Selected ISP Support → DSL Extreme > [Fusion] need to swap Comtrend for alternative dsl2+ modem

[Fusion] need to swap Comtrend for alternative dsl2+ modem

I really need to get this Comtrend 5072T modem swapped with whatever the other brand you currently supply (DLink?). Not only do I lose sync several times a day (which I CAN live with since it eventually will regain sync even though it takes nearly a minute or so) but the main thing is it's near impossible for it to establish lan communication when it needs to. For example, if If I have to power cycle the modem 9 times out of 10 this modem and my pc never establish communication... the lan light never lights up.

To get it to work at all in this scenario I have a very old Westell adsl modem and connect the ethernet cable and phone cable and it almost immediately establishes communication to the pc but it syncs in a mere 15 secs. The only problem is it's not a adsl2+ modem which renders Fusion useless. After it's connected to the Westell for a short while I've found I can reconnect the cables to the Comtrend and lan communication works and will eventually make a net connection after it reaches line sync.

Before I went with Fusion, I had a Comtrend 5072T modem then as well and ended up just using my Westell because the Comtrend got to a point where it could never reach line sync. When I ordered Fusion, DSLX sent me another 5072T but at this point I'm not a Comtrend fan at all for the issues I've always had with them.

Please advise because this is beyond annoying :-\
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If it ain't broke, pray it never will.

Hmmm... odd. I'm looking at your line readings now and I'm seeing some pretty heavy fluctuation on the SNR readings... it looks like the line is straining to maintain a steady connection. Do you currently have the Comtrend or the Westell plugged in?

it's the Comtrend. The only time the Westell is connected is for the temporary reasons I mentioned earlier.
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If it ain't broke, pray it never will.

As you noted, the Westell is an ADSL modem (not ADSL2+), so when it tries to connect, it's not trying to use the ADSL2+ tone band - so it's basically already capping itself lower, which is less stressful on the line.

In looking at your readings further, most of the ADSL2+ tones aren't carrying - too far. So as far as I can tell, the reason the Comtrend takes so long to sync up and seems prone to disconnects, is because the line is currently trying to use more ADSL2+ tones than are actually carrying. It's basically trying too hard when it sees an ADSL2+ modem on the other end.

I've tried racheting it back a bit - but still using ADSL2+ tones, so still better than what the Westell could accomplish, but should be more stable now.

The only point I have attention on now is the LAN connection. It's very odd that it would be behaving the way you describe... swapping between two modems shouldn't be necessary to 'warm up' the LAN port on your computer. THAT is actually more indicative of an issue with your NIC or LAN settings in the computer than anything else. Have you tried disabling and re-enabling the LAN connection on the PC itself, or rebooting the computer, once the modem resyncs?

When the modem (Comtrend) has sync and LAN is fine, rebooting the computer has no ill effects at all and all is still fine. I really appreciate your help but with the adjustments you made I did several speed tests and now it's about 2 mbit's slower DL than before and only about 1 mbit faster than what the Westell was able to allow. Any possibility you could reset it to what it was before? I can live with the minor issues.

I'm also playing with the thought of moving my modem closer to the phone jack and using a shorter cord (it's always been a 20+ foot cord) and purchasing a longer ethernet cable instead. Could that possibly make a difference?
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If it ain't broke, pray it never will.

Will do.

With regards to the phone cord - certainly possible. Bear in mind that the thicker 'round' phone cords are usually better shielded and can provide a solid connection for longer distances than the flat 'ribbon' phone cords. If you were using a 20' ribbon, you definitely should replace it with a shorter cord (10' or less... 6' is standard). If you were using a 20' 'round' cable, you MAY see better performance with a shorter cord, or it may be about the same - I would definitely give it a shot, regardless.

Thanks, Nick. Yes it was of the flat variety. I suppose I'll make a trip to Frys the next couple of days. Thanks again!
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If it ain't broke, pray it never will.

No problem. Since you had a 20' ribbon, would definitely recommend leaving the modem off (a minute or so) before reconnecting with the new shorter cord, to give the line a chance to 'clear its head' before resyncing, so it is better able to determine what your line's capabilities will be with the new cord.