Described herein is a flow control scheme suitably adaptable to Transmission Control Protocol (TCP) and Stream Control Transmission Protocol (SCTP). In an example embodiment, the guaranteed and maximum allowable bandwidths are employed to determine the size of the congestion window. For example, the flow congestion window size starts proportional to the guaranteed bandwidth and increases until reaching the maximum allowable bandwidth. In particular embodiments, a fixed value is used for determining how fast the congestion window increases. For example the congestion window may increase exponentially while the current size of the congestion window is at or below a fixed value, and increase linearly when the current size of the congestion window is above the fixed value. In an example embodiment, the fixed value does not change even if a collision is detected and the current amount of unacknowledged data allowed is reset to an initial value.