Routing Over Alternative Direct Link - Motorola MOSCAD 68P02958C00-B User Manual

mechanism is disabled, the failed link is considered to be restored after a specified period of
time.

Routing over Alternative Direct Link

The Routing of Data Frames section above describes automatic routing between sites which
are not directly connected. The system will also perform automatic alternative routing
between nodes that are directly connected by more than one direct link (if one of them is
failed). In previous versions, finding alternative communication routes across such systems
was performed by the user application.
All relevant links in the example below were defined in the Network Configuration and
downloaded to the units. RTU100 will choose a link which is not failed for communication
with RTUs 1-99 (as will be done in communication between RTU4 and RTU 88.) Thus if
RTU100 is unable to initiate communications with RTU2 over the radio link, due to a radio
failure, it will automatically attempt to communicate using the dial link. If no alternative links
exist, or if all fail, then the transmission will fail. In the case of a failed direct link, the
recovery mechanism described above in Routing of Data Frames is performed, according to
the parameter settings in the site configuration.
RTU
101
RTU
100
Routing over Direct Link is only possible with new versions of both the ToolBox and system.
Note that if you have existing applications which try to transmit over alternate links, these
should be modified to prevent redundancy.
When RTU101 tries to transmit to one of the RTUs (1-99), the routing is actually performed
by RTU100. The behavior of the routing in the system, when one of the links to the
designated RTU is failed, is exactly as described in Routing over Alternative Direct Link
above.
L2
PSTN
5-59
Network Configuration
RTU 1
RTU 2
RTU 3
RTU 4
RTU 5
.
.
RTU 99