diff --git a/src/traffic-control/helper/queue-disc-container.cc b/src/traffic-control/helper/queue-disc-container.cc
index 02cbec27a..06c420565 100644
--- a/src/traffic-control/helper/queue-disc-container.cc
+++ b/src/traffic-control/helper/queue-disc-container.cc
@@ -43,14 +43,14 @@ QueueDiscContainer::End (void) const
   return m_queueDiscs.end ();
 }
 
-uint32_t
+std::size_t
 QueueDiscContainer::GetN (void) const
 {
-  return static_cast<uint32_t>(m_queueDiscs.size ());
+  return m_queueDiscs.size ();
 }
 
 Ptr<QueueDisc>
-QueueDiscContainer::Get (uint32_t i) const
+QueueDiscContainer::Get (std::size_t i) const
 {
   return m_queueDiscs[i];
 }
diff --git a/src/traffic-control/helper/queue-disc-container.h b/src/traffic-control/helper/queue-disc-container.h
index 8dfe7d81e..15a1c4946 100644
--- a/src/traffic-control/helper/queue-disc-container.h
+++ b/src/traffic-control/helper/queue-disc-container.h
@@ -122,7 +122,7 @@ public:
    *
    * \returns the number of Ptr<QueueDisc> stored in this container.
    */
-  uint32_t GetN (void) const;
+  std::size_t GetN (void) const;
 
   /**
    * \brief Get the Ptr<QueueDisc> stored in this container at a given
@@ -145,7 +145,7 @@ public:
    * \param i the index of the requested queue disc pointer.
    * \returns the requested queue disc pointer.
    */
-  Ptr<QueueDisc> Get (uint32_t i) const;
+  Ptr<QueueDisc> Get (std::size_t i) const;
 
   /**
    * \brief Append the contents of another QueueDiscContainer to the end of
diff --git a/src/traffic-control/helper/traffic-control-helper.cc b/src/traffic-control/helper/traffic-control-helper.cc
index aafd95589..f06f07f34 100644
--- a/src/traffic-control/helper/traffic-control-helper.cc
+++ b/src/traffic-control/helper/traffic-control-helper.cc
@@ -367,11 +367,11 @@ TrafficControlHelper::Install (Ptr<NetDevice> d)
   m_queueDiscs.resize (m_queueDiscFactory.size ());
 
   // Create queue discs (from leaves to root)
-  for (auto i = m_queueDiscFactory.size (); i > 0; i--)
+  for (auto i = m_queueDiscFactory.size (); i-- > 0; )
     {
-      Ptr<QueueDisc> q = m_queueDiscFactory[i-1].CreateQueueDisc (m_queueDiscs);
+      Ptr<QueueDisc> q = m_queueDiscFactory[i].CreateQueueDisc (m_queueDiscs);
       q->SetNetDevice (d);
-      m_queueDiscs[i-1] = q;
+      m_queueDiscs[i] = q;
     }
 
   // Set the root queue disc (if any has been created) on the device
diff --git a/src/traffic-control/model/queue-disc.cc b/src/traffic-control/model/queue-disc.cc
index aaa6d7563..f91dbfdbd 100644
--- a/src/traffic-control/model/queue-disc.cc
+++ b/src/traffic-control/model/queue-disc.cc
@@ -584,16 +584,16 @@ QueueDisc::AddInternalQueue (Ptr<InternalQueue> queue)
 }
 
 Ptr<QueueDisc::InternalQueue>
-QueueDisc::GetInternalQueue (uint32_t i) const
+QueueDisc::GetInternalQueue (std::size_t i) const
 {
   NS_ASSERT (i < m_queues.size ());
   return m_queues[i];
 }
 
-uint32_t
+std::size_t
 QueueDisc::GetNInternalQueues (void) const
 {
-  return static_cast<uint32_t>(m_queues.size ());
+  return m_queues.size ();
 }
 
 void
@@ -604,16 +604,16 @@ QueueDisc::AddPacketFilter (Ptr<PacketFilter> filter)
 }
 
 Ptr<PacketFilter>
-QueueDisc::GetPacketFilter (uint32_t i) const
+QueueDisc::GetPacketFilter (std::size_t i) const
 {
   NS_ASSERT (i < m_filters.size ());
   return m_filters[i];
 }
 
-uint32_t
+std::size_t
 QueueDisc::GetNPacketFilters (void) const
 {
-  return static_cast<uint32_t>(m_filters.size ());
+  return m_filters.size ();
 }
 
 void
@@ -642,16 +642,16 @@ QueueDisc::AddQueueDiscClass (Ptr<QueueDiscClass> qdClass)
 }
 
 Ptr<QueueDiscClass>
-QueueDisc::GetQueueDiscClass (uint32_t i) const
+QueueDisc::GetQueueDiscClass (std::size_t i) const
 {
   NS_ASSERT (i < m_classes.size ());
   return m_classes[i];
 }
 
-uint32_t
+std::size_t
 QueueDisc::GetNQueueDiscClasses (void) const
 {
-  return static_cast<uint32_t>(m_classes.size ());
+  return m_classes.size ();
 }
 
 int32_t
diff --git a/src/traffic-control/model/queue-disc.h b/src/traffic-control/model/queue-disc.h
index 50db991d1..b26a67a6a 100644
--- a/src/traffic-control/model/queue-disc.h
+++ b/src/traffic-control/model/queue-disc.h
@@ -409,13 +409,13 @@ public:
    * \param i the index of the queue
    * \return the i-th internal queue.
    */
-  Ptr<InternalQueue> GetInternalQueue (uint32_t i) const;
+  Ptr<InternalQueue> GetInternalQueue (std::size_t i) const;
 
   /**
    * \brief Get the number of internal queues
    * \return the number of internal queues.
    */
-  uint32_t GetNInternalQueues (void) const;
+  std::size_t GetNInternalQueues (void) const;
 
   /**
    * \brief Add a packet filter to the tail of the list of filters used to classify packets.
@@ -428,13 +428,13 @@ public:
    * \param i the index of the packet filter
    * \return the i-th packet filter.
    */
-  Ptr<PacketFilter> GetPacketFilter (uint32_t i) const;
+  Ptr<PacketFilter> GetPacketFilter (std::size_t i) const;
 
   /**
    * \brief Get the number of packet filters
    * \return the number of packet filters.
    */
-  uint32_t GetNPacketFilters (void) const;
+  std::size_t GetNPacketFilters (void) const;
 
   /**
    * \brief Add a queue disc class to the tail of the list of classes.
@@ -447,13 +447,13 @@ public:
    * \param i the index of the queue disc class
    * \return the i-th queue disc class.
    */
-  Ptr<QueueDiscClass> GetQueueDiscClass (uint32_t i) const;
+  Ptr<QueueDiscClass> GetQueueDiscClass (std::size_t i) const;
 
   /**
    * \brief Get the number of queue disc classes
    * \return the number of queue disc classes.
    */
-  uint32_t GetNQueueDiscClasses (void) const;
+  std::size_t GetNQueueDiscClasses (void) const;
 
   /**
    * Classify a packet by calling the packet filters, one at a time, until either