Reliable credit-based communication over long-haul links

A communication apparatus includes input circuitry, an encapsulator, transmission circuitry and flow control circuitry. The input circuitry is to receive packets from a data source in accordance with a first communication protocol that employs credit-based flow control. The encapsulator is to buffer the packets in a memory buffer and to encapsulate the buffered packets in accordance with a second communication protocol. The transmission circuitry is to transmit the encapsulated packets over a communication link in accordance with the second communication protocol. The flow control circuitry is to receive from the encapsulator buffer status indications that are indicative of a fill level of the memory buffer, and to exchange credit messages with the data source, in accordance with the credit-based flow control of the first communication protocol, responsively to the buffer status indications.