Hello!

I have a simple config for routing requests with failover and blacklisting on 408, 480 and 503 codes from servers.

This is a part of config:

# Wrapper for relaying requests
route[RELAY] {

  # the base event routes
  t_on_branch("MANAGE_BRANCH");
  t_on_reply("MANAGE_REPLY");
  t_on_failure("MANAGE_FAILURE");

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

# Manage incoming replies
onreply_route[MANAGE_REPLY] {
  xlog("L_NOTICE", "$rr ($rs) [$cs] ($ci) $si:$sp - $ua\n");
  if ( t_check_status("(503)|(408)|(480)") ) {
    xlog("L_WARN", "Server will be blacklisted: $si:$sp ($rs)\n");
  }
}

# Manage failure routing cases
failure_route[MANAGE_FAILURE] {

  if ( !t_check_status("(503)|(408)|(480)") ) {
    exit;
  }

  ds_mark_dst("IP"); # blacklist

  if (t_is_canceled()) exit;

  if (!ds_next_domain()) {
    send_reply("503", "Service Unavailable");
    exit;
  }

  route(RELAY);
}

If there is a timeout or network error on the server side, it is blacklisted. How can such cases be managed and how can they be logged?
I didn't find this on the module page:

https://www.kamailio.org/docs/modules/stable/modules/tm.html