Do you have attenuation around 52dB?

What kind of sync are you geting? And what SNR do you find gives you a stable line.

The reason I ask is that I am having problems at the moment. I used to get a very reliable line which would stay up for days.

Please don't post and say "my attenuation is 9 and I get 20Mbit" I need some real world figures so that I can decide how far to push my ISP to get BT involved.

For Info, I have a faceplate filter on my master socket right at the front door. I took out the wiring to the upstairs which dropped my attenuation to 52/53dB. (from 56/57)

My SNR starts at 11 or 12 dB but drops like a stone day and night.

During the day my line syncs at 37xx - 38xx (was 44xx when first activated 2 years ago) but drops a lot.

At night line syncs well below 29xx with constant loss of sync.

Interleave causes my line to slow to a crawl and is next to useless.

What do others with my kind of attenuation get?

Any info would be useful.

Kel.

Status: Showtime Channel: INTR, Upstream rate = 448 Kbps, Downstream rate = 5184 Kbps
Link Power State: L0
Mode: G.DMT
Channel: Interleave
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 11.0 18.0
Attn(dB): 51.5 28.0
Pwr(dBm): 19.6 12.3
Max(Kbps): 5728 1008
Rate (Kbps): 5184 448
G.dmt framing
K: 163(0) 15
R: 16 16
S: 1 8
D: 32 4

Attenuation has only gone to 51.5 last couple of days. Was always 52.0 b4. Typically sync between 5120 and 5280 between 8 and 9am. Drops to the 51nn area during the day.

SNR is normally 12.0 8-9am, drops to 11'ish later. Today first time I remember it went down to 10.something. Also today I have had the line drop and resync 3 times. Before today almost never drops except yesterday at least once. I think BT are messing around tho, they have had the main A6 dug up for days very near the exchange, which is about 2 miles away by road, at the same place they dug up last July when the phones around here were all down for 5 days.

So basically line is stable between 5120 and 5280 so I get 4500 BRAS. Unless I have to sync in the evening, can go under 5120 into the 4nnn's, so I drop to 4000 for 3 days. Usual cause of having to sync in evenings is the standard fault with Linksys WAG54GS, it can freeze any time after 2 days switched on . Known problem around here. I try to switch off on the 2+day night and on again in the morning, works fine that way.

Incidentally, if anyone who knows about these things is around, whats this Max(Kbps) above, the reported sync speed via the normal interface is the Rate line. And can I play with the SNR? I have today got the DMT tool but just using it to watch for a while.

Thanks for this.

Does anyone have a poorer performing line with similar attenuation?

Kel.

Netgear dg834g router with Bulldog 8mb.

Downstream:
Connection Speed: 1856 kbps
Line Attenuation: 51 db
Noise Margin: 6 db

Upstream:
Connection Speed: 576 kbps
Line Attenuation: 15.5 db
Noise Margin: 16 db

Sync rate varies between 1.5mb and 2.5mb, downsteam snr varies between 5 and 10. Upstream is very stable.

Hi I have an attenuation of 51db

Stats

Sync 5472 / 448
Attenuation 51 / 24.5
Noise Margin 6.6 / 19
Download speed - 4.3Mb

G

My figures are

Data Rate 5408 768
Margin 6.2 14.0
Power 19.8 10.8
Attenuation 49.5 30.0

my stats:

Line Rate 5536 Kbps 448 Kbps
Noise Margin 9.3 dB 23.0 dB
Line Attenuation 52.0 dB 27.0 dB
Output Power 19.7 dBm 12.1 dBm

however, i had interleaving turned off, then on again due to instability. Before this i was syncing at 6560, dunno why its so much lower all of a sudden.

I have about 51 Attenuation, my router sync's at 3.4meg, my profile gets about 2meg. my noise is about 8.

I did use DMT, that has helped the noise and sync speeds.

In reply to:

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My SNR starts at 11 or 12 dB but drops like a stone day and night.

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It sounds more like a noise issue than anything to do with attenuation. Some of the figures posted here seem a little high, syncing at well over 5mb with attenuation in the low 50s seem high. Modems /routers may well not be reporting accurate figures. Bt say my line is 49 db but depending on what router/ firmware I am using I can see figures between 46 - 51. I can sync up to 4800 but I get two noise bursts around 1600 - 1800 which drops the line, if I sync below 4000 it will stay up continuously.

Your ISP won't be able to get BT involved unless your line speed has dropped to 70% of the MSR (Minimum Stable Rate) that you achieved during the 10 day training period. BT won't want to know. In any case, (as others have said), it's as much to do with line noise as it is with attenuation. I have 2 lines - one has 42dB attenuation, and the other has 46dB, and the 46dB continually syncs 1.5M faster, because it is a quieter line.