--- a/src/core/model/log.cc	Mon Nov 05 14:07:02 2012 -0500
+++ b/src/core/model/log.cc	Mon Nov 05 12:10:55 2012 -0800
@@ -22,16 +22,17 @@
 #include <list>
 #include <utility>
 #include <iostream>
+#include <string.h>
 #include "assert.h"
 #include "ns3/core-config.h"
 #include "fatal-error.h"
 
 #ifdef HAVE_GETENV
-#include <cstring>
+#include <string.h>
 #endif
 
 #ifdef HAVE_STDLIB_H
-#include <cstdlib>
+#include <stdlib.h>
 #endif
 
 namespace ns3 {
@@ -127,7 +128,7 @@
           component = tmp;
           if (component == myName || component == "*")
             {
-              int level = LOG_ALL | LOG_PREFIX_TIME | LOG_PREFIX_FUNC | LOG_PREFIX_NODE;
+              int level = LOG_ALL | LOG_PREFIX_TIME | LOG_PREFIX_FUNC | LOG_PREFIX_NODE | LOG_PREFIX_LEVEL;
               Enable ((enum LogLevel)level);
               return;
             }
@@ -185,6 +186,14 @@
                     {
                       level |= LOG_PREFIX_NODE;
                     }
+                  else if (lev == "prefix_level")
+                    {
+                      level |= LOG_PREFIX_LEVEL;
+                    }
+                  else if (lev == "prefix_all")
+                    {
+                      level |= LOG_PREFIX_FUNC | LOG_PREFIX_TIME | LOG_PREFIX_NODE | LOG_PREFIX_LEVEL;
+                    }
                   else if (lev == "level_error")
                     {
                       level |= LOG_LEVEL_ERROR;
@@ -255,6 +264,26 @@
   return m_name;
 }
 
+std::map<enum LogLevel, std::string>
+LogComponent::LevelLabels() const
+{
+  std::map<enum LogLevel, std::string> labels;
+  labels[LOG_ERROR]    = "ERROR";
+  labels[LOG_WARN]     = "WARN";
+  labels[LOG_DEBUG]    = "DEBUG";
+  labels[LOG_INFO]     = "INFO";
+  labels[LOG_LOGIC]    = "LOGIC";
+
+  return labels;
+}
+
+std::string
+LogComponent::GetLevelLabel(const enum LogLevel level) const
+{
+  static std::map<enum LogLevel, std::string> levelLabel = LevelLabels ();
+  return levelLabel[level];
+}
+  
 
 void 
 LogComponentEnable (char const *name, enum LogLevel level)
@@ -389,7 +418,7 @@
 {
 #ifdef HAVE_GETENV
   char *envVar = getenv ("NS_LOG");
-  if (envVar == 0 || std::strlen(envVar) == 0)
+  if (envVar == 0 || strlen(envVar) == 0)
     {
       return;
     }

--- a/src/core/model/log.h	Mon Nov 05 14:07:02 2012 -0500
+++ b/src/core/model/log.h	Mon Nov 05 12:10:55 2012 -0800
@@ -24,6 +24,7 @@
 #include <string>
 #include <iostream>
 #include <stdint.h>
+#include <map>
 
 namespace ns3 {
 
@@ -48,12 +49,13 @@
   LOG_LOGIC          = 0x00000020, // control flow tracing within functions
   LOG_LEVEL_LOGIC    = 0x0000003f,
 
-  LOG_ALL            = 0x1fffffff, // print everything
+  LOG_ALL            = 0x0fffffff, // print everything
   LOG_LEVEL_ALL      = LOG_ALL,
 
   LOG_PREFIX_FUNC    = 0x80000000, // prefix all trace prints with function
   LOG_PREFIX_TIME    = 0x40000000, // prefix all trace prints with simulation time
-  LOG_PREFIX_NODE    = 0x20000000  // prefix all trace prints with simulation node
+  LOG_PREFIX_NODE    = 0x20000000, // prefix all trace prints with simulation node
+  LOG_PREFIX_LEVEL   = 0x10000000  // prefix all trace prints with log level (severity)
 };
 
 /**
@@ -148,6 +150,13 @@
       __FUNCTION__ << "(): ";                                 \
     }                                                           \
 
+#define NS_LOG_APPEND_LEVEL_PREFIX(level)                       \
+  if (g_log.IsEnabled (ns3::LOG_PREFIX_LEVEL))                  \
+    {                                                           \
+      std::clog << "[" << g_log.GetLevelLabel (level) << "] ";  \
+    }                                                           \
+  
+
 #ifndef NS_LOG_APPEND_CONTEXT
 #define NS_LOG_APPEND_CONTEXT
 #endif /* NS_LOG_APPEND_CONTEXT */
@@ -212,6 +221,7 @@
           NS_LOG_APPEND_NODE_PREFIX;                            \
           NS_LOG_APPEND_CONTEXT;                                \
           NS_LOG_APPEND_FUNC_PREFIX;                            \
+          NS_LOG_APPEND_LEVEL_PREFIX (level);                   \
           std::clog << msg << std::endl;                        \
         }                                                       \
     }                                                           \
@@ -380,7 +390,9 @@
   void Enable (enum LogLevel level);
   void Disable (enum LogLevel level);
   char const *Name (void) const;
+  std::string GetLevelLabel(const enum LogLevel level) const;
 private:
+  std::map<enum LogLevel, std::string> LevelLabels() const;
   int32_t     m_levels;
   char const *m_name;
 };