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.
The feature is applicable only to BRI interfaces.
call forward service can be one of the following:
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“cfu-activate”: Call Forwarding Unconditional activated |
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“cfu-deactivate”: Call Forwarding Unconditional deactivated |
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“cfb-activate”: Call Forward on Busy activated |
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“cfb-deactivate”: Call Forward on Busy deactivated |
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“cfnr-activate”: Call Forward on No Reply activated |
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“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.
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To configure the digit codes for call forwarding services by BRI phones: |
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Open the Supplementary Services Settings page (Setup menu > Signaling & Media tab > Gateway folder > DTMF & Supplementary > Supplementary Services Settings). |
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Under the BRI To SIP Supplementary Codes group, configure the reason codes for call forward: |
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'Call Forward Unconditional code' (SuppServCodeCFU) |
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'Call Forward Unconditional Deactivation' (SuppServCodeCFUDeact) |
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'Call Forward on Busy Code' (SuppServCodeCFB) |
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'Call Forward on Busy Deactivation' (SuppServCodeCFBDeact) |
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'Call Forward on No Reply Code' (SuppServCodeCFNR) |
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'Call Forward on No Reply Deactivation' (SuppServCodeCFNRDeact) |
The call forward codes must be configured according to the settings of the softswitch (i.e., the softswitch must recognize them).
Below is an example of an INVITE message sent by the device indicating an unconditional call forward (“*72”) to extension number 100. The code is configured by the SuppServCodeCFU parameter.
INVITE sip:*72100@10.33.8.53;user=phone SIP/2.0
Via: SIP/2.0/UDP 10.33.2.5:5060;branch=z9hG4bKWDSUKUHWFEXQSVOUVJGM
From: <sip:400@10.33.2.5;user=phone>;tag=DUOROSXSOYJJLNBFRQTG
To: <sip:*72100@10.33.8.53;user=phone>
Call-ID: GMNOVQRRXUUCYCQSFAHS@10.33.2.5
CSeq: 1 INVITE
Contact: <sip:400@10.33.2.5:5060>
Supported: em,100rel,timer,replaces
Allow:
REGISTER,OPTIONS,INVITE,ACK,CANCEL,BYE,NOTIFY,PRACK,REFER,INFO,SUBSCRIBE
User-Agent: Sip Message Generator V1.0.0.5
User-to-User: 31323334;pd=4
Content-Type: application/sdp
Content-Length: 155