Call Forwarding
* Important: The expert settings for the ISDN connection are settings that should only be changed if e. g. country or provider-specific particularities make it absolutely necessary.
Proceed as follows:
Separately for PBX base number
Using the Configuration Manager (page Public switched tel. networks > ISDN > PBX base numbers/trunk bundles > Configure)
Requirements:
Configured PBX base number
GENERAL SETTINGS FOR CALL FORWARDING
Call forwarding method
Call forwardings at the exchange line are configured and performed in different ways. The exchange line, router or the provider determines which of the call forwardings listed below can be used.
CF facility
The call forwarding is controlled in the PTMP exchange line. The standardized message processings are not supported by all providers.
Registro
Special form of the Keypad call forwarding method in Spain.
CR facility
The call forwarding is controlled in the PTP connection. Not every provider supports this method.
Keypad
The call forwarding is controlled in the PTMP exchange line. The digit sequence depends on the provider or router.
CD facility
The call forwarding is controlled in the PTMP connection. Not every provider supports this method.
2. B channel
The call forwarding is performed by the PBX during a call. It is possible for all exchange line types but requires a free voice channel and the number of the caller cannot be displayed unless CLIP no scrrening is used which is not supported by many providers.
* Note: The setting CF facility has priority to the setting 2. B channel.
For call forwarding via the PBX, use any available call channel
Requirements:
Enabled call forwarding method 2. B channel
When an external phone number is forwarded, the call can be forwarded via a call channel on any of the other ports.
* Note: A call can only be redirected via a call channel on the same port. The probability that the call cannot be forwarded because the channels are busy is therefore higher.
Renew call forwarding at PBX reboot
When rebooting the PBX, the saved data of the call forwarding is renewed.
* Important: In Switzerland, the configuration of a call forwarding is chargeable. To avoid costs, the check box must be disabled.
Delay time for Call Forwarding on no reply in the PBX 
This delay time for external numbers specifies the time (in seconds) after which a call is forwarded if the called subscriber does not respond.
* Note: When switched off, the waiting time applies only to call forwarding that was set up using the PBX. If the network provider has configured the call forwarding function, the waiting time depends on their settings and cannot be configured in the PBX.
Routing via exception numbers (VoIP + GSM)
Requirements:
Configured exception numbers (page Routing > VoIP and GSM Routing > Exception numbers)
Enabled call forwarding method 2. B channel
The device checks whether the destination number involved in call forwarding for external numbers has been set up as an exception number. If so, the call is sent along the configured path. If the destination number has not been entered in the routing table, the call to be forwarded is sent either via a free call channel that is assigned to the port or via any free call channel (For call forwarding via the PBX, use any available call channel).
SETTINGS FOR THE CALL FORWARDING METHODS CF-/CR-/CD-FACILITY
Service Indicator
ISDN voice connections can be performed via different services. The Service Indicator selects the service, The provider defines the available services, however, the usual services are not always supported by all providers.
Service Indicator for the call forwarding query
Select the Service Indicator for the call forwarding query (All services,Speech only, Audio 3kHz, Speech & Audio & Telephony 3 kHz, Automatically, not available)
Service Indicator for the switching
Select the Service Indicator for the switching (All services,Speech only, Audio 3kHz, Speech & Audio & Telephony 3 kHz, Automatically, not available)
Destination number (CDPN) of type
Destination number (CDPN) in format
* Note: The settings ‚of type‘ and ‚in format‘ build a group which means both settings must be made in dependency to each other.
Select the type (Unknown, Subscriber, National, International) how the phone number shall be transferred.
Select the phone number format dependent on the phone number type.
Destination number (CDPN) receives prefix
Enter a prefix (*, #, 0-9; max. 4 digits) to send possibly necessary control commands to the provider.
Destination number (CDPN) receives postfix
Enter a postfix (*, #, 0-9; max. 4 digits) to send possibly necessary control commands to the provider.
MSN/DDI fwd. Destination number uses Soft-LCR 4.0 and manual LCR
An LCR prefix is set in front of the phone number.
Own phone number (CGPN) of type
Own phone number (CGPN) of type
* Note: The settings ‚of type‘ and ‚in format‘ build a group which means both settings must be made in dependency to each other.
Select the type (Unknown, Subscriber, National, International) how the phone number shall be transferred.
Select the phone number format dependent on the phone number type.
Use CLIP no screening for call forwarding
Requirements
CLIP no screening switched on for the ISDN connection
If a call is forwarded via the external connection, the caller's phone number is sent to the destination of the forwarded call. If it is an anonymous call, the function behaves as if it was switched off.
* Note: When switched off, the PBX's phone number is sent to the destination of the forwarded call.
CALL FORWARDING UNCONDITIONAL (CFU)
Call forwarding available in exchange line
If the exchange line has a CFU, this function can be enabled.
* Note: If the exchange line does not have a CFU, this function must be disabled.
CALL FORWARDING IF BUSY (CFB)
Call forwarding available in exchange line
If the exchange line has a CFB, this function can be enabled.
* Note: If the exchange line does not have a CFB, this function must be disabled.
CALL FORWARDING ON NO REPLY (CFNR)
Call forwarding available in exchange line
If the exchange line has a CFNR, this function can be enabled.
* Note: If the exchange line does not have a CFNR, this function must be disabled.