UNIVERGE SV8100 Issue 5.0Digital Trunk Clocking 1 - 379Digital Trunk ClockingDescriptionThe UNIVERGE SV8100 CD-CP00 has a built-in clock source for all digital trunk blades. Digital trunkblades are connected via an internal PLO (Phase Locked Oscillator) to derive Primary Clock from thenetwork in priority order. If priority is set up incorrectly, or if two primary clocks are coming in, slips mayoccur causing improper data synchronization. The Phase Locked Oscillator (PLO) equipped with theUNIVERGE SV8100 CD-CP00 is the timing source for all digital trunk blades in the system. The PLOsynchronizes the system and clocks signals from another office. When the UNIVERGE SV8100 is aclock receiver office, the PLO generates the clock signal according to the source clock signals receivedfrom the source office within the network. The source clock signals are extracted from digital trunkblades and are supplied to the PLO.The PLO synchronization source priorities are as follows:1. CD-PRTA2. CD-CCTA (External)3. CD-2BRIA4. CD-CP00Conditions 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 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 looks to see if there are any BRIs installed in the system. If there are no BRIs,the SV8100 CD-CP00 becomes the new synchronization source. The reason for this iswhen a CD-PRTA is installed in the system, all T1s must be assigned as (INTERNAL). T1(INTERNAL) is not a clocking priority.Default SettingNone
