Call routing
182
System functions and features as of R3.0
syd-0367/1.3 – R3.0 – 03.2013
6. 2. 3 Internal Digit Barring
There are several digit barring options available for internal traffic. The same rules 
apply as for external digit barring facilities (see "Digit barring", page 207).
6. 2. 4 Internal ringing duration
The ringing time for an internal user can be configured from 30 to 18000 seconds in 
the AMS Configuration Manager using the Internal ringing duration. The call con-
nection is disconnected once that time has elapsed. The timer is restarted if the call 
is forwarded after a set time (e.g. with Call Deflection or Default call forwarding if no 
answer).
Note:
With calls from the PSTN the connection is cleared down by the network 
provider, usually after approx. 2 minutes.
If the external call is answered by the announcement service, the call is 
considered as switched through for the PSTN. As long as the caller is 
switched to announcement service, a ringing tone is generated internally. 
The configured internal ringing time is therefore also a decisive criterion 
for clearing down the connection.
6. 3 Incoming Traffic
6. 3. 1 Routing
Network interfaces with the same network-specific characteristics are all grouped 
together in a trunk group. It is for example specified whether the network inter-
faces allocated to a trunk group are connected to a private leased-line network or 
to the public network. 
A call is routed via a trunk group to a direct dialling plan, a call distribution element 
or a destination with a number from the internal numbering plan. 
Each direct dial number is allocated a call distribution element. Several direct dial 
numbers can be allocated to the same call distribution element.
A call distribution element is allocated destinations depending on the switch 
group and switch position (see "Call destination", page 130).