netopia router

tinner777

hi there,
a quick question. I'm on the 2 meg package from eircom but the router says my max speed is
Speed
1728/256 (kbps)
Line Attenuation
62/31 dB
is it set up incorrectly?

could i upgrade to 3 meg with this line?

Downstream Upstream
Max Allowed Speed (kbps) 1728 256
SN Margin (dB) 0.50 12.00
Line Attenuation (dB) 62.50 31.50
CRC Errors 63034 302

thanks

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dub45

tinner777 wrote:

hi there,
a quick question. I'm on the 2 meg package from eircom but the router says my max speed is
Speed
1728/256 (kbps)
Line Attenuation
62/31 dB
is it set up incorrectly?

could i upgrade to 3 meg with this line?

Downstream Upstream
Max Allowed Speed (kbps) 1728 256
SN Margin (dB) 0.50 12.00
Line Attenuation (dB) 62.50 31.50
CRC Errors 63034 302

thanks

---

Your line attenuation seems very high and it doesnt look as if you are syncing at the right speed probably due to the attenuation. I would not try the 3MB on that line.

kaizersoze

Yes it is set up correctly. The modem is syncing at the best possible speed (1728) for the line. It wouldn't support 3 meg and going by those stats, I'm surprised it even syncing at your current speed. Aswell as high attenuation your SN Margin is as low as I've ever seen without frequent disconnects.

Sponge Bob

with the crc errors it even seems more like a 1mbit line which is what it should be.

By the way, when did eircom sell you this 2mbit line ???

lucernarian

Strictly speaking, a line should work completely normally with a signal margin of greater than 0 dB. The signal margin is anything over the minimum SNR needed for the line to sync.

So an SNR of 6 dB would be a Signal Margin of 0 dB, or at least that's the case on some modems. It's a small but vital difference.

The reason that there can be disconnects is IMO jointly because of consumer modems not being too accurate at measuring SNR and line conditions, and also because SNR can fluctuate by a fair bit, which means that a headroom of up to 10 dB over signal margin can be needed. Everything from dodgy spark plugs to lightning can suddenly wipe out Signal margin.

Back to the point, there's not a chance in hell of that line supporting 3 mbps unless your phone wiring is seriously fécked up to begin with.

dub45

To_be_confirmed wrote:

Strictly speaking, a line should work completely normally with a signal margin of greater than 0 dB. The signal margin is anything over the minimum SNR needed for the line to sync.

................................

Back to the point, there's not a chance in hell of that line supporting 3 mbps unless your phone wiring is seriously fécked up to begin with.

It might be worthwhile for the poster to let us know what if anything else he has attached to his line and how far he is from the exchange.

If he is getting consistent speeds and few if any drop outs then leave well enough alone for the moment.

lucernarian

That's exactly what I was saying... With stats like that, he should avoid going for any upgrade to 3 Mbps.

And with a signal margin that low, the line would want to be damaged already if there was a chance of any significant improvement. The poster could try connecting at the master socket with all unnecessary extensions/phones etc. removed, but more than likely the line will simply manage to sync at 2048 with still a very low signal margin.

That line should be about 5 km long if working normally.

tinner777

hi again'
disconnected sky + box and dect telephone and now get these results;

Max Allowed Speed (kbps) 1728 256
SN Margin (dB) 6.00 12.00
Line Attenuation (dB) 62.50 31.50
CRC Errors 41 2

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eircom sold me the package. my original speedtest used to be 1.8 but now is 1.1.
i suppose i should be grateful for what i've got.

Sponge Bob

a bit better, snr margin was 0,5 and is now 6 so it may stop disconnecting / juddering . still barely a 2mbit.

whats the distance from the exchange

tinner777

about four miles

Sponge Bob

Its a good line for 4 miles.

Not much more you can do except maybe disconnect your internal wiring bit by bit to see if any socket is dodgily wired . Leave the sky box out , they are a disaster but the dect should be safe enough .

It time you will probably find that adsl2 will stabilise it ...at 2 mbits though not much more.

lucernarian

Damn attenuation stats, they're not reliable at long distances. That's very impressive for 4 full miles. My own line is exactly 4 miles long and I may get DSL with possible speeds like that.