Chapter 1. Commissioning
Vol. V-1-8 Alcatel-Lucent
Link and Ring Protection Logic
Before testing protection switching, ensure you are familiar with the
following switch process and logic for hot-standby, diversity and ring
configurations.
Hot-standby and Diversity
For hot-standby and diversity configurations, the two RAC/ODU combinations
are assigned as primary and secondary. These assignments are configured in the
Protection screen.
• The default online transmitting RAC (and ODU) is the RAC assigned as
primary. Applies to hot-standby and diversity. Online status can be changed in
the System/Controls screen.
• The default online receiving RAC (and ODU) is the RAC assigned as
secondary. Applies to hot-standby and diversity. Online status can be changed
in the System/Controls screen.
• Management of protection switching is controlled by:
• The online Tx RAC for Tx switching (default: primary RAC).
• The online Rx RAC for Rx switching (default: secondary RAC).
• Transmit switching for hot-standby and space diversity is not hitless. Transmit
switching for frequency diversity is hitless providing the online Tx RAC is not
withdrawn.
• The online Tx RAC manages the Tx protection switch function, and is
transferred between RACs to always be with the online Tx RAC.
• Only the online Tx is operational for hot-standby and space diversity.
• Both online Tx and standby Tx are operational for frequency diversity. The
online Tx is managing Tx traffic synchronization.
• Switching from the online to standby transmitter will not be initiated if the
standby transmitter has failed, or the standby Tx RAC has been withdrawn
or replaced by an incorrect plug-in.
• Rx path switching is hitless (hot-standby and space/frequency diversity),
providing the online Rx RAC is not withdrawn. The least errored data stream
from the online and standby receivers is selected on a frame-by-frame basis
within the online Rx RAC.
For information on Node protection options, protection operation, switching
criteria, and switching times refer to Protected Operation on page 3-73,
Volume II, Chapter 3.
For information on protection operation refer to Appendix F.
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