Микроконтроллеры

Про квитирование. Вот нашел в RFC916, думаю должно подойти: 2.3. Sequence Numbers Sequence numbers work with acknowledge numbers to inform the sender that his last data packet was received, and to inform the receiver of the sequence number of the next data packet it expects to see. When the ACK flag is set in a packet the AN field contains the sequence number of the next data packet it expects from the sender. The sender looks at the AN field and by implication knows that the packet he just sent should have had a sequence number of: If it did have that number that packet is considered to have been acknowledged. Similarly, the receiver expects the next data packet it sees to have an SN field value equal to the AN field of the last acknowledge message it sent. If this is not the case then the receiver assumes that it is receiving a duplicate of a data packet it earlier acknowledged. This implies that the packet containing the acknowledgment did not arrive and therefor the packet that contained the acknowledgment should be retransmitted. The duplicate data packet is discarded. The only packets which require acknowledgment are packets containing status flags (SYN, RST, FIN, or SO) or data. A packet which contains only an acknowledgment, i.e. , does not require a response (it contains no status flags or data). Both the AN and SN fields are a single bit wide. Since at most one packet is in the process of being sent/acknowledged in a particular direction at any one time a single bit is sufficient to provide a method of duplicate packet detection and removal of a packet from the retransmission queue. The arithmetic to advance these numbers is modulo 2. Thus when a data packet has been acknowledged the sender's next sequence number will be the current one, plus one modulo 2: The individual acknowledgment of each packet containing data can mislead one into thinking that side A of a connection cannot send data to side B until it receives a packet from B. That only then can it acknowledge B's packet and place in the acknowledging packet some data of its own. This is not the case. As long as its last packet sent requiring a response has been acknowledged each side of a connection is free to send a data packet whenever it wishes. Naturally, if one side is sending a data packet and it also must acknowledge receipt of a data packet from the other side, it is most efficient to combine both functions in a single packet.