User`s guide

Dialogic
®
System Release 6.0 PCI for Windows
®
Release Update, Rev 62 — January 30, 2008 202
Dialogic Corporation
Figure 14. SIP Call Transfer Failure - Party B Drops Transferred Call Early
Party C Is Busy When Transfer Attempted
Figure 15 illustrates a scenario in which the Transfer Target (party C) is busy at the time
the transfer is requested. (This primarily applies to unattended transfers, since the
Transferor would be aware that the Transfer Target is busy in an attended transfer.) In this
case, the Transferor (party A) receives a GCEV_INVOKE_XFER_FAIL termination event
and the Transferee (party B) receives a GCEV_XFER_FAIL termination event. The
original primary call is left connected and in the GCST_CONNECTED state from the
perspective of both party A and party B.
A
(Transferring,
Transferor)
App
A
(Transferring,
Transferor)
IP CCLib
B
(Transferred,
Transferee)
App
B
(Transferred,
Transferee)
IP CCLib
C
(Transferred To,
Transfer Target)
App
C
(Transferred To,
Transfer Target)
IP CCLib
GCEV_REQ_
XFER(CRNp)
Pre condition: Primary call between A and B is connected (not shown).
202 Accepted
GCEV_ACCEPT_
XFER(CRNp)
GCEV_
INVOKE_XFER_
ACCEPTED(CRNp)
NOTIFY(100 Trying)
Subscription-State=active; expires=300
200 OK
REFER
gc_InvokeXfer
(CRNp)
INVITE
GCEV_OFFERED
(CRNt)
gc_MakeCall
(CRNt, CRNp)
GCEV_
DISCONNECTED
(CRNt)
...before C answers...
gc_AcceptXfer
(CRNp)
GCEV_DROPCALL
(CRNt)
gc_ReleaseCallEx
(CRNt)
GCEV_RELEASECALL
(CRNt)
GCEV_XFER_FAIL
(CRNp)
gc_DropCall(CRNt)
Parties A and B remain connected.
Post condition:
Cause = IPEC_SIPReasonStatus487RequestTerminated
NOTIFY (487 Request Terminated)
Subscription-State = terminated
200 OK
Cause = IPEC_SIPReasonStatus487RequestTerminated
GCEV_DROPCALL
(CRNt)
gc_ReleaseCallEx
(CRNt)
GCEV_RELEASECALL
(CRNt)
gc_DropCall(CRNt)
GCEV_
INVOKE_XFER_
FAIL(CRNp)
GCEV_DISCONNECTED
(CRNt)
gc_DropCall(CRNt)
CANCEL
ACK (INVITE)
200 OK (CANCEL)
487 Request Terminated (INVITE)