In fact, even during regular playback (that is, without pausing), if the client
application buffer becomes full, back pressure will cause the TCP buffers to
become full, which will force the server to reduce its rate. To determine the
resulting rate, note that when the client application removes f bits, it creates room
for f bits in the client application buffer, which in turn allows the server to send f
additional bits. Thus, the server send rate can be no higher than the video consumption
rate at the client. Therefore, a full client application buffer indirectly
imposes a limit on the rate that video can be sent from server to client when
streaming over HTTP