Transferring Calls Using Release Link Trunk Transfer

 

 

 

Network

Host

 

ALERTING

<=== L4L3mALERTING (B1)

Now that B-channel #2 is set up, continue

 

 

with normal call setup on B1, sending

 

 

alerting and connect.

CONNECT

<=== L4L3mCONNECT (B1)

 

The call is transferred by the board, but it must maintain active call setup on both B-channels for the duration of the call.

RLT Call Transfer

SETUP

===> L3L4mSETUP_IND (B1)

SETUP

<=== L4L3mCALL_REQUEST (B2)

 

rtl_service = 1

ALERTING

===> L3L4mALERTING (B2)

 

includes 0x1c (FACILITY) IE with

 

call_id.

CONNECT

===> L3L4mCONNECT (B2)

FACILITY

<=== L4L3mFACILITY_REQUEST

The host receives an incoming call on B-channel #1. From the IISDN_CALLED_PARTY info, the host application determines this call needs to be rerouted to an alternate branch office.

The host initiates outbound call on B2, setting the rlt_service flag to ‘1’.

The network sends an ALERTING message with the FACILITY info element containing the call ID for the second link.

The host initiates the transfer and release process by sending a FACILITY message. The call_ref and l4_ref parameters of the initial (B1) call sends a L4L3mFACILITY_REQUEST message, and the application populates the IISDN_CALL_ID field with the call_id information retrieved from the ALERTING message of the second call (B2).

November 2009

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Page 205
Image 205
Dialogic 6.2 manual RLT Call Transfer, November 205