No they don't. I have been using them at home for a couple of years and they are great. I live in a 3 story house and the wireless is very tempremental.
I don't know what brand they are as I got them free off BT when they bodged the installation of a new phone line into our old house.
Simple plug and play. The ones that Batch advertised at the top of the thread are the ones to go for. Read the reviews against them.