As a geek, I like to know my bandwidth usage when I'm gaming/streaming/bored (okay, all the time!). I wanted a device that would sit between my router and cable modem and provide upload / download rates (Mbps) in real time. I wanted to create a standalone device that could be plugged into any 10/100Base-T network and work without any user configuration or complicated installation. I also wanted my device to not interrupt normal network operations. For example, if the device lost power or its software crashed, the network should continue to functional as usual. For this, I decided that a passive network tap was the best solution. There are a few concerns with passive taps, such as extra noise/loading on the line and incompatibility with gigabit connections. As most home connections are well under 100Mbps (except maybe FIOS?), gigabit compatibility isn't a big deal. To mitigate noise/loading issues, cables/board traces are kept as short as possible.