Configuring Internal Clock As Clock Source - AudioCodes Mediant 3000 User Manual

User's Manual
3. Configure the transmission power (in Ohm) between the timing module on the SAT
blade and the E1 external reference clock, using the TME1LineBuildOut parameter:
•
[0] E 75 ohms normal
•
[1] E 120 ohms normal (default)
•
[4] E 75 ohms with high return loss
•
[5] E 120 ohms with high return loss
•
[6] E 75 ohms normal plus enable transmit and receive gapped clock
•
[7] E 120 ohms normal plus enable transmit and receive gapped clock
4. For a BITS reference to return to service, the device must validate the clock. In the
System Timing page, configure the time were reference must have an alarm cleared
before the device declares it as a valid reference, using the 'Reference Validation
Time' parameter (TMReferenceValidationTime).
5. In the System Timing page, set the 'Timing Module Mode' parameter (TMMode) to
External to use BITS inputs.
When one of the BITS reference clock sources fails, the device automatically switches to
the secondary BITS reference source for the device. When a BITS reference clock source
with a higher priority returns to service after failure, the device may either revert to the
higher-priority clock source or continue using the lower-priority clock source. When both
BITS reference clock sources fail, the device enters into clock holdover.

To configure BITS reference clock source redundancy:

In the System Timing page, set the 'TDM Bus Enable Fallback' parameter
(TDMBusEnableFallback) to one of the following:
•
Auto Non-Revertive - enables non-revertive clock fallback between BITS
interfaces.
•
Auto Revertive - enables auto-revertive clock fallback between BITS interfaces.
Notes:
•
BITS synchronization is applicable only when the device's hardware supports
BITS capability.
•
For a full description of the BITS parameters, see ''PSTN Parameters'' on page
865.

22.2.4.3 Configuring Internal Clock as Clock Source

This section describes how to configure the device to use its internal clock source. The
internal clock source is a stratum 4E-compliant clock source. When the device has no line
interfaces, the device should be configured in this mode.

To configure internal clock as clock source:
1. Set the clock source to be from the device's internal oscillator. In the System Timing
page, set the 'TDM Bus Clock Source' parameter (TDMBusClockSource) to Internal.
2. For E1/T1 trunks only, set the line to drive the clock on all trunks: In the Trunk Settings
page, set the 'Clock Master' parameter (ClockMaster) to Generated (for all trunks).
3. If the device has BITS capability, then in the System Timing page, set the 'Timing
Module Mode' parameter (TMMode) to StandAlone (default).
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22. Digital PSTN
Mediant 3000