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DSL problem fixed by hub

This problem was strangly resolved but I have no idea why. For the last few months we have had a problem with our AT&T DSL with a Speedstream

4100 modem; the connection would go down about once a day and rebooting the modem reconnected us. We tried many things including having AT&T techs come out several times, swaping out the modem twice, changing firewall configurations, etc. Finally in an effort to troubleshoot the issue by capturing packets going to the modem I put a hub between the modem and the first switch, and by doing that the problem has been resolved, or I guess I should say we do not lose connection any more. But what the source of the problem is actually I do not know. Can anyone tell me what putting the hub in between the switch and modem would do? Could it be that the switch is bad and sending.... what kind of traffic to the modem to cause it to lose its connection? Any ideas would be appreciated. Thanks.
Reply to
tilopa
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tilopa wrote in part:

A hub will regenerate and strengthen signals. It might help poor [home-crimped] cable.

-- Robert

Reply to
Robert Redelmeier

Thanks for your reply Robert,

We did swap out the cables when troubleshooting though. I was wondering if the fact that hubs run in half-duplex had anything to do with it.

Reply to
tilopa

There's a very good chance your router (make and model?) doesn't deal well with old half-duplex 10base-T. Which I'm seeing more and more lately with new stuff using "off the shelf" chips for 10/100 or

10/100/1000 ports.
Reply to
DLR

Well, if anything, newer electronics might have reduced support for half-duplex 10 [as another poster mentioned].

But half-duplex 10 tends to be more wiring- and interference-tolerant. These faults show up as collisions, and are quickly retried.

-- Robert

Reply to
Robert Redelmeier

The device that we are using (as I mentioned) is a speedstream 4100 DSL modem, and the point is that it IS working with the hub wheras it was not working with just the switch.

Reply to
tilopa

So, you're saying that the hub could be catching some interference (some "bad" packets") and then dropping them, in effect protecting the modem whereas the switch is just letting everything through. Or maybe the switch is causing the problem. In any case I am going to swap out the switch and remove the hub and see if that solves the issue. Thanks.

Reply to
tilopa

Ah, I missed that. I've seen a lot of times where consumer level switches can't deal well with all 10base-T half duplex. And yes I've fixed things like this by putting an extra thing in the middle. I even had to do this with by putting a $50 switch between a $5000 printer and a $3000 gig managed switch. The gig switch and 10/100 printer port would not play nice together. Still waiting on a fix from the printer vendor. But they did admit it was their problem.

Reply to
DLR

Could be that the nic or driver has trouble autonegotiating speed. And if the hub is 10baseT, that is what solves it. I had some nics that with a Linux driver would go into a frenzy with heavy packet loss. My solution was to force those nics to 10baseT with Linux mii-tool (which worked fine full duplex on a switch).

Reply to
David Efflandt

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