synchronized(sentPackets) {
sent = sentPackets.remove(ack);
maxSize = (maxSeenInFlight * 2) + 10;
}
if(sent != null) {
rtt = sent.acked(key);
validAck = true;
} else {
if(logDEBUG) Logger.debug(this, "Already acked or lost "+ack);
long packetSent = lostSentTimes.queryAndRemove(ack);
if(packetSent < 0) {