My topic is a bit off-topic as I don't know yet if it's related to OpenWRT.
Since a few days, Amazon Music does not work properly on my Amazon Echos. The playback pauses every few seconds, does not start or stops completely.
Now I'm trying to detect the cause of this and I'm coming to the end of my network knowledge.
I would like to narrow down the error to a specific area: The amazon-music-server, my lte-based internet connection or my own network configuration. Actually i do not know where the cause of this is.
i changed the APs where the echos connected to (even to a non openwrt device)
I read out the port statistics at the main switch. I got 185 bad received packets from 32043 at all at the router and 103(from 21044) at ap1 and 32(from 41814) at ap2. This sounds too much to me so i tried:
Changing Ports at the switch and the aps
replaced ap 1 with a fresh installed Mi 3G with 19.07.7
replaced cables
the bad received packets still persists.
i made several tcpdumps at the router and the APs.
At the router i got nearly 9% of all packets are tcp.analysis.duplicate_ack, tcp.analysis.retransmission or tcp.analysis.spurious_retransmission
most of them are reated to a amazon-music server (hosted at cloudfront)
However, now I do not know how to break down the problem. I therefore hope that one of the network experts can help me.
Unfortunately no.
My data volume has still ~60GB left and my bandwith is quite stable over the time in the speed tests at 50 Mbit/s down and 25 Mbit/s up.
Yes. The Router has 2 2,4 Ghz Wifis and 2 5Ghz. (in sum 2 SSIDs). I share the ssids over all the APs and separate these networks by VLAN. So i have VLAN 1 for my main network, VLAN 2 for the WAN connection (only untagged at the router wan port) and vlan 3 for guest and vlan 4 for tor.
The APs are not set up as mesh because i have a cable connection so they are real access points.
I have my C2600s as APs too, but they have 802.11r enabled for easy transition between all three of them.
Point is, you don't know your devices are connected to the best AP, signal wise, since there's no set up letting them to roam.
But to try find the issue, kill the WLAN used by your Amazon music devices on the APs, and recreate it on the Xiaomi router. It'll bypass the APs and the switch.
I can try it - even if it's not so easy because the modem is at the attic.
[quote="frollic, post:10, topic:89061"]
ed anyway, and you're (probably) double NATing.
[/quote]Probably yes - the modem is nating to the isp and the router is nating in direction to the modem. Is this configuration kind of wrong?
I also can share the config files or the tcpdumps if this would be helpful.
No - all access points and the router are directly connected to the main switch (with tagged vlan).
If it's suboptimal then I should probably change that. How would I make it better?
Currently the modem spans the subnet 192.168.1.0/24 and has itself the IP 192.168.1.1. The upstream side of the router has the static IP 192.168.1.2 with the 192.168.1.1 as gateway.
The downstream nets (one of the 3) of the router are 192.168.0.0/24 (main private net), 192.168.3.0/24 (for guest net) and 192.168.4.0/24 (for tor net) where the router has the IP 192.168.0.2, 192.168.3.2 and 192.168.4.2. The clients then get their IP from these nets via DHCP. The router make a NAT for the requests towards the modem with its IP 192.168.1.2.
How would the configuration look like without Double-NAT?
Update: I did it like you said.
The LTE modem has the possibility to offer a WLan itself. I have now coupled the Echos to this.
Result: The music plays through without dropouts.
The problem seems to be on the side of the router. However, I am now quite perplexed what exactly could be the cause.
I can also post some tcpdumps if it would be senseful.
My wifi neighbourhood is quite clear. My own wifis use the 2,4Ghz channels 1,5,9,13 at 20Mhz and for 5Ghz 40 and 46 at 40 Mhz and 58 at 80 Mhz. None of these channels is used twice. The neighbours wifis are very poor and should not interference much.
Do not do this. Although it will eliminate double NAT it will also eliminate all control you have over your own network, now a Xiaomi device with who knows what firmware on it is in control. Double NAT is not your problem because your problem only started a few days ago but double NAT has been there the whole time.