Figure 19 – Welltech Dialogic SS7 Protocols ISUP User Manual
Page 103

Dialogic
®
SS7 Protocols ISUP Programmer's Manual Issue 15
Successful continuity test call
To initiate a continuity test call, the application needs to send a Circuit seized
request to the ISUP module. The Circuit seized request must contain the
Nature of connection indicators parameter with the Continuity check indicator
set to “continuity check required on this circuit”. At the same time as the
Circuit seized request is sent, the application must apply the transceiver to
generate the tone and start timer T24 (waiting for sending COT on receipt of
backward check tone) to await completion of the continuity check.
Once the continuity test has completed successfully, the transceiver should
be removed and the call should be released.
Figure 19. Example of a Successful Continuity Check Request Message Sent
SZE
REL
REL
RLC
RLC
CCR
ISUP
MODULE
USER
APPLICATION
NETWORK
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