topic Re: Does Hub2 do automatic throttling to prevent service loss? in My Router

Does Hub2 do automatic throttling to prevent service loss?

MisterPlusBoy — Tue, 28 Feb 2023 15:04:27 GMT

When I was with BT, we had issues that uploading a large file would cripple the home internet - you couldn't load web-pages or anything really. You could try to max out download and things would still work, but maxing an upload we basically had no service while this was going on.

I was surprised that the router didn't try to mitigate this. Is Hub2 any different? I've used a router which lets you throttle but only very crudely by setting absolute limits. It seems like really it should reserve a tiny bit of upload bandwidth so outgoing HTTP requests can still get through.

Some apps like OneDrive tend to intelligently throttle uploads but not all.

Re: Does Hub2 do automatic throttling to prevent service loss?

Mav — Tue, 28 Feb 2023 16:26:47 GMT

Moderator's note(s):

Thread moved from Broadband to My Router.

Re: Does Hub2 do automatic throttling to prevent service loss?

seebee — Tue, 28 Feb 2023 16:58:57 GMT

I don't think PlusNet supply routers with "Smart Queue Management" ( SQM ) which is basically what you want. This is needed to prevent the bufferbloat that causes the latency increase.

I can only get ADSL at home, so 1 Mb/s up, 18 Mb/s down - it's easy to swamp the upload - then downloads also suffer as the required ACK packets struggle to get uploaded. That's typically why a home ISP user sees poor performance when uploading a lot at the same time.

I use an OpenWrt router connected to my PlusNet router, and have SQM enabled and it is a massive improvement. In the early hours of each morning I test the download using Ookla's Speedtest.net (the CLI version, from a Raspberry Pi connected by ethernet cable). Download never suffers particularly, as you have noticed.

Without SQM (ie like a normal user with an ISP router) I get:

ISP: Plusnet Idle Latency: 13.27 ms (jitter: 0.42ms, low: 12.82ms, high: 13.64ms) Download: 19.10 Mbps (data used: 17.9 MB) 78.50 ms (jitter: 6.35ms, low: 21.58ms, high: 113.84ms) Upload: 1.01 Mbps (data used: 1.2 MB) 2507.03 ms (jitter: 112.27ms, low: 381.75ms, high: 4400.32ms) Packet Loss: 0.0% Result URL: https://www.speedtest.net/result/c/7e715020-a0b8-4548-97e4-a9a9ac6b74e3

So typical ADSL maximum download and upload speeds.
But the average latency increase to 2500 ms (peaking at over 4 seconds) when the upload is busy. Compared to a typical latency of 13 ms

With SQM turned on, I get:

ISP: Plusnet Idle Latency: 18.98 ms (jitter: 0.31ms, low: 18.52ms, high: 19.33ms) Download: 17.74 Mbps (data used: 15.7 MB) 21.00 ms (jitter: 2.34ms, low: 18.78ms, high: 65.50ms) Upload: 0.95 Mbps (data used: 1.3 MB) 25.04 ms (jitter: 3.71ms, low: 18.78ms, high: 44.09ms) Packet Loss: 0.0% Result URL: https://www.speedtest.net/result/c/70b877b5-8a06-40bc-ad5f-6cb94b019bad

So by sacrificing say 5% of my upload (0.95 Mb/s compared to 1.01 MB/s) I see an average latency of only 25 ms (peaking at only 44 ms) - a 100 fold improvement in latency.

It does need a bit of tweaking to set it up originally to balance the sacrifice of raw speed to latency.
It is a shame no ISP offers it (that I know of).

Re: Does Hub2 do automatic throttling to prevent service loss?

MisterPlusBoy — Tue, 28 Feb 2023 17:33:57 GMT

Many thanks @seebee I had never heard of most of those terms but they describe exactly the issues.

I'm assuming your PlusNet router is basically serving as just the modem, all your devices connect (whether Wifi or ethernet) to the OpenWrt device and this is the only thing plugged into the back of your PlusNet hub?

Do you have to manually set the upload maximums or does the SQM tool do that automatically?

Re: Does Hub2 do automatic throttling to prevent service loss?

seebee — Tue, 28 Feb 2023 17:39:20 GMT

Correct. Although I am using the Plusnet hub zero as a router, but nothing else connected to it, so I am doing double-NAT which is not recommended. At other times I have used an HG612 in modem mode with my OpenWrt router as you say. I've not used one, but the Plusnet Hub2 does a modem mode.

EDIT - I had to manually enter then test (and repeat...) the upload and download limits in SQM.