Product Guide - A5000 R5.4 – Aastra X series
BPS0121AENAA01
Page 51/74
5.3.9
Duplicated services of the AXD
5.3.9.1 Duplicating the power supply modules
Physical description
The main AXD cabinet can receive two ADS350XD power supply modules, although one is enough to
meet the power supply requirement of a cabinet, even if fully charged.
Furthermore, each expansion cabinet can receive two ADS350XD power supply modules.
The power supply modules connected in the main cabinet cannot be used for providing power to an
expansion cabinet and vice versa.
Switchover procedure
When there are two power supply modules in a cabinet, they work in load-balancing mode.
If one power supply module becomes faulty, the other one carries the entire load. This switchover is
transparent for the cabinet’s equipments. Thus, there is no service interruption.
The faulty power supply module must be replaced manually. The faulty power supply module can be
removed without switching-off the Aastra XD (hot-disconnection). Then a working power supply
module is fitted in the empty position, still without switching-off the system (hot-connection). This new
power supply module now shares the load with the first one.
This procedure applies both to the main cabinet and the expansion cabinet.
If the main cabinet is powered off (due to power failure or the disconnection of a source of power
supply), the expansion cabinet(s) stop(s) working.
On the other hand, if an expansion cabinet is powered off, the main cabinet remains operational, but
the absence of expansion cabinet services (subscriber) will highly disturb the system’s level of service.
5.3.9.2 Duplicating the motherboards
The time required to synchronise the two motherboards must be as short as possible. Therefore, the
link between the two motherboards, and also the protocol used, are optimised.
Physical description
The AXD main cabinet can receive two UCV2D motherboards although one is enough to operate the
entire system services.
The expansion cabinets have one or two RUCVD cards instead of a UCV2D card although one is
enough to operate the entire system services.
Switchover procedure
When there are two motherboards in the main cabinet, one is active and the other passive (that is not
used by any service in the system).
When the active motherboard becomes faulty, or is intentionally removed from the cabinet, or if a
switchover is caused by a MMI or the Management Centre, the passive motherboard becomes active.
This takes within 1 and 6 minutes, depending on the configuration; on average this switchover time
will be about three minutes. Therefore, on-going calls are cut, and all the system services lost for this
period of time.
A hardware failure is a degradation of the motherboard’s hardware or software components, resulting
in the complete stop of this motherboard.
A software failure is an anomaly resulting in the system software reboot. It does not lead to a
switchover to the passive motherboard, the active motherboard is simply restarted.
A faulty motherboard must be replaced manually. The faulty Motherboard can be removed without
switching off the system (hot-disconnection). Then a new motherboard is fitted in this position, still
without switching off the system (hot-connection). Finally, this new passive card must be declared
