Variable speed connection

[PassnThru2]

Looking for help with a problem - basically, I am getting about 1450 from a 4000 cable connection. But only on wired ethernet - when I connect wireless I get a faster speed. This is from multiple computers - and there is a speed difference from the same computer (notebook) depending on the connection type. Very weird problem that I have not been able to resolve. Here is a paste from another forum that details what I am experiencing and my troubleshooting steps:
Start paste
Still working on it. Let me recap:
I use ZoneAlarm and Norton Antivirus - no change when disabled - haven't uninstalled for obvious reasons.
I have a D-Link DI624 and an old 3Com 'sharkfin' modem.
I have borrowed a LinkSys BEFSR11 for testing - no difference wired, wireless unavailable.
I have been testing with 4 computers:
2 wired - both with XP SP2 - one Athlon XP 2500+ Barton and one Athlon64 3500+. 2 notebooks - one XP SP2 and one 2000 Professional. The XP notebook has wired and G - the 2000 notebook has wired and B. I also brought an old 98SE notebook into the testing with wired and G - won't go into that other than to say it really didn't make any difference.
All computers get about 1450 on the wired connections.
The G notebook gets about 2400 on the wireless connection.
The B notebook gets about 3400 on the wireless connection.
Again, the notebooks get about 1450 on the wired connections.
Also, connecting the wired desktop directly to the modem gets me about 2200.
I have been using the speakeasy test from Atlanta - but I have confirmed on actual downloads that there is a real speed difference.
I have tried changing one wired desktop to the RWIN and MTU settings that the fastest notebook had with limited success - got up to 2200. Casual browsing and repeated speed test give me reason to believe that it is not as stable as before.
Most optmizers I have tried seem to believe that my settings are correct and should work well.
So - bottom line - the faster my computers connection to the router is, the slower the speed. It is predictable and infinitely repeatable. Obviously, the different connections are using different parameters and that is definitely making a difference. But I don't believe adjusting these settings is the way to solve the problem. This discrepancy is not the problem, but the symptom of the problem. Rather than forcing my wired connections to work around the issue, I need to find out what is causing it. Since I have tried two different routers with the same result, I don't think it is the router or the switch built into the router. I can really only suspect the modem at this point. Or, my line is just bad enough that I'm limited on what I can push through it at the moment. However, I do not seem to be dropping any packets during testing. I would think if larger packets were causing the problem I would see some retransmits of dropped packets.
So, I'm pretty much stuck at this point. Any thoughts or dialog would be appreciated. Please though - no tweak your settings suggestions. I think that is a symptom of the problem, not the problem itself. I don't think I should really have to do that if the router, modem, and line are OK. One obviously isn't.
End paste
I haven't had much luck at the other forum. I have used some tools from this site but nothing has really helped.

[YARDofSTUF]

EDIT: nm I cant read apparently.

Post your power levels, if you know the address to get them off of, if not someone else here should.

[PassnThru2]

Would this be what you are looking for?

Cable Modem Status
Downstream Status
Downstream Lock: Locked
Downstream Frequency: 567.0000 MHz
Downstream Modulation: 64 QAM
Downstream Interleave Depth: 32,4,32
Downstream Receive Power Level: -15 dB
Upstream Status
Upstream Channel ID: 1
Upstream Frequency: 29.0080 MHz
Upstream Modulation: QPSK
Upstream Symbol Rate: 2560 ksym/sec
Upstream Transmit Power Level: 41 dB
General Status
Cable Modem IP Address: 10.edited
Baseline Privacy Status: Disabled
Registration Status: Operational

I might mention that I have been losing my connection over the past two months on at least a weekly basis. The outage lasts from a few minutes to many hours. Lost connection yesterday for as long as it took to reset the modem - then lost it again last night around 9 - wasn't up again until this morning.
I have spoken with my ISP and they said that my modem looks good from their end. We discussed sending a tech out but weren't sure what he could do since everything was in spec to the modem. That's when I started troubleshooting and found the discrepencies previously stated.

[YARDofSTUF]

Ya, thats it.


ACE, Buickfan, get in here and tell him if those are good

[buckifan]

Your Downstream Receive Power Level is unacceptable. It could be worse that -15 since that is the lowest level that the modem will report. The person that you spoke to at your ISP either lied or is uninformed. They can see the same information that you can and more.

Do you have any splitters installed? If so try removing them and re-check the Receive Power Level. Your Upstream Power Level is fine so a bad connector or splitter would be the likely culprit.

[PassnThru2]

No splitters installed. In fact, I don't have cable TV - satellite instead. Connections are a little difficult to troubleshoot. I guess I could try another coax from the wall to the modem - I did some work to the cabling under the house a few weeks ago but there was no change to the problem. I did notice earlier that -15 was at the very bottom of the scale.

[buckifan]

Try to eliminate as much as possible by using the modem and laptop as a signal strength meter and connecting to where the cable enters the house.

But don't climb the pole

If the receive level is low where the cable enters the house then you'll have to call and schedule a tech to troubleshoot the problem further.

[PassnThru2]

Yeah - I guess so. Outside troubleshooting. And wouldn't you know it - it finally turned cold out there. I'll have to check my outside box more carefully but the last time I glanced at it it seemed to be 'sealed'. I may not be able to go directly to the box.

[buckifan]

The box on my house was fastened with a security torx screw. I threw the box away the last time I painted.

You said you don't have TV. There could be a bandstop filter in the box that is causing a problem with the downstream power level. The filter(s) also could be at the tap.

That's about all I can add. You need to get that downstream level up and if there are still problems those can be addressed.

[PassnThru2]

Thought I'd post back to let everyone know the problem is fixed. Would like to tell you how but I don't know how it got fixed. My box outside had a 'lock' on it and I never did get around to calling the cable company to have it checked out (we were moving the modem and I was waiting till we did that). Anyway, just tested last night at Speakeasy (Chicago) and got this:
Download Speed: 3713 kbps (464.1 KB/sec transfer rate)
Upload Speed: 256 kbps (32 KB/sec transfer rate)
My other desktop reports the same thing so it isn't specific to one computer. My router had died and I bought a new one but that didn't have any effect on the speed. Also, my cable modem specs are the same as I posted earlier in this thread. I can only surmise that Insight did something that I don't know about.