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[Weaver]

Several times recently when I have been watching a streaming movie the movie has suddenly hung. What I should have done at this point is do some pings and the like, but instead, I have tuned off the wireless i/f on my iPad and then straight back on. The fact that this has always immediately fixed the problem leads me to point the finger at one of my WAPs, although I can’t say which one. Looking at the AA clueless CQM graphs, I don’t see any interruptions in the internet link, but then such a gap could well be too short in duration to show up well. Blaming an internet outage of a certain duration makes no sense as my action by cycling the state of the WNIC always instantly cured the problem. When I mentioned this to Janet she said, "oh I have outages several times a day" and I was annoyed that she hadn’t told me so that I could investigate it and fix the problem for her. In over ten years I’ve never had a problem like this before.

If I dig around I may have a spare unused but ancient, ten years old ZyXEL WAP of the same type, buried in my hardware stores.

I suggested to Janet that now might finally be the time to swap out the WAPs for some modern kit, gigabit class or as near as is as achievable. What do you think?

Any debugging tips?

[craigski]

As you are using Apple, and it seems multiple APs, I would suggest using Apple Airport utility and scan network, showing all APs.

Article here showing how iOS devices select an AP and how to use the Airport utility to scan network:

https://support.apple.com/en-us/HT203068

[meritez]

I'd be looking at replacing the WAPs.

[burakkucat]

I'd be looking at replacing the WAPs.

With? Something from the MikroTik stable or that of a.n.other? 

[meritez]

With? Something from the MikroTik stable or that of a.n.other? 

I've got fourteen of the access points Weaver has in a box in the office, ripped out of customer premises nearly four years ago as not suitable.

I have no idea what Weavers current layout is but as the current WAPs only deliver wireless n 5ghz and the iPads and iPhones support wifi6 it maybe in his interest to upgrade.

[Weaver]

My current ZyXEL WAPs, two in use, have two 802.11n radios each, so that’s four radios, and each radio is selectable 2.4GHz or 5GHz. One of the APs has one radio set to 2.4GHz 40MHz channel 1+6 and all the other radios are on 5GHz 40 MHz channels.

I’m talking to AA about supplying suitable kit for a small business, possibly Aruba. Way back in the beginning of time, I was thinking about supplying wifi to B&B guests, but Janet’s ideas regarding that changed - no need as there’s superb 4G coverage, hassle of users wanting support, doesn’t make any money - but things still might change one day.

Do ancient APs get eventually unreliable, or do they just die?

[meritez]

The components end getting frail, capacitor etc.
Aruba is lovely if you can get it.

[Weaver]

Doing a WAP upgrade via wireless is going to be a bit awkward. A bit like pulling up the floorboards while you’re standing on them. I might move first one then the other old AP out of the way first, in the sense that the existing APs’ admin IPv4 addresses get shifted to a ‘secondary’/‘backup’ position. However, dealing with frequencies will be more awkward as I suppose I need to move the old WAPs’ frequencies out of the way of the new ones - what do you think?

I do think there might be an argument for changing one of the old WAPs’ SSIDs to something distinctive, so that I can control whether I’m connecting to old kit or new kit, so I could perhaps rename one of the old SSIDs to something with some suitable suffix.

With more modern hardware, will I be able to use 5 GHz channels above 100 ?

[meritez]

Yes all the way to channel 167 if required.

[Alex Atkin UK]

Yes all the way to channel 167 if required.

AFAIK most if not all APs only support up to 140, as they were developed before Ofcom opened up Band C for unlicensed use.  As I mentioned before, my Zyxel doesn't support Band C and their excuse was that few clients support it so there was no reason to update it to do so.

The real reason I believe is as Band C was opened up quite late, they would have to pay to have the devices tested on that range (to make sure they follow regulatory requirements) and they see no return on that investment.  As these are business APs and a business is going to care more about wide client compatibility so likely not use Band C.

Its a similar situation to what we had with Band B when nobody wanted to pay the cost of supporting DFS so many older devices only support 36-48.

Hopefully WiFi 7 APs will have it by default, but I doubt Apple support it right now as they didn't even add WiFi 6e to their latest devices and only support 80Mhz channel width (though strangely the WiFi applet on MacOS does occasionally incorrectly say 160Mhz).

Also, I take it you're aware of how Band B works?
https://draytek.co.uk/information/blog/ofcom-relax-the-rules-on-the-5ghz-band

On three of the allocated channels (channels 120, 124 and 128) it's considered that radar use is likely so your device must monitor for radar and wait 10 minutes with no radar detected before it can consider transmitting. This means that when you turn your AP on, you have no Wi-Fi for the first 10 minutes and every 24 hours thereafter.

DFS is not entirely reliable - it's subject to false positives (signals wrongly detected) and false negatives (signals not detected).  This is partly due to the 'simple' nature of radar signals compared to Wi-Fi signals.

The effect of a false positive is that your Wi-Fi device shuts down unnecessarily, causing interruption to your connection. If that keeps happening, your connectivity becomes unusable as, once DFS has detected radar, that channel cannot be retried for 30 minutes.  If there's a false negative, your device may transmit on a channel being used by radar, theoretically causing critical interference to it.  There's a more detailed article on this here ( http://wifinigel.blogspot.com/2018/05/the-5ghz-problem-for-wi-fi-networks-dfs.html )

The good news, however, is that in 2020, Ofcom in the UK announced that the requirement for DFS will be removed on more channels. Specifically, frequencies in the range of 5725-5850Mhz (5.8Ghz) which correspond to channels 149, 153, 157, 161 and 165 will be allowed for indoor unlicensed use in the UK, without requiring DFS checks before or during use. Until now, these Group C channels have only been permitted for limited outdoor use in the UK, with licensing granted by Ofcom.

Note that when DFS is detected, a lot of APs will just drop to channel 36, which could explain why simply reconnecting allows it to work again.  In theory it should try to switch back again after 30 minutes, but I've never seen that happen.  My guess would be that some implementations consider that constantly losing WiFi for 10 minutes, every 30 minutes, would kinda be bad so don't bother trying.

[Weaver]

When I tried channel 100, which was a long, long time ago, I couldn’t tell whether or not I was in the wait state or whether it just didn’t support those channels as the device seemed to have moved down to channel 64. Then there’s also the question of what Apple supports.

[Alex Atkin UK]

From what I recall on other forums, even the latest Apple devices do not support Band C.  Although I can't verify that as for some bizarre reason Apple do not mention channels supported in their specifications.

[tubaman]

...

With more modern hardware, will I be able to use 5 GHz channels above 100 ?

Yes, but if you are in a building with thick stone walls you may find it works no better, or even worse than 2.4GHz. Thick walls and 5GHz are not good bedfellows unfortunately.

[Alex Atkin UK]

Indeed, for reliability I'd reduce 2.4Ghz down to 20Mhz also, as the wider the width, the more prone to problems.

[Weaver]

The external stone walls are between four and six feet thick, probably made of stone peat filling and then more stone. The stonework on the gable end walls is exposed downstairs. There’s also an extension built from concrete block work. The interior walls however are entirely thin woodwork. Ceilings have foil-backed plasterboard in some places. In my bedroom I can hear the downstairs and upstairs WAPs; both are very close. WAP 1 the downstairs unit transmits at 40 MHz width on 2.4 GHz channels 1+6 and in the 5 GHz band too, whereas the upstairs  WAP is very close to my bedroom with just a thin wooden wall in the way of line of sight. Both of the upstairs WAP’s radios are set to the 5 GHz band. I’m thinking about moving the upstairs WAP into my bedroom itself to get rid of that thing wooden wall in the way. The guest bedroom upstairs, which is in the blockwork extension, currently gets very poor coverage and moving the upstairs WAP into my bedroom is just a fine way to make that situation much worse still. I either place the upstairs WAP more wisely in a compromise position, or I deploy a third WAP if Janet can find it in her equipment store.