Aastra X Series, Руководство по установке и внедрению

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Page 8-153 10/2008 AMT/PTD/TR/0020/2/7/EN
8.4 Synchronisation on NeXspan S/L/D with UCT-S/UCT-L/UCT-
D
Note:
NeXspan S12 and NeXspan C have no synchronisation port but is capable of DECT
multi-site synchronisation via a third pair.
8.4.1 Principle
In a network containing several PBXs fitted with a UCT-S or UCT-L or UCT-D card (NeXspan S
or NeXspan L or NeXspan D), it is not necessary to wire the DECT base stations with a third pair
for synchronisation (unless the integrated S0 accesses of the first- generation NeXspan S CPU
card (UCT1-S) are used). The UCT-S/UCT-L/UCT-D cards are connected by an ISDN cable via a
synchronisation port. This cable carries the multi-frame and bit clocks.
In a multi-site network with several NeXspan cabinets (XS or XL or XD), synchronisation is
carried out from one or two PBXs declared as "Master":
• Simplex mode: one PBX is configured in "Master" mode and supplies the entire multi-site
network with the DECT synchronisation signal. In this case, the primary port is used. The
secondary port of the master is connected to the primary port of the first slave. The secondary
port of each slave is connected to the primary port of the next slave (cascade wiring).
• Duplex mode: two PBXs are configured in "Master" mode and are capable of supplying the
entire multi-site network with the DECT synchronisation signal. One of the two PBXs must be
configured (via MMC) in "Priority" mode and the other in "Not priority" mode. The PBX
configured in "Priority" mode supplies the DECT synchronisation signal. If a problem is
detected on the "Priority Master" PBX (alarm detected in the clock system or PBX not
synchronized on the PSTN), the "Not priority Master" PBX takes over dynamically and
supplies the entire multi-site network with the DECT synchronisation signal (the distance
between the two “Master” PBXs should not be more than 10 meters) .
Each UCT-L/UCT-S card has two RJ45 DECT synchronisation connectors: a primary port J7A
(on input) and a secondary port J7B (on output).
NeXspan D has two RJ45 connectors for DECT synchronisation: a primary port J8A (on input)
and a secondary port J8B (on output) on the IUCT-D.
The DECT clocks are transmitted from one PBX to another with a timeout depending on:
• the length of the connection cable
• the timeout set for the transmitters/receivers of each PBX.
This delay can be made up for through MMC (see Chapter - Programmation multi-sites, § 11.5).
Adjustment is made in 100 m steps on the slave PBXs, with the following formula applied:
8xN + totalL
where N = number of slave PBXs from master PBX
and totalL = total length of cable between master and slave PBX