Tele

Call Model — DS Ft abstracts a backend provider, natively Jitsi.
Concise story of sameboat en:smart doorbell.

doorbell metaphor: button controls and tracks video conference call states

Ordinal	Color	State	Visibility	Enabled
-1	White	OFFLINE   No subscriber context or caller device rejected.	Caller	No
0	Cyan	ATTENTION   Ordinary ringer state, like a backlit doorbell, ready to join or originate a call. Blinking indicates individual (slow) or group (rapid) incoming call. Single click answers rings moving to IN CALL. Subscriber double clicking when there's no call toggles offhook otherwise moves to LOOKUP/PAGE.	Subscriber	Yes
1	Blue	LOOKUP/PAGE   If no user or group callee is implicit, clicking prompts for the subscriber or group lookup text, which is then looked up. If the lookup finds an active call, the join processing for this Agent and call begin. If there is an implicit callee, they are rung up. After the ring up attempt, returns to ATTENTION.	Caller	Yes
2	Yellow	BUFF/WAIT   Indicates incoming events for the agent. The control is inhibited if it is solidly this color .	Both	If blinking
3	Green	IN CALL   Call active, blinks when additional callers join the call. Single click moves to BUSY. Double click ends call.	Both	Yes
4	Red	AFK/ASIDE/BUSY   A subscriber controlled state which blocks ATTENTION requests. Click toggles, blinks while block active. Caller sees briefly before moving to PAGE.	Both	Yes
5	Black	DOWN/OFFHOOK/REJECT   Agents may be Callers or Subscribers, both can initiate calls but only a Subscriber can receive them, has a doorbell. Both start in this state and may enter it only as a result of network events. Double clicking in response to incoming call rejects the call and the subscribers ringer is briefly in this state to acknowledge the drop. Double clicking during a call disconnects it and while that is being confirmed, the control is this color before returning to ATTENTION.	Both	No