Linksys WRT-1900ACS Reviewed

[htismaqe]

What I'd like to see on these WRT routers is a (recessed) switch that toggles the boot partition. The times that I've bricked my WRT1900AC, I've had one intact boot partition that had a usable firmware image. If I could just switch to that boot partition without going the serial console route, that would be really nice *smile*.

A recessed botton or toggle would be nice but you already can do what you want.

Every time you flash the WRT1900AC, it keeps the previous firmware in the 2nd partition. If you flash to DD-WRT it keeps the stock firmware in the 2nd partition.

The process for backing out is to just power the router on and off 3 times in a row. I've done it and it works just fine.

 

[htismaqe]

That is the number one reason why i've bought the V2, strong hardware, decent build, and at that moment support from both dd-wrt and openwrt, so i would never get stuck on the firmware linksys provides. Only pet peeve until now is the horrible job they've did with the opensource Wifi driver support. Although I (still) have good hopes that will eventually sort itself out.

Thing that bugs me though is that they aren't clear on their hardware specs. My V2 has more ram and a faster CPU than stated on the box. Sounds nice, but as it is a "freebe" it's unsure if the device they sell a month later still has the same hardware.

I have a V1 and DD-WRT runs great. Wireless performance is on par with stock, maybe even a little better. And it's more stable as well.

 

[RogerSC]

A recessed botton or toggle would be nice but you already can do what you want.

Every time you flash the WRT1900AC, it keeps the previous firmware in the 2nd partition. If you flash to DD-WRT it keeps the stock firmware in the 2nd partition.

The process for backing out is to just power the router on and off 3 times in a row. I've done it and it works just fine.

Hmmm...that's not the way my WRT1900AC works. When I flash it, the new flash goes into the other boot partition. For example, if I have stock firmware in boot partition 1 and flash dd-wrt it goes into boot partition 2. If I then update the dd-wrt firmware using the .bin image, that update will go into boot partition 1. So you will have dd-wrt firmware in both partitions. In other words, each time you flash, the new image goes into the other partition.

The way that I prefer to do it is to keep Linksys stock firmware in boot partition 1. Then when I want to flash dd-wrt, it always goes into boot partition 2. If I want to upgrade the dd-wrt version, I reboot back into the stock partition (partition 1), and flash the new dd-wrt image into boot partition 2, and I still have stock firmware in partition 1. Been doing this for maybe 6 months now, and it works well for me. I always have stock firmware to revert to in boot partition 1 if I need it.

I don't know why your router works differently than mine, though.

 

[htismaqe]

No, yours works exactly the same way mine does. Maybe I misread/misunderstood your previous posts.

You are correct, it basically recycles the 2 boot partitions. The way I do it is identical to what you're doing. I was just confused as to why you mentioned the need to access the serial console...

 

[htismaqe]

Oh I see what you're saying now. You're saying you wish we could specify which partition to use and keep using it instead of recycling like it does now 1-2-1-2-1-2 every time you flash.

 

[xtremesniper]

it does..

more later..

It's interesting because I am unable to get an ACS in Canada (so far) so I have to pick from a v1 or a v2... and if people are saying that ACS is just a re-branded v2 (which I don't think it entirely is given the different specs) then I'm thinking I will experience similar issues with v2. If it can be resolved by moving off Mixed mode then that would be handy info to know.

 

[Irken Skoodge]

It's interesting because I am unable to get an ACS in Canada (so far) so I have to pick from a v1 or a v2... and if people are saying that ACS is just a re-branded v2 (which I don't think it entirely is given the different specs) then I'm thinking I will experience similar issues with v2. If it can be resolved by moving off Mixed mode then that would be handy info to know.

Read this page it tells you about the v2 and the ACS
https://wikidevi.com/wiki/Talk:Linksys_WRT1900AC_v2

 

[xtremesniper]

Read this page it tells you about the v2 and the ACS
https://wikidevi.com/wiki/Talk:Linksys_WRT1900AC_v2

Thank you for that link. It re-affirms that they're the same. I just hope they distribute firmware updates equally to both models.

But why would they want to discourage people from buying a v2 if it's more expensive? Wouldn't they want to clear stock? I don't really get the intention behind it...

I haven't been to the store yet to find out what version they have in stock but I will try for tomorrow. I'm still a bit weirded out by the ACS review showing it performing much worse on various aspects compared to the AC v1, though.

 

[Allegator]

New firmware up on the Linksys site:

Firmware version: 1.0.0.169041
Release date: November 10, 2015

- Integrated an updated wireless driver (v7.2.9.2)

Thank you for that link. It re-affirms that they're the same. I just hope they distribute firmware updates equally to both models.

But why would they want to discourage people from buying a v2 if it's more expensive? Wouldn't they want to clear stock? I don't really get the intention behind it...

I haven't been to the store yet to find out what version they have in stock but I will try for tomorrow. I'm still a bit weirded out by the ACS review showing it performing much worse on various aspects compared to the AC v1, though.

 

[htismaqe]

Not particularly promising. Assuming that a V2/V1 release will follow in the next 14 days or so (that's the way it was with the V2/V1 releases previously) they won't have addressed anything significant. I'm guessing this wireless driver addresses some of the reported 2.4Ghz issues that exist in the ACS but don't exist in the V2/V1.

So after nearly 5 months, V2/V1 users are getting nothing in terms of firmware updates.

 

[sfx2000]

Not particularly promising. Assuming that a V2/V1 release will follow in the next 14 days or so (that's the way it was with the V2/V1 releases previously) they won't have addressed anything significant. I'm guessing this wireless driver addresses some of the reported 2.4Ghz issues that exist in the ACS but don't exist in the V2/V1.

So after nearly 5 months, V2/V1 users are getting nothing in terms of firmware updates.

I would expect a kick for the V1/V2 and WRT1200ac with the driver update as well to resolve some TurboQAM issues with AC aware clients...

Would be nice if Belkin/Linksys would clear the air about the ACS vs. V2 - lot of misinformation being pushed around..

 

[htismaqe]

That's a nice-to-have considering so many people are using 20/40 on 2.4Ghz.

Why not address some of the lingering issues with the UI?

 

[sfx2000]

Looked odd to me too. So I ran tests four times vs. the usual two. Only one run was significantly different. But the throughput vs. attenuation curve looked odd, so I didn't use it.

After a fair amount of independent testing and debug - the problem is understood and it does have to do with Marvell's implementation of TurboQAM (QAM256).

Marvell has implemented TurboQAM by basically setting the 2.4GHz radio (wdev1ap0) to 802.11ac mode (opmode 23 in the driver) and certain other client chipsets go into a dark place - putting the chip into opmode7 (b/g/n) fixes it - also noted in 3rd party FW as HT20 mode (HT40 also works, but nobody should be doing wide channels in 2.4 these days) - part of the problem is that if the client chipset is an A/B/G/N/AC, and running in 2.4GHz mode, it goes into AC mode, and in 20MHz channels, the Marvell can stay in MCS9, which is an invalid coding/ec scheme (20MHz, 11ac tops out at MCS8, 40/80MHz, MCS9 is valid)

I've reached out to a contact at Linksys with findings to get their response.

Note - for 2.4GHz, changing the radio mode from the default "Mixed" to B/G/N-Only solves the problem, but basically makes this an AC1750 class router as a result.

5GHz is perfectly fine... (wdev0ap0 running in opmode28 which is VHT80 mode in *WRT)

 

[sfx2000]

To explain opmode, the marvell driver has several:

Opmode:Mode - the ones in bold are for 2.4GHz, unbold is 5GHz, it's the same driver for both bands
1:b
2:g
3:b/g
4:n only [2.4GHz]
6:g/n
7:b/g/n <--- my recommended "B/G/N-Only" setting for WRT1900/WRT1200
8:a
12:a/n
13:n only [5GHz]
23:b/g/n/ac <--- Linksys Mixed Mode default for 2.4GHz
28:a/n/ac <--- Linksys Mixed Mode default for 5GHz

 

[thiggins]

Thanks for the research sfx. Your fix is fine, since there are precious few 2.4 GHz devices that can talk 256-QAM anyway. The main benefit of AC1900 class routers vs. AC1750 is their more powerful processor.

 

[sfx2000]

Thanks for the research sfx. Your fix is fine, since there are precious few 2.4 GHz devices that can talk 256-QAM anyway. The main benefit of AC1900 class routers vs. AC1750 is their more powerful processor.

Concern here is not direct TurboQAM support, but that chipsets that are dual-band and support 802.11ac might run into issues with Marvell based AP's running in b/g/n/ac mode...

Wasn't an issue back last year when the WRT1900acV1 was introduced, but getting to be a bigger problem now...

So again, my recommendation for any of the WRT1900's or the WRT1200ac is to put the 2.4GHz radio into B/G/N-Only mode...

 

[Allegator]

Since updating my 1900acs to the new firmware (1.0.0.169041) I'm noticing that my Dell laptop (2.4GHz b,g,n) does not connect unless I reboot the router. This has happened twice in as many days. The 2.4GHz light comes on briefly and I get the message "cannot connect to this wireless network." No problems at all with any of my 5GHz devices. Does Linksys have any easy way to send such feedback?

 

[sfx2000]

Since updating my 1900acs to the new firmware (1.0.0.169041) I'm noticing that my Dell laptop (2.4GHz b,g,n) does not connect unless I reboot the router. This has happened twice in as many days. The 2.4GHz light comes on briefly and I get the message "cannot connect to this wireless network." No problems at all with any of my 5GHz devices. Does Linksys have any easy way to send such feedback?

On the WRT side, is the 2.4GHz radio set to "Mixed" or "B/G/N-Only" mode?

 

[chadster766]

Since updating my 1900acs to the new firmware (1.0.0.169041) I'm noticing that my Dell laptop (2.4GHz b,g,n) does not connect unless I reboot the router. This has happened twice in as many days. The 2.4GHz light comes on briefly and I get the message "cannot connect to this wireless network." No problems at all with any of my 5GHz devices. Does Linksys have any easy way to send such feedback?

I'm monitoring this thread. If this doesn't resolve after some additional troubleshooting I will notify Linksys engineering.

 

[Allegator]

On the WRT side, is the 2.4GHz radio set to "Mixed" or "B/G/N-Only" mode?

It's set to "Mixed." The dropdown does not list N at all, only B, G, B/G or Mixed.