Looking for an AP to replace an Archer C7

Budget: I expect to pay $100-$150, but I'm willing to pay up to $400 if you can convince me that it's worth it.

Must Have:

  • Very strong OpenWrt support. I'm sick of buying "recommended" devices that turn out to have persistent issues that will never be fixed.

  • At least two gigabit ethernet ports (including one for the uplink.)

  • Runs on 12V DC. (For complicated reasons, that's all I have at the location where the AP will be installed.)

  • Generally at least as good as the Archer C7. I've used C7s for so long that I don't even know what features are standard these days, but I don't want to discover that my new device is missing something that the C7 had. Exception: I can live without USB ports.

Nice to Have:

  • POE powered (for future use, in addition to 12V DC.)

  • Form factor similar to the Archer C7 (i.e. horizontal, with LEDs on the front and ports in the back.)

  • A decent amount of RAM, flash, and CPU. Right now I only plan to use it as an AP, but I'm sure I'll come up with other stuff to run on it in the future.

Use Case: My router is an ER-Lite. It's currently running Ubiquiti software, but I'm planning on switching to OpenWrt when I get around to it. I have a few laptops, and I often transfer files, so I want maximum performance for those. I also have maybe 15 IOT-type devices; they don't transfer much data, but they do need a stable connection. Coverage shouldn't be an issue as long as it's at least as good as the C7.

I am curious to know why you are trying to replace C7 as AP? I reckon you need 2.4GHz (which is not working well on C7)? Other than that, it works as a charm.

There are no 802.11ax devices supporting OpenWRT yet and early benchmarks of .ax devices with OEM sotware are dissapointing. Bandwidth on pair with mature .ac and OFDM is currently either not working or giving marginal gains.

I run mine C7's as AP's off a PoE ejectors (delivering 12V to C7) and they deliver consistent 500Mbit in iperf3 (not a line rate, but real throughput) on 80MHz 5GHz channels, while also acting as edge switches.

I'm not totally sure what the problem is. All I know is that I have a lot of Google Home speakers, and their streaming audio gets unstable after a while. I have a script that resets the radios and temporarily pushes everything to 5GHz, which always fixes the problem, but eventually it comes back. It's gotten worse (possibly because I keep adding more speakers,) and now I have to run the script two or three times a day.

I do have a few 2.4Ghz only devices. If it really is a 2.4GHz problem, I guess I could try using separate SSIDs, but I'd rather not have to deal with that.

That's remarkably similar to my setup. I ran one POE line to the location for the C7, but I had problems with the ethernet switch. When I transfer a large file over ethernet, it would run fine for about thirty seconds, and then start to pause for no reason. I realize this sounds like a server problem, which is why it took me so long to figure out that it was actually caused by the ethernet switch in the C7. I added a separate switch next to the C7, and that fixed the problem completely. I still only have the one POE line, though, so the switch is sharing power with the AP. That's why I need the new AP to be 12V as well.

Now that I think about it, there are a lot of other ways I could solve that problem, including just getting an AP that has a working ethernet switch. Most APs are 12V anyway, though, so sticking to 12V would be the laziest solution.

On my own Archer C7 v2, there were indeed WiFi issues caused by memory overuse by the ath10k driver (but affecting 2.4 GHz too because ath9k was suffering from the consequences). All of them were fixed by removing kmod-ath10k-ct and replacing it with kmod-ath10k-ct-smallbuffers. So maybe give it a try?

Another suggestion is that you should try an updated image, perhaps even a snapshot. There was a memory leak fixed recently that may also be relevant.

I tried the -smallbuffers driver for a day or two, and it didn't seem to help, so I switched back. I think that's mostly an issue for routers, not APs, since APs have a lot of free resources.

I'm on 19.7.4. I haven't tried a snapshot, at least not for a long time. It's worth a shot.

All of this talk about 2.4GHz convinced me to experiment some more with my "fix the wifi" script. It turns out that the problem really is just the 2.4GHz radio, which means that I don't have to reset the 5GHz radio at all. All I have to do is occasionally push everything off of the 2.4GHz radio and back onto the 5GHz radio. That only causes a brief disruption in whatever I'm streaming, so I can do it much more often.

Thanks for brainstorming. I'd still like a new OpenWrt AP so that I don't have to deal with this nonsense, but this solution is enough for now. I'll also try a snapshot build when I get around to it.

No doubt, it is a bit of extra hassle. Nonetheless, I gave up trying to set up smooth roaming and letting devices decide whether to connect to 2.4 or 5 GHz throughout the house. The 2.4 GHz AP's usually won with their stronger signals, but the 5GHz would perform better. So, I now have separate SSID's for 2.4GHz and 5GHz and for upstairs and downstairs routers. Add in some more permutations for my guest and IOT wifi VLANs and things look really crazy on a wifi scan LOL. But, you get used to it, and once you do, FWIW I find I get better performance manually deciding what device connects to which SSID.

Fixing ath9 by fiddling with ath10k is some sort of forum "truth" that is hard to kill. In reality, it is hearsay. You can remove ath10k (as not even load the drivers) and ath9 will still fail after a while. It is broken.

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If you really must have working 2.4GHz then replacing AP's or reverting to OEM software is your only bet. 2.4GHz has been broken (or more accurate "flaky") on C7 since 18.06. It is still not working no matter what you do. People do all kinds of weird voodoo things to make it work (changing ath10 drivers, kissing it in full moon) to make it work but at least in my testing, it is broken on driver level and stops functioning after a while.

That being said, I have disabled 2.4 and pushed everything to 5GHz and it works perfectly, every day and under high load. If you can live with 5GHz only, C7's can give service for a long time to come.

Hmmm... interesting. When was this change made? I look thru the snapshot updates now and then, there's been a lot of changes that may affect things in this area.

I have been chasing some kind of reason for this for a long time. All the evidence I've found is (yeah, I know) ath10k warnings of crashes or resets happening around the time of the 2.4ghz failure, (and sometimes not!) and spikes in memory use that usually result in a router reset. Have only caught this a few times in the logs, before the reset. All still just "maybes" in being part of the reason. Sad that there's been so much complaining about and so little resolution of this issue. Unfortunately, I'm not knowledgeable enough to do much about it, but have a lot of collected logs. I do remember getting months of uptime with perfect performance, back in the 17.x.x.x days..

Lately (last month or two) have returned from snapshots back to 19.07.4, and it's been more stable... maybe our usage has been lower. Unfortunately, I still have a lot of 2.4ghz only devices around the house...

Going back to the OP's original question, now that the EAP-225 and -245's are getting to the point of really being OpenWrt supported, they would make dandy AP's, and their chipsets work with the latest Make-Wifi-Fast project improvements.

The change was made on October 17, 2020. Not sure if that particular leak has any relevance to the 19.07 branch. And yes, the change is not specific to ath10k, so it may fix a different leak.

You're the first one who actually answered my question (although the rest of the discussion has been useful in other ways.) I don't think the EAP245 would work as a straight replacement for my C7, because it's directional, and I wouldn't be able to position it to cover my whole place. However, I do have a good spot for it as a secondary AP. I can just disable 2.4GHz on the C7 and leave both bands on the EAP245, and that should keep everyone happy.

If it works well, I might even replace the C7 with a second EAP245. Between the two of them, I'd have full coverage.

I'm buying an EAP245 entirely on your recommendation, Random Internet Guy, so I hope it's solid. Thanks.

Uh, oh... responsibility!! :wink:

Theres a Small Net Builder review on the EAP-225, that talks well of it. https://www.smallnetbuilder.com/wireless/wireless-reviews/33201-tp-link-eap225v3-ac1350-wireless-mu-mimo-gigabit-ceiling-mount-access-point-reviewed

I dont think they ever did one on the -245. It seems to be very similar, with faster radios

I'm not sure how the directivity is, or if its mapped out in the article. Being a dedicated AP its likely to be omni in a flat circular pattern, if so, centrally located on the ceiling should cover a house, but maybe not as well on a 2nd floor, if you have that.

Hope it works well for you, should be as good or better than a C7, which in its day was considered one of the better performing routers in coverage/performance, radio wise. (ref also Smallnetbuilder.com)

Might want to be sure you get an EAP245v3. The EAP245v1 looks a lot like what you already have - a Wave 1 QCA9880 with 16/128 Flash/RAM, just like an Archer C7. The EAP245v3 gets you the QCA9982 Wave 2 radio upgrade, though still the same 16/128 memory.

Too late. I ordered an EAP245v1.

It looks like the EAP245v1 has the same guts as the Archer C7 v4 or later, but not the Archer C7 v2, which is what I have. I believe the v2 is by far the most common version, so I assume the widespread reports of 2.4GHz problems are talking about that version. Hopefully the EAP245v1/Archer C7 v4 are not affected. If they are, as we've already established, it's that other guy's fault.

The Archer C7 v4 is rock stable.

I have two units at home wired together, both configured with the same 2.4GHz and 5GHz SSIDs, roaming is left to the clients. They're both currently running 19.07.4, longest uptime I had was about 60 days until a power cut happened. I'm on a symmetric 50/50 PPPoE FTTH connection.

Never slowed down during that period, multiple clients on both bands doing their streaming and usual stuff, some wired devices doing their thing, a RPI3 runs Pihole and takes care of DNS for the network. SQM does its magic on the primary C7 and PPPoE connection, no issues whatsoever. Second C7 is on dumbAP duty.

On top of that, both units are overclocked from 775MHz to 1000MHz, that's a solid +30% performance increase on CPU limited scenarios which are bound to happen on single core MIPS hardware. There's a little more heat output on the case over long term usage. You can leave a finger on the SoC indefinitely so it's not getting too hot.

Whatever was wrong on the v2 is fixed on the v4.

Is C7 v4 or V5 better ? V4 has two USB and V5 has one ?

Both revisions are virtually identical, but the v5 is more common among OpenWrt users - so while both should be fine, I would prefer the v5 (not that you'd have much of a choice anyways, as the v4 isn't produced anymore).

I used to use a C7 V2 and also got frustrated with the unstable wireless. I ended up disabling the wifi on the router and adding a Unifi AP AC LR wireless access point. The unifi access point has provided rock solid wifi and I get all the benefits of running openwrt on the C7V2 as my router.

Unifi has just released a wifi 6 version of their access points if you are interested. You can get an access point for $100-200 depending on the exact model.

This particular issue should be better with v5, but I personally wouldn't buy ath79 anymore, if you can get faster/ better ipq40xx devices for just about the same money.

Followup: I ended up ordering both an EAP245v1 and an Archer A7 (which is like the Archer C7, except it's guaranteed to be v5.)

The A7 arrived first, and I swapped it with my C7 v2. It didn't help--I still had unstable connections on 2.4GHz. However, in the course of setting it up, I noticed that turning off "Allow legacy 802.11b rates" fixed the problem completely. Unfortunately, I do have one 802.11b-only device, as well as some 2.4GHz-only 802.11n devices, so the solution wasn't that simple.

The EAP245v1 arrived later. I was surprised to discover that installing OpenWrt on the EAP245v1 requires a root exploit, and is not at all trivial. (Surprises like that are my least favorite OpenWrt feature. Admittedly I would have seen this one coming if I'd read the instructions more carefully, but I hate having to do hours of research just to make sure that a "supported" device is really supported.) It took a while to get it installed, but eventually it worked.

Now I'm using both the Archer A7 and the EAP245v1. The A7 has my main SSID on both bands, with 802.11b disabled. The EAP245 has my main SSID on 5GHz, and a separate "legacy" SSID on 2.4GHz, with 802.11b enabled. Between the two APs, I finally have everything covered. For the first time in years, all of my devices (even the 802.11b holdout) have a rock solid connection. Even roaming is working better for some reason--everything is mostly finding the right connection, instead of getting stuck on something stupid.

Thanks for all the advice.