--- a/src/common/packet-metadata.cc	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/common/packet-metadata.cc	Thu Jun 28 11:07:38 2007 +0200
@@ -953,13 +953,14 @@
       // payload.
       printer.PrintPayload (os, extraItem.packetUid, item->size, 
                             extraItem.fragmentStart, 
-                            extraItem.fragmentEnd);
+                            item->size - extraItem.fragmentEnd);
     }
   else if (extraItem.fragmentStart != 0 ||
            extraItem.fragmentEnd != item->size)
     {
       printer.PrintChunkFragment (uid, os, extraItem.packetUid, item->size, 
-                                  extraItem.fragmentStart, extraItem.fragmentEnd);
+                                  extraItem.fragmentStart, 
+                                  item->size - extraItem.fragmentEnd);
     }
   else if (PacketPrinter::IsHeader (uid))
     {

--- a/src/common/packet-metadata.h	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/common/packet-metadata.h	Thu Jun 28 11:07:38 2007 +0200
@@ -66,27 +66,71 @@
   static void PrintStats (void);
 
 private:
-  /**
-     head -(next)-> tail
-       ^             |
-        \---(prev)---|
-   */
   struct Data {
+    /* number of references to this struct Data instance. */
     uint16_t m_count;
+    /* size (in bytes) of m_data buffer below */
     uint16_t m_size;
+    /* max of the m_used field over all objects which 
+     * reference this struct Data instance */
     uint16_t m_dirtyEnd;
+    /* variable-sized buffer of bytes */
     uint8_t m_data[10];
   };
+  /* Note that since the next and prev fields are 16 bit integers
+     and since the value 0xffff is reserved to identify the 
+     fact that the end or the start of the list is reached,
+     only a limited number of elements can be stored in 
+     a m_data byte buffer.
+   */
   struct SmallItem {
+    /* offset (in bytes) from start of m_data buffer 
+       to next element in linked list. value is 0xffff 
+       if next element does not exist.
+    */
     uint16_t next;
+    /* offset (in bytes) from start of m_data buffer 
+       to previous element in linked list. value is 0xffff 
+       if previous element does not exist.
+     */
     uint16_t prev;
+    /* the high 31 bits of this field identify the 
+       type of the header or trailer represented by 
+       this item: the value zero represents payload.
+       If the low bit of this uid is one, an ExtraItem
+       structure follows this SmallItem structure.
+     */
     uint32_t typeUid;
+    /* the size (in bytes) of the header or trailer represented
+       by this element.
+     */
     uint32_t size;
+    /* this field tries to uniquely identify each header or 
+       trailer _instance_ while the typeUid field uniquely
+       identifies each header or trailer _type_. This field
+       is used to test whether two items are equal in the sense 
+       that they represent the same header or trailer instance.
+       That equality test is based on the typeUid and chunkUid
+       fields so, the likelyhood that two header instances 
+       share the same chunkUid _and_ typeUid is very small 
+       unless they are really representations of the same header
+       instance.
+     */
     uint16_t chunkUid;
   };
   struct ExtraItem {
+    /* offset (in bytes) from start of original header to 
+       the start of the fragment still present.
+     */
     uint32_t fragmentStart;
+    /* offset (in bytes) from start of original header to 
+       the end of the fragment still present.
+     */
     uint32_t fragmentEnd;
+    /* the packetUid of the packet in which this header or trailer
+       was first added. It could be different from the m_packetUid
+       field if the user has aggregated multiple packets into one.
+     */
     uint32_t packetUid;
   };
 
@@ -138,6 +182,11 @@
   static uint16_t m_chunkUid;
   
   struct Data *m_data;
+  /**
+     head -(next)-> tail
+       ^             |
+        \---(prev)---|
+   */
   uint16_t m_head;
   uint16_t m_tail;
   uint16_t m_used;

--- a/src/common/packet-printer.cc	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/common/packet-printer.cc	Thu Jun 28 11:07:38 2007 +0200
@@ -78,7 +78,7 @@
   static PacketPrinter tmp;
   tmp.PrintForward ();
   tmp.AddPayloadPrinter (MakeCallback (&PacketPrinter::DoDefaultPrintPayload));
-  tmp.SetSeparator ("\n");
+  tmp.SetSeparator (" ");
   return &tmp;
 }
 
@@ -158,9 +158,15 @@
                                       uint32_t size,
                                       struct PacketPrinter::FragmentInformation info)
 {
-  os << "data ";
-  os << "[" << info.start << ":" << info.end << "] -> "
-     << "[0:" << size << "]";
+  os << "DATA ("
+     << "length " << size - (info.end + info.start);
+  if (info.start != 0 || info.end != 0)
+    {
+      os << " "
+         << "trim_start " << info.start << " "
+         << "trim_end " << info.end;
+    }
+  os << ")";
 }
 
 void 
@@ -180,9 +186,14 @@
                                        std::string &name,
                                        struct PacketPrinter::FragmentInformation info)
 {
-  os << name << " ";
-  os << "[" << info.start << ":" << info.end << "] -> "
-     << "[0:" << size << "]";
+  NS_ASSERT (info.start != 0 || info.end != 0);
+  os << name << " "
+     << "("
+     << "length " << size - (info.end + info.start) << " "
+     << "trim_start " << info.start << " "
+     << "trim_end " << info.end
+     << ")"
+    ;
 }
 
 void

--- a/src/common/packet-printer.h	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/common/packet-printer.h	Thu Jun 28 11:07:38 2007 +0200
@@ -43,9 +43,19 @@
 class PacketPrinter 
 {
 public:
+  /**
+   * \brief indicates how many bytes were trimmed from a header
+   * or a trailer.
+   */
   struct FragmentInformation
   {
+    /**
+     * The number of bytes trimmed from the start of the header or the trailer.
+     */
     uint32_t start;
+    /**
+     * The number of bytes trimmed from the end of the header or the trailer.
+     */
     uint32_t end;
   };
   /**
@@ -297,6 +307,7 @@
 void 
 PacketPrinter::DoDefaultPrint (std::ostream &os, uint32_t packetUid, uint32_t size, const T *chunk)
 {
+  os << chunk->GetName () << " ";
   chunk->Print (os);
 }
 

--- a/src/internet-node/ipv4-header.cc	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/internet-node/ipv4-header.cc	Thu Jun 28 11:07:38 2007 +0200
@@ -28,17 +28,6 @@
 
 namespace ns3 {
 
-static uint16_t 
-UtilsNtoh16 (uint16_t v)
-{
-  uint16_t val;
-  uint8_t *array;
-  array = (uint8_t *)&v;
-  val = (array[0] << 8) | (array[1] << 0);
-  return val;
-}
-
-
 bool Ipv4Header::m_calcChecksum = false;
 
 Ipv4Header::Ipv4Header ()
@@ -193,24 +182,45 @@
 std::string 
 Ipv4Header::DoGetName (void) const
 {
-  return "Ipv4";
+  return "IPV4";
 }
 
 void 
 Ipv4Header::PrintTo (std::ostream &os) const
 {
   // ipv4, right ?
-  os << "(ipv4)"
-     << " tos=" << (uint32_t)m_tos
-     << ", payload length=" << UtilsNtoh16 (m_payloadSize)
-     << ", id=" << m_identification
-     << ", " << (IsLastFragment ()?"last":"more")
-     << ", " << (IsDontFragment ()?"dont":"may")
-     << ", frag offset=" << m_fragmentOffset
-     << ", ttl=" << m_ttl
-     << ", protocol=" << m_protocol
-     << ", source=" << m_source
-     << ", destination=" << m_destination;
+  std::string flags;
+  if (m_flags == 0)
+    {
+      flags = "none";
+    }
+  else if (m_flags & MORE_FRAGMENTS &&
+           m_flags & DONT_FRAGMENT)
+    {
+      flags = "MF|DF";
+    }
+  else if (m_flags & DONT_FRAGMENT)
+    {
+      flags = "DF";
+    }
+  else if (m_flags & MORE_FRAGMENTS)
+    {
+      flags = "MF";
+    }
+  else
+    {
+      flags = "XX";
+    }
+  os << "("
+     << "tos 0x" << std::hex << m_tos << std::dec << " "
+     << "ttl " << m_ttl << " "
+     << "id " << m_identification << " "
+     << "offset " << m_fragmentOffset << " "
+     << "flags [" << flags << "] "
+     << "length: " << (m_payloadSize + 5 * 4)
+     << ") "
+     << m_source << " > " << m_destination
+    ;
 }
 uint32_t 
 Ipv4Header::GetSerializedSize (void) const

--- a/src/internet-node/udp-header.cc	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/internet-node/udp-header.cc	Thu Jun 28 11:07:38 2007 +0200
@@ -94,16 +94,17 @@
 std::string 
 UdpHeader::DoGetName (void) const
 {
-  return "Udp";
+  return "UDP";
 }
 
 void 
 UdpHeader::PrintTo (std::ostream &os) const
 {
-  os << "(udp)"
-     << ", port source=" << m_sourcePort
-     << ", port destination=" << m_destinationPort
-     << ", length=" << m_payloadSize;
+  os << "(" 
+     << "length: " << m_payloadSize + GetSize ()
+     << ") "
+     << m_sourcePort << " > " << m_destinationPort
+    ;
 }
 
 uint32_t 

--- a/src/node/llc-snap-header.cc	Wed Jun 27 20:51:07 2007 +0200
+++ b/src/node/llc-snap-header.cc	Thu Jun 28 11:07:38 2007 +0200
@@ -50,17 +50,17 @@
 std::string
 LlcSnapHeader::DoGetName (void) const
 {
-  return "LlcSnap";
+  return "LLCSNAP";
 }
 
 void 
 LlcSnapHeader::PrintTo (std::ostream &os) const
 {
-  os << "(mac)"
-      << " EtherType: ";
+  os << "(type 0x";
   os.setf (std::ios::hex, std::ios::basefield);
   os << m_etherType;
   os.setf (std::ios::dec, std::ios::basefield);
+  os << ")";
 }
 
 void