Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Transmission and Synchronization Interfaces
5-4 Issue 3 June 2001
With OC-3 interfaces installed in the function unit positions, the OC-3 Multiplexer
can be configured for the STS-1 drop (Figure 5-2) and OC-3 hubbing (Figure 5-3)
applications. STS-1 drop addresses linear network routes by sending through
traffic directly from the OLIU circuit packs in the main positions to the OLIU circuit
packs in the C Function Group positions. The hubbing application equips the B
and/or A Function Groups with OLIU circuit packs in addition to the OLIUs used in
the main and C groups for STS-1 drop. This allows multiple optical extensions
from one shelf or a fiber hub as shown in Figure 5-2. In this application, STS-1
signals are routed between the main slots and the function group slots. For both
STS-1 drop and hubbing applications, default STS-1 routing is provided based on
circuit pack equipage with other routing options supported through provisioning.
The OC-3 Multiplexer also supports an optimized interface, the IS-3, to the
DDM-2000 OC-12 Multiplexer. This is implemented via a cost-effective optical
interface (21D-U OLIU) in the main slots, allowing all the OC-3 applications to be
upgraded to an OC-12 line rate.
Dual OC-1 interfaces provided by the 27-type OLIU can be equipped in the
function unit slots to support DDM-2000 FiberReach host applications.
The BBG6 STS1E circuit pack converts the seven virtual tributary group (VT-G)
signals into a standard EC-1 electrical signal that reuses the same coaxial
backplane interface as the DS3 signals.