Reduce the registration timeout to keep the connection open

edge_utils.c

@@ -32,7 +32,7 @@
 #define REGISTER_SUPER_INTERVAL_DFL     60 /* sec */
 #endif /* #if defined(DEBUG) */
 
-#define REGISTER_SUPER_INTERVAL_MIN     20   /* sec */
+#define REGISTER_SUPER_INTERVAL_MIN     5    /* sec */
 #define REGISTER_SUPER_INTERVAL_MAX     3600 /* sec */
 
 #define IFACE_UPDATE_INTERVAL           (30) /* sec. How long it usually takes to get an IP lease. */

sn.c

@@ -112,7 +112,8 @@ static void deinit_sn(n2n_sn_t * sss)
  *  should not allow registrations to continue beyond the shutdown point.
  */
 static uint16_t reg_lifetime(n2n_sn_t * sss) {
-  return 120;
+  /* NOTE: UDP firewalls usually have a 30 seconds timeout */
+  return 15;
 }