AASTRA SIP-DECT (Release 3.0)- OM System Manual - Installation, Administration and Maintenance EN - Manual (Page 194)

SIP–DECT OM System Manual Release 3.0 9 Configuration und Administration Aspects
Aastra depl-1624/1.0 Page: 194 (241)
“OMM sync OK” means: OMMs are synchronized with each other and are able to exchange their operational
states
“OMM sync NOK” means: OMMs are not synchronized with each other and are not able to exchange their
operational states
*1) In this state the DECT air interface might not be in a definite state as both OMMs are active but cannot
connect with each other! This is caused by IP network failures and cannot be handled by the SIP-DECT system in
a proper automatic way. In such a scenario it is not predetermined which RFP connects with which of the 2
OMMs. The DECT network can split-up into two unsynchronized DECT sub-networks. This can cause voice
quality and handover problems.
With these new states (“… SIP inactive”) the OMM standby mechanism takes care in the
start up phase that all SIP users does not become active if the PBX is not reachable. This
avoids a possible double SIP registration when the PBX and the other OMM is reachable
again before both OMMs negotiate with each other which OMM becomes the active one.
The double SIP registrations might cause a user not to be reachable when his latest SIP
registration came from that OMM that was negotiated to be the inactive one and the SIP
registrar cannot handle 2 or more simultaneous registrations (non-forking proxy).