An embodiment of a method for credit-based flow control is disclosed. For this embodiment of the method, a first transaction layer packet from a sending device is loaded into a receiver buffer of a receiving device. A second transaction layer packet is loaded into the receiver buffer, where the second transaction layer packet is of a different packet type than the first transaction layer packet. The first transaction layer packet is unloaded from the receiver buffer without return of a credit for the unloading of the first transaction layer packet from the receiver buffer. The first transaction layer packet is loaded into a side buffer, and the credit for the first transaction layer packet is sent to the sending device responsive to unloading or anticipated unloading of the first transaction layer packet from the side buffer.