LineLink is a new device from T-Mobile that gives you home phone service with “HD-quality” calls and unlimited calling from the US to the US, Mexico, and Canada. The LineLink adapter is a little rectangle that you plug a router and phone line into, and it’s also got a SIM slot for a T-Mobile SIM card. The requirements for the LineLink include an 802.11n or better router, an internet connection with speeds of at least 2Mbps up and down, and a home phone with an RJ11 connection.