slow streming

iTinkeralot, I am going to have to print out all the helpful info you provide here.  Thanks for the reboot tip, too.  My gateway just says it's a T-Mobile 5G Gateway.

Keep in mind you can add the local mesh router but everything still depends upon the cellular uplink capability for speed and performance. Local transfers, client to client, on the local LAN can still be much more impressive than the link to the internet. If the traffic on the backend routers for the cell is heavy then the uplink will suffer some. There are lots of factors that come into play. From time to time network congestion does cause issues and it can be a challenge to determine if the problem is local or with the uplink. If there is no internet connection check the cellular signal first and don't assume a local gateway issue. If the problem is upstream a reboot of the gateway will probably not help much. There are cases where the gateway just needs to be rebooted to make it play nice. I have to reboot the Nokia around 45 days or so from time to time.

If you run speed testing with speedtest.net find an optimal server and set it as the preferred one to test off of. If you just allow the application to pick an "optimal" server that is not always the real best solution. Testing of a single source provides a better reference. From here I always use the one out of Charlotte NC and even though the application may try to tell me Nashville is optimal that is not always the case.

The bars on the LED display are a rather generic report for the aggregation of the 4G and 5g signals more or less. They do reflect cellular reception but do not provide any real detail. Yes they do present a representation of speed as more bars are better. T-Mobile uses the 4G LTE band for the uploads and the 5G NR for download. It is probably a little of both but the heavy lifting for downloads is on the 5G. If you are getting 250 Mbps down your gateway is probably on the n41 millimeter frequency for download. If you have the Arcadyan gateway you would need to use the mobile application to look closer and it may provide the cellular metrics for that appliance. I have the Nokia gateway and use the web browser as I don't care for using the mobile application. The Arcadyan now only allows management via the mobile application. You may be able to see some things with the web application still but I am not sure as I don't have one to be sure. 

Here is a chart that explains the metrics. If the gateway shows 3-4 bars probably the RSRP is around -80 dBm or possibly a little less say -87 dBm. If the RSRQ and SINR is good to excellent then performance will be pretty solid. Signal noise due to a poor quality signal will result in poor performance as packet damage results in retransmissions so more delay to session completion. You can get more definition on RSRP, RSRQ and SINR with a web search if you really want to understand it better. 

On average I receive around 125-130 Mbps pretty consistent and have uploads 45-60 Mbps here on the n71 frequency and I am 5.3 miles from the tower, line of sight. Pretty much true line of sight without obstructions so my signal is very clean. With -85 dBm on RSRP, signal receive, I am getting 157 Mbps down and 71.7 Mbps upload with speed test. The 4G only shows 3 bars with -96 dBm RSRP. The signal to noise ratio is good to excellent for both so performance is pretty solid. I use the Nokia gateway alone and have no additional router or extenders and we have a 3300 sq ft home. A couple of weak spots here and there but still coverage is good.

You can play with the gateway for orientation and placement and may be able to get another bar or better signal quality. Signal quality, i.e. clean signal with less noise does improve performance. Speed is not the only part of the equation. A clean signal without packet loss and delay is a good thing.

Do notice the negative values. Just how it works. The SINR, SNR will be a greater positive value whereas the RSRP and RSRQ a lower numerical negative value is better. My 4G LTE signal may be in the low medium range but it is clean with 22 dBm SNR so performance is good as the clean signal makes up for the loss of receive power. 

iTinkeralot, do the bars represent speed or just reception?  I always have three bars and my download speed is always around 250.  If I had four or five bars, would my speed be greater?  Not that I need more speed.  Before I got my eero 6+, it was usually around 100.  After the eero, it went up to 180, and then higher with T-Mobile.  The upload speed now is what amazes me, though.  It was always around 5 before T-Mobile, but now it's like 20!

I've only been using T-Mobile internet for a short time and have streamed a couple of hours every day, mostly Amazon Prime.  There's never been any slowdown of streaming, no buffering, although a few times the picture hasn't looked super sharp for a few seconds.  My big problem was when I first started using my Sony Smart TV after connecting to the T-Mobile tower.  Nothing could be streamed anywhere.  I soon figured, though, it had to be the Wi-Fi setting, so went to the settings on the Sony.  I discovered I had to pick my network name and type in my network password, even though it was the same network name and password I had previously been using.  That happened the first two times I tried to stream, but has not happened since. Hopefully, those who have been streaming longer with T-Mobile will add comments here.