Digital Trunk Clocking - NEC Univerge SV8100 Features And Specifications Manual

UNIVERGE SV8100
Description
The UNIVERGE SV8100 CD-CP00-AU has a built-in clock source for all digital trunk blades. Digital trunk
blades are connected via an internal PLO (Phase Locked Oscillator) to derive Primary Clock from the
network in priority order. If priority is set up incorrectly, or if two primary clocks are coming in, slips may
occur causing improper data synchronization. The Phase Locked Oscillator (PLO) equipped with the
UNIVERGE SV8100 CD-CP00-AU is the timing source for all digital trunk blades in the system. The PLO
synchronizes the system and clocks signals from another office. When the UNIVERGE SV8100 is a clock
receiver office, the PLO generates the clock signal according to the source clock signals received from
the source office in the network. The source clock signals are extracted from digital trunk blades and are
supplied to the PLO.
The PLO synchronization source priorities are as follows:
1. CD-PRTA
2. CD-CCTA (External)
3. CD-2BRIA
4. CD-CP00-AU
Conditions
If multiple PRIs exist, the system chooses the first one that synchronized with the carrier.
If there are multiple PRIs and the one being used for the source goes down, the system
begins to count forward in slot numbers looking for the next available PRI.
If multiple BRIs exist and no CD-PRTA or CD-CCTA (External) exists, the SV8100
CD-CP00-AU chooses the first BRI that synchronized with the carrier.
If there is one CD-PRTA and the one being used for the source goes down, the SV8100
CD-CP00-AU looks to see if there are any BRIs installed in the system. If there are no BRIs,
the SV8100 CD-CP00-AU becomes the new synchronization source. The reason for this is
when a CD-PRTA is installed in the system, all T1s must be assigned as (INTERNAL). T1
(INTERNAL) is not a clocking priority.
Default Setting
None
SV8100 Features and Specifications Manual

Digital Trunk Clocking

Issue 1.0
2 - 365