Hi

I've been trying to identify a problem with a Cisco 802.11 VoIP phone, and as part of the checks, I switched from my 2820Vn back to the standard Sagem as supplied to me by Sky. Out of curiosity, whilst it was in place I tried the broadband speed checker test and was really surprised at how fast the Sagem was in the upload direction. I know what to expect here as I've tried it many times before (using my Draytek) and I just assumed it was a one-off (low contention and with the wind blowing in the right direction) but having now swapped the Draytek and Sagem several times and performing many tests, the results are always very similar:

Draytek:
Down=6 Mb/s
Up=450 Kb/s (most commonly 430 - 450, but once almost 480 Kb/s)

Sagem:
Down=6 Mb/s
Up=570 kbs (normally 560 - 580, but once over 600 Kb/s)

In truth, the download is actually very slightly faster using the Sagem too, but it's so small a difference that it would be within the expected window of variation anyway, but the upload is massively faster using the Sagem (and often reaches 600 KB/s) and I'm really puzzled at why it could be such a large difference. Can anyone think of any custom settings Sky might have in their broadband routers which I could try to emulate in the Draytek (via CLI changes)? Could it just be that the Draytek's transmit level is a little too low?

Bri

The shown connection statistics are 7006 Kb/s down and 796 kb/s up with SNR margin of 9 dB and loop attenuation of 50 dB

The firmware is 3.3.5.2_232201

Ha; I've found the culprit and now fixed things...

Turn off QoS via the CLI:

qos setup -m 0
sys commit
sys reboot

Tried broadband speed checker and the figures were as below

Down 6020 Kb/s
Up 628 kb/s

I thought I had disabled QoS in the GUI but found a forum post here and tried it; the difference is absolutely massive!

So I'd guess that some pretty key questions are:
When you disable QoS via the web interface, why does it still restrict the upload speed to 80% of the available capacity?
Is it really the case that the only way to fix it is by CLI, or have I missed something buried somewhere obscure in the GUI?
How many Draytek customers (ones who don't need QoS) are needlessly suffering this upload bottleneck simply because they don't know about it (I only found it by accident when comparing routers)?
Why is there nothing about this on the Draytek on-line guide to improving broadband speed ?

Bri

Actually, having thought about it, I've turned it back on but tweaked the it to the below:

qos setup -D (factory default)
adsl txpct 100
adsl rxpct 100
sys commit
sys reboot

So that if required, I can reduce these to 85% and thus leave guaranteed capacity for my VoIP phone (I'm assuming that's why it's enabled by default)

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Update (16th April 2012): After watching the excellent 'Security Now' programme (http://www.twit.tv) about buffer bloat, I can see that it makes great sense to set the txpct to somewhere below 100% (so I'm now going to set mine to 95%).