Yes, this is indeed missing. Basically you can do something like this, to give you the idea:

``` route { ... t_on_reply("manage_18X"); t_relay() ... }

onreply_route[manage_18X] { if (t_check_status("183")) { # drop or alter message change_reply_status_code("180"); remove_body() } } ```

Added to the upgrade page in the wiki:

- https://github.com/kamailio/kamailio-wiki/blob/main/docs/install/upgrade/5.5...

If anyone wants to add more (e.g., examples), a commit/PR can be made to the wiki project.

If further discussions are needed for sorting out config solutions, the sr-users@lists.kamailio.org mailing list can be used.