Configuring Native Sync Distribution - Cambium Networks PTP 820G Technical Description

Chapter 5: Feature Description
2MHz via T4 output from Sync interface
E1/DS1 via T4 output from Sync interface
Radio Carrier
Radio Channels
When using a radio channel to distribute a frequency, 2Mbps of bandwidth is used for this purpose.
It is possible to configure up to 16 synchronization sources in the system. At any given moment, only one of
these sources is active; the clock is taken from the active source onto all other appropriately configured
interfaces
Configuring Native Sync Distribution
Frequency is distributed by configuring the following parameters in each node:
System synchronization sources. These are the interfaces from which the frequency is taken and
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distributed to other interfaces. Up to 16 sources can be configured in each node. A revertive timer can be
configured. For each interface, user must configure:
Its clock quality level. The quality level may be fixed (according to ITU‐T G.781 option II) or automatic.
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When the quality level is automatic, it is determined by SSM messages.
Its priority (1‐16). No two interfaces may have the same priority.
o
For each interface, the source of its outgoing signal clock. This can be:
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Local clock: Causes the interface to generate its signal from a local oscillator, unrelated to the system
o
reference frequency.
Synchronization reference: Causes the interface to generate its signal from the system reference clock,
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which is taken from the synchronization source.
Loop Timing: Causes the interface to generate the signal from its own input.
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• The node's synchronization mode. This can be:
Automatic: In this mode, the active source is automatically selected based on the interface with
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highest available quality. Among interfaces with identical quality, the interface with the highest priority
is used.
Force: The user can force the system to use a certain interface as the reference clock source.
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Force mode is planned for future release.
Planned for future release
Planned for future release
Yes
Used for backwards compatibility with FibeAir
IP‐10 units across a radio link.
Otherwise, it is not recommended.
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Synchronization
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