are added [*] when 2 waves have the same frequency or "added" to zero if the freq.'s are 180° shifted and of course all variants between this two extrema.

    that's why I wrote the "but" in the above "if so: nice, a free channel !, but ... "

    particularly, your neigbours running channels beginning with 8 while yours is 13 you'll have increasing trouble.

    [*]

    they don't real "add", you don't get doubled whatsoever here, but waves don't get destroyed.

    if you ever have played with the android app Fritz!WLAN you seen parabola's (2.4 MHz Wifi).

    if they cross their flanks the signal gets deranged what is only in 2 cases not the case: when channels are far enough away (AFAIK: 5) or when they are the same (no flanks crossing: no signal destruction !)

    so, the best is the same strongest channel you see from your strongest neigbour in a crowded wifi

    and keep in mind:

    playing with wifi needs time.

    you maybe won't see the effects immediately.

    your surrounding needs to react on your moves what usually comes time shifted.

    Edited 3 times, last by GDPR-7 (July 31, 2022 at 11:20 PM).

    Thank you, HiassofT and JoeAverage for your comments! This is very helpful for me :)

    I changed 2.4 to channel 13 after looking on a wifi-radar, and indeed, channel 13 is free, and now I am there alone. This works great for me.

    I changed 5 to channel 100, but it does not make any effect (48 hours after the change). The wifi-radar says, I am alone there, too, but the RaspberryPi seems to be very slow with wifi-connections. I will control this the next few days and maybe go the next higher channels.

    Otherwise a solution could be to limit the RaspberryPi to the 2.4-network. But this sounds like a strange workaround.

    I'd recommend also monitoring signal strength / quality at both ends.

    On the RPi you should have a bar indicator roughly showing it, and your AP/router may have that, too (my OpenWrt router shows link quality of each connected wifi device).

    5GHz wifi has benefits if your device is near the router, but if there's a wall in between things can change drastically and 2.4GHz may be the better choice (so that's not actually a workaround but a wise decision based on physical facts - higher frequencies are affected more by obstacles like walls than lower frequencies).

    so long,

    Hias

    For a stronger signal it helps to use an external WiFi adapter. This Ehternet-to-WiFi adapter only uses 2.4GHz, but you don't have to fear driver problems, because it's Ethernet: Click!

    Quote from kubuntu-fan

    Otherwise a solution could be to limit the RaspberryPi to the 2.4-network. But this sounds like a strange workaround.

    Why ?

    AFAIK, with 2.4 you'll NOT have scanning for radar from time to time esp. when using channel 100

    - I'm unsure if the FB does scan for radar on 2.4 too, though -

    As long a the connection is stable and has enough data rate to stream your video (what I've read 40Mbps should be enough)

    Inside the Raspberry Pi 3 » Raspberry Pi Geek
    Inside the Raspberry Pi 3
    www.raspberry-pi-geek.com

    I know it's from RPi 3 B (without "plus"), but

    => Headline "WiFi and Bluetooth"

    => and there the 4. paragraph

    => both last sentence,

    cit: "The throughput measured by using iperf was approximately 38.5Mbps. Theoretically, this data rate suffices, even for streaming 4K videos, which only require up to 16Mbps in H.265"

    On *my* Fritzbox 7590 "iperf" is integrated (maybe on your 7560 too ?):

    - open the website from your FB

    - search on the left side the word "Inhalt" (grey text)

    - click that

    - scroll the right side down until you see "Fritz!box Support"

    - click that

    - scroll to "Durchsatzmessungen"

    For LE the program "iperf" is in either "System Tools" or "Network Tools" Addon

    for the from HiassofT suggested measurment this app might also help (where tp place the router, what channel to use, wifi crowded at place from the RPi ?, etc.):

    FRITZ!App WLAN | AVM Deutschland

    but keep in mind using the app: your measure with your *phone* and NOT with your RPi !

    Quote from HiassofT

    On the RPi you should have a bar indicator roughly showing it, and your AP/router may have that, too (my OpenWrt router shows link quality of each connected wifi device).

    screenshot from my FB 7590 and a connected AX201

    Hey :)

    I set up my Fritz!Box new, so that the 2.4-Wifi and the 5.0-Wifi have their own names, and I logged my RaspberryPi with Libreelec into the 2.4-Wifi. This works like a charme! Since I did, there was no single problem any more, and I hope it stays stable now.

    Thanks for all the help; I learned a lot and see the things clearer now, I think.

    Quote from kubuntu-fan

    so that the 2.4-Wifi and the 5.0-Wifi have their own names

    I guess this has some disadvantages (assuming a wifi device can't dynamically switch between 2 SID's ("wifi names" )

    - you do not have a backup wifi (the 5 GHz band) if your RPi looses the 2.4 wifi (assuming LE doesn't let you configure 2 SID's with diff. password)

    - same goes for all you other devices esp. when moving the device out (and in) a range of the different wifi bands (2.4, 5)

    - you need to configure *all* your wifi device for your special two SID to further have the benefits of each wifi band, what are:

    5 GHz: higher speed on short distance

    2.4 GHz: relative - compared to 5 GHz - lower speed, but on longer distance where 5 GHz isn't reachable anymore

    think of a smartphone playing a movie from internet connected to 5 Wifi and moving with it into your garden...

    with your single SID's. (and having configured both wifi bands) you will notice a *sensible* interrupt of the internet connection, e.g. for password exchange/verify, DHCP, etc. after loosing 5 GHz and connecting to the 2.4 GHz

    with same SID's (and one password for both wifi bands) you'll have a interrupt too, but in a best case you won't notice it.

    means: at best you internet movie keep playing with a maybe short hickup during moving your smartphone into the garden

    here it's just switching the wifi band without password verify and DHCP, etc. involved

    more to read:

    AVM erklärt WLAN Mesh Steering | AVM Deutschland