If all the links between the controlling SIU and the
adjacent signaling point fail, all transmit traffic is
automatically routed to the adjacent signaling point
through the inter-SIU link set as shown in Figure 11. The
application should continue to use the SIU as before,
directing all outgoing circuit requests to SIUA.
If the controlling SIU fails, the application is informed of
the failure and should transfer control of the circuit group
to the remaining unit.
■
Calls in a steady state (speech) will continue uninter-
rupted.
■
Outgoing calls in a set-up state during the transfer
should be re-attempted.
■
Incoming calls being set-up by the interconnected SS7
equipment will also fail and will be re-attempted
remotely.
Building Fault-tolerant SS7 Systems Using the Intel
®
NetStructure™ SIU520 SS7 Signaling Gateway Application Note
11
Figure 11. Routing When All Local Links Have Failed, Group 0 Controlled by SIUA
