Sending Packets

• Parameters:

  • SND Period (microseconds): delay between sending packets

  • RTO Period (microseconds): override of EXP timer calculations

  • Congestion Window (packets): size of the current congestion window

• Timers:

  • QDeadlineTimer _SNDtimer;

  • QDeadlineTimer _EXPtimer;

  • QDeadlineTimer _ACK2SentTimer; // if an ACK2 packet has recently sent, wait SYN before sending another one

  • QElapsedTimer _lastReceiveTime; // the last time we’ve heard something from the remote system

• Stores:

  • PacketIDSet _sendLossList; // loss list

  • MessageEntryList _pendingMessages; // the list of messages queued but not yet sent

  • ReceivedPacketList _receivedPacketList; // list of packets we have not yet processed

  • SendPacketEntryMap _sendPktPend; // list of packets that have been sent but not yet acknowledged

  • SendMessageEntryPointer _msgPartialSend; // when a message can only partially fit in a packet, this is the remainder

• Counters:

  • PacketID _sendPacketID; // the current packet sequence number

  • MessageNumber _messageSequence; // the current message sequence number

  • unsigned _expCount{ 1 }; // number of continuous EXP timeouts.

  • PacketID _lastAckPacketID; // largest packetID we’ve received an ACK from

  • ACKSequence _sentAck2; // largest ACK2 packet we’ve sent

  • unsigned _flowWindowSize{ 16 }; // negotiated maximum number of unacknowledged packets (in packets)