A method for transferring ordered data of a data stream from a Request Node (402, 502, 602, 704) to a target device (406, 506, 606, 710) in a data processing network, the method comprising: sending, by the Request Node (402, 502, 602, 704) to one or more Home Nodes (404, 504, 604, 706, 708) of the data processing network, a plurality of first write requests; for each first write request of the plurality of first write requests: sending, by a Home Node (404, 504, 604, 706) of the one or more Home Nodes (404, 504, 604, 706, 708) to which the first write request was sent, a write data buffer credit message, identifying a data buffer for receiving data associated with the first write request, and a completion message indicating completion by the Home Node (404, 504, 604, 706); sending, by the Request Node (402, 502, 602, 704) to the Home Node (404, 504, 604, 706) responsive to the write data buffer credit message, data to be written; sending, by the Request Node (402, 502, 602, 704) to the Home Node (404, 504, 604, 706) responsive to the completion message, a first completion acknowledgement message; sending, by the Home Node (404, 504, 604, 706) to the target device (406, 506, 606, 710) responsive to the first completion acknowledgement message, the data to be written; and sending, by the target device (406, 506, 606, 710) to the Home Node (404, 504, 604, 706) responsive to receiving the data to be written, a second completion acknowledgement message, where the first completion acknowledgement message is not sent by the Request Node (402, 502, 602, 704) until completion messages for all older write requests of the data stream have been received by the Request Node (402, 502, 602, 704). sending, by the Request Node (402, 502, 602, 704) to one or more Home Nodes (404, 504, 604, 706, 708) of the data processing network, a plurality of first write requests; for each first write request of the plurality of first write requests: sending, by a Home Node (404, 504, 604, 706) of the one or more Home Nodes (404, 504, 604, 706, 708) to which the first write request was sent, a write data buffer credit message, identifying a data buffer for receiving data associated with the first write request, and a completion message indicating completion by the Home Node (404, 504, 604, 706); sending, by the Request Node (402, 502, 602, 704) to the Home Node (404, 504, 604, 706) responsive to the write data buffer credit message, data to be written; sending, by the Request Node (402, 502, 602, 704) to the Home Node (404, 504, 604, 706) responsive to the completion message, a first completion acknowledgement message; sending, by the Home Node (404, 504, 604, 706) to the target device (406, 506, 606, 710) responsive to the first completion acknowledgement message, the data to be written; and sending, by the target device (406, 506, 606, 710) to the Home Node (404, 504, 604, 706) responsive to receiving the data to be written, a second completion acknowledgement message, sending, by a Home Node (404, 504, 604, 706) of the one or more Home Nodes (404, 504, 604, 706, 708) to which the first write request was sent, a write data buffer credit message, identifying a data buffer for receiving data associated with the first write request, and a completion message indicating completion by the Home Node (404, 504, 604, 706); sending, by the Request Node (402, 502, 602, 704) to the Home Node (404, 504, 604, 706) responsive to the write data buffer credit message, data to be written; sending, by the Request Node (402, 502, 602, 704) to the Home Node (404, 504, 604, 706) responsive to the completion message, a first completion acknowledgement message; sending, by the Home Node (404, 504, 604, 706) to the target device (406, 506, 606, 710) responsive to the first completion acknowledgement message, the data to be written; and sending, by the target device (406, 506, 606, 710) to the Home Node (404, 504, 604, 706) responsive to receiving the data to be written, a second completion acknowledgement message,