The Vigor 2862s built in DSL interface will connect to either an ADSL or VDSL2 line. If you have a second line (of either type) you can add an additional modem (or your existing modem from your other line) to the Vigor 2862s Ethernet WAN ports. You can set the two lines up in load balancing mode, where traffic is split across both of them, or into failover mode, where the other DSL line only kicks-in if your primary DSL line fails (or vice versa). ADSL makes a particularly good method of failover for VDSL because they are delivered differently. VDSL service is provided and powered by a cabinet in your street - thats where the line terminates. ADSL service, on the other hand, comes all the way from your local exchange, which could be miles away and is powered from there. That means that if your streets VDSL cabinet is damaged, its DSLAM fails or you lose power to your street, you lose VDSL, but your ADSL line comes via a different method and route, so its less likely that both would be