BT Home hub 5A and poor 5 Ghz to LAN ports speed

Installing and Using OpenWrt
1

Hi,

Just recently flashed a HH5A (actually a a plusnet) router and all is well, apart from i have limited throughput on the 5 Ghz to LAN ports.

My internet speed is like 60+ Mbits and i can that part works ok, but where I would usually see 40-50 Mbytes/sec on LAN transfers using my laptop with 2 x 2 AC 7260 and a TP-Link AP using openwrt, i can only get around 10 Mbytes/sec even though i'm apparently connected at the same 867 Mbps (same room, same distance to router).

Does anyone know what the cause might be?

Thanks,

Neil

2

Two things to test first, enabling flow-offloading (no, it won't directly help your wlan throughput - but it removes some load from the CPU) and installing irqbalance (you need to start it manually).

3

Can I do these things in the 18.06 stable?

Am I right in thinking that the any NAT issue (i.e. offloading) has nothing to do with bridged WLAN to LAN connections?

4

While I remember, I noted the ath10k driver reports the wrong Tx (or it Rx) for the 5 Ghz radio. Is this just cosmetic, or are there other issue's the the 5 Ghz driver?

Thanks

Neil

5

Yes, you can do all that with 18.06.

As mentioned, offloading can ease the CPU load a bit - while you don't strictly need offloading for 60 MBit/s, your wlan is also competing for CPU cycles, so if you don't spend that much on pure routing, you have more cycles left to service the IRQs of your wlan.

6

Yea, I can understand that, just thought it was strange as the Tp-Link RE450 I have that has 5 Ghz works just fine

7

lantiq is a bit marginal in terms of raw CPU power, you need manage your cycles (OEM firmwares tend to have access to further hardware acceleration units, currently unavailable to OpenWrt).

8

Ah, gotcha.... thanks

9

OpenWrt 18.06 for the Home Hub 5A comes with Linux kernel 4.9.x which does not support flow offloading.

10

Ah, yep, I forgot about that - so master snapshots it is; irqbalance can be tested independently of that.

11

I just did a test after installing htop and can report that as slh said, both cores of the CPU are almost flat out during a 5ghz file copy.

I've tested LAN to LAN and there are no such load issue's, so I can assume the ath10k driver is taxing the CPU, would that be right?

So, to resolve... do I need to create my own build, or is the latest snapshot suitable?

Thanks

Neil

12

The latest snapshots are suitable (but don't have the webinterface, luci, preinstalled), keep in mind that LAN-to-LAN transfers are handled exclusively in the switch hardware and never touch the CPU (unlike WAN-to-LAN or LAN-to-WLAN).

13

Ah ok, cool. Yea I've used source and snapshot's before, so no bother there :slight_smile: thanks for the help

14

Hi guys

I've just flashed v19.07.2 and have setup the BT HH5 as dumb AP. The link speed of the 5GhHz WiFi to my phone is 585Mbps but I'm only getting 80Mbps using the Ookla Speedtest app as my testing tool. My WAN speeds are 300Mbps and can easily acquire these speeds on my other two Linksys AP's. What am I missing? There's talk of using the master/snapshots, builds so what's different in those that isn't in the v19.07.2 firmware?

15

Known issue.

There is a thread on same subject, but I can't find it at the moment.

In any case, it refers to section 7.12 of installation guide for HH5A.
https://www.dropbox.com/sh/c8cqmpc6cacs5n8/AAA2f8htk1uMitBckDW8Jq88a?dl=0

Imho, for maximum LAN to wireless performance and wireless device compatibility, I recommend using stock firmware with access points.

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