Jim is frustrated because he'll be watching a video on his phone and it'll buffer. Leo says that's a speed/bandwidth issue. Streaming will buffer about 30 seconds of video before starting to get ahead. Then if the packets come out of order or slow down, the buffer is there. If it happens a lot, the buffer will just run out and rebuffer. So it has to do with connection, bandwidth, and the ability of your system to keep up. Faster internet will solve the problem, as will a lower resolution stream.