[OpenSIPS-Users] Presence route[handle_presence]

[campusvtv]

Hello,

a basic question.

In this block:

route[handle_presence] {
         if (!t_newtran()) {
                 sl_reply_error();
                 exit;
         }

         if(is_method("PUBLISH")) {
                 handle_publish();
         }
         else
         if( is_method("SUBSCRIBE")) {
                 handle_subscribe();
         }
         exit;
}

whic is the meaning of:

if (!t_newtran()) {
                 sl_reply_error();
                 exit;
         }

in other words why I have to use t_newtran function.

Thank you.

Regards