Systems and methods are disclosed for adjusting bandwidth of streams carried on a subscriber loop. One exemplary method comprises the steps of: determining bandwidth in use on a subscriber loop; selecting, for adjustment, at least one of a plurality of TCP streams carried on the subscriber loop; and adjusting at least one flow control parameter of the selected TCP stream based on the bandwidth in use. An exemplary multimedia terminal adapter (MTA) comprises memory and a processor. The memory stores program code, and the code programs the processor to enable the MTA to: determine bandwidth in use on a subscriber loop; select, for adjustment, at least one of a plurality of TCP streams carried on the subscriber loop; and adjust at least one flow control parameter of the selected TCP stream based on the bandwidth in use.