Abstract: Described is a method of error recovery in a data communication system of the kind comprising two nodes connected by a serial link and wherein data is transmitted between the nodes in the form of packets of a predefined format. Each node receives data over an inbound line and transmits data over an outbound line. When an error is detected, both nodes enter a link check state, invoke a Link Error Recovery Procedure (ERP) and exchange status by means of Link Resets. Error recovery is performed separately for each line. Each node is responsible for recovering packets that were lost on its outbound line. In normal operation of the link, the transmitter does not reuse a packet buffer until it has received a response from the connected node indicating that the packet was correctly received. Therefore when an error occurs, the affected packets are still available for retransmission.