For the configuration of user settings with the telephone, the various technologies (SIP, ISDN, analog) each offer specific possibilities. With ISDN telephones, call forwarding can be controlled by the functional protocol in the ISDN signaling or via so-called keypads (character stings). For analog telephones the same character strings are transferred by DTMF. The SIP protocol provides another option with its REFER method that is supported by most SIP phones and SIP softphones. However, call forwarding can only be controlled by the terminal device. To enable a uniform behavior for users in mixed infrastructures, the LANCOM VoIP router offers an further variant of call forwarding for SIP phones. This is presented here in comparison with ISDN and analog telephones.
| Immediate call forwarding |
SIP |
ISDN |
Analog |
| Switch on and define destination for call forwarding |
*21*TargetNo# |
*21*TargetNo# |
*21*TargetNo# |
| Switch off |
#21# |
#21# |
#21# |
| Switch off temporarily, maintain call-forwarding destination |
#22# |
#22# |
#22# |
| Switch on again, maintain defined call-forwarding destination |
*22# |
*22# |
*22# |
| Call forwarding on busy |
SIP |
ISDN |
Analog |
| Switch on and define destination for call forwarding |
*67*TargetNo# |
*67*TargetNo# |
*67*TargetNo# |
| Switch off |
#67# |
#67# |
#67# |
| Call-forwarding on no reply |
SIP |
ISDN |
Analog |
| Switch on and define destination for call forwarding |
*61*TargetNo# |
*61*TargetNo# |
*61*TargetNo# |
| Switch off |
#61# |
#61# |
#61# |
Please note the following when using character stings to configure call forwarding:
Note: Some ISDN telephones feature special keys or menu entries to configure call forwarding, and these can be used as an alternative to the listed character strings. Refer to the documentation from the corresponding manufacturers.
