3.2.1.5.1.1 Receiving RPC PDUs

As it receives RPC PDUs, an implementation of this protocol MUST queue the PDUs in its ReceiveWindow. As it queues the PDUs, the recipient MUST do the following:

• Decrement Receiver AvailableWindow by the number of bytes in the RPC PDU it queued.

• Increment BytesReceived by the same amount.

• If a protocol implementation implements AvailableWindowAdvertised, decrement it by the same amount.

When the sender receives a FlowControlAck RTS PDU, it MUST use the following formula to recalculate its Sender AvailableWindow variable:

Sender AvailableWindow = Receiver AvailableWindow_from_ack - (BytesSent - BytesReceived_from_ack).

Where:

Receiver AvailableWindow_from_ack is the Available Window field in the FlowControl Acknowledgement Structure (section 2.2.3.4) in the PDU received.

BytesReceived_from_ack is the Bytes Received field in the Flow Control Acknowledgement structure in the PDU received.

If the Receiver AvailableWindow becomes negative or becomes greater than the ReceiveWindow advertised by the recipient, a sender SHOULD treat the FlowControlAck RTS PDU as an invalid PDU and process it according to the rules for processing invalid PDUs, as defined in the section for the respective role.