Testing modem, DSL, & phone

[Martyn]

Have had a few minor disruptions on our DSL line recently and I'm trying to work out how to trouble shoot the system.

We have a DSL line going to a DSL modem, to a router, to various computers.

Sometimes we lose connectivity to the internet. Usually it's just a matter of restarting the modem and all is well.

Last time this happened restarting the modem didn't solve the problem.

To check the modem I unplugged it from the router and ran the Ethernet cable direct to the computer. Restarted to computer and modem. Didn't work.

Called a friend in the neighborhood who has the same service and they were connected, so I knew it was us.

I checked the phone line to the modem, checked the lights on the modem ( power, Ethernet, DSL, activity) and they initially all came on. The activity light then went out which is normal for this modem.

After making sure all the connections were good the system came back up and has been running ever since.

If this occurs again how can I check the following with simple tools like a voltmeter?

Phone line to the modem
Modem
Ethernet cable

I've done some web searching but haven't been able to find much. Thanks for any help.

 

[Grim Reaper]

Unless you live right next door to said friend I would not count on theirs being up as a determination that it is “you” and not a carrier problem.

Nodes on DSL only carry so many people. A neighborhood on 100 homes may have several nodes to cover it.

The DSL Modem has to register to the network. Your router has to register to the Modem, The computer also has more or less a Modem. (Ethernet card) that has to register to the router.

What I have had happed on several occasions is that my Modem had to reset and to establish a new connection to the carrier. That leaves the Router in limbo sometimes and I have too reset that to get it to connect back to the Modem. Then I have to close all the Windows on the computer and reopen them to get connected back to the Router.

After realizing what the problem was after some frustration on my part I always follow this sequence.

UNPLUG the modem from power (some times the rest button is a soft boot and I have found I more often then not need a hard boot that can be achieved from unplugging the power). Disconnect the cable to the router. Power the modem back up and let it go through a full registration sequence.

Plug the Router back in and reset it.

Close all browsers and reopen them if they do not reregister on the router.

 

[mmtoy]

Martyn,

Is this a dedicated DSL line (separate from your telephone line)? If not, you may need to filter the telephones on the line.

http://en.wikipedia.org/wiki/DSL_filter

If you had this professionally installed, this should have been done for you, but...

 

[Dave]

What kind (brand) of modem is it? You might be able to access the admin side of the modem to check line/PPoE status.

 

[njtaco]

I had problems like yours, Martyn. Verizon and I worked on it for about 45 minutes, and came up with "Your modem has the wrong IP address."

Now I'm no internet guru, and this didn't make sense at the time, but Tech Support "reset" my modem with a new IP address, and it has worked flawlessly ever since.

I should add that I got DSL when it first came into my area, and it has since been upgraded. Chances are, I was on the oldest lines, and they gave me a newer one, in over-simple-terms-even-I-understand.

Hope that helped.

Addited: I have a Westell model 2200 modem, and share with my phone lines, which are filtered.

 

[Martyn]

What kind (brand) of modem is it? You might be able to access the admin side of the modem to check line/PPoE status.

Steedstream 5100b for AT&T

 

[Martyn]

Martyn,

Is this a dedicated DSL line (separate from your telephone line)? If not, you may need to filter the telephones on the line.

http://en.wikipedia.org/wiki/DSL_filter

If you had this professionally installed, this should have been done for you, but...

Filters on everything including the fax, spare filters in the draw.

 

[wagner_joe]

So far all good advice Martyn. I've had problems with Quest here in Phx. Mostly it's been on their end. I'm out there past the normal length from the central switch.. I've had to have them check their speed on their end. once I had to be downgraded on the speed I orignally was signed up for.

Mostly I picked up a better modem than they sent me. I upgraded to a motorola modem and it resolved my problems. Early on the drops of modems were on Qwests end and when I reported it they either came out and fixed it or fixed it while on the phone..

AKA.. don't forget to call them.

 

[bovw]

Definately call the phone co. There could be trouble with the line coming to your house. Any physical problem on the line could affect how the DSL performs, too much wire on your line could also affect it.

 

[Dave]

Steedstream 5100b for AT&T

Check this link for instructions on how to access the admin side of your modem:

http://www.broadbandreports.com/faq/sbc/3.1_Speedstream_5100

When your link goes down, log in to the admin side before you reboot the modem. I don't remember all the screen names, but somewhere in there you should be able to get to a page that will show if your PPoE link is up or down. This will probably be somewhere in the "advanced" section. If it's up, the problem could be your router and not your modem or DSL service.

I was having problems with my Internet dropping and I kept thinking it was the modem, after doing some troubleshooting on the modem itself, I was able to determine it was the router. It kept rebooting and would not sync up with the modem correctly. Replaced the router and it's been solid ever since. I hate to throw new parts at a problem like this, but they've got these modems and routers down so cheap, they're practically disposable.

The reason I would go through this first is because telco DSL support will likely ask you to plug directly into the modem first as a test anyway. At least this way you can say you looked at the modem information already and relay what you're seeing to them.

Note: You will probably need to plug your PC directly into the modem instead of going through the router to access the admin side of your modem.

 

[Martyn]

My internet connection went down again today. I fiddled with everything and it came back up for a few minutes only to fail again.

I had a feeling it was an intermittent hardware problem so I started with the phone line into the modem. I undid the phone socket and did a voltage check across the two wires and got 50 volts. Also got 50 volts where the jack plugs in. Plugged the phone line into the socket and tested the center wires at the jack on the other end 0 volts. Replaced the phone line still 0 volts. Replaced the phone socket everything is working well.

Hopefully that is the end of it.