[DavePlus]

(Sorry, this is a lot longer than I had originally planned!)
TL:DR: DD-WRT beta r32753 working great on Netgear R6300, but I still want to use faster WiFi LAN speed on my Linksys EA9500.

I've got a router that had great reviews, thought it would take care of all my needs (and wants). It's a Linksys EA9500, which is a big box with AC5400 MU-MIMO
...but if I just start one cloud backup, then no one can hear me on my VoIP phone, 'Alexa' in my Amazon Echo starts ignoring me...and even streaming video becomes choppy.

I think to myself, I've got 100Mbps down and 5Mbps up, which should be plenty. Even with cloud backup slowed to 3Mbps, real-time apps just got hammered.

FINALLY figured out it's: BufferBloat! In DSLReports speed test, I see bufferbloat number jumping to over 1000ms, and they graded me with an F.
I tried fiddling with QoS on the Linksys, but couldn't find anything that helped.

I found out about the FQ-CoDel packet queueing in DD-WRT, so, I pulled a Netgear R6300 (v1) out of the garage and crossed my fingers.

This was the first time I've tried using DD-WRT. I downloaded the
DD-WRT v3.0-r32753 giga (07/19/17)
from:
http://download1.dd-wrt.com/dd-wrtv2/downloads/betas/2017/07-19-2017-r32753/netgear-r6300/

Installation was a piece of cake using the .chk file on the original Netgear firmware.

Turning on FQ-CoDel, now I've got an 'A' for bufferbloat from dslreports, and I can use my phone & talk to Alexa while doing big uploads.
I did have to throttle download to 80Mbps and upload to 3Mbps to make it work, but the slowdown is well worth it for CONTINUOUS connection.

Question though... All my IoT devices are configured for my Linksys, and I didn't want to lose the LAN WiFi speeds using media server, roku, chromecast, NAS backup, etc.
..so I've connected: Cable Modem <----> Netgear R6300 <------> Linksys EA9500, and the WiFi turned off for the Netgear. Using just the WAN and one LAN port on the Netgear. I'm double-NATted.

It's been up and running for 3 days straight, but I can't help but wonder if there is some better way to configure DD-WRT settings (bridging? )
I want to keep the LAN WiFi performance of the Linksys, but the packet queueing of the FQ-CoDEL QoS.
As far as I know, there's no DD-WRT for the Linksys (yet?).

Thanks!

[egc]

Use the EA9500 as a WAP (wireless access point) see: https://www.dd-wrt.com/wiki/index.php/Wireless_access_point
Basically connect netgear LAN to EA9500 LAN, on the EA9500 disable DHCP and disable WAN.

[DavePlus]

Thanks. I've changed configuration so EA9500 no longer does DHCP, and now it's connected to the Netgear via LAN ports at both ends.

Everything seems to be working well.... bufferbloat is gone!