diff --git a/container/SharedRingBuffer.cpp b/container/SharedRingBuffer.cpp
index 800e75d3..48bdb9df 100644
--- a/container/SharedRingBuffer.cpp
+++ b/container/SharedRingBuffer.cpp
@@ -9,6 +9,7 @@ SharedRingBuffer::SharedRingBuffer(object_id_t objectId, const size_t size,
 	mutex = MutexFactory::instance()->createMutex();
 }
 
+
 SharedRingBuffer::SharedRingBuffer(object_id_t objectId, uint8_t *buffer,
 		const size_t size, bool overwriteOld, size_t maxExcessBytes):
 		SystemObject(objectId), SimpleRingBuffer(buffer, size, overwriteOld,
@@ -16,6 +17,11 @@ SharedRingBuffer::SharedRingBuffer(object_id_t objectId, uint8_t *buffer,
 	mutex = MutexFactory::instance()->createMutex();
 }
 
+
+void SharedRingBuffer::setToUseReceiveSizeFIFO(uint32_t fifoDepth) {
+	this->fifoDepth = fifoDepth;
+}
+
 ReturnValue_t SharedRingBuffer::lockRingBufferMutex(
         MutexIF::TimeoutType timeoutType, dur_millis_t timeout) {
     return mutex->lockMutex(timeoutType, timeout);
@@ -25,6 +31,25 @@ ReturnValue_t SharedRingBuffer::unlockRingBufferMutex() {
     return mutex->unlockMutex();
 }
 
+
+
 MutexIF* SharedRingBuffer::getMutexHandle() const {
     return mutex;
 }
+
+ReturnValue_t SharedRingBuffer::initialize() {
+	if(fifoDepth > 0) {
+		receiveSizesFIFO = new DynamicFIFO<size_t>(fifoDepth);
+	}
+	return SystemObject::initialize();
+}
+
+DynamicFIFO<size_t>* SharedRingBuffer::getReceiveSizesFIFO() {
+	if(receiveSizesFIFO == nullptr) {
+		// Configuration error.
+		sif::warning << "SharedRingBuffer::getReceiveSizesFIFO: Ring buffer"
+				<< " was not configured to have sizes FIFO, returning nullptr!"
+				<< std::endl;
+	}
+	return receiveSizesFIFO;
+}
diff --git a/container/SharedRingBuffer.h b/container/SharedRingBuffer.h
index 80c068b3..fdc9d626 100644
--- a/container/SharedRingBuffer.h
+++ b/container/SharedRingBuffer.h
@@ -2,6 +2,7 @@
 #define FSFW_CONTAINER_SHAREDRINGBUFFER_H_
 
 #include "SimpleRingBuffer.h"
+#include "DynamicFIFO.h"
 #include "../ipc/MutexIF.h"
 #include "../objectmanager/SystemObject.h"
 #include "../timemanager/Clock.h"
@@ -26,6 +27,8 @@ public:
 	SharedRingBuffer(object_id_t objectId, const size_t size,
 			bool overwriteOld, size_t maxExcessBytes);
 
+	void setToUseReceiveSizeFIFO(uint32_t fifoDepth);
+
 	/**
 	 * This constructor takes an external buffer with the specified size.
 	 * @param buffer
@@ -59,8 +62,21 @@ public:
 	 * @return
 	 */
 	MutexIF* getMutexHandle() const;
+
+	ReturnValue_t initialize() override;
+
+	/**
+	 * If the shared ring buffer was configured to have a sizes FIFO, a handle
+	 * to that FIFO can be retrieved with this function.
+	 * Do not forget to protect access with a lock if required!
+	 * @return
+	 */
+	DynamicFIFO<size_t>* getReceiveSizesFIFO();
 private:
 	MutexIF* mutex = nullptr;
+
+	size_t fifoDepth = 0;
+	DynamicFIFO<size_t>* receiveSizesFIFO = nullptr;
 };
 
 
diff --git a/timemanager/Countdown.cpp b/timemanager/Countdown.cpp
index 95cce029..dfe0e1ec 100644
--- a/timemanager/Countdown.cpp
+++ b/timemanager/Countdown.cpp
@@ -1,14 +1,7 @@
-/**
- * @file	Countdown.cpp
- * @brief	This file defines the Countdown class.
- * @date	21.03.2013
- * @author	baetz
- */
+#include "Countdown.h"
 
-
-#include "../timemanager/Countdown.h"
-
-Countdown::Countdown(uint32_t initialTimeout) : startTime(0), timeout(initialTimeout) {
+Countdown::Countdown(uint32_t initialTimeout): startTime(0),
+		timeout(initialTimeout) {
 }
 
 Countdown::~Countdown() {
diff --git a/timemanager/Countdown.h b/timemanager/Countdown.h
index 20380e71..f6a41e73 100644
--- a/timemanager/Countdown.h
+++ b/timemanager/Countdown.h
@@ -1,18 +1,13 @@
+#ifndef FSFW_TIMEMANAGER_COUNTDOWN_H_
+#define FSFW_TIMEMANAGER_COUNTDOWN_H_
+
+#include "Clock.h"
+
 /**
- * @file	Countdown.h
  * @brief	This file defines the Countdown class.
- * @date	21.03.2013
  * @author	baetz
  */
-
-#ifndef COUNTDOWN_H_
-#define COUNTDOWN_H_
-
-#include "../timemanager/Clock.h"
-
 class Countdown {
-private:
-	uint32_t startTime;
 public:
 	uint32_t timeout;
 	Countdown(uint32_t initialTimeout = 0);
@@ -23,9 +18,14 @@ public:
 
 	bool isBusy() const;
 
-	ReturnValue_t resetTimer(); //!< Use last set timeout value and restart timer.
+	//!< Use last set timeout value and restart timer.
+	ReturnValue_t resetTimer();
 
-	void timeOut(); //!< Make hasTimedOut() return true
+	//!< Make hasTimedOut() return true
+	void timeOut();
+
+private:
+	uint32_t startTime = 0;
 };
 
-#endif /* COUNTDOWN_H_ */
+#endif /* FSFW_TIMEMANAGER_COUNTDOWN_H_ */
diff --git a/tmtcservices/CommandingServiceBase.cpp b/tmtcservices/CommandingServiceBase.cpp
index 3a124f5d..0ebc3944 100644
--- a/tmtcservices/CommandingServiceBase.cpp
+++ b/tmtcservices/CommandingServiceBase.cpp
@@ -384,10 +384,10 @@ void CommandingServiceBase::acceptPacket(uint8_t reportId,
 }
 
 
-void CommandingServiceBase::checkAndExecuteFifo(CommandMapIter iter) {
+void CommandingServiceBase::checkAndExecuteFifo(CommandMapIter& iter) {
 	store_address_t address;
 	if (iter->second.fifo.retrieve(&address) != RETURN_OK) {
-		commandMap.erase(iter->first);
+		commandMap.erase(&iter);
 	} else {
 		TcPacketStored newPacket(address);
 		startExecution(&newPacket, iter);
@@ -411,12 +411,7 @@ void CommandingServiceBase::checkTimeout() {
 	uint32_t uptime;
 	Clock::getUptime(&uptime);
 	CommandMapIter iter;
-	// TODO: BUG HERE! Problems with comparison operator of iterator.
 	for (iter = commandMap.begin(); iter != commandMap.end(); ++iter) {
-		if(commandMap.empty()) {
-			// intermediate solution!
-			break;
-		}
 		if ((iter->second.uptimeOfStart + (timeoutSeconds * 1000)) < uptime) {
 			verificationReporter.sendFailureReport(
 					TC_VERIFY::COMPLETION_FAILURE, iter->second.tcInfo.ackFlags,
diff --git a/tmtcservices/CommandingServiceBase.h b/tmtcservices/CommandingServiceBase.h
index 8237415a..252b6943 100644
--- a/tmtcservices/CommandingServiceBase.h
+++ b/tmtcservices/CommandingServiceBase.h
@@ -316,7 +316,7 @@ protected:
 	ReturnValue_t sendTmPacket(uint8_t subservice, SerializeIF* content,
 			SerializeIF* header = nullptr);
 
-	void checkAndExecuteFifo(CommandMapIter iter);
+	void checkAndExecuteFifo(CommandMapIter& iter);
 
 private:
 	/**
diff --git a/tmtcservices/TmTcBridge.cpp b/tmtcservices/TmTcBridge.cpp
index 8c2f15e5..8abe37a2 100644
--- a/tmtcservices/TmTcBridge.cpp
+++ b/tmtcservices/TmTcBridge.cpp
@@ -95,8 +95,9 @@ ReturnValue_t TmTcBridge::handleTm() {
     ReturnValue_t status = HasReturnvaluesIF::RETURN_OK;
 	ReturnValue_t result = handleTmQueue();
 	if(result != RETURN_OK) {
-		sif::error << "TmTcBridge::handleTm: Error handling TM queue!"
-		        << std::endl;
+		sif::error << "TmTcBridge::handleTm: Error handling TM queue with "
+		       << "error code 0x" << std::hex << result  << std::dec
+			   << "!" << std::endl;
 		status = result;
 	}