UNIVERGE SV8100 Issue 7.0Digital Trunk Clocking 2 - 411Digital Trunk ClockingDescriptionThe UNIVERGE SV8100 CD-CP00-US has a built-in clock source for all digital trunk blades. Digitaltrunk blades are connected via an internal PLO (Phase Locked Oscillator) to derive Primary Clock fromthe network in priority order. If priority is set up incorrectly, or if two primary clocks are coming in, slipsmay occur causing improper data synchronization. The PLO, equipped with the UNIVERGE SV8100CD-CP00-US is the timing source for all digital trunk blades in the system. The PLO synchronizes thesystem 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 officein the network. The source clock signals are extracted from digital trunk blades and are supplied to thePLO.The PLO synchronization source priorities are as follows:1. CD-PRTA2. CD-CCTA (External)3. CD-2BRIA4. CD-CP00-USConditions 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 systembegins 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 SV8100CD-CP00-US 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 SV8100CD-CP00-US looks to see if there are any BRIs installed in the system. If there are noBRIs, the SV8100 CD-CP00-US becomes the new synchronization source. The reason forthis 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 SettingNone
