I use a DSL modem from At&t and it has provided me with so much joy I can barely contain myself. Over the last six months or so and I have noticed that despite my paying for 3mb down I usually got .9 to 1.5 on average, but after several days it would slowly dwindle until it finally reached about .2mb and I would reset the modem. This would start the whole process over again. Every time I reset the modem, I would notice that it was incredibly hot. Finally I got fed up and I decided to take it apart and attempt to improve its airflow if I could. Taking it apart was not hard at all, and I found that it worked fine when put together without its case. I went to RadioShack and bought a heat sink and attached it to the most important looking chip on the board. I then cut a hole through the case above the chip, which permitted the heat sink to sit in fresh air. Once I put it all back together, I plugged it back in and ran it for a few hours. I tested the speed and I was getting a solid 3.5 mb down without any variation. After a week I have still not reset the modem and I am still getting 3.5 mb down. When you touch the heat sink it is very, very hot. I have considered attaching a small fan, but at the moment their appears to be no need. I make this post because I had done a little research into this before I made this attempt, and I found mixed feeling about how effective this might be. I can say that from my experiment, that adding a heat sink to improve the cooling of your modem may be a good idea if you are getting sub-par service and you find your modem is excessively hot to the touch.