It could be very nice of dlg_end_dlg will be able to send extra headers only to the chosen direction ("downstream","upstream","both"). Currently extra headers sent to both directions.
Have you tried to set local_route and to intercept the BYEs there and to do custom processing - like adding different headers ?
This is good idea, thanks! I fought that local_route is only in a roadmap, didn't notice that it's already available. I already started to use it for accounting.
I have another idea for direction. Unfortunately is_direction() from RR module is not available in local_route. What do you think to implement is_direction() in dialog module (based of tags)? It can easily and more reliably detect direction of requests and will be available for every route type.
yes, this will be an idea - please open a separate request for that. This one will be closed.