4 ms·
> why is a router broken say 10% of the time? My guess would be that WiFi drivers are kind of quirky - if you follow OpenWRT/LEDE development there a lot of is
by nisa 9y ago
> why is a router broken say 10% of the time?
My guess would be that WiFi drivers are kind of quirky - if you follow OpenWRT/LEDE development there a lot of issues that appear only on heavy load or under certain situations - causes range from driver bugs / chip bugs / firmware bugs - most of the stuff is NDA or closed source. You've got the problem on both sides - especially the situation on Linux is still dire for lot's of chipsets. Even my years old intel card in my notebook does not really work well with Linux und the current kernel/firmware. I blame the vendors.
> Do the frames in the air get corrupted or dropped? What portion of frames makes it through?
That also depends on the rate and encoding that the frames are sent. Then there is stuff like frame aggretation that sometimes work sometimes not.
> I see the SSID, so it can transmit something. Why can't I connect and get at least a slow connection?
SSID is send with the lowest rate (1Mbit) and with the most solid encoding - usally the transmit power and antenna sensitivity is also the strongest on the lowest rate so the SSID can be seen quite far away - often so far away that your clients wifi is able to receive the SSID beacons but unable to send something back that reaches the router.
> What is it doing now, sending, waiting for a response, did it negotiate encryption yet?
Wrong crypto results in no association - difficult to tell apart from low signal.
> Is the low-level connection OK, and we have a problem with DHCP? This you can detect, but the OS obscures it from you.
Yes. You can look at network-manager logs from Linux but sometimes it's difficult to tell - especially on Windows.
> There is no easy way to see signal strength.
There is also noise, antenna properties and everything depends on the rate and encoding used - it's not exactly easy.
> Why does the connection suddenly drop out or get slow?
Add also the rate control algorithms, the amount of clients, for certain 5GHz channels you have to obey radar then there is interference with bluetooth and microwaves. Also all that funky physics stuff with reflection and antenna positioning where moving a little bit might be just enough to cause problems for you.
- captainmuon 9y ago> SSID is send with the lowest rate (1Mbit) and with the most solid encoding - usally the transmit power and antenna sensitivity is also the strongest on the lowest rate so the SSID can be seen quite far away - often so far away that your clients wifi is able to receive the SSID beacons but unable to send something back that reaches the router. Thats what I mean. It would be great if you could click "debug", and it says "Receiving beacons from router, but router is not responding to frames". Maybe it would even be smart enough to do a back-of-the-envelope calculation if details about the router are known, e.g. router transmits with X watt, the recieved signal strength is Y. I can transmit with Z watt, so the router should / should not be able to hear me. Then it could suggest "You have to move closer to the router, use a better antenna, or increase power to the antenna (reduces battery life)". Nowadays you don't get anything, not even an error message. It silently stops connecting on most platforms, and the WiFi symbol slightly changes.