diff --git a/src/simulator.cc b/src/simulator.cc
index 7b288e4..95e36f9 100644
--- a/src/simulator.cc
+++ b/src/simulator.cc
@@ -68,9 +68,9 @@ public:
     double hint; // The timestamp that should be used by the receiver
     double duration; // The duration that should be used by the receiver
     bool HasHint;
-    bool HasData;
+    bool HasData; // This way observer could check if they want to receive data (maybe they already received data)
     bool HisForward;
-    bool Abort;
+    bool Abort; // Allow the receiver to abort a communication (if they already received the data for example) and unlock the sender
     u32 DataSize;
     std::string DedicatedMailbox; // Dedicated mailbox used by the sender/receiver
 };
@@ -78,7 +78,6 @@ public:
 /// @brief Observation node code
 static void obs_node(std::vector<std::string> args);
 
-
 /**
  * No arguments are require (cf inputs.json)
  */
@@ -98,7 +97,7 @@ int main(int argc, char **argv) {
     // Init all nodes actors
     u32 nON=simgrid::s4u::Engine::get_instance()->get_host_count();
     for(u32 i=0;i<nON;i++){
-        std::vector<std::string> args;
+        std::vector<std::string> args; // No args
         std::ostringstream ss;
         ss<< "on" <<i;
         simgrid::s4u::Actor::create("ON", simgrid::s4u::Host::by_name(ss.str()), obs_node, args);
@@ -118,7 +117,7 @@ static void obs_node(std::vector<std::string> args) {
     // Init various variables
     std::string selfName = simgrid::s4u::this_actor::get_host()->get_name();
     simgrid::s4u::this_actor::get_host()->turn_on();
-    Inputs i(selfName);
+    Inputs i(selfName); // Load node input parameters from the json file 
     simgrid::s4u::Mailbox *m = simgrid::s4u::Mailbox::by_name("medium");
     XBT_INFO("Deploying observation node %s",CNAME);
     
@@ -167,10 +166,7 @@ static void obs_node(std::vector<std::string> args) {
                         SEND(m_ded->put(p,p->DataSize,uptime)); // Send the actual hint
                         XBT_INFO("%s sent a hint successfully",CNAME);
                     }
-                    catch(...){
-                        
-                    }
-
+                    catch(...){}
                 }
                 // Send data if send hint mode is disable
                 else{
@@ -245,9 +241,10 @@ static void obs_node(std::vector<std::string> args) {
                             }
                         } while(p->HisForward);
                         simgrid::s4u::Mailbox *m_ded= simgrid::s4u::Mailbox::by_name(p->DedicatedMailbox);
+                        // Inform the sender that we do not want to abort
                         Payload *ack=new Payload();
                         ack->Abort=false;
-                        m_ded->put(ack,0);
+                        m_ded->put(ack,0); // Instantaneous msg
                         // Start receiving data
                         MODE_RX();
                         if(p->HasHint && !p->HasData){
@@ -288,6 +285,7 @@ static void obs_node(std::vector<std::string> args) {
             else {
                 XBT_INFO("%s is observing his environment...",CNAME);
                 MODE_ON();
+                // If use hint we should listen for the sender
                 if(i.use_hint){
                     if((forward_mode|forward_only) && hint_forward!=NULL && CLOCK < hint_forward->hint){
                         FORWARD_HINT(FOR(1));
@@ -332,7 +330,7 @@ static void obs_node(std::vector<std::string> args) {
         // Load next event
         i.GotoNextEvent();
         nWakeUp++; // Increase the number of wake up
-        totalUptime+=CLOCK-upsince;
+        totalUptime+=CLOCK-upsince; // Synchronize total uptime
     }
     // Done
     MODE_OFF()