Last week, 3 March to be precise, my immediate neighbours changed their Internet service from Virgin Media to another ISP, necessitating the reconnection of a BT line. The Openreach van was outside our properties most of the afternoon, during which time my download speed dropped from 7 mbps to 4.3 mbps. It swiftly returned to normal. Between 4 and 7 , the SNR margin fell to a range of 14-11.5 dB. Moreover, a very stable router began to lose sync for brief periods a couple of times per day.
On 8 March, I found that my line had been interleaved. Downstream SNR rose to 15-14, though the line continued to lose sync briefly. FEC errors ran into thousands. I plugged into the test socket, hoping to locate the source, but the problem continued. I installed a new set of micro-filters. I then emailed IDNet support, which has always been second to none.
My first email did not get a reply. My second message got a response just as I was sending through email No 3. The very local BT work was simply written off as coincidence. Itís a whopper coincidence if true. Either way, I did not think the agent took the issue as seriously as did IDNet staff to whom I have spoken about relatively minor issues.
The line was stable yesterday. However, this morning I found that my IP Profile had dropped from 7500 kbps to 7000 kbps and I lost sync for about 12 seconds. I phoned IDNet and spoke to the agent who had answered my email. He insisted the BT work at my neighboursí property is coincidental and suggested I try a new router. Iím doing this right now. Here are the stats from a BT Voyager 2500 I bought as a test router about 3 years ago:
Line Mode G.DMT Line State Show Time
Latency Type Interleave Line Up Time 00:01:49:49
Line Coding Trellis On Line Up Count 1
Statistics Downstream Upstream
Line Rate 8096 Kbps 992 Kbps
Noise Margin 14.9 dB 10.0 dB
Line Attenuation 22.0 dB 12.5 dB
Output Power 19.8 dBm 12.5 dBm
K (number of bytes in DMT frame) 254 32
R (number of check bytes in RS code word) 20 16
S (RS code word size in DMT frame) 1 4
D (interleaver depth) 32 4
Super Frames 387570 387568
Super Frame Errors 4 0
RS Words 52709616 6588656
RS Correctable Errors 554 0
RS Uncorrectable Errors 36 0
HEC Errors 1 0
OCD Errors 0 0
LCD Errors 0 0
ES Errors 0 0
This might prove things one way or the other. If the issue is routerĖrelated perhaps Iíll get my excellent stats back eventually. If not, Iíll probably have to live with a line/BT environment that was not what it was on the morning of 3 March.
Whatever the outcome, Iíve had better support as a BT Yahoo customer back in 2002-05. IDNet charge premium prices and, until now Iíve never begrudged a penny. Now Iím thinking I could do as well, if not better, with one of sever ISPs with UK-based support.
I ramble. The principle purpose of this post was to query what you make of the fact that my issue began with my neighbours' reconnection to BT.
Sync: Was 8128 / 896 + kbps; now interleaved at 8096/896 kbps
IP Profile was 7150 kbps; now 7000 kbps
SNR Margin: 15-12.5 dB
Line Attenuation: 20.0 dB
I am approximately 930 metres from the exchange (straight line distance)