Question : Problem: How to find out internet connection problem?

sometimes my connection to internet is up and down. Is there any way I can check to see where is the problem?
my understanding is that I can use tracert to check if the router is down.... anything else I can check to find out where is the problem?

Answer : Problem: How to find out internet connection problem?

Here is a link that describes what the stats mean: http://www.dslreports.com/faq/13287

The DSLAM is located at the telco and is out of your control.  A DSLAM is the central "modem" that all of the DSL modems connect to.

tracert is useless in this situation.

Think of networking as layers (which it really is).  Each layer building the on previous layer.  Layer 1 must be up for layer 2 to work, and layer 2 must be up for layer 3 to work, layer 3 must be up for layer 4 to work, layer 4 must be up for layer 5 to work, and so on.  There are actually 7 layers in network.

Layer 1 is the physical layer.  In DSL's case this is the actual wire between your DSL modem all the way to the local telco's co.  This wire is, of course, not a single long wire, but a bunch of short wires connected. It is the phone cord between the modem and the wall jack, the wire between your wall jack the where the phone line enters your house, the wire from there to whereever it may go until it finally gets to your local CO.

Next is layer2, which is the DSL connection.

Then layer 3, which is IP, this is where tracert comes into play.  If the problem is with layer 1 or layer 2, tracert can't help you because it does not know the details of layer 1 or 2 and can't tell you which is broke.

If your Internet connection is down you need to check your DSL status.  If it is down, pick up the phone.  If you do not have dial tone then the problem is most likely a layer 1 problem, the physical problem.  You can try and test the wiring in your house.  The phone company is typically only responsible for the wire up to the DEMARC, normally a box on the outside of your house (but this depends on when you house was built).

Think of tracert as your voice going over the telephone wire.  If your phone is disconnected from the wall jack, you can't talk on the phone.  If you phone is connected to the wall jack, but there is no dial tone, you can't talk on the phone.  You can only talk on the phone if it is physically connected via the wire and logically connected by getting the dial tone.  Only then may you dial and talk.

If you have dial tone.  This it would most likely be a layer 2 issue, which is really out of your hands, this is something that the DSL provider would need to figure out.