User's Manual  582  Document #: LTRT-27055 
 
  Mediant 1000B Gateway & E-SBC 
Alert-Info: <http://127.0.0.1/Tono-Espec-Invitacion>;lpi-
aviso=Desvio-Inmediato 
This special tone is a stutter dial tone (Tone Type = 15), as defined in the CPT file (see 
''Call Progress Tones File'' on page 789).   
The FXS phone user, connected to the device, activates the call forwarding service by 
dialing a special number (e.g., *21*xxxxx) and as a result, the device sends a regular SIP 
INVITE  message to the softswitch. The softswitch later notifies of the activation of the 
forwarding service by sending an unsolicited NOTIFY message with the Alert-Info header, 
as mentioned above. When the call forwarding service is de-activated, for example, by 
dialing #21# and sending an INVITE with this number, the softswitch sends another SIP 
NOTIFY message with the following Alert-Info header: 
Alert-Info: <http://127.0.0.1/ Tono-Normal-Invitacion>; Aviso = 
Desvió-Inmediato 
From this point on, the device plays a normal dial tone to the FXS phone when it goes off-
hook. 
 
27.6.5  Remote Handling of BRI Call Forwarding 
The device supports call forwarding (CF) services initiated by ISDN Basic BRI phones 
connected to it. Upon receipt of an ISDN Facility message for call forward from the BRI 
phone, the device sends a SIP INVITE to the softswitch with a user-defined code (see 
procedure below) in the SIP To header, indicating the call forward reason.  
You can also enable the device to indicate the type of CF service in the Request-URI of the 
outgoing SIP INVITE message. Upon receipt of an ISDN Facility message for call forward 
(Diversion) from the BRI phone, the device indicates the call forwarding service in the 
Request-URI header using a proprietary parameter “facility=<call forward service>”, where 
call forward service can be one of the following: 
  “cfu-activate”:  Call Forwarding Unconditional activated  
  “cfu-deactivate”: Call Forwarding Unconditional deactivated 
  “cfb-activate”: Call Forward on Busy activated 
  “cfb-deactivate”: Call Forward on Busy deactivated 
  “cfnr-activate”: Call Forward on No Reply activated 
  “cfnr-deactivate”: Call Forward on No Reply deactivated 
For example:  
INVITE sip:400@10.33.2.48;user=phone;facility=cfu-activate SIP/2.0 
To enable the feature, configure the UseFacilityInRequest ini file parameter to 1.