It is common opinion that typical network cables, like CAT5, do not emit harmful electromagnetic radiation, but it is not so。 CAT5 cables used for network connections between computers, and between computers and modems, emit a noticeable amount of electromagnetic radiation of a particular type。
Just by replacing the unshielded CAT5 cables with double shielded cables, like CAT7, most electromagnetic emissions from the cable are avoided. However the CAT7 cables give better results, in terms of reduction of electromagnetic emissions, when they are grounded at both sides. CAT7 cables have metal plates around the RJ45 connectors. The corresponding connectors on the devices should have metal plates too, and these metal plates have to be connected to ground in a suitable way.