AASTRA SIP-DECT (Release 3.0)- OM System Manual - Installation, Administration and Maintenance EN - Manual (Page 195)

SIP–DECT OM System Manual Release 3.0 9 Configuration und Administration Aspects
Aastra depl-1624/1.0 Page: 195 (241)
9.13.4 Specific Standby Situations
Some aspects have to looked at in case of OMM state changes when they are
unsynchronized.
9.13.4.1 How A Standby OMM Becomes Active
As the above figure shows in case of an unsynchronized OMM state the standby OMM has
to decide whether to become active or not.
For this purpose the OMM tries to contact the configured SIP proxy and registrar. The OMM
starts a SIP registration for the handset with the lowest phone number and sends an
OPTIONS request to the configured proxy. If there is an answer the SIP proxy/registrar will
be considered as reachable and the OMM becomes active.
9.13.4.2 Handling When Both OMMs Are Not Synchronized
In an unsynchronized OMM Standby state the connection between the OMMs is broken. In
case of a network problem both OMMs might be in this state. During this time an inconsistent
OpenMobility system is working with some constraints.
The Web service will warn with the warning “No Standby” for both OMMs in this situation and
possible made configuration changes are not save.
In any case, when both OMMs get in contact again with each other, the longer running one
becomes the active one and that will overwrite the database file in the standby OMM.
Configurations made in this becoming standby OMM would be lost!
9.13.4.3 Two DECT Air Interfaces
In case of both OMMs are in an unsynchronized and active state they are fully working.
RFPs which lose connection to the OMM because of the network break down might connect
to the other OMM. Two DECT air interfaces will be present but are working parallel.
Note: Both air interfaces are using the same PARK. So it can not determined to which
OMM a location registration succeeds.
For PPs different situations are possible:
•
They do not notice this situation:
- active calls stay established, depending on network conditions;
- PPs can make and receive new calls, depending on an available PBX connection;
- PPs can do handover to RFPs connected to the same OMM;
- PPs can call PPs that are registered to the other OMM
•
They lose their RFP base station and perform a new location registration:
- active calls are broken;
- PPs can make and receive new calls, depending on an available PBX connection;
- PPs can do handover to RFPs connected to the same OMM;
- PPs can call PPs that are registered to the other OMM;