Hi, I've been trying to get some support from the BT Technical Support helpdesk resolving my issues, maybe somebody here could help...
In the beginning, I was getting 6Mbps throughput at an 8Mbps sync rate - I'm 900m from the exchange as the crow flies, typical line power was 7dB margin and 18dB attenuation downstream using a Voyager 220V - overall I was pretty happy with the service. Time goes on and I decide to change the broadband package I'm on as there are more up to date packages from BT offering similar at a lower price.
So I called up BT and told them to switch my package over, then, during an large download last week, I noticed that my throughput has dropped from 6Mbps (800kBps avg) to <2Mbps (220kBps avg). I investigated and found the BT speed tester site - this is what it tells me:
Download speed
achieved during the test was - 1.87 Mbps
For your connection, the acceptable range of speeds is 0.4 Mbps-2 Mbps.
Additional Information:
Your DSL Connection Rate :8.06 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 2 Mbps
I started contacting BT and they tell me everything's ok - well it's not, I'm sync'd at 8Mbps and BT's only letting 2Mbps through.
I started looking at the voyager 220V's statistics pages - 30 days up time, sync rate 8Mbps, Super frame errors: ~500, HEC errors ~450, line attenuation: 18dB, Margin: 7.1dB... all good....
BT tells me to leave it 72 hours and see if it'll pop back - nope, wednesday comes around, been running a speed test each morning and the IP profile is still capped, and despite resetting the router, the only change I see is a reset in the timers and the error rate rising slowly (1 or 2 errors per hour perhaps)
Yesterday a new BT business home hub arrives, and despite leaving everything disconnected for an hour before hooking it all back up, I still have a cap.
Here's what the Hub's telling me:
| DSL Line (Wire Pair): | Line 1 (inner pair) | |
| Downstream Rate Cap: | 8128 kbps | |
| Downstream Atten. at 300kHz: | 14.7 dB | |
| Uncancelled Echo: | -18.3 dB | Ok |
| VCXO Frequency Offset: | -76.7 ppm | Ok |
| Final Rx Gain: | 17.0 dB | Ok |
| Excessive Impulse Noise: | 0 | Ok |
| Downstream Required Impulse Noise Protection: | 1 | |
| Downstream Impulse Noise Protection: | 0.13 | |
| Downstream Delay of Latency Path: | 8.00 ms | |
| Upstream Impulse Noise Protection: | 1.00 | |
| Upstream Delay of Latency Path: | 8.00 ms | |
| Framing Mode | ATM |
And here's the training history for the past 24 hours
| ime | Line | Rate | Max1 | Max2 | Max3 | Mgn1 | Mgn2 | Attn | Pwr | CRCs | FECs | INP | DLY | Rate | Max | Mgn1 | Mgn2 | Attn | Pwr | CRCs | FECs | INP | DLY | Mode | Vendor | State | Exit Code | Echo | VCXO | Rx Gain | ||
| 2012/09/28 09:16:04 BST | 1 | 8064 | 8128 | 8128 | 8128 | 7.1 | 7.0 | 17.9 | 17.7 | 3 | 4 | 0.13 | 8.00 | 448 | 1088 | 25.0 | 25.0 | 8.0 | 12.2 | 0 | 1 | 1.00 | 8.00 | G.DMT Annex A | Unknown | 240/104 | N/A | -18.3 | -76.7 | 17.0 |
I did print a log from the beginning of the week with info from the Voyager 220V:
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:20:35:34
Line Coding Trellis On Line Up Count 1
Statistics Downstream Upstream
Line Rate 8128 Kbps 448 Kbps
Noise Margin 7.6 dB 25.0 dB
Line Attenuation 19.0 dB 10.5 dB
Output Power 19.8 dBm 12.2 dBm
K (number of bytes in DMT frame) 255 15
R (number of check bytes in RS code word) 0 8
S (RS code word size in DMT frame) 1 8
D (interleaver depth) 32 4
Super Frames 4360748 4360746
Super Frame Errors 4 0
RS Words 296530894 37066341
RS Correctable Errors 0 0
RS Uncorrectable Errors 0 0
HEC Errors 2 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0
Can anyone help at all? I've been chasing this around all week now, and wondering what all this "prompt care" is all about....
Well... seems it's resolved, but it's taken a week to get it done - prompt care is supposed to guarantee a fix by the end of the next working day, but this has taken a lot longer than that and I'm annoyed.
For anyone else who's interested, my research pointed to a fault in the software running in the exchange leading to a "locked" 2Mbps profile. To fix the problem, the chaps ran what's called an "SNR Reset" - I'm guessing that this is a Signal/Noise ratio monitoring system reset (the bit of software that sets the profile)
Download speedachieved during the test was - 6.53 Mbps
For your connection, the acceptable range of speeds is 0.6 Mbps-7.15 Mbps.
Additional Information:
Your DSL Connection Rate :8.06 Mbps(DOWN-STREAM), 0.45 Mbps(UP-STREAM)
IP Profile for your line is - 7 Mbps
Maybe this will help someone else out in the future, in the meantime, disregard this thread... this thread will self destruct in the next 5 seconds.....
