Switchboard error codes (mpbx-api switchboard routes, mpbx-b2bua switchboard)

Returned by the switchboard routes (W6-WEB-01b): GET /api/v1/switchboard/calls and POST /api/v1/switchboard/calls/{id}/transfer|park|drop; MPBX-BOARD-CALL-NOT-FOUND and MPBX-BOARD-FORBIDDEN are also the codes of the engine's B2bua::drop_call. A transfer or park also returns the transfer codes of transfers.md (MPBX-XFER-STATE: the call is not answered or another transfer runs; MPBX-XFER-TARGET: the dial plan refused the destination, or the park slot is full; MPBX-XFER-FORBIDDEN: the freed party is not a device of the company). Without a call engine every route is 503 MPBX-CALL-ENGINE-UNAVAILABLE, and an API key is 403 MPBX-CALL-SESSION-REQUIRED (calls.md). Messages never contain numbers or names. Guide: Switchboard and BLF panel.

Code	HTTP	Meaning	What to do
MPBX-BOARD-CALL-NOT-FOUND	404	No live call with this id that you may act on: it ended, it is another company's, or none of its parties is a member of a department your calls:control covers (these look the same on purpose).	Refresh the list; ask an administrator to extend your Receptionist grant if the call should be yours to handle.
MPBX-BOARD-FORBIDDEN	403	The call is an emergency call: it is listed, never transferred, parked or dropped.	Leave it; the caller hangs up on the phone.
MPBX-BOARD-ORBIT	400	The park slot is not one of the company's (GET /park-slots lists them: 0 to orbits - 1 of the dial codes).	Pick a listed slot.
MPBX-BOARD-UNSUPPORTED	503	The call engine of this server has no switchboard (an engine build without it).	Use a node that runs the current engine.

Also: MPBX-RATE-LIMITED (429, api.md) beyond 60 call-control requests a minute per user.

Audit records (W3-AUD-01): switchboard.call_transferred (details destination, by, caller_user_id, callee_user_id, result: ok or the error code), switchboard.call_parked (orbit, by, the parties, result), switchboard.call_dropped (state, the parties, result). An attempt on a call outside your reach or on an emergency call is recorded with outcome denied (result MPBX-BOARD-CALL-NOT-FOUND or MPBX-BOARD-FORBIDDEN). Saving your BLF panel is me.blf_keys_changed (details keys: how many).