22
Central Switching Module PTN-CSM310-A/PTN-CSM540-A
Release 03 05/2020
NOTE:
This SD card is neither required nor essential for the CSM to operate, but it makes a
possible CSM replacement in the future a lot easier and faster.
NOTE:
If the reset button has been pushed at least for seven seconds (see §2.1.3), the latest
configuration on the SD card will be replaced with the factory default settings.
NOTE:
A new SD Card can be ordered via order number: V30812-A6073-C3.
2.4
CSM Redundancy
2.4.1
General
Prerequisite: both CSMs must have the same firmware version.
All the Dragon PTN node types, except for the Dragon PTN aggregation node PTN1104, can be
equipped with redundant CSM modules.
CSM Redundancy means that two CSMs are installed in the node. One CSM will be the active
one while the other CSM will be the redundant one. Both CSMs will contain the complete
configuration data of all connections that are configured in that node.
CSM Redundancy provides a higher availability of the services through a node if one CSM
should fail. If one fails, the redundant hot-standby CSM will take over automatically to keep
the node and all its services alive (with a minimal service interrupt).
In normal operation one CSM actively controls the backplane and IFMs, whereas the other
CSM is in standby mode. Both CSMs have a dedicated heartbeat mechanism to control which
CSM is active and which CSM is in standby mode.
2.4.2
Redundancy States
A CSM can be in three different redundancy states: ACT (=Active), STB (=Standby) or PAS
(=Passive). The current state of each CSM can be viewed on the CSM display (see §2.1.4) or on
the LEDs of the NSM.
CAUTION: At installation time, if the spare LED (for CSM310-A) or the ACT LED (for
CSM540-A) on both redundant CSMs are lit together, it means that both CSMs are active
at the same time. This is not allowed! Make sure that both CSMs are plugged in properly.
2.4.3
CSM Switchover
An automatic switchover from the active CSM (=ACT) to the standby CSM (=STB) occurs when:
The active CSM gets broken;
The active CSM is pulled out from the node. It is strongly advised not to pull out the active
CSM intentionally! When a CSM has to be pulled out, make sure it is in standby/passive
mode first via switching-over.
A manual switchover from the active CSM (=ACT) to the standby CSM (=STB) can be done via:
The hidden CSM1/2 switchover button on the NSM module has been pushed for
approximately 4 seconds until the other CSM becomes active, indicated by the LEDs on the
NSM;
The hidden reset button on the active CSM has been pushed (see also §2.1.3);
HiProvision, see Ref. [2Net] in Table 2;
