Technical data

Release 5.0.x Turin Networks Page 4-1
4.1 Introduction
This section describes the equipment level protection provided in the TE-2020 architecture. There are sev-
eral levels of protection when it comes to the signal flow through a node. Each card type has a redundant
card capable of handling traffic in the event of a failure from the first card. Also described is the inherent
protection in the LEI (Local Equipment Interconnect) cabling scheme.
4.2 TE-2020 Main Shelf CCT Protection
The various versions of CCT (Common Control and Timing) cards provide the power and processing func-
tionality for the TE-2020 Main Shelf, OTS2, ETS1, and ETS2. There are up to two TE-2020 Main Shelf
CCT cards installed in the Main Shelf and two OTS2 CCT cards in the OTS2 for protected operation. Each
CCT can be “hot-swapped” while the system is operational, providing full redundancy of connections, tim-
ing, and administrative functions.
The TE-2020 Main Shelf CCTs and the OTS2 CCTs are similar in appearance, but may not be swapped
between the shelves. The software and hardware contained on the OTS2 CCT is not capable of controlling
the TE-2020 Main Shelf CCT functionality. The CCTs each provide physical and electrical connectivity to
the system for two optical PLMs each. They reside in the shelves in an upper and lower configuration.
Refer to Figure 4-1.
Figure 4-1 TE-2020 CCT Card Placement
Synchronization
The CCTs in the TE-2020 Main Shelf provide synchronization to the system. They accept redundant tim-
ing reference inputs from any optical interface or BITS (Building Integrated Timing Supply) inputs, or
may be internally timed. The user may select up to 6 timing references in order of reliability. Failure of a
timing reference will cause the CCT to select the second timing reference selection. Failure of both timing
reference sources will cause the CCT to switch to the third timing reference and so on. Failure of a CCT
card will cause the system to select the timing references from the functioning CCT starting with the pri-
mary reference selection, then the secondary reference selection, etc. The CCT distributes synchronization
to any tributary shelves via the LEI cables.
LEI
The TE-2020 Main Shelf CCTs provide redundancy for the LEI (Local Equipment Interconnect) ports that
interface with any tributary shelves in the node. There are eight LEI connections (four protected LEIs) pro-
vided on the rear of the TE-2020 Main Shelf. At lest two LEI cables are connected to each tributary shelf to
provide full redundancy of timing, traffic, and internal management connectivity between the shelves.