Send Data That Does Not Contain Data to Be Retransmitted
The following figure shows how the SndUna, SndNxt, and SndMax members of the TCP_OFFLOAD_STATE_DELEGATED structure segment send data that does not contain data to be retransmitted.
The data from the byte that is indicated by SndUna up to the byte before the byte that is indicated by SndNxt is data that the host stack transmitted but for which the host stack did not receive an acknowledgment from the remote host. The offload target must process any acknowledgments for this data and retransmit the data later, if necessary.
Because the send data does not contain any data to be retransmitted, the byte that is indicated by SndNxt equals the byte that is indicated by SndMax. The data to the right of the byte that is indicated by SndNxt and SndMax is unsent data that the offload target must send before sending any other data on the offloaded connection.