In a communications system implementing Transmission Control Protocol/Internet Protocol (TCP/IP), an apparatus and method for increasing the number of NAKs transmitted by a receiving device when an RLP error is detected in cases where the link speed into the RLP receiver is high, when the TCP window of the sender approaches the maximum or when the percentage of NAKs for which retransmissions cannot be fulfilled approaches a threshold. In a second aspect of the invention, the apparatus and method increases the number of retransmissions transmitted by a sending device when an RLP NAK is received in cases where the link speed out of the RLP sender is high and the transmission round is the first, when the TCP window of the sender approaches the maximum or when the percentage of NAKs for which retransmissions cannot be fulfilled approaches a threshold.