System information

FCD 901 48
Issue R2A, 07.2009
XMP1 Release 5.5 System Description
Central Unit Redundancy
Page 2-78 Proprietary Information Aastra
2.8 Central Unit Redundancy
In order to protect the node from failure due to a defective Central Unit, the
XMP1 system offers the possibility to double the Central Unit.
With Central Unit redundancy, only one Central Unit is active at a time. In
case of a fault, the system switches over to the passive Central Unit
automatically and an alarm is generated.
Connection
Information exchange between the two Central Units takes place via their
redundancy interface. All data and clock information necessary for
communication is routed via the cable (ZT redundancy) interconnecting the
two Central Units. The information on which Central Unit is active or passive
is also transmitted via this cable.
A special Y-cable is available for connecting the Operator Terminal (Control
Computer, MSP). The clock and ServiceOn XMP1 system are provided by
a special cabling.
Please note the relevant descriptions.
Caution !
A certain procedure must be followed when you want to mount or extract
one of the two Central Units. For further information, please refer to the
description of the Central Units.
Requesting the redundancy status
Using the Online functions and the debugging commands it is possible to
request the redundancy status. The latter is requested together with the
system information (command "mc 40").
Besides other system information, the answer from the node also includes
the status of the passive Central Unit as well as the alignment status of the
configuration data and firmware.