Callback If User Busy - Aastra 400 Serie Manual Del Sistema

Prestaciones
9. 6. 17. 1

Callback if user busy

User A has the possibility of activating a callback to busy user B (callback request).
As soon as the busy user B becomes free, user A will be called back within 10 s. As
soon as A picks up the phone, the system automatically calls user B, who is now
free.
Fig. 220 Callback if user busy
Detailed Description
Tab. 271 Callback if user busy
Interface Operating sequence / signalling on the terminal Scope
A Once the function has been executed, A obtains the
acknowledgement tone.
B
1)
Callback to the busy external user is possible only if the public network supports the service "Completion of
Calls to Busy Subscriber" (CCBS) end-to-end.
2)
If the PISN user is reached via the public network, the conditions of the public network for callback when
busy will apply.
The callback is triggered only to user A, who set the callback, regardless of whether
a CFU or CFNR to a user C has been activated at A.
Amount of time a callback if busy remains valid:
• B is internal: 45 min
• B is external: 30 min
• B is in the PISN: can vary in an heterogeneous PISN (system: 45 minutes)
Callback to a busy external user B:
If user B is a communication server user, he must have his own direct dial number
and his communication server must also support the feature. There are three possi-
ble DDI variants:
470
A
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Funciones y prestaciones del sistema a partir de R2.1
B
C
Restriction:
User A can only initiate one callback at a
time.
Possible interfaces:
1) 2)
internal, external , PISN
Restriction:
Only one callback at a time can be loaded
onto an external user or a PISN user.
syd-0370/1.2 – R2.1 – 07.2012