Forum Discussion
My tmobile cell tower is overloading my router settings to make it worse
I just got this tmobile home internet last monday and for two days it was amazing and then someone started messing with the settings to make it worse by alot. One thing they did was change the TCP ...
I am curious as to how you determined "they" changed the way TCP is functioning. Are you taking packet captures and doing in depth packet analysis of the sessions or what? The normal operations with TCP when there is congestion is to use a sliding window dynamically, making it smaller or larger when possible. The two hosts in the session communicate back and forth to optimize the flow based upon how much data can be received before the acknowledgement. It is a function of the TCP/IP stack operation based upon IEEE standards. The two end devices determine the window size. That is normal.
“One thing they did was change the TCP so any new connection starts out with a very slow download and then it ramps up to better speeds” (the two devices in the session)=they
I would guess that there was some congestion and the routers and the hosts in the session were compensating with a dynamic window size to address the congestion. Analysis of the packets in a capture should provide some profile of the traffic. I am just going to make a guess you are in an urban area and not a rural location. Please correct me if I am wrong. What I have observed from community conversations that users on the n41 band in a urban area where tower density is greater tend to see more congestion due to more users and I personally think the cells are loaded heavy. I could be wrong as I have no way to know how many subscribers are loaded on a given n41 cell source but I have seen more people in urban areas complaining about congestion. I live in a rural area with n41 and my downloads can be 250-400 MBps and varies depending upon the time of day/night and load.
The cellular signal metrics you have posted on the middle capture are pretty awesome. The RSRP, reference signal receive power for both the 4G LTE and the 5G frequencies is in the good & excellent range and the SINR is excellent as well. The RSRQ, reference signal quality for the LTE is good and the RSRQ for the 5G is excellent.
The signal quality in all three captures is good to excellent and the SINR though down on the middle capture after the gateway was restarted is still in the excellent range. So the metrics changed but the reason appears to be maybe not what is speculated. More data is needed to reveal a better picture. IF you notice on the first and last the 4G LTE band is a B66 frequency. The middle capture reflects B71 on the 4G LTE. So, I would expect the upload traffic to be a bit lower. It is not possible to tell with just the cellular metrics for the signal power, quality, and signal to noise ratio IF the gateway acquired a lock on a different cell or not as there are NO PCI values for the specific 4G LTE signals nor the 5G signals.
I can only speculate that there might be another tower or cells that the gateway gets a lock on and makes a transition from one cell to another on both the 4G LTE and the 5G NR frequencies. If you see the significant cellular metrics change AND the bands change look for the PCI, physical cell identifier, and see if you can locate both cell sources. Goto CellMapper.net and confirm both 4G and 5G cells. It might be that your location is between the cell sources and makes a transition in part due to the RSRP change and congestion. I am not sure how far your location is from the n41 source but 168 MBps down with n41 is not that impressive. Clearly the b71 and b66 are two different 4G LTE cells. Confirm the n41 5G cells as those will do the heavy lifting for the download traffic. A little more digging suggested.
The signal quality as you put it is not changed by someone. It is changed by environmental factors and cell fuente lock more than likely. Just like mobile handsets can jump from one cellular source to another the gateway might be making the same signal handoff or transition.
So you recorded the SINR = 40 value reported from two of the first cellular metric recordings. I think one thing to consider or question to ask is, how accurate is the recording/reporting device or application that is being used? If the values reported are truly accurate or not we cannot be sure. It may depend upon the software and the interpretation of the available information. One thing I learned long ago is to always question the data and not take it at face value. I find the mobile application to be buggy and often will hang up and fail on my iPhone 12 Pro to the point that I have had to reboot my phone because the app crashed and hung everything up. Do I trust that application. No I do not.
Below according to XYXEL Networks
SINR
SINR (Signal Interference + Noise Ratio) also called CINR (Carrier to Interference + Noise Ratio) is the ratio of the signal level to the noise level (or simply the signal-to-noise ratio). The SINR value is measured in dB (dB). It's simple: the higher the value, the better the signal quality. At SINR values below 0, the connection speed will be very low, since This means that there is more noise in the received signal than the useful part, and the probability of losing a connection also exists.
Your most recent record of the n71 cellular metrics reflects the SINR = 14 which is good but not excellent. Still a pretty clean signal at 14. I have to question the n41 reporting a value of 40 for accuracy as i don't trust the TMO mobile application nor am I very impressed with the Arcadyan or Sagemcon gateways. The Nokia also has a few warts but I have grown fond of mine after reading various conversations about the warts of the other two gateways.
WE, you, me or any other subscriber does not have control to get a lock on a given cell. You can contact support and IF you get with a really good support engineer that listens to what you are asking and also will take the request up the chain to a higher level support engineer then you might be able to get them to move the preference or lock to one of the n71 towers. They can see where your gateway gets a signal source and can preference the signal source IF they will. I have seen conversations where users have had success with this. I think, in part, it is holding a respectful, polite conversation with the engineer and requesting the connection preference/lock where you have seen it provide a respectable level of service. Please and thank you are always appreciated.
I worked as an enterprise network escalation support engineer for 22 years. Our team dealt with what we referred to as the ugly 5%. I know how important it is to take care with the conversation and work for a mutual outcome. If you are respectful it is usually more helpful. Sometimes you have to ask to talk to someone else. A support engineer that is treated with mutual respect is more likely to work harder for you. I have dealt with many very difficult, demanding customers but also some that were just elated I had flown in to work out the problems. I always appreciated the forgiving customers even though they could still be demanding. They had to be as they had superiors demanding answers from them. In the end when the problem is resolved it is a good feeling of achievement.
Until the n41 cells are properly vetted the n71 may be a more comfortable place. From January 2021 to March-April of 2022 the n71 cell we can use was unstable only twice about 3-4 days each time. When T-Mobile recently moved us onto an n41 cell I was instantly apprehensive as I had seen numerous community conversations about problems when on the n41 cell source. So far in this location the n41 has been just as solid as the n71 and shows no symptoms of congestion. I really suspect that what you were seeing was just that. It could be the prioritization of the traffic on the n41 cells in the area or some other configurations need to be improved to make it sing. You will not get as much potential for blazing speeds out of the n71 but it may be more stable and provide a solid average for speeds. I would take stable over flashy fast when the flashy fast is unreliable. Could the problem be buffer bloat? Maybe.
If the community is hungry for lower cost internet and users are flocking to T-Mobile for the home internet solution in the area then they may be selling more subscriptions than the current infrastructure can properly handle. The 5G internet solutions are still maturing and cellular delivery is not a simple venture. As you stand up cells you also have to make sure the back haul can handle the end user demands. If the upstream pipes cannot carry the volume of course you have issues. Then more investment must be made and well timelines and plans are all good but not always properly executed.
