Welltech Dialogic SS7 Protocols ISUP - Manual (Page 99)

Dialogic ® SS7 Protocols ISUP Programmer's Manual Issue 15
Unsuccessful continuity check during call set up
When the COT message is received from the network, indicating that the
continuity test was unsuccessful, the call is released to the application, except
that no Release confirmation (RLC) is sent at this stage because a CCR
message is expected. When the CCR is received, a Circuit seized indication
(SZE) is sent to the application.
Figure 16. Example of an Unsuccessful Continuity Check Received During Incoming
Call Set Up
RLC
REL
IAM
IAM
COT (failure)
COT (failure)
RLC
REL
RLC
CCR
SZE
REL
REL
NETWORK
USER
APPLICATION
ISUP
MODULE
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