A little tweak for the better - removed scaling of max delay values (which...

A little tweak for the better - removed scaling of max delay values (which used to depend on packet size).

pelab/magent/UdpMaxDelaySensor.cc

@@ -10,10 +10,10 @@
 using namespace std;
 
 UdpMaxDelaySensor::UdpMaxDelaySensor(UdpPacketSensor const *udpPacketSensorVal, UdpMinDelaySensor const *minDelaySensorVal, UdpLossSensor const *lossSensorVal)
-	: maxDelay(0),sentDelay(0),
-	packetHistory(udpPacketSensorVal),
-	minDelaySensor(minDelaySensorVal),
-	lossSensor(lossSensorVal)
+: maxDelay(0),sentDelay(0),
+    packetHistory(udpPacketSensorVal),
+    minDelaySensor(minDelaySensorVal),
+    lossSensor(lossSensorVal)
 {
 
 }
@@ -31,77 +31,82 @@ void UdpMaxDelaySensor::localSend(PacketInfo *packet)
 
 void UdpMaxDelaySensor::localAck(PacketInfo *packet)
 {
-	 // This is a re-ordered ACK or a corrupted packet - don't do anything
-	// with it - just return.
-	// If this packet is ACKing a packet that we lost due to libpcap send loss,
-	// dont use this packet timestamp for RTT calculations.
-	if( packetHistory->isAckValid() == false || packetHistory->isAckFake() == true)
-		return;
-
-        unsigned short int seqNum = *(unsigned short int *)(packet->payload + 1);
-        unsigned long long oneWayQueueDelay;
-
-	vector<UdpPacketInfo>::iterator vecIterator;
-	vector<UdpPacketInfo> ackedPackets = packetHistory->getAckedPackets();
-        vecIterator = find_if(ackedPackets.begin(), ackedPackets.end(), bind2nd(equalSeqNum(), seqNum));
-
-	if(vecIterator == ackedPackets.end())
-	{
-		logWrite(ERROR,"UdpMaxDelay: Cannot find seqNum=%d in AckedPacketList", seqNum);
-		return;
-	}
-
-
-	unsigned long long timeStamp = packet->packetTime.toMicroseconds();
-
-	// Find the one way RTT for this packet.
-	oneWayQueueDelay = (timeStamp - (*vecIterator).timeStamp)/2;
-
-	// Scale the value of one way RTT, so that it is correct for a transmission
-	// size of 1518 bytes.
-
-	// We lost this packet size details due to loss in libpcap, use the
-	// size echoed in the ACK packet - this does not included the header
-	// overhead for the packet - we assume that the packet on the reverse path
-	// has the same overhead length as the original packet.
-	oneWayQueueDelay = ( oneWayQueueDelay )*1518 / ((*vecIterator).packetSize);
-
-	if(oneWayQueueDelay < minDelaySensor->getMinDelay())
-	{
-		logWrite(ERROR,"Incorrect oneWayQueueDelay value = %llu, minDelay = %llu, seqNum=%d, SENDTS=%llu,RECVTS=%llu", oneWayQueueDelay, minDelaySensor->getMinDelay(),seqNum, (*vecIterator).timeStamp, timeStamp);
-		return;
-
-	}
-	// Find the queuing delay for this packet, by subtracting the
-	// one way minimum delay from the above value.
-	oneWayQueueDelay = oneWayQueueDelay - minDelaySensor->getMinDelay();
-
-
-	if(oneWayQueueDelay > 90000000)
-	{
-		logWrite(ERROR,"Incorrect oneWayQueueDelay value = %llu, minDelay = %llu, seqNum=%d, SENDTS=%llu,RECVTS=%llu", oneWayQueueDelay, minDelaySensor->getMinDelay(),seqNum, (*vecIterator).timeStamp, timeStamp);
-		return;
-	}
-
-        // Set this as the new maximum one way queuing delay.
-        if(oneWayQueueDelay > maxDelay)
-                maxDelay = oneWayQueueDelay;
-
-        // Send an event message to the monitor to change the value of maximum one way delay.
-	if(lossSensor->getPacketLoss() > 0)
+    // This is a re-ordered ACK or a corrupted packet - don't do anything
+    // with it - just return.
+    // If this packet is ACKing a packet that we lost due to libpcap send loss,
+    // dont use this packet timestamp for RTT calculations.
+    if( packetHistory->isAckValid() == false || packetHistory->isAckFake() == true)
+        return;
+
+    unsigned short int seqNum = *(unsigned short int *)(packet->payload + 1);
+    unsigned long long oneWayQueueDelay;
+
+    vector<UdpPacketInfo>::iterator vecIterator;
+    vector<UdpPacketInfo> ackedPackets = packetHistory->getAckedPackets();
+    vecIterator = find_if(ackedPackets.begin(), ackedPackets.end(), bind2nd(equalSeqNum(), seqNum));
+
+    if(vecIterator == ackedPackets.end())
+    {
+        logWrite(ERROR,"UdpMaxDelay: Cannot find seqNum=%d in AckedPacketList", seqNum);
+        return;
+    }
+
+
+    unsigned long long timeStamp = packet->packetTime.toMicroseconds();
+
+    // Find the one way RTT for this packet.
+    oneWayQueueDelay = (timeStamp - (*vecIterator).timeStamp)/2;
+
+    // Scale the value of one way RTT, so that it is correct for a transmission
+    // size of 1518 bytes.
+
+    // We lost this packet size details due to loss in libpcap, use the
+    // size echoed in the ACK packet - this does not included the header
+    // overhead for the packet - we assume that the packet on the reverse path
+    // has the same overhead length as the original packet.
+    //oneWayQueueDelay = ( oneWayQueueDelay )*1518 / ((*vecIterator).packetSize);
+    // NOTE: Do not scale the queuing delay - the results are bad for small
+    // packet transmissions.
+
+    //if(oneWayQueueDelay < minDelaySensor->getMinDelay())
+    //{
+    //	logWrite(ERROR,"Incorrect oneWayQueueDelay value = %llu, minDelay = %llu, seqNum=%d, SENDTS=%llu,RECVTS=%llu", oneWayQueueDelay, minDelaySensor->getMinDelay(),seqNum, (*vecIterator).timeStamp, timeStamp);
+    //	return;
+
+    //}
+    // Find the queuing delay for this packet, by subtracting the
+    // one way minimum delay from the above value.
+    if(oneWayQueueDelay > minDelaySensor->getMinDelay())
+        oneWayQueueDelay = oneWayQueueDelay - minDelaySensor->getMinDelay();
+    else
+        oneWayQueueDelay = 0;
+
+
+    if(oneWayQueueDelay > 90000000)
+    {
+        logWrite(ERROR,"Incorrect oneWayQueueDelay value = %llu, minDelay = %llu, seqNum=%d, SENDTS=%llu,RECVTS=%llu", oneWayQueueDelay, minDelaySensor->getMinDelay(),seqNum, (*vecIterator).timeStamp, timeStamp);
+        return;
+    }
+
+    // Set this as the new maximum one way queuing delay.
+    if(oneWayQueueDelay > maxDelay)
+        maxDelay = oneWayQueueDelay;
+
+    // Send an event message to the monitor to change the value of maximum one way delay.
+    if(lossSensor->getPacketLoss() > 0)
+    {
+        // Report the maximum delay
+        ostringstream messageBuffer;
+        if(maxDelay > sentDelay)
         {
-		// Report the maximum delay
-		ostringstream messageBuffer;
-		if(maxDelay > sentDelay)
-		{
-			messageBuffer<<"MAXINQ="<<(maxDelay+minDelaySensor->getMinDelay())/1000;
-			global::output->eventMessage(messageBuffer.str(), packet->elab);
-			sentDelay = maxDelay;
-		}
-
-		logWrite(SENSOR,"VALUE::New Max Delay = %llu",maxDelay);
+            messageBuffer<<"MAXINQ="<<(maxDelay+minDelaySensor->getMinDelay())/1000;
+            global::output->eventMessage(messageBuffer.str(), packet->elab);
+            sentDelay = maxDelay;
         }
-	logWrite(SENSOR,"MAXD:TIME=%llu,MAXD=%llu",timeStamp,maxDelay);
-	logWrite(SENSOR,"ACTUAL_MAXD:TIME=%llu,ACTUAL_MAXD=%llu",timeStamp,oneWayQueueDelay);
+
+        logWrite(SENSOR,"VALUE::New Max Delay = %llu",maxDelay);
+    }
+    logWrite(SENSOR,"MAXD:TIME=%llu,MAXD=%llu",timeStamp,maxDelay);
+    logWrite(SENSOR,"ACTUAL_MAXD:TIME=%llu,ACTUAL_MAXD=%llu",timeStamp,oneWayQueueDelay);
 
 }