Although it can be rack mounted with other equipment above it, I would hesitate putting the direct weight of additional equipment on top of this unit. The cooling vents are on the side but it does not appear that the unit was designed to support the weight of other equipment. I would doubt that a lightweight router would be a problem but I wouldn't want to put anything weighing more than a few ounces on top of it. I put a cable modem on top of one that I had for a number of years and the fan started to make noise.