Draytek provided me some new firmware to test on the 28th Mar, I have now loaded and completed the same tests as before, sadly the results are the same, here are the details :-

VDSL Modem Code : 1414c3




BT SpeedTest run with new Firmware on the Draytek


BT SpeedTest after switching back to BT Modem and TP Link Router

An observation- your downstream snr is similar to my 2850n but your upstream is only 63 compared to 92 on mine (my IP profile is also 20 and I get approx 14mb upload with the Draytek). You also seem to have a lot of errors.The high Total UAS figure suggests a lot of errors causing drops in connection. I'm confused as to why this is only affecting the upload speed. Possible hardware fault with the Draytek? Bad filter in the master socket?

niggly54 wrote: An observation- your downstream snr is similar to my 2850n but your upstream is only 63 compared to 92 on mine (my IP profile is also 20 and I get approx 14mb upload with the Draytek). You also seem to have a lot of errors.The high Total UAS figure suggests a lot of errors causing drops in connection. I'm confused as to why this is only affecting the upload speed. Possible hardware fault with the Draytek? Bad filter in the master socket?

This is not just happening for me, the results are repeated by others, ie 50% drop in upload speed while download remains the same.

Also the same filter and cable are used when I switch back to the supplied BT equipment, the speed then goes back to what I would expect, it doesnt slowly increase, straight away its back.

I can understand your frustration, and I know others have had this issue. My comments were based on the data you supplied from the VDSL setup screen of the Draytek- there are a lot of errors reported on the upload side. It may well be the BT modem is more tolerant of errors, and I notice the Draytek reports it is connected to a Broadcom DSLAM at the cabinet (Server information Broadcom v10 etc). You have a Huawei HG612- that also contains a Broadcom chipset. The matching of chipsets is supposed to improve speed and compatability. I don't recall- but have you tried disabling QoS? My Draytek's upload speed drops with this enabled. In my experience, the Drayteks in general sacrifice speed in the pursuit of a reliable connection. It may well be that your high error rate is causing the speed drop, and this is something your BT modem is less concerned about. Without 'hacking' the firmware on the BT modem, you cannot otherwise interrogate it to see what the statistics are.

I notice that, in all but one example, you seem to be using the BT speed tester. I, too, noticed an apparent halving in the reported upload speed, after BT updated there tester, recently. However, if I use other speed testers, such as http://www.thinkbroadband.com/speedtest.html or http://www.speedtest.net/ I get excellent results.

Even though I can't think what it could be, there may be a compatibility problem the 2750 and the BT speed tester.

Mike.

That's a good point Mike. I too have noticed some variation in the results from the BT tester. Speedtest.net seems to give the most consistent results. There are still however, a lot of errors occurring on the upload side with the Draytek, which may explain it's poor performance. One other thought- what is your MTU set to in the internet set up?

EDIT: Just found this on the BT Care Forum-
Problem solved,it was the QoS settings in my DrayTek 2750n,I had not set an upload port setting properly and was getting a conflict on one of my Gb LAN ports,which was stopping the WAN port on upload getting above 5000kbps approx.