Line stats: how am I doing?

[solunauk]

Hi, We're new to IDNET, on Home Max, in a rural house with a line length of 6.2km (confirmed by the very helpful BT engineer upon install). Router is connected directly to the BT NTE5 fitted with an ADSLNation filtered faceplate in order to bypass any extension wiring. Service up since 22 June (when we moved in here), so well past the 10 day training period.

Line stats
                 Down            Up
SNR            5.5               17
Attn.          63                 31.5
Power         17.8              11.9
Rate           2720              448

BT speedtest shows a profile set at 2000kbs and throughput of 1864kbps. BBMax tests show typically 1900kbs.

I'm happy to be getting close to 2mb at this line length, but just wondering why there's a 35% disparity between the sync rate and the profile setting? Is this typical? As far as I know the router (Linksys WAG54GS) has held steady at 2720 for well over a week - don't think it provides disconnect logs, but I've kept a close eye on the rate. The BT engineer's own router got about the same sync rate.

I'm not complaining - just wondering if anyone has any comments. Certainly happy with IDNET so far.

Chris

[Lance]

From the FAQ sticky...

The following is a list of the profiles, which determine throughput, you will achieve for a given, sustained, sync speed:

Only sync at 8128 = Profile of 7150 (and probably means you live in the exchange! Smiley )
Sync between 7968 & 8127 = Profile of 7000
Sync between 7392 & 7967 = Profile of 6500
Sync between 6816 & 7391 = Profile of 6000
Sync between 6240 & 6815 = Profile of 5500
Sync between 5696 & 6239 = Profile of 5000
Sync between 5120 & 5695 = Profile of 4500
Sync between 4544 & 5219 = Profile of 4000
Sync between 4000 & 4543 = Profile of 3500
Sync between 3424 & 3999 = Profile of 3000
Sync between 2848 & 3423 = Profile of 2500
Sync between 2272 & 2847 = Profile of 2000
Sync between 1728 & 2271 = Profile of 1500
Sync between 1152 & 1727 = Profile of 1000
Sync between 576 & 1151 = Profile of 500

Note that actual throughput will be lower than the profile due to protocol overheads.


This shows that for your sync speed you have the correct profile. Hope this helps!

[Rik]

Hi Chris

Welcome to the forum.

As Lance says, for your sync speed you are on the right profile. Unfortunately, BT use very coarse steps, 500kbps, so that a small difference in sync speed (32k) can have a disproportionate effect on throughput. You might sneak a little extra throughput by tweaking your RWIN and MTU settings (assuming you use Windows).

It would be worth checking whether the bell wire is connected on your internal wiring. If it is, remobing it might just reduce noise pickup enough to bump you into the 2500 profile range.

[solunauk]

Thanks Rik and Lance. That's clear.

There is no extension wiring attached at all, currently, so it's not being troubled by a ring wire. I did use TCP Optimizer at my old house - would it be any different now? MTU is 1500, not sure about RWIN. Don't those only affect Windows' transmission rates, and not the router sync rate?

I did initially use another router (BT Voyager 240) that synced at about 2240, so I'm quite pleased with the Linksys. Looking at the logs, though, I see masses of these messages:

Thu, 2007-07-05 13:58:01 - eth0 Link DOWN.
Thu, 2007-07-05 13:58:02 - eth0 Link UP.
Thu, 2007-07-05 13:58:05 - eth0 Link DOWN.
Thu, 2007-07-05 13:58:07 - eth0 Link UP.
Thu, 2007-07-05 13:58:10 - eth0 Link DOWN.
Thu, 2007-07-05 13:58:12 - eth0 Link UP.

Anything suspicious about that?

[Rik]

Hi Chris

MTU and RWIN can affect throughput on the machine, but they won't affect the sync rate. Fine-tuning just might extract a little more from your connection, but we're only talking about 20-40kbps in all likelihood. It's a shame you don't have a ringwire to disconnect, the improvement that can bring about is our party piece.

I've not used a Linksys, so I'm not sure what terminology it uses in its logs, but my suspicion would be that that group or errors represented a re-sync events triggered by a noise burst. Did you notice the DSL light flashing?

[solunauk]

No, the DSL light stays solid green as far as I can tell.

I'll do some digging about the eth0 messages on a Linksys forum.

Chris

[Rik]

I was just reading the manual on the Linksys site, Chris, but I can find no reference (yet!) to that error message. I'll post back if I track it...

[solunauk]

I think I've solved it. Someone at ThinkBroadband forums suggested that it could be a dodgy network cable, so I tried unplugging the cables one by one and found out that the eth0 messages are being caused by a PC that is currently powered down. It's still connected to the mains, though, and I did enable wake on LAN a few weeks ago, so I guess it's just a side-effect of the network card looking for a wake-up call. Using a different cable makes no difference. Just one of those things....

Thanks for the help, guys.

Chris

[Rik]

I saw you over on TB.

Having Googled the message, I was wondering cable myself, but what you say makes perfect sense - wake up, look, go back to sleep...

Good detective work.

[solunauk]

Not such good detective work, I'm afraid.  The guy on TB further suggested checking the network card. I thought, "Nah, worked fine yesterday". A few hours later my daughter complained that 'her' internet wouldn't work. Hmmm. Turns out the onboard LAN (Nvidia) had gone wrong, so I had to put in a PCI card and that sorted it (after the usual driver installation hassles). No eth0 messages in the router logs any more.

Got there in the end....

[Rik]

When I was Googling the message, I came across another person having problems with and nVidia on-board network card. Still, it's one of the cheapest PCI cards you can buy!