Using power lines to transmit telecommunications has become one of most suitable options to offer tele-communications services over IP protocol, due to an economic benefit that comes from utilizing a preexisting infrastructure. However, electric grid wasn’t made for telecommunications purposes, causing several undesired effects such as: multipath behavior similar to wireless network without fast fading, electromagnetic interference, different sources of noise and change of channel’s response due to loads connected to the grid. This paper shows what kinds of variations of response exist and how this effects can be treated using a stochastic modification of Zimmerman’s model of PLT network.