BT Broadband Speed halved and DU Meter

[DWhitley]

My BT Broadband speed has recently halved to around 2245 Kbps using the same computer/software/antivirus etc. regardless of time of day or night. A couple of weeks ago, some sort of upgrade was performed at my exchange at Eltham, London SE9, and I wonder if this is connected.

My specific query is this. When I monitor a large file download using DU Meter, the speed is clearly and evenly truncated so that the graph appears as a smooth, rectangular block of red. I'm not an engineer but this suggests to me that the speed is being deliberately throttled at a specific maximum and is not a result of noise etc. which I would expect to be more spiky and variable.

Am I on the right track here please?

The contract is up for renewal around now and I'm tempted to tell BT to get lost.

[dangel]

BT do throttle - but the first question is what your synch speed is on your router? Could be line degradation in which case your BRAS profile might have dropped to compensate for it, which would explain a drop in speed. If it's not that, then you might well just be being throttled in which case, leave BT as I did.

[DWhitley]

Many thanks.

According to Home Hub admin, "Bandwidth" is 440 / 3,255 kbps Up/Down. I'm sure this used to be higher but can't vouch for it. Seems very low to me.

According to the BT speedtest, the IP Profile for my line is - 2500 Kbps. Even lower.

Looking around, IDNET looks promising.

Full info from Home Hub:

Link Information

Uptime: 5 days, 12:08:21
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 440 / 3,255
Data Transferred (Sent/Received) [MB/GB]: 969.47 / 20.09
Output Power (Up/Down) [dBm]: 9.5 / 0.0
Line Attenuation (Up/Down) [dB]: 7.0 / 16.0
SN Margin (Up/Down) [dB]: 17.0 / 32.0
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 0 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 0
HEC Errors (Up/Down): 0 / 0
Line Profile: Fast

[dangel]

Sounds like you're getting the maximum speed your line supports - as to why it (may have) dropped.. good question. Your IP profile is always lower than the synch speed BTW - they're fixed in predefined steps and so it's sounds about right (without looking). You could raise it with your ISP (BT) but they'll probably flannel you - it took me three months and dozens of calls to sort an issue with my line whilst on BT

[DWhitley]

Thanks once again.

This problem has focused my attention on the deal I'm getting from BT and encouraged me to leave. I've registered a complaint but don't expect to get a result. Last time I spoke to the call centre, they couldn't help but somehow found the time to tick me off for overusing the service.

The BT Vision box was a good deal at the time but the remote is playing up - another good reason to change (and buy a better one in case VAT goes up!).

[dangel]

Thanks once again.

This problem has focused my attention on the deal I'm getting from BT and encouraged me to leave. I've registered a complaint but don't expect to get a result. Last time I spoke to the call centre, they couldn't help but somehow found the time to tick me off for overusing the service.

The BT Vision box was a good deal at the time but the remote is playing up - another good reason to change (and buy a better one in case VAT goes up!).

I used to be with BT Business - service at that level is terrible too! Vote with your feet - there's plenty of choice out there

[watercooled]

Try rebooting your router to see if the sync speed increases.

[DWhitley]

Thanks everyone for your help.

I rebooted the home hub in the early hours based on the hunch that, if the problem is confined to daytime, it would stand a better chance of synchronising at a high speed at night (I'm not an expert at this, you understand). Sure enough, it synchronised at 8125 Kbps.

BT then redeemed themselves somewhat. The following day I had a phone call from a helpful Irish guy who knew what he was talking about. He said that my IP Profile had been reset (or something) and all should be OK.

The latest results are:

Download speed achieved during the test was - 6878 Kbps
For your connection, the acceptable range of speeds is 600-7150 Kbps.
Additional Information:
Your DSL Connection Rate :8125 Kbps(DOWN-STREAM), 440 Kbps(UP-STREAM)
IP Profile for your line is - 7150 Kbps
The throughput of Best Efforts (BE) classes achieved during the test is - 12.2:21.56:66.24 (SBE: NBE: PBE)

That'll do for the time being.

BTW: speedtest.net gave me the following figures:

Download 27 Mbps !!!!!!
Upload 0.29 Mbps

which is just bizarre.

[watercooled]

Glad you got it sorted. But ignore those Speedtest results, sometimes the test data gets cached somewhere (often antivirus software) so you don't see your true speed. Try downloading a large file such a Linux CD and see what the speed evens out at or try temporarily disabling your AV/clearing browser cache/using different server and run speedtest again - this is a problem that really needs sorting though!

[arbitrabbit]

Don't know what your new SNR looks like... the old one was massive and you don't need that high SNR....you can try reducing it if your router allows it and see if that increases your speed even further

[DWhitley]

Interesting - not aware of any such adjustment in the Home Hub but I'll look again. The S/N ratio has gone down a bit:

Uptime: 4 days, 12:59:18
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 440 / 8,126
Data Transferred (Sent/Received) [MB/MB]: 89.95 / 496.58
Output Power (Up/Down) [dBm]: 11.0 / 0.0
Line Attenuation (Up/Down) [dB]: 7.0 / 16.0
SN Margin (Up/Down) [dB]: 33.0 / 24.5
Vendor ID (Local/Remote): TMMB / IFTN
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 0 / 0
FEC Errors (Up/Down): 0 / 59
CRC Errors (Up/Down): 0 / 0
HEC Errors (Up/Down): 0 / 0
Line Profile: Fast

[arbitrabbit]

Ya, your SNR is massive

For example, my stats are

ADSL Link Downstream Upstream
Connection Speed 20787 kbps 1356 kbps
Line Attenuation 13.5 db 8.1 db
Noise Margin 4.9 db 6.6 db

With my stats, I don't see any errors, so I am sure you can increase your line speed quite significantly (unless your ISP is capping your speed, in which case tough luck). Unfortunately many routers don't allow this setting, especially the ones supplied by the ISPs. Which one do you have?

[DWhitley]

I use BT's Home Hub v1.5 which has been trouble free. My DECT phones are registered to it for better performance.

I still have a Draytek Vigor 2600 around somewhere. As I recall, it's highly configurable (ie: complicated). Now that my curiosity has been well and truly aroused, I'll dig it out and give it a try.

Late night coming up!

[arbitrabbit]

I use BT's Home Hub v1.5 which has been trouble free. My DECT phones are registered to it for better performance.

I still have a Draytek Vigor 2600 around somewhere. As I recall, it's highly configurable (ie: complicated). Now that my curiosity has been well and truly aroused, I'll dig it out and give it a try.

Late night coming up!

I could be wrong but I don't think you can set the target SNR on Vigor 2600. That feature was introduced in the 2800 series I believe.