Typically a home has other equipment connected to the phone lines in the house. Phones, other computers modems, security systems and answering devices to name a few. Isolating these devices from the DSL line to your DSL modem, Router or other DSL service device is the only way to eliminate suspected attached equipment problems. Sometimes other equipment on the same line can "load" the line causing attenuation or even noise. This lowers signal strength and consequentially can interrupt DSL service. Typically Home Security systems are one of the most illusive problems to find. If you have one, start by disconnecting your Security System from the DSL line first. You might need to keep it off line for a few days while you evaluate your DSL response. If this does not cure your problem try removing each other piece of equipment from the DSL phone line, one at a time and noticing if removing it fixes your problems. Dont forget the DSL line filters and any extension wiring from the phone jacks as a potential problem also. Remember to plug the equipment back in before you unplug the next piece of equipment to check. This will help you locate load problems. If you find that removing one item makes your problem dissapear, this item may be the problem. Plug that item back in and see if your problem returns. If so, leave this piece of equipment connected and disconnect all other equipment on the line except your DSL modem or router. If your problem is still there, you have located the source of the trouble. This piece of equipment may operate fine by itself, but it is causing interference with your DSL line. You will need to remove it from your DSL service line. If your problem is not there, then you may be dealing with a line load problem. One option is to have your Telco come out and wire a new line inside your house and use a DSL splitter at the junction box outside your house. This will give you an isolated and dedicated line from the junction box outside to the input of the DSL line to your DSL equipment. Usually with new installs, you can have this done as "Reasonable" inside wiring by asking for it and is worth having done.
by additude edited by DrTCP