Procedure – Welltech Dialogic SS7 Protocols ISUP User Manual
Page 110
Section 6 Interface to Application
110
Procedure
When the autoblocking feature is activated, the ISUP module will periodically
send a Heartbeat message, CAL_MSG_HEARTBEAT, 0x7718, to the user
application, to determine its status. A single heartbeat message will be sent
every 30 seconds regardless of the number of circuit groups configured per
user instance.
If the user application fails to respond to a Heartbeat message (from the
ISUP module) within 3 seconds the ISUP module will consider the user
application to be unavailable and out of service. Circuit groups associated
with the application and for which autoblocking has been invoked (refer to
Section
8.2 Configure Circuit Group Request on page 126
) will be hardware
blocked and a blocking message (CGB) will be sent by the ISUP module to the
network for those circuit groups affected.
If autoblocking is executed, ISUP will continue to send, to the user
application, Heartbeat messages with the UIHB_FLAGS_CGRPS_BLOCKED flag
(bit 0) set to a value of 1 indicating that the ISUP circuit groups have been
blocked.
A user application, when it subsequently recovers, will indicate to the ISUP
module that it is again available and in service. The user application may do
this using the following methods:
• The user application will wait for a Heartbeat message from the ISUP
module. When received, the user application will respond with a
heartbeat message with the UIHB_FLAGS_CGRPS_BLOCKED flag set to 1.
• The user application will generate a Heartbeat message to request a
Heartbeat message immediately from the ISUP module, in order to
determine whether the circuit groups have been blocked. For such cases,
where the user instance id is not known, the user should ensure that the