Unexpected speed change after fitting BT equipment.

[WKYoung]

Firstly I should make it clear that this isn't a moan, just a question.

Until 10 days ago I was using a third party modem-router, ASUS DSL-AC68U, and was experiencing speeds of 27/6.9.  These results were comparable with those of a previous installation using a BT Openreach modem and RT-AC68U.  I assumed, therefore, that this was the limit of performance on the aluminium cable feed to my premises.

Imagine my surprise when, due to a problem with the modem-router which forced me to restore the older configuration of separate modem and router (in this case an ASUS RT-AC86U), the download speed started to wind up from 27 to 39Mbps over 5 days.  Sadly, the upload speed dropped from 6.9 to 6.3!

These changes fit exactly with the re-introduction of a BT Openreach (Huawei HG612-3B) modem and beg the question "Have I been punished in the past for using a non-BT modem?"  Additionally, whereas I couldn't run the BTW Speed test with the ASUS modem-router, it now works due to the BT modem. 

Has any one of you experienced similar performance behaviour when changing kit and does anyone think there is a hidden throttle based on the type of interface used with BT services?

[imjolly · Accepted solution]

there is no throttle of speed by using 3rd party kit and many report better speed using 3rd party modem and router

problem could easily be due to the problems you had resulting a possibly higher noise margin resulting in drop in speed.  post router stats which would help

[WKYoung]

Thanks, imjolly! (Loved Rikki Fulton and saw him in Edinburgh Kings Theatre quite often.)

I would have to go back over the stats for the different periods to get a clearer picture.  I do have SamKnows records to check.  It seemed quite surprising that a 50% speed increase should occur for what is basically a modem swap.  It would infer that the ASUS interface is much more susceptible to noise or signal level.  At least the change in speed was beneficial!

There is no router internal data as I had to factory reset the unit 3 times to restore its funtion.  This was all done offline and the unit is now in storage.

I have pulled Download, Upload, Latency and Jitter values for the connection since December, 2020.  Nothing untoward in the files.

[bkehoe]

It's pretty well known on most of the tech forums that Asus DSL routers (most have a Mediatek chipset) have a bad reputation and perform poorly on most lines with instability often resulting in banding at lower speeds to maintain stability. So what you've reported isn't actually that surprising and lots of people still seek to buy the HG612 (and unlock the firmware to enable viewing of line stats) due to the fact it's still one of the best performers, along with Zyxel devices that all use Broadcom chipsets.

[WKYoung]

Thanks for that info.  I am surprised that such a step change between the devices is possible and it raises questions as to why I bothered with a Modem-Router at all, rather than separate devices as I have now and had before!